Merge branch 'release/1.4.0' into main

Feature/fga/fix UI test

.github/ISSUE_TEMPLATE/release.yml

@@ -1,6 +1,6 @@
 name: Release checklist
 description: Checklist for each release. This template is only for the core team.
-title: "[Release] Element Android v"
+title: "[Release] Element Android v"
 labels: [🚀 Release]
 assignees:
   - bmarty
@@ -10,7 +10,7 @@ body:
     id: checklist
     attributes:
       label: Release checklist
-      description: For the template example, we are releasing the version 1.1.10. Replace 1.1.10 with the version in the issue body.
+      description: For the template example, we are releasing the version 1.2.3. Replace 1.2.3 with the version in the issue body.
       placeholder: |
         If you are reading this, you have deleted the content of the release template: undo the deletion or start again.
       value: |
@@ -22,35 +22,41 @@ body:
 
         ### Do the release
 
-        - [ ] Create release with gitflow, branch name `release/1.1.10`
+        - [ ] Create release with gitflow, branch name `release/1.2.3`
         - [ ] Check the crashes from the PlayStore
-        - [ ] Check the rageshake with the current dev version: https://github.com/matrix-org/element-android-rageshakes/labels/1.1.10-dev
+        - [ ] Check the rageshake with the current dev version: https://github.com/matrix-org/element-android-rageshakes/labels/1.2.3-dev
         - [ ] Run the integration test, and especially `UiAllScreensSanityTest.allScreensTest()`
-        - [ ] Create an account on matrix.org
-        - [ ] Run towncrier: `towncrier --version v1.1.10 --draft` (remove `--draft` do write the file CHANGES.md)
+        - [ ] Create an account on matrix.org and do some smoke tests that the sanity test does not cover like: 1-1 call, 1-1 video call, Jitsi call for instance
+        - [ ] Run towncrier: `towncrier --version v1.2.3 --draft` (remove `--draft` do write the file CHANGES.md)
+        - [ ] Check that the folder `changelog.d` is empty. It can happen that some remaining files stay here
+        - [ ] Check the file CHANGES.md consistency. It's possible to reorder items (most important changes first) or change their section if relevant. Also an opportunity to fix some typo, or rewrite things
         - [ ] Add file for fastlane under ./fastlane/metadata/android/en-US/changelogs
-        - [ ] Push the branch and start a draft PR (will not be merged), to check that the CI is happy with all the changes.
-        - [ ] Finish release with gitflow, delete the draft PR
-        - [ ] Push `main` and the new tag `v1.1.10` to origin
+        - [ ] (optional) Push the branch and start a draft PR (will not be merged), to check that the CI is happy with all the changes.
+        - [ ] Finish release with gitflow, delete the draft PR (if created)
+        - [ ] Push `main` and the new tag `v1.2.3` to origin
         - [ ] Checkout `develop`
-        - [ ] Increase version in `./vector/build.gradle`
+        - [ ] Increase version (versionPatch + 2) in `./vector/build.gradle`
         - [ ] Change the value of SDK_VERSION in the file `./matrix-sdk-android/build.gradle`
         - [ ] Commit and push `develop`
         - [ ] Wait for [Buildkite](https://buildkite.com/matrix-dot-org/element-android/builds?branch=main) to build the `main` branch.
         - [ ] Run the script `~/scripts/releaseElement.sh`. It will download the APKs from Buildkite check them and sign them.
         - [ ] Install the APK on your phone to check that the upgrade went well (no init sync, etc.)
+        - [ ] Create the release on gitHub [from the tag](https://github.com/vector-im/element-android/tags), copy paste the block from the file CHANGES.md
+        - [ ] Add the 4 signed APKs to the GitHub release
+        - [ ] Ping the Android Internal room
+
+        ### Once tested and validated internally
+
         - [ ] Create a new beta release on the GooglePlay console and upload the 4 signed Apks.
         - [ ] Check that the version codes are correct
         - [ ] Copy the fastlane change to the GooglePlay console in the section en-GB.
         - [ ] Push to beta release to 100% of the users
-        - [ ] Create the release on gitHub [from the tag](https://github.com/vector-im/element-android/tags), copy paste the block from the file CHANGES.md
-        - [ ] Add the 4 signed APKs to the GitHub release
-        - [ ] Ping the Android Internal room
-        - [ ] Add an entry in the internal diary
+        - [ ] Notify the F-Droid team so that they can schedule the publication on F-Droid
 
         ### Once Live on PlayStore
 
         - [ ] Ping the Android public room and update its topic
+        - [ ] Add an entry in the internal diary
 
         ### After at least 2 days
 
@@ -62,6 +68,8 @@ body:
 
         ### Android SDK2
 
+        The SDK2 and the sample app are released only when Element has been pushed to production.
+
         - [ ] Checkout the `main` branch on Element Android project
 
         #### On the SDK2 project

.github/workflows/integration_tests.yml

@@ -180,6 +180,7 @@ jobs:
           body="$(cat ./matrix-sdk-android/build/outputs/androidTest-results/connected/*.xml | grep "<testsuite" | sed "s@.*tests=\(.*\)time=.*@\1@")"
           echo "::set-output name=permalink::passed=$body"
       - name: Find Comment
+        if: github.event_name == 'pull_request'
         uses: peter-evans/find-comment@v1
         id: fc
         with:
@@ -187,6 +188,7 @@ jobs:
           comment-author: 'github-actions[bot]'
           body-includes: Integration Tests Results
       - name: Publish results to PR
+        if: github.event_name == 'pull_request'
         uses: peter-evans/create-or-update-comment@v1
         with:
           comment-id: ${{ steps.fc.outputs.comment-id }}

.github/workflows/quality.yml

@@ -54,7 +54,7 @@ jobs:
             echo "::set-output name=body::$body"
           fi
       - name: Find Comment
-        if: always()
+        if: always() && github.event_name == 'pull_request'
         uses: peter-evans/find-comment@v1
         id: fc
         with:
@@ -62,7 +62,7 @@ jobs:
           comment-author: 'github-actions[bot]'
           body-includes: Ktlint Results
       - name: Add comment if needed
-        if: always() && steps.ktlint-results.outputs.add_comment == 'true'
+        if: always() && github.event_name == 'pull_request' && steps.ktlint-results.outputs.add_comment == 'true'
         uses: peter-evans/create-or-update-comment@v1
         with:
           comment-id: ${{ steps.fc.outputs.comment-id }}
@@ -73,7 +73,7 @@ jobs:
             ${{ steps.ktlint-results.outputs.body }}
           edit-mode: replace
       - name: Delete comment if needed
-        if: always() && steps.fc.outputs.comment-id != '' && steps.ktlint-results.outputs.add_comment == 'false'
+        if: always() && github.event_name == 'pull_request' && steps.fc.outputs.comment-id != '' && steps.ktlint-results.outputs.add_comment == 'false'
         uses: actions/github-script@v3
         with:
           script: |

.github/workflows/triage-labelled.yml

@@ -202,3 +202,53 @@ jobs:
         env:
           PROJECT_ID: "PN_kwDOAM0swc3m-g"
           GITHUB_TOKEN: ${{ secrets.ELEMENT_BOT_TOKEN }}
+ 
+  move_ftue_issues:
+    name: Z-FTUE to Mobile FTUE board
+    runs-on: ubuntu-latest
+    # Skip in forks
+    if: >
+      github.repository == 'vector-im/element-android' &&
+      contains(github.event.issue.labels.*.name, 'Z-FTUE')
+    steps:
+      - uses: octokit/graphql-action@v2.x
+        with:
+          headers: '{"GraphQL-Features": "projects_next_graphql"}'
+          query: |
+            mutation add_to_project($projectid:ID!,$contentid:ID!) {
+              addProjectNextItem(input:{projectId:$projectid contentId:$contentid}) {
+                projectNextItem {
+                  id
+                }
+              }
+            }
+          projectid: ${{ env.PROJECT_ID }}
+          contentid: ${{ github.event.issue.node_id }}
+        env:
+          PROJECT_ID: "PN_kwDOAM0swc4AAqVx"
+          GITHUB_TOKEN: ${{ secrets.ELEMENT_BOT_TOKEN }}
+
+  move_WTF_issues:
+    name: Z-WTF to WTF board
+    runs-on: ubuntu-latest
+    # Skip in forks
+    if: >
+      github.repository == 'vector-im/element-android' &&
+      contains(github.event.issue.labels.*.name, 'Z-WTF')
+    steps:
+      - uses: octokit/graphql-action@v2.x
+        with:
+          headers: '{"GraphQL-Features": "projects_next_graphql"}'
+          query: |
+            mutation add_to_project($projectid:ID!,$contentid:ID!) {
+              addProjectNextItem(input:{projectId:$projectid contentId:$contentid}) {
+                projectNextItem {
+                  id
+                }
+              }
+            }
+          projectid: ${{ env.PROJECT_ID }}
+          contentid: ${{ github.event.issue.node_id }}
+        env:
+          PROJECT_ID: "PN_kwDOAM0swc4AArk0"
+          GITHUB_TOKEN: ${{ secrets.ELEMENT_BOT_TOKEN }}

CHANGES.md

@@ -1,3 +1,35 @@
+Changes in Element v1.4.0 (2022-02-09)
+======================================
+
+Features ✨
+----------
+ - Initial implementation of thread messages ([#4746](https://github.com/vector-im/element-android/issues/4746))
+ - Support message bubbles in timeline. ([#4937](https://github.com/vector-im/element-android/issues/4937))
+ - Support generic location pin ([#5146](https://github.com/vector-im/element-android/issues/5146))
+ - Retrieve map style url from .well-known ([#5175](https://github.com/vector-im/element-android/issues/5175))
+
+Bugfixes 🐛
+----------
+ - Fixes non sans-serif font weights being ignored ([#3907](https://github.com/vector-im/element-android/issues/3907))
+ - Fixing missing/intermittent notifications on the google play variant when wifi is enabled ([#5038](https://github.com/vector-im/element-android/issues/5038))
+ - Fixes call statuses in the timeline for missed/rejected calls and connected calls. ([#5088](https://github.com/vector-im/element-android/issues/5088))
+ - Fix fallback permalink when threads are disabled ([#5128](https://github.com/vector-im/element-android/issues/5128))
+ - Analytics: aligns use case identifying with iOS implementation ([#5142](https://github.com/vector-im/element-android/issues/5142))
+ - Fix location rendering in timeline if map cannot be loaded ([#5143](https://github.com/vector-im/element-android/issues/5143))
+
+Other changes
+-------------
+ - "Invite users to space" dialog now closed when user choose invite method ([#4295](https://github.com/vector-im/element-android/issues/4295))
+ - Changed layout for space card and room card used at "explore room" screen and space/room invite dialogs ([#4304](https://github.com/vector-im/element-android/issues/4304))
+ - Removed spaces restricted search hint dialogs ([#4315](https://github.com/vector-im/element-android/issues/4315))
+ - Remove Search from room options if not available ([#4641](https://github.com/vector-im/element-android/issues/4641))
+ - Qr code scanning fragments merged into one ([#4873](https://github.com/vector-im/element-android/issues/4873))
+ - Fix CI/CD errors after merges for quality and integration tests ([#5118](https://github.com/vector-im/element-android/issues/5118))
+ - Added automation for the Z-FTUE label to add issues to the FTUE Project Board ([#5120](https://github.com/vector-im/element-android/issues/5120))
+ - Added automation for WTF labels to move to WTF project board ([#5148](https://github.com/vector-im/element-android/issues/5148))
+ - Update WTF automation to fix it ([#5173](https://github.com/vector-im/element-android/issues/5173))
+
+
 Changes in Element v1.3.18 (2022-02-03)
 =======================================
 

README.md

@@ -14,7 +14,8 @@ It is a total rewrite of [Riot-Android](https://github.com/vector-im/riot-androi
 [<img src="resources/img/google-play-badge.png" alt="Get it on Google Play" height="60">](https://play.google.com/store/apps/details?id=im.vector.app)
 [<img src="resources/img/f-droid-badge.png" alt="Get it on F-Droid" height="60">](https://f-droid.org/app/im.vector.app)
 
-Nightly build: [![Buildkite](https://badge.buildkite.com/ad0065c1b70f557cd3b1d3d68f9c2154010f83c4d6f71706a9.svg?branch=develop)](https://buildkite.com/matrix-dot-org/element-android/builds?branch=develop)
+Nightly build: [![Buildkite](https://badge.buildkite.com/ad0065c1b70f557cd3b1d3d68f9c2154010f83c4d6f71706a9.svg?branch=develop)](https://buildkite.com/matrix-dot-org/element-android/builds?branch=develop) Nighly sanity test status: [![allScreensTest](https://github.com/vector-im/element-android/actions/workflows/sanity_test.yml/badge.svg)](https://github.com/vector-im/element-android/actions/workflows/sanity_test.yml)
+
 
 # New Android SDK
 

build.gradle

@@ -36,6 +36,12 @@ allprojects {
     apply plugin: "org.jlleitschuh.gradle.ktlint"
 
     repositories {
+        mavenCentral {
+            content {
+                groups.mavenCentral.regex.each { includeGroupByRegex it }
+                groups.mavenCentral.group.each { includeGroup it }
+            }
+        }
         maven {
             url 'https://jitpack.io'
             content {
@@ -59,12 +65,6 @@ allprojects {
                 groups.google.group.each { includeGroup it }
             }
         }
-        mavenCentral {
-            content {
-                groups.mavenCentral.regex.each { includeGroupByRegex it }
-                groups.mavenCentral.group.each { includeGroup it }
-            }
-        }
         //noinspection JcenterRepositoryObsolete
         jcenter {
             content {
@@ -144,6 +144,11 @@ project(":diff-match-patch") {
     }
 }
 
+// Global configurations across all modules
+ext {
+    isThreadingEnabled = true
+}
+
 //project(":matrix-sdk-android") {
 //    sonarqube {
 //        properties {

fastlane/metadata/android/cs-CZ/changelogs/40103160.txt

@@ -0,0 +1,2 @@
+Hlavní změny v této verzi: Odeslání vlastní polohy do libovolné místnosti. Možnost úpravy hlasování.
+Úplný seznam změn: https://github.com/vector-im/element-android/releases/tag/v1.3.16

fastlane/metadata/android/de-DE/changelogs/40103160.txt

@@ -0,0 +1,2 @@
+Hauptänderungen: Du kannst ab sofort deinen Standort an deine Räume senden und Abstimmungen bearbeiten.
+Alle Änderungen: https://github.com/vector-im/element-android/releases/tag/v1.3.16

fastlane/metadata/android/en-US/changelogs/40104000.txt

@@ -0,0 +1,2 @@
+Main changes in this version:  Initial implementation of thread messages. Message bubbles.
+Full changelog: https://github.com/vector-im/element-android/releases/tag/v1.4.0

fastlane/metadata/android/et/changelogs/40103160.txt

@@ -0,0 +1,2 @@
+Põhilised muutused selles versioonis: oma asukoha saatmine jututuppa ja küsitluste muutmise võimalus.
+Kogu ingliskeelne muudatuste logi: https://github.com/vector-im/element-android/releases/tag/v1.3.16

fastlane/metadata/android/fa/changelogs/40103130.txt

@@ -0,0 +1,2 @@
+تغییرات عمده در این نگارشنخستین تغییر در صفحه‌های راه‌اندازی شامل وارد شدن به تجزیه‌ها. پشتیبانی از رویدادهایی با ریاضیات افزوده در آزمایشگاه‌ها.
+گزارش دگرگونی کامل: https://github.com/vector-im/element-android/releases/tag/v1.3.13

fastlane/metadata/android/fa/changelogs/40103140.txt

@@ -0,0 +1,2 @@
+تغییرات عمده در این نگارشنخستین تغییر در صفحه‌های راه‌اندازی شامل وارد شدن به تجزیه‌ها. پشتیبانی از رویدادهایی با ریاضیات افزوده در آزمایشگاه‌ها.
+گزارش دگرگونی کامل: https://github.com/vector-im/element-android/releases/tag/v1.3.14

fastlane/metadata/android/fa/changelogs/40103150.txt

@@ -0,0 +1,2 @@
+تغییرات عمده در این نگارشنخستین تغییر در صفحه‌های راه‌اندازی شامل وارد شدن به تجزیه‌ها. پشتیبانی از رویدادهایی با ریاضیات افزوده در آزمایشگاه‌ها.
+گزارش دگرگونی کامل: https://github.com/vector-im/element-android/releases/tag/v1.3.15

fastlane/metadata/android/fa/changelogs/40103160.txt

@@ -0,0 +1,2 @@
+تغییرات عمده در این نگارش: فرستادن مکانتان به هر اتاقی. ویرایش نظرسنجی.
+گزارش دگرگونی کامل: https://github.com/vector-im/element-android/releases/tag/v1.3.16

fastlane/metadata/android/fr-FR/changelogs/40103130.txt

@@ -0,0 +1,2 @@
+Principaux changements pour cette version : Premier changement dans l’écran de bienvenue, y compris l’adhésion aux données d’analyses. Support des événements avec opération mathématiques ajoutées dans les labs.
+Intégralité des changements : https://github.com/vector-im/element-android/releases/tag/v1.3.13

fastlane/metadata/android/fr-FR/changelogs/40103140.txt

@@ -0,0 +1,2 @@
+Principaux changements pour cette version : Premier changement dans l’écran de bienvenue, y compris l’adhésion aux données d’analyses. Support des événements avec opération mathématiques ajoutées dans les labs.
+Intégralité des changements : https://github.com/vector-im/element-android/releases/tag/v1.3.14

fastlane/metadata/android/fr-FR/changelogs/40103150.txt

@@ -0,0 +1,2 @@
+Principaux changements pour cette version : Premier changement dans l’écran de bienvenue, y compris l’adhésion aux données d’analyses. Support des événements avec opération mathématiques ajoutées dans les labs.
+Intégralité des changements : https://github.com/vector-im/element-android/releases/tag/v1.3.15

fastlane/metadata/android/fr-FR/changelogs/40103160.txt

@@ -0,0 +1,2 @@
+Principaux changements pour cette version : envoi de votre position dans n’importe quelle salon. Édition des sondage.
+Intégralité des changements : https://github.com/vector-im/element-android/releases/tag/v1.3.16

fastlane/metadata/android/hu-HU/changelogs/40103160.txt

@@ -0,0 +1,2 @@
+Fő változás ebben a verzióban: földrajzi helyzet küldése bármely szobába. Szavazás szerkesztése
+Teljes változásnapló: https://github.com/vector-im/element-android/releases/tag/v1.3.16

fastlane/metadata/android/id/changelogs/40103130.txt

@@ -1,2 +1,2 @@
 Perubahan utama dalam versi ini: Perubahan pertama di layar permulaan, termasuk analitik opt-in. Dukungan untuk Peristiwa dengan Matematika ditambahkan di Uji Coba.
-Changelog lanjutan:
+Changelog lanjutan: https://github.com/vector-im/element-android/releases/tag/v1.3.13

fastlane/metadata/android/id/changelogs/40103160.txt

@@ -0,0 +1,2 @@
+Perubahan utama dalam versi ini: Kirim lokasi Anda ke ruangan apa saja. Edit poll.
+Changelog lanjutan: https://github.com/vector-im/element-android/releases/tag/v1.3.16

fastlane/metadata/android/it-IT/changelogs/40103160.txt

@@ -0,0 +1,2 @@
+Modifiche principali in questa versione: invia la tua posizione in qualsiasi stanza. Modifica sondaggi.
+Cronologia completa: https://github.com/vector-im/element-android/releases/tag/v1.3.16

fastlane/metadata/android/pt-BR/changelogs/40103160.txt

@@ -0,0 +1,2 @@
+Principais mudanças nesta versão: envie sua localização para qualquer sala. Editar sondagem.
+Changelog completo: https://github.com/vector-im/element-android/releases/tag/v1.3.16

fastlane/metadata/android/ru-RU/changelogs/40103160.txt

@@ -0,0 +1,2 @@
+Основные изменения в этой версии: отправьте свое местоположение в любую комнату. Редактирование опроса.
+Полный список изменений: https://github.com/vector-im/element-android/releases/tag/v1.3.16

