Fix / visibility bug after scroll

+ refine animation

vector/src/main/java/im/vector/riotredesign/features/home/room/list/RoomListFragment.kt

@@ -93,7 +93,8 @@ class RoomListFragment : VectorBaseFragment(), RoomSummaryController.Callback, O
         }
 
         // Hide FAB when list is scrolling
-        epoxyRecyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
+        epoxyRecyclerView.addOnScrollListener(
+                object : RecyclerView.OnScrollListener() {
                     override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
                         createChatFabMenu.removeCallbacks(showFabRunnable)
 
@@ -220,7 +221,7 @@ class RoomListFragment : VectorBaseFragment(), RoomSummaryController.Callback, O
         return super.onBackPressed()
     }
 
-    // RoomSummaryController.Callback **************************************************************
+// RoomSummaryController.Callback **************************************************************
 
     override fun onRoomSelected(room: RoomSummary) {
         roomListViewModel.accept(RoomListActions.SelectRoom(room))

vector/src/main/java/im/vector/riotredesign/features/home/room/list/widget/FabMenuView.kt

@@ -19,6 +19,8 @@ package im.vector.riotredesign.features.home.room.list.widget
 import android.content.Context
 import android.util.AttributeSet
 import androidx.constraintlayout.motion.widget.MotionLayout
+import androidx.core.view.isVisible
+import com.google.android.material.floatingactionbutton.FloatingActionButton
 import im.vector.riotredesign.R
 import im.vector.riotredesign.features.themes.ThemeUtils
 import kotlinx.android.synthetic.main.motion_fab_menu_merge.view.*
@@ -62,14 +64,17 @@ class FabMenuView @JvmOverloads constructor(context: Context, attrs: AttributeSe
     }
 
     fun show() {
-        // Ensure visibility is well restored
+        isVisible = true
-        // FIXME It does not work, FAB is not visible, alpha is 0... And cannot set it to 1
-
         createRoomButton.show()
     }
 
     fun hide() {
-        createRoomButton.hide()
+        createRoomButton.hide(object : FloatingActionButton.OnVisibilityChangedListener() {
+            override fun onHidden(fab: FloatingActionButton?) {
+                super.onHidden(fab)
+                isVisible = false
+            }
+        })
     }
 
     private fun closeFabMenu() {

vector/src/main/res/xml/motion_scene_fab_menu.xml

@@ -6,12 +6,44 @@
     <Transition
         motion:constraintSetEnd="@+id/constraint_set_fab_menu_open"
         motion:constraintSetStart="@+id/constraint_set_fab_menu_close"
-        motion:duration="200">
+        motion:motionInterpolator="easeInOut"
+        motion:duration="300">
 
         <OnClick
             motion:clickAction="toggle"
             motion:targetId="@+id/createRoomButton" />
 
+        <KeyFrameSet>
+
+            <!-- First icon goes up quickly to let room for other-->
+            <KeyPosition
+                motion:motionTarget="@id/createRoomItemGroup"
+                motion:framePosition="50"
+                motion:percentX="0.8"
+                motion:percentY="0.8"
+                motion:keyPositionType="deltaRelative"
+                />
+            <KeyPosition
+                motion:motionTarget="@id/createRoomItemGroupLabel"
+                motion:framePosition="50"
+                motion:percentX="0.9"
+                motion:percentY="0.8"
+                motion:keyPositionType="deltaRelative"
+                />
+
+            <!-- Delay apparition of labels-->
+            <KeyAttribute
+                motion:motionTarget="@id/createRoomItemChatLabel"
+                android:alpha="0.4"
+                motion:framePosition="80"
+                />
+            <KeyAttribute
+                motion:motionTarget="@id/createRoomItemGroupLabel"
+                android:alpha="0.4"
+                motion:framePosition="80"
+                />
+
+        </KeyFrameSet>
     </Transition>
 
     <ConstraintSet android:id="@+id/constraint_set_fab_menu_close" >
@@ -96,7 +128,7 @@
 
     </ConstraintSet>
 
-    <ConstraintSet android:id="@+id/constraint_set_fab_menu_open">
+    <ConstraintSet android:id="@+id/constraint_set_fab_menu_open" >
 
         <Constraint
             android:id="@+id/createRoomTouchGuard"