layout: Move scrolling width resolution to workspace

This is required now with per-output and per-workspace options.

src/layout/mod.rs

@@ -865,7 +865,6 @@ impl<W: LayoutElement> Layout<W> {
         is_floating: bool,
         activate: ActivateWindow,
     ) -> Option<&Output> {
-        let scrolling_width = self.resolve_scrolling_width(&window, width);
         let scrolling_height = height.map(SizeChange::from);
         let id = window.id().clone();
 
@@ -933,6 +932,10 @@ impl<W: LayoutElement> Layout<W> {
                 };
                 let mon = &mut monitors[mon_idx];
 
+                let (ws_idx, _) = mon.resolve_add_window_target(target);
+                let ws = &mon.workspaces[ws_idx];
+                let scrolling_width = ws.resolve_scrolling_width(&window, width);
+
                 mon.add_window(
                     window,
                     target,
@@ -1012,6 +1015,8 @@ impl<W: LayoutElement> Layout<W> {
                 };
                 let ws = &mut workspaces[ws_idx];
 
+                let scrolling_width = ws.resolve_scrolling_width(&window, width);
+
                 let tile = ws.make_tile(window);
                 ws.add_tile(
                     tile,
@@ -4901,25 +4906,6 @@ impl<W: LayoutElement> Layout<W> {
     pub fn is_overview_open(&self) -> bool {
         self.overview_open
     }
-
-    fn resolve_scrolling_width(&self, window: &W, width: Option<PresetSize>) -> ColumnWidth {
-        let width = width.unwrap_or_else(|| PresetSize::Fixed(window.size().w));
-        match width {
-            PresetSize::Fixed(fixed) => {
-                let mut fixed = f64::from(fixed);
-
-                // Add border width since ColumnWidth includes borders.
-                let rules = window.rules();
-                let border = self.options.layout.border.merged_with(&rules.border);
-                if !border.off {
-                    fixed += border.width * 2.;
-                }
-
-                ColumnWidth::Fixed(fixed)
-            }
-            PresetSize::Proportion(prop) => ColumnWidth::Proportion(prop),
-        }
-    }
 }
 
 impl<W: LayoutElement> Default for MonitorSet<W> {

src/layout/monitor.rs

@@ -480,6 +480,34 @@ impl<W: LayoutElement> Monitor<W> {
         }
     }
 
+    pub(super) fn resolve_add_window_target<'a>(
+        &mut self,
+        target: MonitorAddWindowTarget<'a, W>,
+    ) -> (usize, WorkspaceAddWindowTarget<'a, W>) {
+        match target {
+            MonitorAddWindowTarget::Auto => {
+                (self.active_workspace_idx, WorkspaceAddWindowTarget::Auto)
+            }
+            MonitorAddWindowTarget::Workspace { id, column_idx } => {
+                let idx = self.workspaces.iter().position(|ws| ws.id() == id).unwrap();
+                let target = if let Some(column_idx) = column_idx {
+                    WorkspaceAddWindowTarget::NewColumnAt(column_idx)
+                } else {
+                    WorkspaceAddWindowTarget::Auto
+                };
+                (idx, target)
+            }
+            MonitorAddWindowTarget::NextTo(win_id) => {
+                let idx = self
+                    .workspaces
+                    .iter_mut()
+                    .position(|ws| ws.has_window(win_id))
+                    .unwrap();
+                (idx, WorkspaceAddWindowTarget::NextTo(win_id))
+            }
+        }
+    }
+
     pub fn add_window(
         &mut self,
         window: W,
@@ -539,28 +567,7 @@ impl<W: LayoutElement> Monitor<W> {
         is_full_width: bool,
         is_floating: bool,
     ) {
-        let (mut workspace_idx, target) = match target {
+        let (mut workspace_idx, target) = self.resolve_add_window_target(target);
-            MonitorAddWindowTarget::Auto => {
-                (self.active_workspace_idx, WorkspaceAddWindowTarget::Auto)
-            }
-            MonitorAddWindowTarget::Workspace { id, column_idx } => {
-                let idx = self.workspaces.iter().position(|ws| ws.id() == id).unwrap();
-                let target = if let Some(column_idx) = column_idx {
-                    WorkspaceAddWindowTarget::NewColumnAt(column_idx)
-                } else {
-                    WorkspaceAddWindowTarget::Auto
-                };
-                (idx, target)
-            }
-            MonitorAddWindowTarget::NextTo(win_id) => {
-                let idx = self
-                    .workspaces
-                    .iter_mut()
-                    .position(|ws| ws.has_window(win_id))
-                    .unwrap();
-                (idx, WorkspaceAddWindowTarget::NextTo(win_id))
-            }
-        };
 
         let workspace = &mut self.workspaces[workspace_idx];
 

src/layout/workspace.rs

@@ -2,6 +2,7 @@ use std::cmp::max;
 use std::rc::Rc;
 use std::time::Duration;
 
+use niri_config::utils::MergeWith as _;
 use niri_config::{
     CenterFocusedColumn, CornerRadius, OutputName, PresetSize, Workspace as WorkspaceConfig,
 };
@@ -882,6 +883,29 @@ impl<W: LayoutElement> Workspace<W> {
         });
     }
 
+    pub(super) fn resolve_scrolling_width(
+        &self,
+        window: &W,
+        width: Option<PresetSize>,
+    ) -> ColumnWidth {
+        let width = width.unwrap_or_else(|| PresetSize::Fixed(window.size().w));
+        match width {
+            PresetSize::Fixed(fixed) => {
+                let mut fixed = f64::from(fixed);
+
+                // Add border width since ColumnWidth includes borders.
+                let rules = window.rules();
+                let border = self.options.layout.border.merged_with(&rules.border);
+                if !border.off {
+                    fixed += border.width * 2.;
+                }
+
+                ColumnWidth::Fixed(fixed)
+            }
+            PresetSize::Proportion(prop) => ColumnWidth::Proportion(prop),
+        }
+    }
+
     pub fn focus_left(&mut self) -> bool {
         if self.floating_is_active.get() {
             self.floating.focus_left()