fastlane/metadata/android/sk/changelogs/40103160.txt

@@ -0,0 +1,2 @@
+Hlavné zmeny v tejto verzii: odoslanie polohy do ľubovoľnej miestnosti. Úprava ankety.
+Úplný zoznam zmien: https://github.com/vector-im/element-android/releases/tag/v1.3.16

fastlane/metadata/android/sq/changelogs/40103140.txt

@@ -0,0 +1,2 @@
+Ndryshimet kryesore në këtë version: Ndryshimi i parë në skenat e mirëseardhjes, përfshi zgjedhje për pjesëmarrje në Analiza. Në laboratorë u shtua mbulim për Akte me Formula Matematikore.
+Regjistër i plotë ndryshimesh: https://github.com/vector-im/element-android/releases/tag/v1.3.14

fastlane/metadata/android/sq/changelogs/40103150.txt

@@ -0,0 +1,2 @@
+Ndryshimet kryesore në këtë version: Ndryshimi i parë në skenat e mirëseardhjes, përfshi zgjedhje për pjesëmarrje në Analiza. Në laboratorë u shtua mbulim për Akte me Formula Matematikore.
+Regjistër i plotë ndryshimesh: https://github.com/vector-im/element-android/releases/tag/v1.3.15

fastlane/metadata/android/sq/changelogs/40103160.txt

@@ -0,0 +1,2 @@
+Ndryshimet kryesore në këtë version: dërgojeni vendndodhjen tuaj te cilado dhomë. Përpunoni pyetësor.
+Regjistër i plotës ndryshimesh: https://github.com/vector-im/element-android/releases/tag/v1.3.16

fastlane/metadata/android/sv-SE/changelogs/40103130.txt

@@ -0,0 +1,2 @@
+Huvudsakliga ändringar i den här versionen: Första ändringen på introduktionsskärmar, inklusive opt-in för statistik. Stöd för händelser med matte tillagd i experiment.
+Full ändringslogg: https://github.com/vector-im/element-android/releases/tag/v1.3.13

fastlane/metadata/android/sv-SE/changelogs/40103140.txt

@@ -0,0 +1,2 @@
+Huvudsakliga ändringar i den här versionen: Första ändringen på introduktionsskärmar, inklusive opt-in för statistik. Stöd för händelser med matte tillagd i experiment.
+Full ändringslogg: https://github.com/vector-im/element-android/releases/tag/v1.3.14

fastlane/metadata/android/sv-SE/changelogs/40103150.txt

@@ -0,0 +1,2 @@
+Huvudsakliga ändringar i den här versionen: Första ändringen på introduktionsskärmar, inklusive opt-in för statistik. Stöd för händelser med matte tillagd i experiment.
+Full ändringslogg: https://github.com/vector-im/element-android/releases/tag/v1.3.15

fastlane/metadata/android/sv-SE/changelogs/40103160.txt

@@ -0,0 +1,2 @@
+Huvudsakliga ändringar i den här versionen: skicka din plats till vilket rum som helst. Redigera omröstningar.
+Full ändringslogg: https://github.com/vector-im/element-android/releases/tag/v1.3.16

fastlane/metadata/android/uk/changelogs/40103160.txt

@@ -0,0 +1,2 @@
+Основні зміни у цій версії: надсилання свого місцеперебування у будь-яку кімнату. Редагування опитувань.
+Вичерпний перелік змін: https://github.com/vector-im/element-android/releases/tag/v1.3.16

fastlane/metadata/android/zh-TW/changelogs/40103160.txt

@@ -0,0 +1,2 @@
+此版本中的主要變動：將您的位置傳送給任何聊天室。編輯投票。
+完整的變更紀錄：https://github.com/vector-im/element-android/releases/tag/v1.3.16

library/ui-styles/src/main/res/anim/animation_slide_in_left.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<set xmlns:android="http://schemas.android.com/apk/res/android">
+    <translate
+        android:fromXDelta="-100%p" android:toXDelta="0"
+        android:duration="@android:integer/config_mediumAnimTime"/>
+</set>

library/ui-styles/src/main/res/anim/animation_slide_in_right.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<set xmlns:android="http://schemas.android.com/apk/res/android">
+    <translate
+        android:startOffset="250"
+        android:fromXDelta="100%p" android:toXDelta="0"
+        android:duration="@android:integer/config_mediumAnimTime"/>
+</set>

library/ui-styles/src/main/res/anim/animation_slide_out_left.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<set xmlns:android="http://schemas.android.com/apk/res/android">
+    <translate
+        android:startOffset="250"
+        android:fromXDelta="0" android:toXDelta="-100%p"
+        android:duration="@android:integer/config_mediumAnimTime"/>
+</set>

library/ui-styles/src/main/res/anim/animation_slide_out_right.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<set xmlns:android="http://schemas.android.com/apk/res/android">
+    <translate
+        android:fromXDelta="0" android:toXDelta="100%p"
+        android:duration="@android:integer/config_mediumAnimTime"/>
+</set>

library/ui-styles/src/main/res/drawable/bg_media_pill.xml

@@ -2,9 +2,6 @@
 <shape xmlns:android="http://schemas.android.com/apk/res/android">
     <!-- Tint color is provided by the theme -->
     <solid android:color="@android:color/black" />
-    <size
-        android:width="240dp"
-        android:height="44dp" />
     <corners
         android:bottomLeftRadius="12dp"
         android:bottomRightRadius="12dp"

library/ui-styles/src/main/res/drawable/file_progress_bar.xml

@@ -2,16 +2,14 @@
 <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
 
     <item android:id="@android:id/background">
-        <shape>
-            <corners android:radius="8dp" />
-            <solid android:color="?vctr_room_active_widgets_banner_bg" />
+        <shape android:shape="oval">
+            <solid android:color="?vctr_system" />
         </shape>
     </item>
 
     <item android:id="@android:id/progress">
         <clip>
-            <shape>
-                <corners android:radius="8dp" />
+            <shape android:shape="oval">
                 <solid android:color="@color/vctr_notice_secondary_alpha12" />
             </shape>
         </clip>

library/ui-styles/src/main/res/values-v23/dimens.xml

@@ -1,6 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-
-    <bool name="is_rtl">true</bool>
-
+    <dimen name="menu_item_ripple_size">28dp</dimen>
 </resources>

library/ui-styles/src/main/res/values/bools.xml

@@ -4,6 +4,4 @@
     <!-- Created to detect what has to be implemented (especially in the settings) -->
     <bool name="false_not_implemented">false</bool>
 
-    <bool name="is_rtl">false</bool>
-
 </resources>

library/ui-styles/src/main/res/values/colors.xml

@@ -137,4 +137,5 @@
     <attr name="vctr_presence_indicator_offline" format="color" />
     <color name="vctr_presence_indicator_offline_light">@color/palette_gray_100</color>
     <color name="vctr_presence_indicator_offline_dark">@color/palette_gray_450</color>
+
 </resources>

library/ui-styles/src/main/res/values/colors_message_bubble.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+
+    <!-- Timeline bubble background colors -->
+    <attr name="vctr_message_bubble_inbound" format="color" />
+    <color name="vctr_message_bubble_inbound_light">#E8EDF4</color>
+    <color name="vctr_message_bubble_inbound_dark">#21262C</color>
+    <attr name="vctr_message_bubble_outbound" format="color" />
+    <color name="vctr_message_bubble_outbound_light">#E7F8F3</color>
+    <color name="vctr_message_bubble_outbound_dark">#133A34</color>
+</resources>

library/ui-styles/src/main/res/values/dimens.xml

@@ -15,6 +15,8 @@
     <dimen name="item_decoration_left_margin">72dp</dimen>
     <dimen name="item_event_message_state_size">16dp</dimen>
 
+    <dimen name="item_event_message_media_button_size">32dp</dimen>
+
     <dimen name="chat_avatar_size">40dp</dimen>
     <dimen name="member_list_avatar_size">60dp</dimen>
 
@@ -42,12 +44,23 @@
 
     <!--  Preview Url  -->
     <dimen name="preview_url_view_corner_radius">8dp</dimen>
+    <dimen name="preview_url_view_image_max_height">160dp</dimen>
+
+    <dimen name="menu_item_icon_size">24dp</dimen>
+    <dimen name="menu_item_size">48dp</dimen>
+    <dimen name="menu_item_ripple_size">48dp</dimen>
 
     <!-- Composer -->
     <dimen name="composer_min_height">56dp</dimen>
     <dimen name="composer_attachment_size">52dp</dimen>
     <dimen name="composer_attachment_margin">1dp</dimen>
 
+
+    <dimen name="chat_bubble_margin_start">28dp</dimen>
+    <dimen name="chat_bubble_margin_end">62dp</dimen>
+    <dimen name="chat_bubble_fixed_size">300dp</dimen>
+    <dimen name="chat_bubble_corner_radius">12dp</dimen>
+
     <!--  Onboarding   -->
     <item name="ftue_auth_gutter_start_percent" format="float" type="dimen">0.05</item>
     <item name="ftue_auth_gutter_end_percent" format="float" type="dimen">0.95</item>

library/ui-styles/src/main/res/values/stylable_message_bubble.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+
+    <declare-styleable name="MessageBubble">
+        <attr name="incoming_style" format="boolean" />
+        <attr name="show_time_overlay" format="boolean" />
+        <attr name="is_first" format="boolean" />
+        <attr name="is_last" format="boolean" />
+    </declare-styleable>
+
+</resources>

library/ui-styles/src/main/res/values/styles_progress.xml

@@ -6,6 +6,7 @@
     <style name="Widget.Vector.ProgressBar.Horizontal.File">
         <item name="android:indeterminateOnly">false</item>
         <item name="android:progressDrawable">@drawable/file_progress_bar</item>
+        <item name="android:progressBackgroundTint">?android:colorBackground</item>
         <item name="android:minHeight">10dp</item>
         <item name="android:maxHeight">40dp</item>
     </style>

library/ui-styles/src/main/res/values/styles_timeline.xml

@@ -4,12 +4,23 @@
     <style name="TimelineContentStubBaseParams">
         <item name="android:layout_width">match_parent</item>
         <item name="android:layout_height">wrap_content</item>
-        <item name="android:layout_marginStart">8dp</item>
-        <item name="android:layout_marginLeft">8dp</item>
-        <item name="android:layout_marginEnd">8dp</item>
-        <item name="android:layout_marginRight">8dp</item>
-        <item name="android:layout_marginBottom">4dp</item>
-        <item name="android:layout_marginTop">4dp</item>
+    </style>
+
+    <style name="TimelineContentStubContainerParams">
+        <item name="android:paddingStart">8dp</item>
+        <item name="android:paddingEnd">8dp</item>
+        <item name="android:paddingTop">4dp</item>
+        <item name="android:paddingBottom">4dp</item>
+    </style>
+
+    <style name="TimelineContentMediaPillStyle">
+        <item name="android:paddingStart">8dp</item>
+        <item name="android:paddingEnd">8dp</item>
+        <item name="android:paddingTop">6dp</item>
+        <item name="android:paddingBottom">6dp</item>
+        <item name="minHeight">48dp</item>
+        <item name="android:background">@drawable/bg_media_pill</item>
+        <item name="android:backgroundTint">?vctr_content_quinary</item>
     </style>
 
 </resources>

library/ui-styles/src/main/res/values/theme_dark.xml

@@ -31,6 +31,8 @@
         <item name="vctr_waiting_background_color">@color/vctr_waiting_background_color_dark</item>
         <item name="vctr_chat_effect_snow_background">@color/vctr_chat_effect_snow_background_dark</item>
         <item name="vctr_toolbar_background">@color/element_system_dark</item>
+        <item name="vctr_message_bubble_inbound">@color/vctr_message_bubble_inbound_dark</item>
+        <item name="vctr_message_bubble_outbound">@color/vctr_message_bubble_outbound_dark</item>
 
         <!-- room message colors -->
         <item name="vctr_notice_secondary">#61708B</item>
@@ -105,9 +107,6 @@
         <!-- disable the overscroll because setOverscrollHeader/Footer don't always work -->
         <item name="android:overScrollMode">never</item>
 
-        <!-- fonts -->
-        <item name="android:typeface">sans</item>
-
         <item name="preferenceTheme">@style/PreferenceThemeOverlay.v14.Material</item>
 
         <item name="pf_lock_screen">@style/PinCodeScreenStyle</item>

library/ui-styles/src/main/res/values/theme_light.xml

@@ -31,6 +31,8 @@
         <item name="vctr_waiting_background_color">@color/vctr_waiting_background_color_light</item>
         <item name="vctr_chat_effect_snow_background">@color/vctr_chat_effect_snow_background_light</item>
         <item name="vctr_toolbar_background">@color/element_background_light</item>
+        <item name="vctr_message_bubble_inbound">@color/vctr_message_bubble_inbound_light</item>
+        <item name="vctr_message_bubble_outbound">@color/vctr_message_bubble_outbound_light</item>
 
         <!-- room message colors -->
         <item name="vctr_notice_secondary">#61708B</item>
@@ -105,9 +107,6 @@
         <!-- disable the overscroll because setOverscrollHeader/Footer don't always work -->
         <item name="android:overScrollMode">never</item>
 
-        <!-- fonts -->
-        <item name="android:typeface">sans</item>
-
         <item name="preferenceTheme">@style/PreferenceThemeOverlay.v14.Material</item>
 
         <item name="pf_lock_screen">@style/PinCodeScreenStyle</item>

matrix-sdk-android-flow/src/main/java/org/matrix/android/sdk/flow/FlowRoom.kt

@@ -32,6 +32,8 @@ import org.matrix.android.sdk.api.session.room.timeline.TimelineEvent
 import org.matrix.android.sdk.api.util.Optional
 import org.matrix.android.sdk.api.util.toOptional
 
+typealias ThreadRootEvent = TimelineEvent
+
 class FlowRoom(private val room: Room) {
 
     fun liveRoomSummary(): Flow<Optional<RoomSummary>> {
@@ -98,6 +100,20 @@ class FlowRoom(private val room: Room) {
     fun liveNotificationState(): Flow<RoomNotificationState> {
         return room.getLiveRoomNotificationState().asFlow()
     }
+
+    fun liveThreadList(): Flow<List<ThreadRootEvent>> {
+        return room.getAllThreadsLive().asFlow()
+                .startWith(room.coroutineDispatchers.io) {
+                    room.getAllThreads()
+                }
+    }
+
+    fun liveLocalUnreadThreadList(): Flow<List<ThreadRootEvent>> {
+        return room.getMarkedThreadNotificationsLive().asFlow()
+                .startWith(room.coroutineDispatchers.io) {
+                    room.getMarkedThreadNotifications()
+                }
+    }
 }
 
 fun Room.flow(): FlowRoom {

matrix-sdk-android/build.gradle

@@ -31,13 +31,15 @@ android {
         // that the app's state is completely cleared between tests.
         testInstrumentationRunnerArguments clearPackageData: 'true'
 
-        buildConfigField "String", "SDK_VERSION", "\"1.3.18\""
+        buildConfigField "String", "SDK_VERSION", "\"1.3.19\""
 
         buildConfigField "String", "GIT_SDK_REVISION", "\"${gitRevision()}\""
         resValue "string", "git_sdk_revision", "\"${gitRevision()}\""
         resValue "string", "git_sdk_revision_unix_date", "\"${gitRevisionUnixDate()}\""
         resValue "string", "git_sdk_revision_date", "\"${gitRevisionDate()}\""
 
+        // Indicates whether or not threading support is enabled
+        buildConfigField "Boolean", "THREADING_ENABLED", "${isThreadingEnabled}"
         defaultConfig {
             consumerProguardFiles 'proguard-rules.pro'
         }
@@ -139,6 +141,9 @@ dependencies {
 
     kapt 'dk.ilios:realmfieldnameshelper:2.0.0'
 
+    // Shared Preferences
+    implementation libs.androidx.preferenceKtx
+
     // Work
     implementation libs.androidx.work
 

matrix-sdk-android/src/androidTest/java/org/matrix/android/sdk/common/CommonTestHelper.kt

@@ -157,14 +157,20 @@ class CommonTestHelper(context: Context) {
     /**
      * Will send nb of messages provided by count parameter but waits every 10 messages to avoid gap in sync
      */
-    private fun sendTextMessagesBatched(timeline: Timeline, room: Room, message: String, count: Int, timeout: Long): List<TimelineEvent> {
+    private fun sendTextMessagesBatched(timeline: Timeline, room: Room, message: String, count: Int, timeout: Long, rootThreadEventId: String? = null): List<TimelineEvent> {
         val sentEvents = ArrayList<TimelineEvent>(count)
         (1 until count + 1)
                 .map { "$message #$it" }
                 .chunked(10)
                 .forEach { batchedMessages ->
                     batchedMessages.forEach { formattedMessage ->
-                        room.sendTextMessage(formattedMessage)
+                        if (rootThreadEventId != null) {
+                            room.replyInThread(
+                                    rootThreadEventId = rootThreadEventId,
+                                    replyInThreadText = formattedMessage)
+                        } else {
+                            room.sendTextMessage(formattedMessage)
+                        }
                     }
                     waitWithLatch(timeout) { latch ->
                         val timelineListener = object : Timeline.Listener {
@@ -196,6 +202,27 @@ class CommonTestHelper(context: Context) {
         return sentEvents
     }
 
+    /**
+     * Reply in a thread
+     * @param room         the room where to send the messages
+     * @param message      the message to send
+     * @param numberOfMessages the number of time the message will be sent
+     */
+    fun replyInThreadMessage(
+            room: Room,
+            message: String,
+            numberOfMessages: Int,
+            rootThreadEventId: String,
+            timeout: Long = TestConstants.timeOutMillis): List<TimelineEvent> {
+        val timeline = room.createTimeline(null, TimelineSettings(10))
+        timeline.start()
+        val sentEvents = sendTextMessagesBatched(timeline, room, message, numberOfMessages, timeout, rootThreadEventId)
+        timeline.dispose()
+        // Check that all events has been created
+        assertEquals("Message number do not match $sentEvents", numberOfMessages.toLong(), sentEvents.size.toLong())
+        return sentEvents
+    }
+
     // PRIVATE METHODS *****************************************************************************
 
     /**

matrix-sdk-android/src/androidTest/java/org/matrix/android/sdk/session/room/threads/ThreadMessagingTest.kt

@@ -0,0 +1,339 @@
+/*
+ * Copyright 2022 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.android.sdk.session.room.threads
+
+import org.amshove.kluent.shouldBe
+import org.amshove.kluent.shouldBeEqualTo
+import org.amshove.kluent.shouldBeFalse
+import org.amshove.kluent.shouldBeNull
+import org.amshove.kluent.shouldBeTrue
+import org.junit.FixMethodOrder
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+import org.junit.runners.MethodSorters
+import org.matrix.android.sdk.InstrumentedTest
+import org.matrix.android.sdk.api.session.events.model.getRootThreadEventId
+import org.matrix.android.sdk.api.session.events.model.isTextMessage
+import org.matrix.android.sdk.api.session.events.model.isThread
+import org.matrix.android.sdk.api.session.room.timeline.Timeline
+import org.matrix.android.sdk.api.session.room.timeline.TimelineSettings
+import org.matrix.android.sdk.common.CommonTestHelper
+import org.matrix.android.sdk.common.CryptoTestHelper
+import java.util.concurrent.CountDownLatch
+
+@RunWith(JUnit4::class)
+@FixMethodOrder(MethodSorters.JVM)
+class ThreadMessagingTest : InstrumentedTest {
+
+    @Test
+    fun reply_in_thread_should_create_a_thread() {
+        val commonTestHelper = CommonTestHelper(context())
+        val cryptoTestHelper = CryptoTestHelper(commonTestHelper)
+        val cryptoTestData = cryptoTestHelper.doE2ETestWithAliceInARoom(false)
+
+        val aliceSession = cryptoTestData.firstSession
+        val aliceRoomId = cryptoTestData.roomId
+
+        val aliceRoom = aliceSession.getRoom(aliceRoomId)!!
+
+        // Let's send a message in the normal timeline
+        val textMessage = "This is a normal timeline message"
+        val sentMessages = commonTestHelper.sendTextMessage(
+                room = aliceRoom,
+                message = textMessage,
+                nbOfMessages = 1)
+
+        val initMessage = sentMessages.first()
+
+        initMessage.root.isThread().shouldBeFalse()
+        initMessage.root.isTextMessage().shouldBeTrue()
+        initMessage.root.getRootThreadEventId().shouldBeNull()
+        initMessage.root.threadDetails?.isRootThread?.shouldBeFalse()
+
+        // Let's reply in timeline to that message
+        val repliesInThread = commonTestHelper.replyInThreadMessage(
+                room = aliceRoom,
+                message = "Reply In the above thread",
+                numberOfMessages = 1,
+                rootThreadEventId = initMessage.root.eventId.orEmpty())
+
+        val replyInThread = repliesInThread.first()
+        replyInThread.root.isThread().shouldBeTrue()
+        replyInThread.root.isTextMessage().shouldBeTrue()
+        replyInThread.root.getRootThreadEventId().shouldBeEqualTo(initMessage.root.eventId)
+
+        // The init normal message should now be a root thread event
+        val timeline = aliceRoom.createTimeline(null, TimelineSettings(30))
+        timeline.start()
+
+        aliceSession.startSync(true)
+        run {
+            val lock = CountDownLatch(1)
+            val eventsListener = commonTestHelper.createEventListener(lock) { snapshot ->
+                val initMessageThreadDetails = snapshot.firstOrNull {
+                    it.root.eventId == initMessage.root.eventId
+                }?.root?.threadDetails
+                initMessageThreadDetails?.isRootThread?.shouldBeTrue()
+                initMessageThreadDetails?.numberOfThreads?.shouldBe(1)
+                true
+            }
+            timeline.addListener(eventsListener)
+            commonTestHelper.await(lock, 600_000)
+        }
+        aliceSession.stopSync()
+    }
+
+    @Test
+    fun reply_in_thread_should_create_a_thread_from_other_user() {
+        val commonTestHelper = CommonTestHelper(context())
+        val cryptoTestHelper = CryptoTestHelper(commonTestHelper)
+        val cryptoTestData = cryptoTestHelper.doE2ETestWithAliceAndBobInARoom(false)
+
+        val aliceSession = cryptoTestData.firstSession
+        val aliceRoomId = cryptoTestData.roomId
+        val aliceRoom = aliceSession.getRoom(aliceRoomId)!!
+
+        // Let's send a message in the normal timeline
+        val textMessage = "This is a normal timeline message"
+        val sentMessages = commonTestHelper.sendTextMessage(
+                room = aliceRoom,
+                message = textMessage,
+                nbOfMessages = 1)
+
+        val initMessage = sentMessages.first()
+
+        initMessage.root.isThread().shouldBeFalse()
+        initMessage.root.isTextMessage().shouldBeTrue()
+        initMessage.root.getRootThreadEventId().shouldBeNull()
+        initMessage.root.threadDetails?.isRootThread?.shouldBeFalse()
+
+        // Let's reply in timeline to that message from another user
+        val bobSession = cryptoTestData.secondSession!!
+        val bobRoomId = cryptoTestData.roomId
+        val bobRoom = bobSession.getRoom(bobRoomId)!!
+
+        val repliesInThread = commonTestHelper.replyInThreadMessage(
+                room = bobRoom,
+                message = "Reply In the above thread",
+                numberOfMessages = 1,
+                rootThreadEventId = initMessage.root.eventId.orEmpty())
+
+        val replyInThread = repliesInThread.first()
+        replyInThread.root.isThread().shouldBeTrue()
+        replyInThread.root.isTextMessage().shouldBeTrue()
+        replyInThread.root.getRootThreadEventId().shouldBeEqualTo(initMessage.root.eventId)
+
+        // The init normal message should now be a root thread event
+        val timeline = aliceRoom.createTimeline(null, TimelineSettings(30))
+        timeline.start()
+
+        aliceSession.startSync(true)
+        run {
+            val lock = CountDownLatch(1)
+            val eventsListener = commonTestHelper.createEventListener(lock) { snapshot ->
+                val initMessageThreadDetails = snapshot.firstOrNull { it.root.eventId == initMessage.root.eventId }?.root?.threadDetails
+                initMessageThreadDetails?.isRootThread?.shouldBeTrue()
+                initMessageThreadDetails?.numberOfThreads?.shouldBe(1)
+                true
+            }
+            timeline.addListener(eventsListener)
+            commonTestHelper.await(lock, 600_000)
+        }
+        aliceSession.stopSync()
+
+        bobSession.startSync(true)
+        run {
+            val lock = CountDownLatch(1)
+            val eventsListener = commonTestHelper.createEventListener(lock) { snapshot ->
+                val initMessageThreadDetails = snapshot.firstOrNull { it.root.eventId == initMessage.root.eventId }?.root?.threadDetails
+                initMessageThreadDetails?.isRootThread?.shouldBeTrue()
+                initMessageThreadDetails?.numberOfThreads?.shouldBe(1)
+                true
+            }
+            timeline.addListener(eventsListener)
+            commonTestHelper.await(lock, 600_000)
+        }
+        bobSession.stopSync()
+    }
+
+    @Test
+    fun reply_in_thread_to_timeline_message_multiple_times() {
+        val commonTestHelper = CommonTestHelper(context())
+        val cryptoTestHelper = CryptoTestHelper(commonTestHelper)
+        val cryptoTestData = cryptoTestHelper.doE2ETestWithAliceInARoom(false)
+
+        val aliceSession = cryptoTestData.firstSession
+        val aliceRoomId = cryptoTestData.roomId
+
+        val aliceRoom = aliceSession.getRoom(aliceRoomId)!!
+
+        // Let's send 5 messages in the normal timeline
+        val textMessage = "This is a normal timeline message"
+        val sentMessages = commonTestHelper.sendTextMessage(
+                room = aliceRoom,
+                message = textMessage,
+                nbOfMessages = 5)
+
+        sentMessages.forEach {
+            it.root.isThread().shouldBeFalse()
+            it.root.isTextMessage().shouldBeTrue()
+            it.root.getRootThreadEventId().shouldBeNull()
+            it.root.threadDetails?.isRootThread?.shouldBeFalse()
+        }
+        // let's start the thread from the second message
+        val selectedInitMessage = sentMessages[1]
+
+        // Let's reply 40 times in the timeline to the second message
+        val repliesInThread = commonTestHelper.replyInThreadMessage(
+                room = aliceRoom,
+                message = "Reply In the above thread",
+                numberOfMessages = 40,
+                rootThreadEventId = selectedInitMessage.root.eventId.orEmpty())
+
+        repliesInThread.forEach {
+            it.root.isThread().shouldBeTrue()
+            it.root.isTextMessage().shouldBeTrue()
+            it.root.getRootThreadEventId()?.shouldBeEqualTo(selectedInitMessage.root.eventId.orEmpty()) ?: assert(false)
+        }
+
+        // The init normal message should now be a root thread event
+        val timeline = aliceRoom.createTimeline(null, TimelineSettings(30))
+        timeline.start()
+
+        aliceSession.startSync(true)
+        run {
+            val lock = CountDownLatch(1)
+            val eventsListener = commonTestHelper.createEventListener(lock) { snapshot ->
+                val initMessageThreadDetails = snapshot.firstOrNull { it.root.eventId == selectedInitMessage.root.eventId }?.root?.threadDetails
+                // Selected init message should be the thread root
+                initMessageThreadDetails?.isRootThread?.shouldBeTrue()
+                // All threads should be 40
+                initMessageThreadDetails?.numberOfThreads?.shouldBeEqualTo(40)
+                true
+            }
+            // Because we sent more than 30 messages we should paginate a bit more
+            timeline.paginate(Timeline.Direction.BACKWARDS, 50)
+            timeline.addListener(eventsListener)
+            commonTestHelper.await(lock, 600_000)
+        }
+        aliceSession.stopSync()
+    }
+
+    @Test
+    fun thread_summary_advanced_validation_after_multiple_messages_in_multiple_threads() {
+        val commonTestHelper = CommonTestHelper(context())
+        val cryptoTestHelper = CryptoTestHelper(commonTestHelper)
+        val cryptoTestData = cryptoTestHelper.doE2ETestWithAliceAndBobInARoom(false)
+
+        val aliceSession = cryptoTestData.firstSession
+        val aliceRoomId = cryptoTestData.roomId
+
+        val aliceRoom = aliceSession.getRoom(aliceRoomId)!!
+
+        // Let's send 5 messages in the normal timeline
+        val textMessage = "This is a normal timeline message"
+        val sentMessages = commonTestHelper.sendTextMessage(
+                room = aliceRoom,
+                message = textMessage,
+                nbOfMessages = 5)
+
+        sentMessages.forEach {
+            it.root.isThread().shouldBeFalse()
+            it.root.isTextMessage().shouldBeTrue()
+            it.root.getRootThreadEventId().shouldBeNull()
+            it.root.threadDetails?.isRootThread?.shouldBeFalse()
+        }
+        // let's start the thread from the second message
+        val firstMessage = sentMessages[0]
+        val secondMessage = sentMessages[1]
+
+        // Alice will reply in thread to the second message 35 times
+        val aliceThreadRepliesInSecondMessage = commonTestHelper.replyInThreadMessage(
+                room = aliceRoom,
+                message = "Alice reply In the above second thread message",
+                numberOfMessages = 35,
+                rootThreadEventId = secondMessage.root.eventId.orEmpty())
+
+        // Let's reply in timeline to that message from another user
+        val bobSession = cryptoTestData.secondSession!!
+        val bobRoomId = cryptoTestData.roomId
+        val bobRoom = bobSession.getRoom(bobRoomId)!!
+
+        // Bob will reply in thread to the first message 35 times
+        val bobThreadRepliesInFirstMessage = commonTestHelper.replyInThreadMessage(
+                room = bobRoom,
+                message = "Bob reply In the above first thread message",
+                numberOfMessages = 42,
+                rootThreadEventId = firstMessage.root.eventId.orEmpty())
+
+        // Bob will also reply in second thread 5 times
+        val bobThreadRepliesInSecondMessage = commonTestHelper.replyInThreadMessage(
+                room = bobRoom,
+                message = "Another Bob reply In the above second thread message",
+                numberOfMessages = 20,
+                rootThreadEventId = secondMessage.root.eventId.orEmpty())
+
+        aliceThreadRepliesInSecondMessage.forEach {
+            it.root.isThread().shouldBeTrue()
+            it.root.isTextMessage().shouldBeTrue()
+            it.root.getRootThreadEventId()?.shouldBeEqualTo(secondMessage.root.eventId.orEmpty()) ?: assert(false)
+        }
+
+        bobThreadRepliesInFirstMessage.forEach {
+            it.root.isThread().shouldBeTrue()
+            it.root.isTextMessage().shouldBeTrue()
+            it.root.getRootThreadEventId()?.shouldBeEqualTo(firstMessage.root.eventId.orEmpty()) ?: assert(false)
+        }
+
+        bobThreadRepliesInSecondMessage.forEach {
+            it.root.isThread().shouldBeTrue()
+            it.root.isTextMessage().shouldBeTrue()
+            it.root.getRootThreadEventId()?.shouldBeEqualTo(secondMessage.root.eventId.orEmpty()) ?: assert(false)
+        }
+
+        // The init normal message should now be a root thread event
+        val timeline = aliceRoom.createTimeline(null, TimelineSettings(30))
+        timeline.start()
+
+        aliceSession.startSync(true)
+        run {
+            val lock = CountDownLatch(1)
+            val eventsListener = commonTestHelper.createEventListener(lock) { snapshot ->
+                val firstMessageThreadDetails = snapshot.firstOrNull { it.root.eventId == firstMessage.root.eventId }?.root?.threadDetails
+                val secondMessageThreadDetails = snapshot.firstOrNull { it.root.eventId == secondMessage.root.eventId }?.root?.threadDetails
+
+                // first & second message should be the thread root
+                firstMessageThreadDetails?.isRootThread?.shouldBeTrue()
+                secondMessageThreadDetails?.isRootThread?.shouldBeTrue()
+
+                // First thread message should contain 42
+                firstMessageThreadDetails?.numberOfThreads shouldBeEqualTo 42
+                // Second thread message should contain 35+20
+                secondMessageThreadDetails?.numberOfThreads shouldBeEqualTo 55
+
+                true
+            }
+            // Because we sent more than 30 messages we should paginate a bit more
+            timeline.paginate(Timeline.Direction.BACKWARDS, 50)
+            timeline.paginate(Timeline.Direction.BACKWARDS, 50)
+            timeline.addListener(eventsListener)
+            commonTestHelper.await(lock, 600_000)
+        }
+        aliceSession.stopSync()
+    }
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/events/model/Event.kt

@@ -25,9 +25,14 @@ import org.matrix.android.sdk.api.session.crypto.MXCryptoError
 import org.matrix.android.sdk.api.session.room.model.Membership
 import org.matrix.android.sdk.api.session.room.model.RoomMemberContent
 import org.matrix.android.sdk.api.session.room.model.message.MessageContent
+import org.matrix.android.sdk.api.session.room.model.message.MessagePollContent
+import org.matrix.android.sdk.api.session.room.model.message.MessageStickerContent
 import org.matrix.android.sdk.api.session.room.model.message.MessageType
 import org.matrix.android.sdk.api.session.room.model.relation.RelationDefaultContent
+import org.matrix.android.sdk.api.session.room.model.relation.shouldRenderInThread
 import org.matrix.android.sdk.api.session.room.send.SendState
+import org.matrix.android.sdk.api.session.threads.ThreadDetails
+import org.matrix.android.sdk.api.util.ContentUtils
 import org.matrix.android.sdk.api.util.JsonDict
 import org.matrix.android.sdk.internal.crypto.algorithms.olm.OlmDecryptionResult
 import org.matrix.android.sdk.internal.crypto.model.event.EncryptedEventContent
@@ -98,6 +103,9 @@ data class Event(
     @Transient
     var sendStateDetails: String? = null
 
+    @Transient
+    var threadDetails: ThreadDetails? = null
+
     fun sendStateError(): MatrixError? {
         return sendStateDetails?.let {
             val matrixErrorAdapter = MoshiProvider.providesMoshi().adapter(MatrixError::class.java)
@@ -123,6 +131,7 @@ data class Event(
             it.mCryptoErrorReason = mCryptoErrorReason
             it.sendState = sendState
             it.ageLocalTs = ageLocalTs
+            it.threadDetails = threadDetails
         }
     }
 
@@ -185,6 +194,51 @@ data class Event(
         return contentMap?.let { JSONObject(adapter.toJson(it)).toString(4) }
     }
 
+    /**
+     * Returns a user friendly content depending on the message type.
+     * It can be used especially for message summaries.
+     * It will return a decrypted text message or an empty string otherwise.
+     */
+    fun getDecryptedTextSummary(): String? {
+        if (isRedacted()) return "Message Deleted"
+        val text = getDecryptedValue() ?: return null
+        return when {
+            isReplyRenderedInThread() || isQuote() -> ContentUtils.extractUsefulTextFromReply(text)
+            isFileMessage()                        -> "sent a file."
+            isAudioMessage()                       -> "sent an audio file."
+            isImageMessage()                       -> "sent an image."
+            isVideoMessage()                       -> "sent a video."
+            isSticker()                            -> "sent a sticker"
+            isPoll()                               -> getPollQuestion() ?: "created a poll."
+            else                                   -> text
+        }
+    }
+
+    private fun Event.isQuote(): Boolean {
+        if (isReplyRenderedInThread()) return false
+        return getDecryptedValue("formatted_body")?.contains("<blockquote>") ?: false
+    }
+
+    /**
+     * Determines whether or not current event has mentioned the user
+     */
+    fun isUserMentioned(userId: String): Boolean {
+        return getDecryptedValue("formatted_body")?.contains(userId) ?: false
+    }
+
+    /**
+     * Decrypt the message, or return the pure payload value if there is no encryption
+     */
+    private fun getDecryptedValue(key: String = "body"): String? {
+        return if (isEncrypted()) {
+            @Suppress("UNCHECKED_CAST")
+            val decryptedContent = mxDecryptionResult?.payload?.get("content") as? JsonDict
+            decryptedContent?.get(key) as? String
+        } else {
+            content?.get(key) as? String
+        }
+    }
+
     /**
      * Tells if the event is redacted
      */
@@ -217,7 +271,7 @@ data class Event(
         if (mCryptoError != other.mCryptoError) return false
         if (mCryptoErrorReason != other.mCryptoErrorReason) return false
         if (sendState != other.sendState) return false
-
+        if (threadDetails != other.threadDetails) return false
         return true
     }
 
@@ -236,6 +290,8 @@ data class Event(
         result = 31 * result + (mCryptoError?.hashCode() ?: 0)
         result = 31 * result + (mCryptoErrorReason?.hashCode() ?: 0)
         result = 31 * result + sendState.hashCode()
+        result = 31 * result + threadDetails.hashCode()
+
         return result
     }
 }
@@ -243,70 +299,101 @@ data class Event(
 fun Event.isTextMessage(): Boolean {
     return getClearType() == EventType.MESSAGE &&
             when (getClearContent()?.get(MessageContent.MSG_TYPE_JSON_KEY)) {
-        MessageType.MSGTYPE_TEXT,
-        MessageType.MSGTYPE_EMOTE,
-        MessageType.MSGTYPE_NOTICE -> true
-        else                       -> false
-    }
+                MessageType.MSGTYPE_TEXT,
+                MessageType.MSGTYPE_EMOTE,
+                MessageType.MSGTYPE_NOTICE -> true
+                else                       -> false
+            }
 }
 
 fun Event.isImageMessage(): Boolean {
     return getClearType() == EventType.MESSAGE &&
             when (getClearContent()?.get(MessageContent.MSG_TYPE_JSON_KEY)) {
-        MessageType.MSGTYPE_IMAGE -> true
-        else                      -> false
-    }
+                MessageType.MSGTYPE_IMAGE -> true
+                else                      -> false
+            }
 }
 
 fun Event.isVideoMessage(): Boolean {
     return getClearType() == EventType.MESSAGE &&
             when (getClearContent()?.get(MessageContent.MSG_TYPE_JSON_KEY)) {
-        MessageType.MSGTYPE_VIDEO -> true
-        else                      -> false
-    }
+                MessageType.MSGTYPE_VIDEO -> true
+                else                      -> false
+            }
 }
 
 fun Event.isAudioMessage(): Boolean {
     return getClearType() == EventType.MESSAGE &&
             when (getClearContent()?.get(MessageContent.MSG_TYPE_JSON_KEY)) {
-        MessageType.MSGTYPE_AUDIO -> true
-        else                      -> false
-    }
+                MessageType.MSGTYPE_AUDIO -> true
+                else                      -> false
+            }
 }
 
 fun Event.isFileMessage(): Boolean {
     return getClearType() == EventType.MESSAGE &&
             when (getClearContent()?.get(MessageContent.MSG_TYPE_JSON_KEY)) {
-        MessageType.MSGTYPE_FILE -> true
-        else                     -> false
-    }
+                MessageType.MSGTYPE_FILE -> true
+                else                     -> false
+            }
 }
 
 fun Event.isAttachmentMessage(): Boolean {
     return getClearType() == EventType.MESSAGE &&
             when (getClearContent()?.get(MessageContent.MSG_TYPE_JSON_KEY)) {
-        MessageType.MSGTYPE_IMAGE,
-        MessageType.MSGTYPE_AUDIO,
-        MessageType.MSGTYPE_VIDEO,
-        MessageType.MSGTYPE_FILE -> true
-        else                     -> false
-    }
+                MessageType.MSGTYPE_IMAGE,
+                MessageType.MSGTYPE_AUDIO,
+                MessageType.MSGTYPE_VIDEO,
+                MessageType.MSGTYPE_FILE -> true
+                else                     -> false
+            }
 }
 
+fun Event.isPoll(): Boolean = getClearType() == EventType.POLL_START || getClearType() == EventType.POLL_END
+
+fun Event.isSticker(): Boolean = getClearType() == EventType.STICKER
+
 fun Event.getRelationContent(): RelationDefaultContent? {
     return if (isEncrypted()) {
         content.toModel<EncryptedEventContent>()?.relatesTo
     } else {
-        content.toModel<MessageContent>()?.relatesTo
+        content.toModel<MessageContent>()?.relatesTo ?: run {
+            // Special case to handle stickers, while there is only a local msgtype for stickers
+            if (getClearType() == EventType.STICKER) {
+                getClearContent().toModel<MessageStickerContent>()?.relatesTo
+            } else {
+                null
+            }
+        }
     }
 }
 
+/**
+ * Returns the poll question or null otherwise
+ */
+fun Event.getPollQuestion(): String? =
+        getPollContent()?.pollCreationInfo?.question?.question
+
+/**
+ * Returns the relation content for a specific type or null otherwise
+ */
+fun Event.getRelationContentForType(type: String): RelationDefaultContent? =
+        getRelationContent()?.takeIf { it.type == type }
+
 fun Event.isReply(): Boolean {
     return getRelationContent()?.inReplyTo?.eventId != null
 }
 
+fun Event.isReplyRenderedInThread(): Boolean {
+    return isReply() && getRelationContent()?.inReplyTo?.shouldRenderInThread() == true
+}
+
+fun Event.isThread(): Boolean = getRelationContentForType(RelationType.IO_THREAD)?.eventId != null
+
+fun Event.getRootThreadEventId(): String? = getRelationContentForType(RelationType.IO_THREAD)?.eventId
+
 fun Event.isEdition(): Boolean {
-    return getRelationContent()?.takeIf { it.type == RelationType.REPLACE }?.eventId != null
+    return getRelationContentForType(RelationType.REPLACE)?.eventId != null
 }
 
 fun Event.getPresenceContent(): PresenceContent? {
@@ -315,3 +402,7 @@ fun Event.getPresenceContent(): PresenceContent? {
 
 fun Event.isInvitation(): Boolean = type == EventType.STATE_ROOM_MEMBER &&
         content?.toModel<RoomMemberContent>()?.membership == Membership.INVITE
+
+fun Event.getPollContent(): MessagePollContent? {
+    return content.toModel<MessagePollContent>()
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/events/model/RelationType.kt

@@ -28,9 +28,9 @@ object RelationType {
     /** Lets you define an event which references an existing event.*/
     const val REFERENCE = "m.reference"
 
-    /** Lets you define an thread event that belongs to another existing event.*/
-//    const val THREAD = "m.thread"         // m.thread is not yet released in the backend
-    const val THREAD = "io.element.thread"  // io.element.thread will be replaced by m.thread when it is released
+    /** Lets you define an event which is a thread reply to an existing event.*/
+    const val THREAD = "m.thread"
+    const val IO_THREAD = "io.element.thread"
 
     /** Lets you define an event which adds a response to an existing event.*/
     const val RESPONSE = "org.matrix.response"

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/media/PreviewUrlData.kt

@@ -47,5 +47,9 @@ data class PreviewUrlData(
         // Value of field "og:description"
         val description: String?,
         // Value of field "og:image"
-        val mxcUrl: String?
+        val mxcUrl: String?,
+        // Value of field "og:image:width"
+        val imageWidth: Int?,
+        // Value of field "og:image:height"
+        val imageHeight: Int?
 )

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/Room.kt

@@ -32,6 +32,7 @@ import org.matrix.android.sdk.api.session.room.send.DraftService
 import org.matrix.android.sdk.api.session.room.send.SendService
 import org.matrix.android.sdk.api.session.room.state.StateService
 import org.matrix.android.sdk.api.session.room.tags.TagsService
+import org.matrix.android.sdk.api.session.room.threads.ThreadsService
 import org.matrix.android.sdk.api.session.room.timeline.TimelineService
 import org.matrix.android.sdk.api.session.room.typing.TypingService
 import org.matrix.android.sdk.api.session.room.uploads.UploadsService
@@ -45,6 +46,7 @@ import org.matrix.android.sdk.api.util.Optional
  */
 interface Room :
         TimelineService,
+        ThreadsService,
         SendService,
         DraftService,
         ReadService,

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/model/message/MessageLocationContent.kt

@@ -64,4 +64,12 @@ data class MessageLocationContent(
 ) : MessageContent {
 
     fun getBestGeoUri() = locationInfo?.geoUri ?: geoUri
+
+    /**
+     * @return true if the location asset is a user location, not a generic one.
+     */
+    fun isSelfLocation(): Boolean {
+        // Should behave like m.self if locationAsset is null
+        return locationAsset?.type == null || locationAsset.type == LocationAssetType.SELF
+    }
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/model/relation/RelationService.kt

@@ -18,6 +18,7 @@ package org.matrix.android.sdk.api.session.room.model.relation
 import androidx.lifecycle.LiveData
 import org.matrix.android.sdk.api.session.events.model.Event
 import org.matrix.android.sdk.api.session.room.model.EventAnnotationsSummary
+import org.matrix.android.sdk.api.session.room.model.message.MessageType
 import org.matrix.android.sdk.api.session.room.model.message.PollType
 import org.matrix.android.sdk.api.session.room.timeline.TimelineEvent
 import org.matrix.android.sdk.api.util.Cancelable
@@ -45,6 +46,9 @@ import org.matrix.android.sdk.api.util.Optional
  *  m.reference - lets you define an event which references an existing event.
  *              When aggregated, currently doesn't do anything special, but in future could bundle chains of references (i.e. threads).
  *              These are primarily intended for handling replies (and in future threads).
+ *
+ *  m.thread - lets you define an event which is a thread reply to an existing event.
+ *             When aggregated, returns the most thread event
  */
 interface RelationService {
 
@@ -62,8 +66,8 @@ interface RelationService {
      * @param targetEventId the id of the event being reacted
      * @param reaction the reaction (preferably emoji)
      */
-    fun undoReaction(targetEventId: String,
-                     reaction: String): Cancelable
+    suspend fun undoReaction(targetEventId: String,
+                             reaction: String): Cancelable
 
     /**
      * Edit a poll.
@@ -118,10 +122,15 @@ interface RelationService {
      * @param eventReplied the event referenced by the reply
      * @param replyText the reply text
      * @param autoMarkdown If true, the SDK will generate a formatted HTML message from the body text if markdown syntax is present
+     * @param showInThread If true, relation will be added to the reply in order to be visible from within threads
+     * @param rootThreadEventId If show in thread is true then we need the rootThreadEventId to generate the relation
      */
     fun replyToMessage(eventReplied: TimelineEvent,
                        replyText: CharSequence,
-                       autoMarkdown: Boolean = false): Cancelable?
+                       autoMarkdown: Boolean = false,
+                       showInThread: Boolean = false,
+                       rootThreadEventId: String? = null
+    ): Cancelable?
 
     /**
      * Get the current EventAnnotationsSummary
@@ -136,4 +145,31 @@ interface RelationService {
      * @return the LiveData of EventAnnotationsSummary
      */
     fun getEventAnnotationsSummaryLive(eventId: String): LiveData<Optional<EventAnnotationsSummary>>
+
+    /**
+     * Creates a thread reply for an existing timeline event
+     * The replyInThreadText can be a Spannable and contains special spans (MatrixItemSpan) that will be translated
+     * by the sdk into pills.
+     * @param rootThreadEventId the root thread eventId
+     * @param replyInThreadText the reply text
+     * @param msgType the message type: MessageType.MSGTYPE_TEXT (default) or MessageType.MSGTYPE_EMOTE
+     * @param formattedText The formatted body using MessageType#FORMAT_MATRIX_HTML
+     * @param autoMarkdown If true, the SDK will generate a formatted HTML message from the body text if markdown syntax is present
+     * @param eventReplied the event referenced by the reply within a thread
+     */
+    fun replyInThread(rootThreadEventId: String,
+                      replyInThreadText: CharSequence,
+                      msgType: String = MessageType.MSGTYPE_TEXT,
+                      autoMarkdown: Boolean = false,
+                      formattedText: String? = null,
+                      eventReplied: TimelineEvent? = null): Cancelable?
+
+    /**
+     * Get all the thread replies for the specified rootThreadEventId
+     * The return list will contain the original root thread event and all the thread replies to that event
+     * Note: We will use a large limit value in order to avoid using pagination until it would be 100% ready
+     * from the backend
+     * @param rootThreadEventId the root thread eventId
+     */
+    suspend fun fetchThreadTimeline(rootThreadEventId: String): Boolean
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/model/relation/ReplyToContent.kt

@@ -21,5 +21,8 @@ import com.squareup.moshi.JsonClass
 
 @JsonClass(generateAdapter = true)
 data class ReplyToContent(
-        @Json(name = "event_id") val eventId: String? = null
+        @Json(name = "event_id") val eventId: String? = null,
+        @Json(name = "render_in") val renderIn: List<String>? = null
 )
+
+fun ReplyToContent.shouldRenderInThread(): Boolean = renderIn?.contains("m.thread") == true

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/send/SendService.kt

@@ -64,7 +64,7 @@ interface SendService {
      * @param autoMarkdown If true, the SDK will generate a formatted HTML message from the body text if markdown syntax is present
      * @return a [Cancelable]
      */
-    fun sendQuotedTextMessage(quotedEvent: TimelineEvent, text: String, autoMarkdown: Boolean): Cancelable
+    fun sendQuotedTextMessage(quotedEvent: TimelineEvent, text: String, autoMarkdown: Boolean, rootThreadEventId: String? = null): Cancelable
 
     /**
      * Method to send a media asynchronously.
@@ -72,11 +72,13 @@ interface SendService {
      * @param compressBeforeSending set to true to compress images before sending them
      * @param roomIds set of roomIds to where the media will be sent. The current roomId will be add to this set if not present.
      *                It can be useful to send media to multiple room. It's safe to include the current roomId in this set
+     * @param rootThreadEventId when this param is not null, the Media will be sent in this specific thread
      * @return a [Cancelable]
      */
     fun sendMedia(attachment: ContentAttachmentData,
                   compressBeforeSending: Boolean,
-                  roomIds: Set<String>): Cancelable
+                  roomIds: Set<String>,
+                  rootThreadEventId: String? = null): Cancelable
 
     /**
      * Method to send a list of media asynchronously.
@@ -84,11 +86,13 @@ interface SendService {
      * @param compressBeforeSending set to true to compress images before sending them
      * @param roomIds set of roomIds to where the media will be sent. The current roomId will be add to this set if not present.
      *                It can be useful to send media to multiple room. It's safe to include the current roomId in this set
+     * @param rootThreadEventId when this param is not null, all the Media will be sent in this specific thread
      * @return a [Cancelable]
      */
     fun sendMedias(attachments: List<ContentAttachmentData>,
                    compressBeforeSending: Boolean,
-                   roomIds: Set<String>): Cancelable
+                   roomIds: Set<String>,
+                   rootThreadEventId: String? = null): Cancelable
 
     /**
      * Send a poll to the room.

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/threads/ThreadsService.kt

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2022 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.android.sdk.api.session.room.threads
+
+import androidx.lifecycle.LiveData
+import org.matrix.android.sdk.api.session.room.timeline.TimelineEvent
+
+/**
+ * This interface defines methods to interact with threads related features.
+ * It's implemented at the room level within the main timeline.
+ */
+interface ThreadsService {
+
+    /**
+     * Returns a [LiveData] list of all the thread root TimelineEvents that exists at the room level
+     */
+    fun getAllThreadsLive(): LiveData<List<TimelineEvent>>
+
+    /**
+     * Returns a list of all the thread root TimelineEvents that exists at the room level
+     */
+    fun getAllThreads(): List<TimelineEvent>
+
+    /**
+     * Returns a [LiveData] list of all the marked unread threads that exists at the room level
+     */
+    fun getMarkedThreadNotificationsLive(): LiveData<List<TimelineEvent>>
+
+    /**
+     * Returns a list of all the marked unread threads that exists at the room level
+     */
+    fun getMarkedThreadNotifications(): List<TimelineEvent>
+
+    /**
+     * Returns whether or not the current user is participating in the thread
+     * @param rootThreadEventId the eventId of the current thread
+     */
+    fun isUserParticipatingInThread(rootThreadEventId: String): Boolean
+
+    /**
+     * Enhance the provided root thread TimelineEvent [List] by adding the latest
+     * message edition for that thread
+     * @return the enhanced [List] with edited updates
+     */
+    fun mapEventsWithEdition(threads: List<TimelineEvent>): List<TimelineEvent>
+
+    /**
+     * Marks the current thread as read in local DB.
+     * note: read receipts within threads are not yet supported with the API
+     * @param rootThreadEventId the root eventId of the current thread
+     */
+    suspend fun markThreadAsRead(rootThreadEventId: String)
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/timeline/Timeline.kt

@@ -43,7 +43,7 @@ interface Timeline {
     /**
      * This must be called before any other method after creating the timeline. It ensures the underlying database is open
      */
-    fun start()
+    fun start(rootThreadEventId: String? = null)
 
     /**
      * This must be called when you don't need the timeline. It ensures the underlying database get closed.

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/timeline/TimelineEvent.kt

@@ -22,7 +22,9 @@ import org.matrix.android.sdk.api.session.events.model.EventType
 import org.matrix.android.sdk.api.session.events.model.RelationType
 import org.matrix.android.sdk.api.session.events.model.getRelationContent
 import org.matrix.android.sdk.api.session.events.model.isEdition
+import org.matrix.android.sdk.api.session.events.model.isPoll
 import org.matrix.android.sdk.api.session.events.model.isReply
+import org.matrix.android.sdk.api.session.events.model.isSticker
 import org.matrix.android.sdk.api.session.events.model.toModel
 import org.matrix.android.sdk.api.session.room.model.EventAnnotationsSummary
 import org.matrix.android.sdk.api.session.room.model.ReadReceipt
@@ -149,6 +151,13 @@ fun TimelineEvent.isEdition(): Boolean {
     return root.isEdition()
 }
 
+fun TimelineEvent.isPoll(): Boolean =
+        root.isPoll()
+
+fun TimelineEvent.isSticker(): Boolean {
+    return root.isSticker()
+}
+
 /**
  * Get the latest message body, after a possible edition, stripping the reply prefix if necessary
  */

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/timeline/TimelineSettings.kt

@@ -27,5 +27,14 @@ data class TimelineSettings(
         /**
          * If true, will build read receipts for each event.
          */
-        val buildReadReceipts: Boolean = true
-)
+        val buildReadReceipts: Boolean = true,
+        /**
+         * The root thread eventId if this is a thread timeline, or null if this is NOT a thread timeline
+         */
+        val rootThreadEventId: String? = null) {
+
+    /**
+     * Returns true if this is a thread timeline or false otherwise
+     */
+    fun isThreadTimeline() = rootThreadEventId != null
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/threads/ThreadDetails.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2021 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.android.sdk.api.session.threads
+
+import org.matrix.android.sdk.api.session.room.sender.SenderInfo
+
+/**
+ * This class contains all the details needed for threads.
+ * Is is mainly used from within an Event.
+ */
+data class ThreadDetails(
+        val isRootThread: Boolean = false,
+        val numberOfThreads: Int = 0,
+        val threadSummarySenderInfo: SenderInfo? = null,
+        val threadSummaryLatestTextMessage: String? = null,
+        val lastMessageTimestamp: Long? = null,
+        var threadNotificationState: ThreadNotificationState = ThreadNotificationState.NO_NEW_MESSAGE,
+        val isThread: Boolean = false,
+        val lastRootThreadEdition: String? = null
+)

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/threads/ThreadNotificationBadgeState.kt

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2021 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.android.sdk.api.session.threads
+
+/**
+ * This class defines the state of a thread notification badge
+ */
+data class ThreadNotificationBadgeState(
+        val numberOfLocalUnreadThreads: Int = 0,
+        val isUserMentioned: Boolean = false
+)

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/threads/ThreadNotificationState.kt

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2021 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.android.sdk.api.session.threads
+
+/**
+ * This class defines the state of a thread notification
+ */
+enum class ThreadNotificationState {
+
+    // There are no new message
+    NO_NEW_MESSAGE,
+
+    // There is at least one new message
+    NEW_MESSAGE,
+
+    // The is at least one new message that should be highlighted
+    // ex. "Hello @aris.kotsomitopoulos"
+    NEW_HIGHLIGHTED_MESSAGE;
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/threads/ThreadTimelineEvent.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2021 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.android.sdk.api.session.threads
+
+import org.matrix.android.sdk.api.session.room.timeline.TimelineEvent
+
+/**
+ * This class contains a thread TimelineEvent along with a boolean that
+ * determines if the current user has participated in that event
+ */
+data class ThreadTimelineEvent(
+        val timelineEvent: TimelineEvent,
+        val isParticipating: Boolean
+)

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/algorithms/megolm/MXOutboundSessionInfo.kt

@@ -35,7 +35,7 @@ internal class MXOutboundSessionInfo(
         val sessionLifetime = System.currentTimeMillis() - creationTime
 
         if (useCount >= rotationPeriodMsgs || sessionLifetime >= rotationPeriodMs) {
-            Timber.v("## needsRotation() : Rotating megolm session after " + useCount + ", " + sessionLifetime + "ms")
+            Timber.v("## needsRotation() : Rotating megolm session after $useCount, ${sessionLifetime}ms")
             needsRotation = true
         }
 

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/RealmSessionStoreMigration.kt

@@ -25,6 +25,7 @@ import org.matrix.android.sdk.api.session.room.model.RoomJoinRulesContent
 import org.matrix.android.sdk.api.session.room.model.VersioningState
 import org.matrix.android.sdk.api.session.room.model.create.RoomCreateContent
 import org.matrix.android.sdk.api.session.room.model.tag.RoomTag
+import org.matrix.android.sdk.api.session.threads.ThreadNotificationState
 import org.matrix.android.sdk.internal.crypto.model.event.EncryptionEventContent
 import org.matrix.android.sdk.internal.database.model.ChunkEntityFields
 import org.matrix.android.sdk.internal.database.model.CurrentStateEventEntityFields
@@ -56,7 +57,7 @@ internal class RealmSessionStoreMigration @Inject constructor(
 ) : RealmMigration {
 
     companion object {
-        const val SESSION_STORE_SCHEMA_VERSION = 22L
+        const val SESSION_STORE_SCHEMA_VERSION = 24L
     }
 
     /**
@@ -91,6 +92,8 @@ internal class RealmSessionStoreMigration @Inject constructor(
         if (oldVersion <= 19) migrateTo20(realm)
         if (oldVersion <= 20) migrateTo21(realm)
         if (oldVersion <= 21) migrateTo22(realm)
+        if (oldVersion <= 22) migrateTo23(realm)
+        if (oldVersion <= 23) migrateTo24(realm)
     }
 
     private fun migrateTo1(realm: DynamicRealm) {
@@ -462,4 +465,28 @@ internal class RealmSessionStoreMigration @Inject constructor(
             realm.deleteAll()
         }
     }
+
+    private fun migrateTo23(realm: DynamicRealm) {
+        Timber.d("Step 22 -> 23")
+        val eventEntity = realm.schema.get("TimelineEventEntity") ?: return
+
+        realm.schema.get("EventEntity")
+                ?.addField(EventEntityFields.IS_ROOT_THREAD, Boolean::class.java, FieldAttribute.INDEXED)
+                ?.addField(EventEntityFields.ROOT_THREAD_EVENT_ID, String::class.java, FieldAttribute.INDEXED)
+                ?.addField(EventEntityFields.NUMBER_OF_THREADS, Int::class.java)
+                ?.addField(EventEntityFields.THREAD_NOTIFICATION_STATE_STR, String::class.java)
+                ?.transform {
+                    it.setString(EventEntityFields.THREAD_NOTIFICATION_STATE_STR, ThreadNotificationState.NO_NEW_MESSAGE.name)
+                }
+                ?.addRealmObjectField(EventEntityFields.THREAD_SUMMARY_LATEST_MESSAGE.`$`, eventEntity)
+    }
+
+    private fun migrateTo24(realm: DynamicRealm) {
+        Timber.d("Step 23 -> 24")
+        realm.schema.get("PreviewUrlCacheEntity")
+                ?.addField(PreviewUrlCacheEntityFields.IMAGE_WIDTH, Int::class.java)
+                ?.setNullable(PreviewUrlCacheEntityFields.IMAGE_WIDTH, true)
+                ?.addField(PreviewUrlCacheEntityFields.IMAGE_HEIGHT, Int::class.java)
+                ?.setNullable(PreviewUrlCacheEntityFields.IMAGE_HEIGHT, true)
+    }
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/helper/ChunkEntityHelper.kt

@@ -34,6 +34,7 @@ import org.matrix.android.sdk.internal.database.model.TimelineEventEntityFields
 import org.matrix.android.sdk.internal.database.query.find
 import org.matrix.android.sdk.internal.database.query.getOrCreate
 import org.matrix.android.sdk.internal.database.query.where
+import org.matrix.android.sdk.internal.database.query.whereRoomId
 import org.matrix.android.sdk.internal.extensions.assertIsManaged
 import org.matrix.android.sdk.internal.session.room.timeline.PaginationDirection
 import timber.log.Timber
@@ -81,7 +82,7 @@ internal fun ChunkEntity.addStateEvent(roomId: String, stateEvent: EventEntity,
 internal fun ChunkEntity.addTimelineEvent(roomId: String,
                                           eventEntity: EventEntity,
                                           direction: PaginationDirection,
-                                          roomMemberContentsByUser: Map<String, RoomMemberContent?>) {
+                                          roomMemberContentsByUser: Map<String, RoomMemberContent?>? = null) {
     val eventId = eventEntity.eventId
     if (timelineEvents.find(eventId) != null) {
         return
@@ -101,7 +102,7 @@ internal fun ChunkEntity.addTimelineEvent(roomId: String,
                 ?.also { it.cleanUp(eventEntity.sender) }
         this.readReceipts = readReceiptsSummaryEntity
         this.displayIndex = displayIndex
-        val roomMemberContent = roomMemberContentsByUser[senderId]
+        val roomMemberContent = roomMemberContentsByUser?.get(senderId)
         this.senderAvatar = roomMemberContent?.avatarUrl
         this.senderName = roomMemberContent?.displayName
         isUniqueDisplayName = if (roomMemberContent?.displayName != null) {
@@ -157,9 +158,21 @@ private fun ChunkEntity.addTimelineEventFromMerge(realm: Realm, timelineEventEnt
         this.senderName = timelineEventEntity.senderName
         this.isUniqueDisplayName = timelineEventEntity.isUniqueDisplayName
     }
+    handleThreadSummary(realm, eventId, copied)
     timelineEvents.add(copied)
 }
 
+/**
+ * Upon copy of the timeline events we should update the latestMessage TimelineEventEntity with the new one
+ */
+private fun handleThreadSummary(realm: Realm, oldEventId: String, newTimelineEventEntity: TimelineEventEntity) {
+    EventEntity
+            .whereRoomId(realm, newTimelineEventEntity.roomId)
+            .equalTo(EventEntityFields.IS_ROOT_THREAD, true)
+            .equalTo(EventEntityFields.THREAD_SUMMARY_LATEST_MESSAGE.EVENT_ID, oldEventId)
+            .findFirst()?.threadSummaryLatestMessage = newTimelineEventEntity
+}
+
 private fun handleReadReceipts(realm: Realm, roomId: String, eventEntity: EventEntity, senderId: String): ReadReceiptsSummaryEntity {
     val readReceiptsSummaryEntity = ReadReceiptsSummaryEntity.where(realm, eventEntity.eventId).findFirst()
             ?: realm.createObject<ReadReceiptsSummaryEntity>(eventEntity.eventId).apply {

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/helper/ThreadEventsHelper.kt

@@ -0,0 +1,321 @@
+/*
+ * Copyright 2021 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.android.sdk.internal.database.helper
+
+import io.realm.Realm
+import io.realm.RealmQuery
+import io.realm.Sort
+import org.matrix.android.sdk.api.session.room.timeline.TimelineEvent
+import org.matrix.android.sdk.api.session.threads.ThreadNotificationState
+import org.matrix.android.sdk.internal.database.mapper.asDomain
+import org.matrix.android.sdk.internal.database.model.ChunkEntity
+import org.matrix.android.sdk.internal.database.model.EventAnnotationsSummaryEntity
+import org.matrix.android.sdk.internal.database.model.EventEntity
+import org.matrix.android.sdk.internal.database.model.ReadReceiptEntity
+import org.matrix.android.sdk.internal.database.model.TimelineEventEntity
+import org.matrix.android.sdk.internal.database.model.TimelineEventEntityFields
+import org.matrix.android.sdk.internal.database.query.find
+import org.matrix.android.sdk.internal.database.query.findIncludingEvent
+import org.matrix.android.sdk.internal.database.query.findLastForwardChunkOfRoom
+import org.matrix.android.sdk.internal.database.query.where
+import org.matrix.android.sdk.internal.database.query.whereRoomId
+
+private typealias ThreadSummary = Pair<Int, TimelineEventEntity>?
+
+/**
+ * Finds the root thread event and update it with the latest message summary along with the number
+ * of threads included. If there is no root thread event no action is done
+ */
+internal fun Map<String, EventEntity>.updateThreadSummaryIfNeeded(
+        roomId: String,
+        realm: Realm, currentUserId: String,
+        chunkEntity: ChunkEntity? = null,
+        shouldUpdateNotifications: Boolean = true) {
+    for ((rootThreadEventId, eventEntity) in this) {
+        eventEntity.threadSummaryInThread(eventEntity.realm, rootThreadEventId, chunkEntity)?.let { threadSummary ->
+
+            val numberOfMessages = threadSummary.first
+            val latestEventInThread = threadSummary.second
+
+            // If this is a thread message, find its root event if exists
+            val rootThreadEvent = if (eventEntity.isThread()) eventEntity.findRootThreadEvent() else eventEntity
+
+            rootThreadEvent?.markEventAsRoot(
+                    threadsCounted = numberOfMessages,
+                    latestMessageTimelineEventEntity = latestEventInThread
+            )
+        }
+    }
+
+    if (shouldUpdateNotifications) {
+        updateNotificationsNew(roomId, realm, currentUserId)
+    }
+}
+
+/**
+ * Finds the root event of the the current thread event message.
+ * Returns the EventEntity or null if the root event do not exist
+ */
+internal fun EventEntity.findRootThreadEvent(): EventEntity? =
+        rootThreadEventId?.let {
+            EventEntity
+                    .where(realm, it)
+                    .findFirst()
+        }
+
+/**
+ * Mark or update the current event a root thread event
+ */
+internal fun EventEntity.markEventAsRoot(
+        threadsCounted: Int,
+        latestMessageTimelineEventEntity: TimelineEventEntity?) {
+    isRootThread = true
+    numberOfThreads = threadsCounted
+    threadSummaryLatestMessage = latestMessageTimelineEventEntity
+}
+
+/**
+ * Count the number of threads for the provided root thread eventId, and finds the latest event message
+ * @param rootThreadEventId The root eventId that will find the number of threads
+ * @return A ThreadSummary containing the counted threads and the latest event message
+ */
+internal fun EventEntity.threadSummaryInThread(realm: Realm, rootThreadEventId: String, chunkEntity: ChunkEntity?): ThreadSummary {
+    // Number of messages
+    val messages = TimelineEventEntity
+            .whereRoomId(realm, roomId = roomId)
+            .equalTo(TimelineEventEntityFields.ROOT.ROOT_THREAD_EVENT_ID, rootThreadEventId)
+            .count()
+            .toInt()
+
+    if (messages <= 0) return null
+
+    // Find latest thread event, we know it exists
+    var chunk = ChunkEntity.findLastForwardChunkOfRoom(realm, roomId) ?: chunkEntity ?: return null
+    var result: TimelineEventEntity? = null
+
+    // Iterate the chunk until we find our latest event
+    while (result == null) {
+        result = findLatestSortedChunkEvent(chunk, rootThreadEventId)
+        chunk = ChunkEntity.find(realm, roomId, nextToken = chunk.prevToken) ?: break
+    }
+
+    if (result == null && chunkEntity != null) {
+        // Find latest event from our current chunk
+        result = findLatestSortedChunkEvent(chunkEntity, rootThreadEventId)
+    } else if (result != null && chunkEntity != null) {
+        val currentChunkLatestEvent = findLatestSortedChunkEvent(chunkEntity, rootThreadEventId)
+        result = findMostRecentEvent(result, currentChunkLatestEvent)
+    }
+
+    result ?: return null
+
+    return ThreadSummary(messages, result)
+}
+
+/**
+ * Lets compare them in case user is moving forward in the timeline and we cannot know the
+ * exact chunk sequence while currentChunk is not yet committed in the DB
+ */
+private fun findMostRecentEvent(result: TimelineEventEntity, currentChunkLatestEvent: TimelineEventEntity?): TimelineEventEntity {
+    currentChunkLatestEvent ?: return result
+    val currentChunkEventTimestamp = currentChunkLatestEvent.root?.originServerTs ?: return result
+    val resultTimestamp = result.root?.originServerTs ?: return result
+    if (currentChunkEventTimestamp > resultTimestamp) {
+        return currentChunkLatestEvent
+    }
+    return result
+}
+
+/**
+ * Find the latest event of the current chunk
+ */
+private fun findLatestSortedChunkEvent(chunk: ChunkEntity, rootThreadEventId: String): TimelineEventEntity? =
+        chunk.timelineEvents.sort(TimelineEventEntityFields.DISPLAY_INDEX, Sort.DESCENDING)?.firstOrNull {
+            it.root?.rootThreadEventId == rootThreadEventId
+        }
+
+/**
+ * Find all TimelineEventEntity that are root threads for the specified room
+ * @param roomId The room that all stored root threads will be returned
+ */
+internal fun TimelineEventEntity.Companion.findAllThreadsForRoomId(realm: Realm, roomId: String): RealmQuery<TimelineEventEntity> =
+        TimelineEventEntity
+                .whereRoomId(realm, roomId = roomId)
+                .equalTo(TimelineEventEntityFields.ROOT.IS_ROOT_THREAD, true)
+                .sort("${TimelineEventEntityFields.ROOT.THREAD_SUMMARY_LATEST_MESSAGE}.${TimelineEventEntityFields.ROOT.ORIGIN_SERVER_TS}", Sort.DESCENDING)
+
+/**
+ * Map each root thread TimelineEvent with the equivalent decrypted text edition/replacement
+ */
+internal fun List<TimelineEvent>.mapEventsWithEdition(realm: Realm, roomId: String): List<TimelineEvent> =
+        this.map {
+            EventAnnotationsSummaryEntity
+                    .where(realm, roomId, eventId = it.eventId)
+                    .findFirst()
+                    ?.editSummary
+                    ?.editions
+                    ?.lastOrNull()
+                    ?.eventId
+                    ?.let { editedEventId ->
+                        TimelineEventEntity.where(realm, roomId, eventId = editedEventId).findFirst()?.let { editedEvent ->
+                            it.root.threadDetails = it.root.threadDetails?.copy(lastRootThreadEdition = editedEvent.root?.asDomain()?.getDecryptedTextSummary()
+                                    ?: "(edited)")
+                            it
+                        } ?: it
+                    } ?: it
+        }
+
+/**
+ * Returns a list of all the marked unread threads that exists for the specified room
+ * @param roomId The roomId that the user is currently in
+ */
+internal fun TimelineEventEntity.Companion.findAllLocalThreadNotificationsForRoomId(realm: Realm, roomId: String): RealmQuery<TimelineEventEntity> =
+        TimelineEventEntity
+                .whereRoomId(realm, roomId = roomId)
+                .equalTo(TimelineEventEntityFields.ROOT.IS_ROOT_THREAD, true)
+                .beginGroup()
+                .equalTo(TimelineEventEntityFields.ROOT.THREAD_NOTIFICATION_STATE_STR, ThreadNotificationState.NEW_MESSAGE.name)
+                .or()
+                .equalTo(TimelineEventEntityFields.ROOT.THREAD_NOTIFICATION_STATE_STR, ThreadNotificationState.NEW_HIGHLIGHTED_MESSAGE.name)
+                .endGroup()
+
+/**
+ * Returns whether or not the given user is participating in a current thread
+ * @param roomId the room that the thread exists
+ * @param rootThreadEventId the thread that the search will be done
+ * @param senderId the user that will try to find participation
+ */
+internal fun TimelineEventEntity.Companion.isUserParticipatingInThread(realm: Realm, roomId: String, rootThreadEventId: String, senderId: String): Boolean =
+        TimelineEventEntity
+                .whereRoomId(realm, roomId = roomId)
+                .equalTo(TimelineEventEntityFields.ROOT.ROOT_THREAD_EVENT_ID, rootThreadEventId)
+                .equalTo(TimelineEventEntityFields.ROOT.SENDER, senderId)
+                .findFirst()
+                ?.let { true }
+                ?: false
+
+/**
+ * Returns whether or not the given user is mentioned in a current thread
+ * @param roomId the room that the thread exists
+ * @param rootThreadEventId the thread that the search will be done
+ * @param userId the user that will try to find if there is a mention
+ */
+internal fun TimelineEventEntity.Companion.isUserMentionedInThread(realm: Realm, roomId: String, rootThreadEventId: String, userId: String): Boolean =
+        TimelineEventEntity
+                .whereRoomId(realm, roomId = roomId)
+                .equalTo(TimelineEventEntityFields.ROOT.ROOT_THREAD_EVENT_ID, rootThreadEventId)
+                .equalTo(TimelineEventEntityFields.ROOT.SENDER, userId)
+                .findAll()
+                .firstOrNull { isUserMentioned(userId, it) }
+                ?.let { true }
+                ?: false
+
+/**
+ * Find the read receipt for the current user
+ */
+internal fun findMyReadReceipt(realm: Realm, roomId: String, userId: String): String? =
+        ReadReceiptEntity.where(realm, roomId = roomId, userId = userId)
+                .findFirst()
+                ?.eventId
+
+/**
+ * Returns whether or not the user is mentioned in the event
+ */
+internal fun isUserMentioned(currentUserId: String, timelineEventEntity: TimelineEventEntity?): Boolean {
+    return timelineEventEntity?.root?.asDomain()?.isUserMentioned(currentUserId) == true
+}
+
+/**
+ * Update badge notifications. Count the number of new thread events after the latest
+ * read receipt and aggregate. This function will find and notify new thread events
+ * that the user is either mentioned, or the user had participated in.
+ * Important: If the root thread event is not fetched notification will not work
+ * Important: It will work only with the latest chunk, while read marker will be changed
+ * immediately so we should not display wrong notifications
+ */
+internal fun updateNotificationsNew(roomId: String, realm: Realm, currentUserId: String) {
+    val readReceipt = findMyReadReceipt(realm, roomId, currentUserId) ?: return
+
+    val readReceiptChunk = ChunkEntity
+            .findIncludingEvent(realm, readReceipt) ?: return
+
+    val readReceiptChunkTimelineEvents = readReceiptChunk
+            .timelineEvents
+            .where()
+            .equalTo(TimelineEventEntityFields.ROOM_ID, roomId)
+            .sort(TimelineEventEntityFields.DISPLAY_INDEX, Sort.ASCENDING)
+            .findAll() ?: return
+
+    val readReceiptChunkPosition = readReceiptChunkTimelineEvents.indexOfFirst { it.eventId == readReceipt }
+
+    if (readReceiptChunkPosition == -1) return
+
+    if (readReceiptChunkPosition < readReceiptChunkTimelineEvents.lastIndex) {
+        // If the read receipt is found inside the chunk
+
+        val threadEventsAfterReadReceipt = readReceiptChunkTimelineEvents
+                .slice(readReceiptChunkPosition..readReceiptChunkTimelineEvents.lastIndex)
+                .filter { it.root?.isThread() == true }
+
+        // In order for the below code to work for old events, we should save the previous read receipt
+        // and then continue with the chunk search for that read receipt
+        /*
+       val newThreadEventsList = arrayListOf<TimelineEventEntity>()
+        newThreadEventsList.addAll(threadEventsAfterReadReceipt)
+
+        // got from latest chunk all new threads, lets move to the others
+        var nextChunk = ChunkEntity
+                .find(realm = realm, roomId = roomId, nextToken = readReceiptChunk.nextToken)
+                .takeIf { readReceiptChunk.nextToken != null }
+        while (nextChunk != null) {
+            newThreadEventsList.addAll(nextChunk.timelineEvents
+                    .filter { it.root?.isThread() == true })
+            nextChunk = ChunkEntity
+                    .find(realm = realm, roomId = roomId, nextToken = nextChunk.nextToken)
+                    .takeIf { readReceiptChunk.nextToken != null }
+        }*/
+
+        // Find if the user is mentioned in those events
+        val userMentionsList = threadEventsAfterReadReceipt
+                .filter {
+                    isUserMentioned(currentUserId = currentUserId, it)
+                }.map {
+                    it.root?.rootThreadEventId
+                }
+
+        // Find the root events in the new thread events
+        val rootThreads = threadEventsAfterReadReceipt.distinctBy { it.root?.rootThreadEventId }.mapNotNull { it.root?.rootThreadEventId }
+
+        // Update root thread events only if the user have participated in
+        rootThreads.forEach { eventId ->
+            val isUserParticipating = TimelineEventEntity.isUserParticipatingInThread(
+                    realm = realm,
+                    roomId = roomId,
+                    rootThreadEventId = eventId,
+                    senderId = currentUserId)
+            val rootThreadEventEntity = EventEntity.where(realm, eventId).findFirst()
+
+            if (isUserParticipating) {
+                rootThreadEventEntity?.threadNotificationState = ThreadNotificationState.NEW_MESSAGE
+            }
+
+            if (userMentionsList.contains(eventId)) {
+                rootThreadEventEntity?.threadNotificationState = ThreadNotificationState.NEW_HIGHLIGHTED_MESSAGE
+            }
+        }
+    }
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/lightweight/LightweightSettingsStorage.kt

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2022 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.android.sdk.internal.database.lightweight
+
+import android.content.Context
+import androidx.core.content.edit
+import androidx.preference.PreferenceManager
+import javax.inject.Inject
+
+/**
+ * The purpose of this class is to provide an alternative and lightweight way to store settings/data
+ * on the sdi without using the database. This should be used just for sdk/user preferences and
+ * not for large data sets
+ */
+
+class LightweightSettingsStorage  @Inject constructor(context: Context) {
+
+    private val sdkDefaultPrefs = PreferenceManager.getDefaultSharedPreferences(context.applicationContext)
+
+    fun setThreadMessagesEnabled(enabled: Boolean) {
+        sdkDefaultPrefs.edit {
+            putBoolean(MATRIX_SDK_SETTINGS_THREAD_MESSAGES_ENABLED, enabled)
+        }
+    }
+
+    fun areThreadMessagesEnabled(): Boolean {
+        return sdkDefaultPrefs.getBoolean(MATRIX_SDK_SETTINGS_THREAD_MESSAGES_ENABLED, false)
+    }
+
+    companion object {
+        const val MATRIX_SDK_SETTINGS_THREAD_MESSAGES_ENABLED = "MATRIX_SDK_SETTINGS_THREAD_MESSAGES_ENABLED"
+    }
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/mapper/EventMapper.kt

@@ -21,7 +21,11 @@ import org.matrix.android.sdk.api.session.crypto.MXCryptoError
 import org.matrix.android.sdk.api.session.events.model.Event
 import org.matrix.android.sdk.api.session.events.model.EventType
 import org.matrix.android.sdk.api.session.events.model.UnsignedData
+import org.matrix.android.sdk.api.session.events.model.getRootThreadEventId
 import org.matrix.android.sdk.api.session.room.send.SendState
+import org.matrix.android.sdk.api.session.room.sender.SenderInfo
+import org.matrix.android.sdk.api.session.threads.ThreadDetails
+import org.matrix.android.sdk.api.session.threads.ThreadNotificationState
 import org.matrix.android.sdk.internal.crypto.algorithms.olm.OlmDecryptionResult
 import org.matrix.android.sdk.internal.database.model.EventEntity
 import org.matrix.android.sdk.internal.di.MoshiProvider
@@ -51,6 +55,10 @@ internal object EventMapper {
         }
         eventEntity.decryptionErrorReason = event.mCryptoErrorReason
         eventEntity.decryptionErrorCode = event.mCryptoError?.name
+        eventEntity.isRootThread = event.threadDetails?.isRootThread ?: false
+        eventEntity.rootThreadEventId = event.getRootThreadEventId()
+        eventEntity.numberOfThreads = event.threadDetails?.numberOfThreads ?: 0
+        eventEntity.threadNotificationState = event.threadDetails?.threadNotificationState ?: ThreadNotificationState.NO_NEW_MESSAGE
         return eventEntity
     }
 
@@ -93,6 +101,23 @@ internal object EventMapper {
                 MXCryptoError.ErrorType.valueOf(errorCode)
             }
             it.mCryptoErrorReason = eventEntity.decryptionErrorReason
+            it.threadDetails = ThreadDetails(
+                    isRootThread = eventEntity.isRootThread,
+                    isThread = if (it.threadDetails?.isThread == true) true else eventEntity.isThread(),
+                    numberOfThreads = eventEntity.numberOfThreads,
+                    threadSummarySenderInfo = eventEntity.threadSummaryLatestMessage?.let { timelineEventEntity ->
+                        SenderInfo(
+                                userId = timelineEventEntity.root?.sender ?: "",
+                                displayName = timelineEventEntity.senderName,
+                                isUniqueDisplayName = timelineEventEntity.isUniqueDisplayName,
+                                avatarUrl = timelineEventEntity.senderAvatar
+                        )
+                    },
+                    threadNotificationState = eventEntity.threadNotificationState,
+                    threadSummaryLatestTextMessage = eventEntity.threadSummaryLatestMessage?.root?.asDomain()?.getDecryptedTextSummary(),
+                    lastMessageTimestamp = eventEntity.threadSummaryLatestMessage?.root?.originServerTs
+
+            )
         }
     }
 }
@@ -101,9 +126,15 @@ internal fun EventEntity.asDomain(castJsonNumbers: Boolean = false): Event {
     return EventMapper.map(this, castJsonNumbers)
 }
 
-internal fun Event.toEntity(roomId: String, sendState: SendState, ageLocalTs: Long?): EventEntity {
+internal fun Event.toEntity(roomId: String, sendState: SendState, ageLocalTs: Long?, contentToInject: String? = null): EventEntity {
     return EventMapper.map(this, roomId).apply {
         this.sendState = sendState
         this.ageLocalTs = ageLocalTs
+        contentToInject?.let {
+            this.content = it
+            if (this.type == EventType.STICKER) {
+                this.type = EventType.MESSAGE
+            }
+        }
     }
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/model/EventEntity.kt

@@ -19,7 +19,7 @@ package org.matrix.android.sdk.internal.database.model
 import io.realm.RealmObject
 import io.realm.annotations.Index
 import org.matrix.android.sdk.api.session.room.send.SendState
-import org.matrix.android.sdk.api.util.JsonDict
+import org.matrix.android.sdk.api.session.threads.ThreadNotificationState
 import org.matrix.android.sdk.internal.crypto.MXEventDecryptionResult
 import org.matrix.android.sdk.internal.crypto.algorithms.olm.OlmDecryptionResult
 import org.matrix.android.sdk.internal.di.MoshiProvider
@@ -40,7 +40,12 @@ internal open class EventEntity(@Index var eventId: String = "",
                                 var unsignedData: String? = null,
                                 var redacts: String? = null,
                                 var decryptionResultJson: String? = null,
-                                var ageLocalTs: Long? = null
+                                var ageLocalTs: Long? = null,
+                                // Thread related, no need to create a new Entity for performance
+                                @Index var isRootThread: Boolean = false,
+                                @Index var rootThreadEventId: String? = null,
+                                var numberOfThreads: Int = 0,
+                                var threadSummaryLatestMessage: TimelineEventEntity? = null
 ) : RealmObject() {
 
     private var sendStateStr: String = SendState.UNKNOWN.name
@@ -53,6 +58,15 @@ internal open class EventEntity(@Index var eventId: String = "",
             sendStateStr = value.name
         }
 
+    private var threadNotificationStateStr: String = ThreadNotificationState.NO_NEW_MESSAGE.name
+    var threadNotificationState: ThreadNotificationState
+        get() {
+            return ThreadNotificationState.valueOf(threadNotificationStateStr)
+        }
+        set(value) {
+            threadNotificationStateStr = value.name
+        }
+
     var decryptionErrorCode: String? = null
         set(value) {
             if (value != field) field = value
@@ -65,10 +79,10 @@ internal open class EventEntity(@Index var eventId: String = "",
 
     companion object
 
-    fun setDecryptionResult(result: MXEventDecryptionResult, clearEvent: JsonDict? = null) {
+    fun setDecryptionResult(result: MXEventDecryptionResult) {
         assertIsManaged()
         val decryptionResult = OlmDecryptionResult(
-                payload = clearEvent ?: result.clearEvent,
+                payload = result.clearEvent,
                 senderKey = result.senderCurve25519Key,
                 keysClaimed = result.claimedEd25519Key?.let { mapOf("ed25519" to it) },
                 forwardingCurve25519KeyChain = result.forwardingCurve25519KeyChain
@@ -84,4 +98,6 @@ internal open class EventEntity(@Index var eventId: String = "",
                 .findFirst()
                 ?.canBeProcessed = true
     }
+
+    fun isThread(): Boolean = rootThreadEventId != null
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/model/PreviewUrlCacheEntity.kt

@@ -28,7 +28,8 @@ internal open class PreviewUrlCacheEntity(
         var title: String? = null,
         var description: String? = null,
         var mxcUrl: String? = null,
-
+        var imageWidth: Int? = null,
+        var imageHeight: Int? = null,
         var lastUpdatedTimestamp: Long = 0L
 ) : RealmObject() {
 

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/query/EventEntityQueries.kt

@@ -49,6 +49,11 @@ internal fun EventEntity.Companion.where(realm: Realm, eventId: String): RealmQu
             .equalTo(EventEntityFields.EVENT_ID, eventId)
 }
 
+internal fun EventEntity.Companion.whereRoomId(realm: Realm, roomId: String): RealmQuery<EventEntity> {
+    return realm.where<EventEntity>()
+            .equalTo(EventEntityFields.ROOM_ID, roomId)
+}
+
 internal fun EventEntity.Companion.where(realm: Realm, eventIds: List<String>): RealmQuery<EventEntity> {
     return realm.where<EventEntity>()
             .`in`(EventEntityFields.EVENT_ID, eventIds.toTypedArray())
@@ -85,3 +90,8 @@ internal fun RealmList<EventEntity>.find(eventId: String): EventEntity? {
 internal fun RealmList<EventEntity>.fastContains(eventId: String): Boolean {
     return this.find(eventId) != null
 }
+
+internal fun EventEntity.Companion.whereRootThreadEventId(realm: Realm, rootThreadEventId: String): RealmQuery<EventEntity> {
+    return realm.where<EventEntity>()
+            .equalTo(EventEntityFields.ROOT_THREAD_EVENT_ID, rootThreadEventId)
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/query/ReadQueries.kt

@@ -34,27 +34,29 @@ internal fun isEventRead(realmConfiguration: RealmConfiguration,
     if (LocalEcho.isLocalEchoId(eventId)) {
         return true
     }
-    // If we don't know if the event has been read, we assume it's not
-    var isEventRead = false
 
-    Realm.getInstance(realmConfiguration).use { realm ->
-        val latestEvent = TimelineEventEntity.latestEvent(realm, roomId, true)
-        // If latest event is from you we are sure the event is read
-        if (latestEvent?.root?.sender == userId) {
-            return true
-        }
+    return Realm.getInstance(realmConfiguration).use { realm ->
         val eventToCheck = TimelineEventEntity.where(realm, roomId, eventId).findFirst()
-        isEventRead = when {
-            eventToCheck == null                -> false
-            eventToCheck.root?.sender == userId -> true
-            else                                -> {
-                val readReceipt = ReadReceiptEntity.where(realm, roomId, userId).findFirst() ?: return@use
-                val readReceiptEvent = TimelineEventEntity.where(realm, roomId, readReceipt.eventId).findFirst() ?: return@use
-                readReceiptEvent.isMoreRecentThan(eventToCheck)
-            }
+        when {
+            // The event doesn't exist locally, let's assume it hasn't been read
+            eventToCheck == null                                          -> false
+            eventToCheck.root?.sender == userId                           -> true
+            // If new event exists and the latest event is from ourselves we can infer the event is read
+            latestEventIsFromSelf(realm, roomId, userId)                  -> true
+            eventToCheck.isBeforeLatestReadReceipt(realm, roomId, userId) -> true
+            else                                                          -> false
         }
     }
-    return isEventRead
+}
+
+private fun latestEventIsFromSelf(realm: Realm, roomId: String, userId: String) = TimelineEventEntity.latestEvent(realm, roomId, true)
+        ?.root?.sender == userId
+
+private fun TimelineEventEntity.isBeforeLatestReadReceipt(realm: Realm, roomId: String, userId: String): Boolean {
+    return ReadReceiptEntity.where(realm, roomId, userId).findFirst()?.let { readReceipt ->
+        val readReceiptEvent = TimelineEventEntity.where(realm, roomId, readReceipt.eventId).findFirst()
+        readReceiptEvent?.isMoreRecentThan(this)
+    } ?: false
 }
 
 /**

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/query/TimelineEventEntityQueries.kt

@@ -59,6 +59,7 @@ internal fun TimelineEventEntity.Companion.latestEvent(realm: Realm,
                                                        filters: TimelineEventFilters = TimelineEventFilters()): TimelineEventEntity? {
     val roomEntity = RoomEntity.where(realm, roomId).findFirst() ?: return null
     val sendingTimelineEvents = roomEntity.sendingTimelineEvents.where().filterEvents(filters)
+
     val liveEvents = ChunkEntity.findLastForwardChunkOfRoom(realm, roomId)?.timelineEvents?.where()?.filterEvents(filters)
     val query = if (includesSending && sendingTimelineEvents.findAll().isNotEmpty()) {
         sendingTimelineEvents
@@ -100,6 +101,7 @@ internal fun RealmQuery<TimelineEventEntity>.filterEvents(filters: TimelineEvent
     if (filters.filterRedacted) {
         not().like(TimelineEventEntityFields.ROOT.UNSIGNED_DATA, TimelineEventFilter.Unsigned.REDACTED)
     }
+
     return this
 }
 

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/content/ThumbnailExtractor.kt

@@ -66,7 +66,7 @@ internal class ThumbnailExtractor @Inject constructor(
                 thumbnail.recycle()
                 outputStream.reset()
             } ?: run {
-                Timber.e("Cannot extract video thumbnail at %s", attachment.queryUri.toString())
+                Timber.e("Cannot extract video thumbnail at ${attachment.queryUri}")
             }
         } catch (e: Exception) {
             Timber.e(e, "Cannot extract video thumbnail")

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/filter/RoomEventFilter.kt

@@ -48,6 +48,16 @@ data class RoomEventFilter(
          * a wildcard to match any sequence of characters.
          */
         @Json(name = "types") val types: List<String>? = null,
+        /**
+         * A list of relation types which must be exist pointing to the event being filtered.
+         * If this list is absent then no filtering is done on relation types.
+         */
+        @Json(name = "relation_types") val relationTypes: List<String>? = null,
+        /**
+         *  A list of senders of relations which must exist pointing to the event being filtered.
+         *  If this list is absent then no filtering is done on relation types.
+         */
+        @Json(name = "relation_senders") val relationSenders: List<String>? = null,
         /**
          * A list of room IDs to include. If this list is absent then all rooms are included.
          */

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/GetPreviewUrlTask.kt

@@ -48,8 +48,8 @@ internal class DefaultGetPreviewUrlTask @Inject constructor(
 
     override suspend fun execute(params: GetPreviewUrlTask.Params): PreviewUrlData {
         return when (params.cacheStrategy) {
-            CacheStrategy.NoCache -> doRequest(params.url, params.timestamp)
-            is CacheStrategy.TtlCache -> doRequestWithCache(
+            CacheStrategy.NoCache       -> doRequest(params.url, params.timestamp)
+            is CacheStrategy.TtlCache   -> doRequestWithCache(
                     params.url,
                     params.timestamp,
                     params.cacheStrategy.validityDurationInMillis,
@@ -77,7 +77,9 @@ internal class DefaultGetPreviewUrlTask @Inject constructor(
                 siteName = (get("og:site_name") as? String)?.unescapeHtml(),
                 title = (get("og:title") as? String)?.unescapeHtml(),
                 description = (get("og:description") as? String)?.unescapeHtml(),
-                mxcUrl = get("og:image") as? String
+                mxcUrl = get("og:image") as? String,
+                imageHeight = (get("og:image:height") as? Double)?.toInt(),
+                imageWidth = (get("og:image:width") as? Double)?.toInt(),
         )
     }
 
@@ -114,7 +116,8 @@ internal class DefaultGetPreviewUrlTask @Inject constructor(
             previewUrlCacheEntity.title = data.title
             previewUrlCacheEntity.description = data.description
             previewUrlCacheEntity.mxcUrl = data.mxcUrl
-
+            previewUrlCacheEntity.imageHeight = data.imageHeight
+            previewUrlCacheEntity.imageWidth = data.imageWidth
             previewUrlCacheEntity.lastUpdatedTimestamp = Date().time
         }
 

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/PreviewUrlMapper.kt

@@ -27,5 +27,7 @@ internal fun PreviewUrlCacheEntity.toDomain() = PreviewUrlData(
         siteName = siteName,
         title = title,
         description = description,
-        mxcUrl = mxcUrl
+        mxcUrl = mxcUrl,
+        imageWidth = imageWidth,
+        imageHeight = imageHeight
 )

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/DefaultRoom.kt

@@ -35,6 +35,7 @@ import org.matrix.android.sdk.api.session.room.send.DraftService
 import org.matrix.android.sdk.api.session.room.send.SendService
 import org.matrix.android.sdk.api.session.room.state.StateService
 import org.matrix.android.sdk.api.session.room.tags.TagsService
+import org.matrix.android.sdk.api.session.room.threads.ThreadsService
 import org.matrix.android.sdk.api.session.room.timeline.TimelineService
 import org.matrix.android.sdk.api.session.room.typing.TypingService
 import org.matrix.android.sdk.api.session.room.uploads.UploadsService
@@ -54,6 +55,7 @@ import java.security.InvalidParameterException
 internal class DefaultRoom(override val roomId: String,
                            private val roomSummaryDataSource: RoomSummaryDataSource,
                            private val timelineService: TimelineService,
+                           private val threadsService: ThreadsService,
                            private val sendService: SendService,
                            private val draftService: DraftService,
                            private val stateService: StateService,
@@ -77,6 +79,7 @@ internal class DefaultRoom(override val roomId: String,
 ) :
         Room,
         TimelineService by timelineService,
+        ThreadsService by threadsService,
         SendService by sendService,
         DraftService by draftService,
         StateService by stateService,

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/EventRelationsAggregationProcessor.kt

@@ -44,6 +44,7 @@ import org.matrix.android.sdk.api.session.room.timeline.getLastMessageContent
 import org.matrix.android.sdk.internal.SessionManager
 import org.matrix.android.sdk.internal.crypto.model.event.EncryptedEventContent
 import org.matrix.android.sdk.internal.crypto.verification.toState
+import org.matrix.android.sdk.internal.database.helper.findRootThreadEvent
 import org.matrix.android.sdk.internal.database.mapper.ContentMapper
 import org.matrix.android.sdk.internal.database.mapper.EventMapper
 import org.matrix.android.sdk.internal.database.model.EditAggregatedSummaryEntity
@@ -332,6 +333,29 @@ internal class EventRelationsAggregationProcessor @Inject constructor(
                 )
             }
         }
+
+        if (!isLocalEcho) {
+            val replaceEvent = TimelineEventEntity.where(realm, roomId, eventId).findFirst()
+            handleThreadSummaryEdition(editedEvent, replaceEvent, existingSummary?.editions)
+        }
+    }
+
+    /**
+     * Check if the edition is on the latest thread event, and update it accordingly
+     */
+    private fun handleThreadSummaryEdition(editedEvent: EventEntity?,
+                                           replaceEvent: TimelineEventEntity?,
+                                           editions: List<EditionOfEvent>?) {
+        replaceEvent ?: return
+        editedEvent ?: return
+        editedEvent.findRootThreadEvent()?.apply {
+            val threadSummaryEventId = threadSummaryLatestMessage?.eventId
+            if (editedEvent.eventId == threadSummaryEventId || editions?.any { it.eventId == threadSummaryEventId } == true) {
+                // The edition is for the latest event or for any event replaced, this is to handle multiple
+                // edits of the same latest event
+                threadSummaryLatestMessage = replaceEvent
+            }
+        }
     }
 
     private fun handleResponse(realm: Realm,

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/RoomAPI.kt

@@ -226,7 +226,8 @@ internal interface RoomAPI {
     suspend fun getRelations(@Path("roomId") roomId: String,
                              @Path("eventId") eventId: String,
                              @Path("relationType") relationType: String,
-                             @Path("eventType") eventType: String
+                             @Path("eventType") eventType: String,
+                             @Query("limit") limit: Int? = null
     ): RelationsResponse
 
     /**

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/RoomFactory.kt

@@ -35,6 +35,7 @@ import org.matrix.android.sdk.internal.session.room.state.DefaultStateService
 import org.matrix.android.sdk.internal.session.room.state.SendStateTask
 import org.matrix.android.sdk.internal.session.room.summary.RoomSummaryDataSource
 import org.matrix.android.sdk.internal.session.room.tags.DefaultTagsService
+import org.matrix.android.sdk.internal.session.room.threads.DefaultThreadsService
 import org.matrix.android.sdk.internal.session.room.timeline.DefaultTimelineService
 import org.matrix.android.sdk.internal.session.room.typing.DefaultTypingService
 import org.matrix.android.sdk.internal.session.room.uploads.DefaultUploadsService
@@ -50,6 +51,7 @@ internal interface RoomFactory {
 internal class DefaultRoomFactory @Inject constructor(private val cryptoService: CryptoService,
                                                       private val roomSummaryDataSource: RoomSummaryDataSource,
                                                       private val timelineServiceFactory: DefaultTimelineService.Factory,
+                                                      private val threadsServiceFactory: DefaultThreadsService.Factory,
                                                       private val sendServiceFactory: DefaultSendService.Factory,
                                                       private val draftServiceFactory: DefaultDraftService.Factory,
                                                       private val stateServiceFactory: DefaultStateService.Factory,
@@ -76,6 +78,7 @@ internal class DefaultRoomFactory @Inject constructor(private val cryptoService:
                 roomId = roomId,
                 roomSummaryDataSource = roomSummaryDataSource,
                 timelineService = timelineServiceFactory.create(roomId),
+                threadsService = threadsServiceFactory.create(roomId),
                 sendService = sendServiceFactory.create(roomId),
                 draftService = draftServiceFactory.create(roomId),
                 stateService = stateServiceFactory.create(roomId),

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/RoomModule.kt

@@ -77,6 +77,8 @@ import org.matrix.android.sdk.internal.session.room.relation.DefaultUpdateQuickR
 import org.matrix.android.sdk.internal.session.room.relation.FetchEditHistoryTask
 import org.matrix.android.sdk.internal.session.room.relation.FindReactionEventForUndoTask
 import org.matrix.android.sdk.internal.session.room.relation.UpdateQuickReactionTask
+import org.matrix.android.sdk.internal.session.room.relation.threads.DefaultFetchThreadTimelineTask
+import org.matrix.android.sdk.internal.session.room.relation.threads.FetchThreadTimelineTask
 import org.matrix.android.sdk.internal.session.room.reporting.DefaultReportContentTask
 import org.matrix.android.sdk.internal.session.room.reporting.ReportContentTask
 import org.matrix.android.sdk.internal.session.room.state.DefaultSendStateTask
@@ -289,4 +291,7 @@ internal abstract class RoomModule {
 
     @Binds
     abstract fun bindGetRoomSummaryTask(task: DefaultGetRoomSummaryTask): GetRoomSummaryTask
+
+    @Binds
+    abstract fun bindFetchThreadTimelineTask(task: DefaultFetchThreadTimelineTask): FetchThreadTimelineTask
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/prune/RedactionEventProcessor.kt

@@ -83,7 +83,9 @@ internal class RedactionEventProcessor @Inject constructor() : EventInsertLivePr
 //                    }
 
                     val modified = unsignedData.copy(redactedEvent = redactionEvent)
-                    eventToPrune.content = ContentMapper.map(emptyMap())
+                    // I Commented the line below, it should not be empty while we lose all the previous info about
+                    // the redacted event
+//                    eventToPrune.content = ContentMapper.map(emptyMap())
                     eventToPrune.unsignedData = MoshiProvider.providesMoshi().adapter(UnsignedData::class.java).toJson(modified)
                     eventToPrune.decryptionResultJson = null
                     eventToPrune.decryptionErrorCode = null

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/relation/DefaultRelationService.kt

@@ -21,7 +21,6 @@ import com.zhuinden.monarchy.Monarchy
 import dagger.assisted.Assisted
 import dagger.assisted.AssistedFactory
 import dagger.assisted.AssistedInject
-import org.matrix.android.sdk.api.MatrixCallback
 import org.matrix.android.sdk.api.session.events.model.Event
 import org.matrix.android.sdk.api.session.room.model.EventAnnotationsSummary
 import org.matrix.android.sdk.api.session.room.model.message.PollType
@@ -38,10 +37,9 @@ import org.matrix.android.sdk.internal.database.model.EventAnnotationsSummaryEnt
 import org.matrix.android.sdk.internal.database.model.TimelineEventEntity
 import org.matrix.android.sdk.internal.database.query.where
 import org.matrix.android.sdk.internal.di.SessionDatabase
+import org.matrix.android.sdk.internal.session.room.relation.threads.FetchThreadTimelineTask
 import org.matrix.android.sdk.internal.session.room.send.LocalEchoEventFactory
 import org.matrix.android.sdk.internal.session.room.send.queue.EventSenderProcessor
-import org.matrix.android.sdk.internal.task.TaskExecutor
-import org.matrix.android.sdk.internal.task.configureWith
 import org.matrix.android.sdk.internal.util.fetchCopyMap
 import timber.log.Timber
 
@@ -53,10 +51,10 @@ internal class DefaultRelationService @AssistedInject constructor(
         private val cryptoSessionInfoProvider: CryptoSessionInfoProvider,
         private val findReactionEventForUndoTask: FindReactionEventForUndoTask,
         private val fetchEditHistoryTask: FetchEditHistoryTask,
+        private val fetchThreadTimelineTask: FetchThreadTimelineTask,
         private val timelineEventMapper: TimelineEventMapper,
-        @SessionDatabase private val monarchy: Monarchy,
-        private val taskExecutor: TaskExecutor) :
-    RelationService {
+        @SessionDatabase private val monarchy: Monarchy
+) : RelationService {
 
     @AssistedFactory
     interface Factory {
@@ -78,39 +76,31 @@ internal class DefaultRelationService @AssistedInject constructor(
                         .none { it.addedByMe && it.key == reaction }) {
             val event = eventFactory.createReactionEvent(roomId, targetEventId, reaction)
                     .also { saveLocalEcho(it) }
-            return eventSenderProcessor.postEvent(event, false /* reaction are not encrypted*/)
+            eventSenderProcessor.postEvent(event, false /* reaction are not encrypted*/)
         } else {
             Timber.w("Reaction already added")
             NoOpCancellable
         }
     }
 
-    override fun undoReaction(targetEventId: String, reaction: String): Cancelable {
+    override suspend fun undoReaction(targetEventId: String, reaction: String): Cancelable {
         val params = FindReactionEventForUndoTask.Params(
                 roomId,
                 targetEventId,
                 reaction
         )
-        // TODO We should avoid using MatrixCallback internally
-        val callback = object : MatrixCallback<FindReactionEventForUndoTask.Result> {
-            override fun onSuccess(data: FindReactionEventForUndoTask.Result) {
-                if (data.redactEventId == null) {
-                    Timber.w("Cannot find reaction to undo (not yet synced?)")
-                    // TODO?
-                }
-                data.redactEventId?.let { toRedact ->
-                    val redactEvent = eventFactory.createRedactEvent(roomId, toRedact, null)
-                            .also { saveLocalEcho(it) }
-                    eventSenderProcessor.postRedaction(redactEvent, null)
-                }
-            }
+
+        val data = findReactionEventForUndoTask.executeRetry(params, Int.MAX_VALUE)
+
+        return if (data.redactEventId == null) {
+            Timber.w("Cannot find reaction to undo (not yet synced?)")
+            // TODO?
+            NoOpCancellable
+        } else {
+            val redactEvent = eventFactory.createRedactEvent(roomId, data.redactEventId, null)
+                    .also { saveLocalEcho(it) }
+            eventSenderProcessor.postRedaction(redactEvent, null)
         }
-        return findReactionEventForUndoTask
-                .configureWith(params) {
-                    this.retryCount = Int.MAX_VALUE
-                    this.callback = callback
-                }
-                .executeBy(taskExecutor)
     }
 
     override fun editPoll(targetEvent: TimelineEvent,
@@ -139,8 +129,20 @@ internal class DefaultRelationService @AssistedInject constructor(
         return fetchEditHistoryTask.execute(FetchEditHistoryTask.Params(roomId, eventId))
     }
 
-    override fun replyToMessage(eventReplied: TimelineEvent, replyText: CharSequence, autoMarkdown: Boolean): Cancelable? {
-        val event = eventFactory.createReplyTextEvent(roomId, eventReplied, replyText, autoMarkdown)
+    override fun replyToMessage(
+            eventReplied: TimelineEvent,
+            replyText: CharSequence,
+            autoMarkdown: Boolean,
+            showInThread: Boolean,
+            rootThreadEventId: String?
+    ): Cancelable? {
+        val event = eventFactory.createReplyTextEvent(
+                roomId = roomId,
+                eventReplied = eventReplied,
+                replyText = replyText,
+                autoMarkdown = autoMarkdown,
+                rootThreadEventId = rootThreadEventId,
+                showInThread = showInThread)
                 ?.also { saveLocalEcho(it) }
                 ?: return null
 
@@ -166,6 +168,47 @@ internal class DefaultRelationService @AssistedInject constructor(
         }
     }
 
+    override fun replyInThread(
+            rootThreadEventId: String,
+            replyInThreadText: CharSequence,
+            msgType: String,
+            autoMarkdown: Boolean,
+            formattedText: String?,
+            eventReplied: TimelineEvent?): Cancelable? {
+        val event = if (eventReplied != null) {
+            // Reply within a thread
+            eventFactory.createReplyTextEvent(
+                    roomId = roomId,
+                    eventReplied = eventReplied,
+                    replyText = replyInThreadText,
+                    autoMarkdown = autoMarkdown,
+                    rootThreadEventId = rootThreadEventId,
+                    showInThread = false
+            )
+                    ?.also {
+                        saveLocalEcho(it)
+                    }
+                    ?: return null
+        } else {
+            // Normal thread reply
+            eventFactory.createThreadTextEvent(
+                    rootThreadEventId = rootThreadEventId,
+                    roomId = roomId,
+                    text = replyInThreadText,
+                    msgType = msgType,
+                    autoMarkdown = autoMarkdown,
+                    formattedText = formattedText)
+                    .also {
+                        saveLocalEcho(it)
+                    }
+        }
+        return eventSenderProcessor.postEvent(event, cryptoSessionInfoProvider.isRoomEncrypted(roomId))
+    }
+
+    override suspend fun fetchThreadTimeline(rootThreadEventId: String): Boolean {
+        return fetchThreadTimelineTask.execute(FetchThreadTimelineTask.Params(roomId, rootThreadEventId))
+    }
+
     /**
      * Saves the event in database as a local echo.
      * SendState is set to UNSENT and it's added to a the sendingTimelineEvents list of the room.

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/relation/EventEditor.kt

@@ -97,7 +97,13 @@ internal class EventEditor @Inject constructor(private val eventSenderProcessor:
         val roomId = replyToEdit.roomId
         if (replyToEdit.root.sendState.hasFailed()) {
             // We create a new in memory event for the EventSenderProcessor but we keep the eventId of the failed event.
-            val editedEvent = eventFactory.createReplyTextEvent(roomId, originalTimelineEvent, newBodyText, false)?.copy(
+            val editedEvent = eventFactory.createReplyTextEvent(
+                    roomId = roomId,
+                    eventReplied = originalTimelineEvent,
+                    replyText = newBodyText,
+                    autoMarkdown = false,
+                    showInThread = false
+            )?.copy(
                     eventId = replyToEdit.eventId
             ) ?: return NoOpCancellable
             updateFailedEchoWithEvent(roomId, replyToEdit.eventId, editedEvent)

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/relation/threads/FetchThreadTimelineTask.kt

@@ -0,0 +1,207 @@
+/*
+ * Copyright 2021 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.matrix.android.sdk.internal.session.room.relation.threads
+
+import com.zhuinden.monarchy.Monarchy
+import io.realm.Realm
+import org.matrix.android.sdk.api.session.crypto.MXCryptoError
+import org.matrix.android.sdk.api.session.events.model.Event
+import org.matrix.android.sdk.api.session.events.model.EventType
+import org.matrix.android.sdk.api.session.events.model.RelationType
+import org.matrix.android.sdk.api.session.room.model.RoomMemberContent
+import org.matrix.android.sdk.api.session.room.send.SendState
+import org.matrix.android.sdk.internal.crypto.CryptoSessionInfoProvider
+import org.matrix.android.sdk.internal.crypto.DefaultCryptoService
+import org.matrix.android.sdk.internal.crypto.algorithms.olm.OlmDecryptionResult
+import org.matrix.android.sdk.internal.database.helper.addTimelineEvent
+import org.matrix.android.sdk.internal.database.helper.updateThreadSummaryIfNeeded
+import org.matrix.android.sdk.internal.database.mapper.asDomain
+import org.matrix.android.sdk.internal.database.mapper.toEntity
+import org.matrix.android.sdk.internal.database.model.ChunkEntity
+import org.matrix.android.sdk.internal.database.model.CurrentStateEventEntity
+import org.matrix.android.sdk.internal.database.model.EventAnnotationsSummaryEntity
+import org.matrix.android.sdk.internal.database.model.EventEntity
+import org.matrix.android.sdk.internal.database.model.EventInsertType
+import org.matrix.android.sdk.internal.database.model.ReactionAggregatedSummaryEntity
+import org.matrix.android.sdk.internal.database.query.copyToRealmOrIgnore
+import org.matrix.android.sdk.internal.database.query.findLastForwardChunkOfRoom
+import org.matrix.android.sdk.internal.database.query.getOrCreate
+import org.matrix.android.sdk.internal.database.query.getOrNull
+import org.matrix.android.sdk.internal.database.query.where
+import org.matrix.android.sdk.internal.di.SessionDatabase
+import org.matrix.android.sdk.internal.di.UserId
+import org.matrix.android.sdk.internal.network.GlobalErrorReceiver
+import org.matrix.android.sdk.internal.network.executeRequest
+import org.matrix.android.sdk.internal.session.events.getFixedRoomMemberContent
+import org.matrix.android.sdk.internal.session.room.RoomAPI
+import org.matrix.android.sdk.internal.session.room.timeline.PaginationDirection
+import org.matrix.android.sdk.internal.task.Task
+import org.matrix.android.sdk.internal.util.awaitTransaction
+import timber.log.Timber
+import javax.inject.Inject
+
+internal interface FetchThreadTimelineTask : Task<FetchThreadTimelineTask.Params, Boolean> {
+    data class Params(
+            val roomId: String,
+            val rootThreadEventId: String
+    )
+}
+
+internal class DefaultFetchThreadTimelineTask @Inject constructor(
+        private val roomAPI: RoomAPI,
+        private val globalErrorReceiver: GlobalErrorReceiver,
+        private val cryptoSessionInfoProvider: CryptoSessionInfoProvider,
+        @SessionDatabase private val monarchy: Monarchy,
+        @UserId private val userId: String,
+        private val cryptoService: DefaultCryptoService
+) : FetchThreadTimelineTask {
+
+    override suspend fun execute(params: FetchThreadTimelineTask.Params): Boolean {
+        val isRoomEncrypted = cryptoSessionInfoProvider.isRoomEncrypted(params.roomId)
+        val response = executeRequest(globalErrorReceiver) {
+            roomAPI.getRelations(
+                    roomId = params.roomId,
+                    eventId = params.rootThreadEventId,
+                    relationType = RelationType.IO_THREAD,
+                    eventType = if (isRoomEncrypted) EventType.ENCRYPTED else EventType.MESSAGE,
+                    limit = 2000
+            )
+        }
+
+        val threadList = response.chunks + listOfNotNull(response.originalEvent)
+
+        return storeNewEventsIfNeeded(threadList, params.roomId)
+    }
+
+    /**
+     * Store new events if they are not already received, and returns weather or not,
+     * a timeline update should be made
+     * @param threadList is the list containing the thread replies
+     * @param roomId the roomId of the the thread
+     * @return
+     */
+    private suspend fun storeNewEventsIfNeeded(threadList: List<Event>, roomId: String): Boolean {
+        var eventsSkipped = 0
+        monarchy
+                .awaitTransaction { realm ->
+                    val chunk = ChunkEntity.findLastForwardChunkOfRoom(realm, roomId)
+
+                    val optimizedThreadSummaryMap = hashMapOf<String, EventEntity>()
+                    val roomMemberContentsByUser = HashMap<String, RoomMemberContent?>()
+
+                    for (event in threadList.reversed()) {
+                        if (event.eventId == null || event.senderId == null || event.type == null) {
+                            eventsSkipped++
+                            continue
+                        }
+
+                        if (EventEntity.where(realm, event.eventId).findFirst() != null) {
+                            //  Skip if event already exists
+                            eventsSkipped++
+                            continue
+                        }
+                        if (event.isEncrypted()) {
+                            // Decrypt events that will be stored
+                            decryptIfNeeded(event, roomId)
+                        }
+
+                        handleReaction(realm, event, roomId)
+
+                        val ageLocalTs = event.unsignedData?.age?.let { System.currentTimeMillis() - it }
+                        val eventEntity = event.toEntity(roomId, SendState.SYNCED, ageLocalTs).copyToRealmOrIgnore(realm, EventInsertType.INCREMENTAL_SYNC)
+
+                        // Sender info
+                        roomMemberContentsByUser.getOrPut(event.senderId) {
+                            // If we don't have any new state on this user, get it from db
+                            val rootStateEvent = CurrentStateEventEntity.getOrNull(realm, roomId, event.senderId, EventType.STATE_ROOM_MEMBER)?.root
+                            rootStateEvent?.asDomain()?.getFixedRoomMemberContent()
+                        }
+
+                        chunk?.addTimelineEvent(roomId, eventEntity, PaginationDirection.FORWARDS, roomMemberContentsByUser)
+                        eventEntity.rootThreadEventId?.let {
+                            // This is a thread event
+                            optimizedThreadSummaryMap[it] = eventEntity
+                        } ?: run {
+                            // This is a normal event or a root thread one
+                            optimizedThreadSummaryMap[eventEntity.eventId] = eventEntity
+                        }
+                    }
+
+                    optimizedThreadSummaryMap.updateThreadSummaryIfNeeded(
+                            roomId = roomId,
+                            realm = realm,
+                            currentUserId = userId,
+                            shouldUpdateNotifications = false
+                    )
+                }
+        Timber.i("----> size: ${threadList.size} | skipped: $eventsSkipped | threads: ${threadList.map { it.eventId }}")
+
+        return eventsSkipped == threadList.size
+    }
+
+    /**
+     * Invoke the event decryption mechanism for a specific event
+     */
+
+    private fun decryptIfNeeded(event: Event, roomId: String) {
+        try {
+            // Event from sync does not have roomId, so add it to the event first
+            val result = cryptoService.decryptEvent(event.copy(roomId = roomId), "")
+            event.mxDecryptionResult = OlmDecryptionResult(
+                    payload = result.clearEvent,
+                    senderKey = result.senderCurve25519Key,
+                    keysClaimed = result.claimedEd25519Key?.let { k -> mapOf("ed25519" to k) },
+                    forwardingCurve25519KeyChain = result.forwardingCurve25519KeyChain
+            )
+        } catch (e: MXCryptoError) {
+            if (e is MXCryptoError.Base) {
+                event.mCryptoError = e.errorType
+                event.mCryptoErrorReason = e.technicalMessage.takeIf { it.isNotEmpty() } ?: e.detailedErrorDescription
+            }
+        }
+    }
+
+    private fun handleReaction(realm: Realm,
+                               event: Event,
+                               roomId: String) {
+        val unsignedData = event.unsignedData ?: return
+        val relatedEventId = event.eventId ?: return
+
+        unsignedData.relations?.annotations?.chunk?.forEach { relationChunk ->
+
+            if (relationChunk.type == EventType.REACTION) {
+                val reaction = relationChunk.key
+                Timber.i("----> Annotation found in ${event.eventId} ${relationChunk.key} ")
+
+                val eventSummary = EventAnnotationsSummaryEntity.getOrCreate(realm, roomId, relatedEventId)
+                var sum = eventSummary.reactionsSummary.find { it.key == reaction }
+
+                if (sum == null) {
+                    sum = realm.createObject(ReactionAggregatedSummaryEntity::class.java)
+                    sum.key = reaction
+                    sum.firstTimestamp = event.originServerTs ?: 0
+                    Timber.v("Adding synced reaction $reaction")
+                    sum.count = 1
+                    // reactionEventId not included in the /relations API
+//                    sum.sourceEvents.add(reactionEventId)
+                    eventSummary.reactionsSummary.add(sum)
+                } else {
+                    sum.count += 1
+                }
+            }
+        }
+    }
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/send/DefaultSendService.kt

@@ -98,8 +98,14 @@ internal class DefaultSendService @AssistedInject constructor(
                 .let { sendEvent(it) }
     }
 
-    override fun sendQuotedTextMessage(quotedEvent: TimelineEvent, text: String, autoMarkdown: Boolean): Cancelable {
-        return localEchoEventFactory.createQuotedTextEvent(roomId, quotedEvent, text, autoMarkdown)
+    override fun sendQuotedTextMessage(quotedEvent: TimelineEvent, text: String, autoMarkdown: Boolean, rootThreadEventId: String?): Cancelable {
+        return localEchoEventFactory.createQuotedTextEvent(
+                roomId = roomId,
+                quotedEvent = quotedEvent,
+                text = text,
+                autoMarkdown = autoMarkdown,
+                rootThreadEventId = rootThreadEventId
+        )
                 .also { createLocalEcho(it) }
                 .let { sendEvent(it) }
     }
@@ -254,22 +260,37 @@ internal class DefaultSendService @AssistedInject constructor(
 
     override fun sendMedias(attachments: List<ContentAttachmentData>,
                             compressBeforeSending: Boolean,
-                            roomIds: Set<String>): Cancelable {
+                            roomIds: Set<String>,
+                            rootThreadEventId: String?
+    ): Cancelable {
         return attachments.mapTo(CancelableBag()) {
-            sendMedia(it, compressBeforeSending, roomIds)
+            sendMedia(
+                    attachment = it,
+                    compressBeforeSending = compressBeforeSending,
+                    roomIds = roomIds,
+                    rootThreadEventId = rootThreadEventId)
         }
     }
 
     override fun sendMedia(attachment: ContentAttachmentData,
                            compressBeforeSending: Boolean,
-                           roomIds: Set<String>): Cancelable {
+                           roomIds: Set<String>,
+                           rootThreadEventId: String?
+    ): Cancelable {
+        // Ensure that the event will not be send in a thread if we are a different flow.
+        // Like sending files to multiple rooms
+        val rootThreadId = if (roomIds.isNotEmpty()) null else rootThreadEventId
+
         // Create an event with the media file path
         // Ensure current roomId is included in the set
         val allRoomIds = (roomIds + roomId).toList()
 
         // Create local echo for each room
         val allLocalEchoes = allRoomIds.map {
-            localEchoEventFactory.createMediaEvent(it, attachment).also { event ->
+            localEchoEventFactory.createMediaEvent(
+                    roomId = it,
+                    attachment = attachment,
+                    rootThreadEventId = rootThreadId).also { event ->
                 createLocalEcho(event)
             }
         }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/send/LocalEchoEventFactory.kt

@@ -28,6 +28,7 @@ import org.matrix.android.sdk.api.session.events.model.LocalEcho
 import org.matrix.android.sdk.api.session.events.model.RelationType
 import org.matrix.android.sdk.api.session.events.model.UnsignedData
 import org.matrix.android.sdk.api.session.events.model.toContent
+import org.matrix.android.sdk.api.session.events.model.toModel
 import org.matrix.android.sdk.api.session.room.model.message.AudioInfo
 import org.matrix.android.sdk.api.session.room.model.message.AudioWaveformInfo
 import org.matrix.android.sdk.api.session.room.model.message.FileInfo
@@ -45,6 +46,7 @@ import org.matrix.android.sdk.api.session.room.model.message.MessageImageContent
 import org.matrix.android.sdk.api.session.room.model.message.MessageLocationContent
 import org.matrix.android.sdk.api.session.room.model.message.MessagePollContent
 import org.matrix.android.sdk.api.session.room.model.message.MessagePollResponseContent
+import org.matrix.android.sdk.api.session.room.model.message.MessageStickerContent
 import org.matrix.android.sdk.api.session.room.model.message.MessageTextContent
 import org.matrix.android.sdk.api.session.room.model.message.MessageType
 import org.matrix.android.sdk.api.session.room.model.message.MessageVideoContent
@@ -292,13 +294,16 @@ internal class LocalEchoEventFactory @Inject constructor(
                 ))
     }
 
-    fun createMediaEvent(roomId: String, attachment: ContentAttachmentData): Event {
+    fun createMediaEvent(roomId: String,
+                         attachment: ContentAttachmentData,
+                         rootThreadEventId: String?
+    ): Event {
         return when (attachment.type) {
-            ContentAttachmentData.Type.IMAGE         -> createImageEvent(roomId, attachment)
-            ContentAttachmentData.Type.VIDEO         -> createVideoEvent(roomId, attachment)
-            ContentAttachmentData.Type.AUDIO         -> createAudioEvent(roomId, attachment, isVoiceMessage = false)
-            ContentAttachmentData.Type.VOICE_MESSAGE -> createAudioEvent(roomId, attachment, isVoiceMessage = true)
-            ContentAttachmentData.Type.FILE          -> createFileEvent(roomId, attachment)
+            ContentAttachmentData.Type.IMAGE         -> createImageEvent(roomId, attachment, rootThreadEventId)
+            ContentAttachmentData.Type.VIDEO         -> createVideoEvent(roomId, attachment, rootThreadEventId)
+            ContentAttachmentData.Type.AUDIO         -> createAudioEvent(roomId, attachment, isVoiceMessage = false, rootThreadEventId = rootThreadEventId)
+            ContentAttachmentData.Type.VOICE_MESSAGE -> createAudioEvent(roomId, attachment, isVoiceMessage = true, rootThreadEventId = rootThreadEventId)
+            ContentAttachmentData.Type.FILE          -> createFileEvent(roomId, attachment, rootThreadEventId)
         }
     }
 
@@ -321,7 +326,7 @@ internal class LocalEchoEventFactory @Inject constructor(
                 unsignedData = UnsignedData(age = null, transactionId = localId))
     }
 
-    private fun createImageEvent(roomId: String, attachment: ContentAttachmentData): Event {
+    private fun createImageEvent(roomId: String, attachment: ContentAttachmentData, rootThreadEventId: String?): Event {
         var width = attachment.width
         var height = attachment.height
 
@@ -345,12 +350,19 @@ internal class LocalEchoEventFactory @Inject constructor(
                         height = height?.toInt() ?: 0,
                         size = attachment.size
                 ),
-                url = attachment.queryUri.toString()
+                url = attachment.queryUri.toString(),
+                relatesTo = rootThreadEventId?.let {
+                    RelationDefaultContent(
+                            type = RelationType.IO_THREAD,
+                            eventId = it,
+                            inReplyTo = ReplyToContent(eventId = localEchoRepository.getLatestThreadEvent(it))
+                    )
+                }
         )
         return createMessageEvent(roomId, content)
     }
 
-    private fun createVideoEvent(roomId: String, attachment: ContentAttachmentData): Event {
+    private fun createVideoEvent(roomId: String, attachment: ContentAttachmentData, rootThreadEventId: String?): Event {
         val mediaDataRetriever = MediaMetadataRetriever()
         mediaDataRetriever.setDataSource(context, attachment.queryUri)
 
@@ -381,12 +393,23 @@ internal class LocalEchoEventFactory @Inject constructor(
                         thumbnailUrl = attachment.queryUri.toString(),
                         thumbnailInfo = thumbnailInfo
                 ),
-                url = attachment.queryUri.toString()
+                url = attachment.queryUri.toString(),
+                relatesTo = rootThreadEventId?.let {
+                    RelationDefaultContent(
+                            type = RelationType.IO_THREAD,
+                            eventId = it,
+                            inReplyTo = ReplyToContent(eventId = localEchoRepository.getLatestThreadEvent(it))
+                    )
+                }
         )
         return createMessageEvent(roomId, content)
     }
 
-    private fun createAudioEvent(roomId: String, attachment: ContentAttachmentData, isVoiceMessage: Boolean): Event {
+    private fun createAudioEvent(roomId: String,
+                                 attachment: ContentAttachmentData,
+                                 isVoiceMessage: Boolean,
+                                 rootThreadEventId: String?
+    ): Event {
         val content = MessageAudioContent(
                 msgType = MessageType.MSGTYPE_AUDIO,
                 body = attachment.name ?: "audio",
@@ -400,12 +423,19 @@ internal class LocalEchoEventFactory @Inject constructor(
                         duration = attachment.duration?.toInt(),
                         waveform = waveformSanitizer.sanitize(attachment.waveform)
                 ),
-                voiceMessageIndicator = if (!isVoiceMessage) null else emptyMap()
+                voiceMessageIndicator = if (!isVoiceMessage) null else emptyMap(),
+                relatesTo = rootThreadEventId?.let {
+                    RelationDefaultContent(
+                            type = RelationType.IO_THREAD,
+                            eventId = it,
+                            inReplyTo = ReplyToContent(eventId = localEchoRepository.getLatestThreadEvent(it))
+                    )
+                }
         )
         return createMessageEvent(roomId, content)
     }
 
-    private fun createFileEvent(roomId: String, attachment: ContentAttachmentData): Event {
+    private fun createFileEvent(roomId: String, attachment: ContentAttachmentData, rootThreadEventId: String?): Event {
         val content = MessageFileContent(
                 msgType = MessageType.MSGTYPE_FILE,
                 body = attachment.name ?: "file",
@@ -413,7 +443,14 @@ internal class LocalEchoEventFactory @Inject constructor(
                         mimeType = attachment.getSafeMimeType()?.takeIf { it.isNotBlank() },
                         size = attachment.size
                 ),
-                url = attachment.queryUri.toString()
+                url = attachment.queryUri.toString(),
+                relatesTo = rootThreadEventId?.let {
+                    RelationDefaultContent(
+                            type = RelationType.IO_THREAD,
+                            eventId = it,
+                            inReplyTo = ReplyToContent(eventId = localEchoRepository.getLatestThreadEvent(it))
+                    )
+                }
         )
         return createMessageEvent(roomId, content)
     }
@@ -423,6 +460,7 @@ internal class LocalEchoEventFactory @Inject constructor(
     }
 
     fun createEvent(roomId: String, type: String, content: Content?): Event {
+        val newContent = enhanceStickerIfNeeded(type, content) ?: content
         val localId = LocalEcho.createLocalEchoId()
         return Event(
                 roomId = roomId,
@@ -430,19 +468,65 @@ internal class LocalEchoEventFactory @Inject constructor(
                 senderId = userId,
                 eventId = localId,
                 type = type,
-                content = content,
+                content = newContent,
                 unsignedData = UnsignedData(age = null, transactionId = localId)
         )
     }
 
+    /**
+     * Enhance sticker to support threads fallback if needed
+     */
+    private fun enhanceStickerIfNeeded(type: String, content: Content?): Content? {
+        var newContent: Content? = null
+        if (type == EventType.STICKER) {
+            val isThread = (content.toModel<MessageStickerContent>())?.relatesTo?.type == RelationType.IO_THREAD
+            val rootThreadEventId = (content.toModel<MessageStickerContent>())?.relatesTo?.eventId
+            if (isThread && rootThreadEventId != null) {
+                val newRelationalDefaultContent = (content.toModel<MessageStickerContent>())?.relatesTo?.copy(
+                        inReplyTo = ReplyToContent(eventId = localEchoRepository.getLatestThreadEvent(rootThreadEventId))
+                )
+                newContent = (content.toModel<MessageStickerContent>())?.copy(
+                        relatesTo = newRelationalDefaultContent
+                ).toContent()
+            }
+        }
+        return newContent
+    }
+
+    /**
+     * Creates a thread event related to the already existing root event
+     */
+    fun createThreadTextEvent(
+            rootThreadEventId: String,
+            roomId: String,
+            text: CharSequence,
+            msgType: String,
+            autoMarkdown: Boolean,
+            formattedText: String?): Event {
+        val content = formattedText?.let { TextContent(text.toString(), it) } ?: createTextContent(text, autoMarkdown)
+        return createEvent(
+                roomId,
+                EventType.MESSAGE,
+                content.toThreadTextContent(
+                        rootThreadEventId = rootThreadEventId,
+                        latestThreadEventId = localEchoRepository.getLatestThreadEvent(rootThreadEventId),
+                        msgType = msgType)
+                        .toContent())
+    }
+
     private fun dummyOriginServerTs(): Long {
         return System.currentTimeMillis()
     }
 
+    /**
+     * Creates a reply to a regular timeline Event or a thread Event if needed
+     */
     fun createReplyTextEvent(roomId: String,
                              eventReplied: TimelineEvent,
                              replyText: CharSequence,
-                             autoMarkdown: Boolean): Event? {
+                             autoMarkdown: Boolean,
+                             rootThreadEventId: String? = null,
+                             showInThread: Boolean): Event? {
         // Fallbacks and event representation
         // TODO Add error/warning logs when any of this is null
         val permalink = permalinkFactory.createPermalink(eventReplied.root, false) ?: return null
@@ -473,11 +557,33 @@ internal class LocalEchoEventFactory @Inject constructor(
                 format = MessageFormat.FORMAT_MATRIX_HTML,
                 body = replyFallback,
                 formattedBody = replyFormatted,
-                relatesTo = RelationDefaultContent(null, null, ReplyToContent(eventId))
-        )
+                relatesTo = generateReplyRelationContent(
+                        eventId = eventId,
+                        rootThreadEventId = rootThreadEventId,
+                        showAsReply = showInThread))
         return createMessageEvent(roomId, content)
     }
 
+    /**
+     * Generates the appropriate relatesTo object for a reply event.
+     * It can either be a regular reply or a reply within a thread
+     * "m.relates_to": {
+     *      "rel_type": "m.thread",
+     *      "event_id": "$thread_root",
+     *      "m.in_reply_to": {
+     *          "event_id": "$event_target",
+     *          "render_in": ["m.thread"]
+     *        }
+     *   }
+     */
+    private fun generateReplyRelationContent(eventId: String, rootThreadEventId: String? = null, showAsReply: Boolean): RelationDefaultContent =
+            rootThreadEventId?.let {
+                RelationDefaultContent(
+                        type = RelationType.IO_THREAD,
+                        eventId = it,
+                        inReplyTo = ReplyToContent(eventId = eventId, renderIn = if (showAsReply) arrayListOf("m.thread") else null))
+            } ?: RelationDefaultContent(null, null, ReplyToContent(eventId = eventId))
+
     private fun buildFormattedReply(permalink: String, userLink: String, userId: String, bodyFormatted: String, newBodyFormatted: String): String {
         return REPLY_PATTERN.format(
                 permalink,
@@ -488,6 +594,7 @@ internal class LocalEchoEventFactory @Inject constructor(
                 newBodyFormatted
         )
     }
+
     private fun buildReplyFallback(body: TextContent, originalSenderId: String?, newBodyText: String): String {
         return buildString {
             append("> <")
@@ -593,11 +700,28 @@ internal class LocalEchoEventFactory @Inject constructor(
             quotedEvent: TimelineEvent,
             text: String,
             autoMarkdown: Boolean,
+            rootThreadEventId: String?
     ): Event {
         val messageContent = quotedEvent.getLastMessageContent()
         val textMsg = messageContent?.body
         val quoteText = legacyRiotQuoteText(textMsg, text)
-        return createFormattedTextEvent(roomId, markdownParser.parse(quoteText, force = true, advanced = autoMarkdown), MessageType.MSGTYPE_TEXT)
+
+        return if (rootThreadEventId != null) {
+            createMessageEvent(
+                    roomId,
+                    markdownParser
+                            .parse(quoteText, force = true, advanced = autoMarkdown)
+                            .toThreadTextContent(
+                                    rootThreadEventId = rootThreadEventId,
+                                    latestThreadEventId = localEchoRepository.getLatestThreadEvent(rootThreadEventId),
+                                    msgType = MessageType.MSGTYPE_TEXT)
+            )
+        } else {
+            createFormattedTextEvent(
+                    roomId,
+                    markdownParser.parse(quoteText, force = true, advanced = autoMarkdown),
+                    MessageType.MSGTYPE_TEXT)
+        }
     }
 
     private fun legacyRiotQuoteText(quotedText: String?, myText: String): String {
@@ -631,6 +755,7 @@ internal class LocalEchoEventFactory @Inject constructor(
         // </mx-reply>
         // No whitespace because currently breaks temporary formatted text to Span
         const val REPLY_PATTERN = """<mx-reply><blockquote><a href="%s">In reply to</a> <a href="%s">%s</a><br />%s</blockquote></mx-reply>%s"""
+        const val QUOTE_PATTERN = """<blockquote><p>%s</p></blockquote><p>%s</p>"""
 
         // This is used to replace inner mx-reply tags
         val MX_REPLY_REGEX = "<mx-reply>.*</mx-reply>".toRegex()

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/send/LocalEchoRepository.kt

@@ -138,7 +138,7 @@ internal class LocalEchoRepository @Inject constructor(@SessionDatabase private
         }
     }
 
-     fun deleteFailedEchoAsync(roomId: String, eventId: String?) {
+    fun deleteFailedEchoAsync(roomId: String, eventId: String?) {
         monarchy.runTransactionSync { realm ->
             TimelineEventEntity.where(realm, roomId = roomId, eventId = eventId ?: "").findFirst()?.deleteFromRealm()
             EventEntity.where(realm, eventId = eventId ?: "").findFirst()?.deleteFromRealm()
@@ -215,4 +215,13 @@ internal class LocalEchoRepository @Inject constructor(@SessionDatabase private
                     }
         }
     }
+
+    /**
+     * Returns the latest known thread event message, or the rootThreadEventId if no other event found
+     */
+    fun getLatestThreadEvent(rootThreadEventId: String): String {
+        return realmSessionProvider.withRealm { realm ->
+            EventEntity.where(realm, eventId = rootThreadEventId).findFirst()?.threadSummaryLatestMessage?.eventId
+        } ?: rootThreadEventId
+    }
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/send/TextContent.kt

@@ -16,9 +16,12 @@
 
 package org.matrix.android.sdk.internal.session.room.send
 
+import org.matrix.android.sdk.api.session.events.model.RelationType
 import org.matrix.android.sdk.api.session.room.model.message.MessageFormat
 import org.matrix.android.sdk.api.session.room.model.message.MessageTextContent
 import org.matrix.android.sdk.api.session.room.model.message.MessageType
+import org.matrix.android.sdk.api.session.room.model.relation.RelationDefaultContent
+import org.matrix.android.sdk.api.session.room.model.relation.ReplyToContent
 import org.matrix.android.sdk.api.util.ContentUtils.extractUsefulTextFromHtmlReply
 import org.matrix.android.sdk.api.util.ContentUtils.extractUsefulTextFromReply
 
@@ -41,6 +44,29 @@ fun TextContent.toMessageTextContent(msgType: String = MessageType.MSGTYPE_TEXT)
     )
 }
 
+/**
+ * Transform a TextContent to a thread message content. It will also add the inReplyTo
+ * latestThreadEventId in order for the clients without threads enabled to render it appropriately
+ * If latest event not found, we pass rootThreadEventId
+ */
+fun TextContent.toThreadTextContent(
+        rootThreadEventId: String,
+        latestThreadEventId: String,
+        msgType: String = MessageType.MSGTYPE_TEXT): MessageTextContent {
+    return MessageTextContent(
+            msgType = msgType,
+            format = MessageFormat.FORMAT_MATRIX_HTML.takeIf { formattedText != null },
+            body = text,
+            relatesTo = RelationDefaultContent(
+                    type = RelationType.IO_THREAD,
+                    eventId = rootThreadEventId,
+                    inReplyTo = ReplyToContent(
+                            eventId = latestThreadEventId
+                    )),
+            formattedBody = formattedText
+    )
+}
+
 fun TextContent.removeInReplyFallbacks(): TextContent {
     return copy(
             text = extractUsefulTextFromReply(this.text),

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/threads/DefaultThreadsService.kt

@@ -0,0 +1,103 @@
+/*
+ * Copyright 2022 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.android.sdk.internal.session.room.threads
+
+import androidx.lifecycle.LiveData
+import com.zhuinden.monarchy.Monarchy
+import dagger.assisted.Assisted
+import dagger.assisted.AssistedFactory
+import dagger.assisted.AssistedInject
+import io.realm.Realm
+import org.matrix.android.sdk.api.session.room.threads.ThreadsService
+import org.matrix.android.sdk.api.session.room.timeline.TimelineEvent
+import org.matrix.android.sdk.api.session.threads.ThreadNotificationState
+import org.matrix.android.sdk.internal.database.helper.findAllLocalThreadNotificationsForRoomId
+import org.matrix.android.sdk.internal.database.helper.findAllThreadsForRoomId
+import org.matrix.android.sdk.internal.database.helper.isUserParticipatingInThread
+import org.matrix.android.sdk.internal.database.helper.mapEventsWithEdition
+import org.matrix.android.sdk.internal.database.mapper.TimelineEventMapper
+import org.matrix.android.sdk.internal.database.model.EventEntity
+import org.matrix.android.sdk.internal.database.model.TimelineEventEntity
+import org.matrix.android.sdk.internal.database.query.where
+import org.matrix.android.sdk.internal.di.SessionDatabase
+import org.matrix.android.sdk.internal.di.UserId
+import org.matrix.android.sdk.internal.util.awaitTransaction
+
+internal class DefaultThreadsService @AssistedInject constructor(
+        @Assisted private val roomId: String,
+        @UserId private val userId: String,
+        @SessionDatabase private val monarchy: Monarchy,
+        private val timelineEventMapper: TimelineEventMapper,
+) : ThreadsService {
+
+    @AssistedFactory
+    interface Factory {
+        fun create(roomId: String): DefaultThreadsService
+    }
+
+    override fun getMarkedThreadNotificationsLive(): LiveData<List<TimelineEvent>> {
+        return monarchy.findAllMappedWithChanges(
+                { TimelineEventEntity.findAllLocalThreadNotificationsForRoomId(it, roomId = roomId) },
+                { timelineEventMapper.map(it) }
+        )
+    }
+
+    override fun getMarkedThreadNotifications(): List<TimelineEvent> {
+        return monarchy.fetchAllMappedSync(
+                { TimelineEventEntity.findAllLocalThreadNotificationsForRoomId(it, roomId = roomId) },
+                { timelineEventMapper.map(it) }
+        )
+    }
+
+    override fun getAllThreadsLive(): LiveData<List<TimelineEvent>> {
+        return monarchy.findAllMappedWithChanges(
+                { TimelineEventEntity.findAllThreadsForRoomId(it, roomId = roomId) },
+                { timelineEventMapper.map(it) }
+        )
+    }
+
+    override fun getAllThreads(): List<TimelineEvent> {
+        return monarchy.fetchAllMappedSync(
+                { TimelineEventEntity.findAllThreadsForRoomId(it, roomId = roomId) },
+                { timelineEventMapper.map(it) }
+        )
+    }
+
+    override fun isUserParticipatingInThread(rootThreadEventId: String): Boolean {
+        return Realm.getInstance(monarchy.realmConfiguration).use {
+            TimelineEventEntity.isUserParticipatingInThread(
+                    realm = it,
+                    roomId = roomId,
+                    rootThreadEventId = rootThreadEventId,
+                    senderId = userId)
+        }
+    }
+
+    override fun mapEventsWithEdition(threads: List<TimelineEvent>): List<TimelineEvent> {
+        return Realm.getInstance(monarchy.realmConfiguration).use {
+            threads.mapEventsWithEdition(it, roomId)
+        }
+    }
+
+    override suspend fun markThreadAsRead(rootThreadEventId: String) {
+        monarchy.awaitTransaction {
+            EventEntity.where(
+                    realm = it,
+                    eventId = rootThreadEventId).findFirst()?.threadNotificationState = ThreadNotificationState.NO_NEW_MESSAGE
+        }
+    }
+}