Add set-window-width action

niri-config/src/lib.rs

@@ -1241,6 +1241,12 @@ pub enum Action {
     MoveColumnToMonitorRight,
     MoveColumnToMonitorDown,
     MoveColumnToMonitorUp,
+    SetWindowWidth(#[knuffel(argument, str)] SizeChange),
+    #[knuffel(skip)]
+    SetWindowWidthById {
+        id: u64,
+        change: SizeChange,
+    },
     SetWindowHeight(#[knuffel(argument, str)] SizeChange),
     #[knuffel(skip)]
     SetWindowHeightById {
@@ -1373,6 +1379,11 @@ impl From<niri_ipc::Action> for Action {
             niri_ipc::Action::MoveColumnToMonitorRight {} => Self::MoveColumnToMonitorRight,
             niri_ipc::Action::MoveColumnToMonitorDown {} => Self::MoveColumnToMonitorDown,
             niri_ipc::Action::MoveColumnToMonitorUp {} => Self::MoveColumnToMonitorUp,
+            niri_ipc::Action::SetWindowWidth { id: None, change } => Self::SetWindowWidth(change),
+            niri_ipc::Action::SetWindowWidth {
+                id: Some(id),
+                change,
+            } => Self::SetWindowWidthById { id, change },
             niri_ipc::Action::SetWindowHeight { id: None, change } => Self::SetWindowHeight(change),
             niri_ipc::Action::SetWindowHeight {
                 id: Some(id),

niri-ipc/src/lib.rs

@@ -362,6 +362,22 @@ pub enum Action {
     MoveColumnToMonitorDown {},
     /// Move the focused column to the monitor above.
     MoveColumnToMonitorUp {},
+    /// Change the width of a window.
+    #[cfg_attr(
+        feature = "clap",
+        clap(about = "Change the width of the focused window")
+    )]
+    SetWindowWidth {
+        /// Id of the window whose width to set.
+        ///
+        /// If `None`, uses the focused window.
+        #[cfg_attr(feature = "clap", arg(long))]
+        id: Option<u64>,
+
+        /// How to change the width.
+        #[cfg_attr(feature = "clap", arg())]
+        change: SizeChange,
+    },
     /// Change the height of a window.
     #[cfg_attr(
         feature = "clap",

src/input/mod.rs

@@ -1237,6 +1237,16 @@ impl State {
             Action::SetColumnWidth(change) => {
                 self.niri.layout.set_column_width(change);
             }
+            Action::SetWindowWidth(change) => {
+                self.niri.layout.set_window_width(None, change);
+            }
+            Action::SetWindowWidthById { id, change } => {
+                let window = self.niri.layout.windows().find(|(_, m)| m.id().get() == id);
+                let window = window.map(|(_, m)| m.window.clone());
+                if let Some(window) = window {
+                    self.niri.layout.set_window_width(Some(&window), change);
+                }
+            }
             Action::SetWindowHeight(change) => {
                 self.niri.layout.set_window_height(None, change);
             }

src/layout/mod.rs

@@ -2592,6 +2592,29 @@ impl<W: LayoutElement> Layout<W> {
         monitor.set_column_width(change);
     }
 
+    pub fn set_window_width(&mut self, window: Option<&W::Id>, change: SizeChange) {
+        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
+            if window.is_none() || window == Some(move_.tile.window().id()) {
+                return;
+            }
+        }
+
+        let workspace = if let Some(window) = window {
+            Some(
+                self.workspaces_mut()
+                    .find(|ws| ws.has_window(window))
+                    .unwrap(),
+            )
+        } else {
+            self.active_workspace_mut()
+        };
+
+        let Some(workspace) = workspace else {
+            return;
+        };
+        workspace.set_window_width(window, change);
+    }
+
     pub fn set_window_height(&mut self, window: Option<&W::Id>, change: SizeChange) {
         if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
             if window.is_none() || window == Some(move_.tile.window().id()) {
@@ -4319,6 +4342,12 @@ mod tests {
         },
         MaximizeColumn,
         SetColumnWidth(#[proptest(strategy = "arbitrary_size_change()")] SizeChange),
+        SetWindowWidth {
+            #[proptest(strategy = "proptest::option::of(1..=5usize)")]
+            id: Option<usize>,
+            #[proptest(strategy = "arbitrary_size_change()")]
+            change: SizeChange,
+        },
         SetWindowHeight {
             #[proptest(strategy = "proptest::option::of(1..=5usize)")]
             id: Option<usize>,
@@ -4829,6 +4858,10 @@ mod tests {
                 }
                 Op::MaximizeColumn => layout.toggle_full_width(),
                 Op::SetColumnWidth(change) => layout.set_column_width(change),
+                Op::SetWindowWidth { id, change } => {
+                    let id = id.filter(|id| layout.has_window(id));
+                    layout.set_window_width(id.as_ref(), change);
+                }
                 Op::SetWindowHeight { id, change } => {
                     let id = id.filter(|id| layout.has_window(id));
                     layout.set_window_height(id.as_ref(), change);

src/layout/scrolling.rs

@@ -1996,13 +1996,26 @@ impl<W: LayoutElement> ScrollingSpace<W> {
         cancel_resize_for_column(&mut self.interactive_resize, col);
     }
 
-    pub fn set_column_width(&mut self, change: SizeChange) {
+    pub fn set_window_width(&mut self, window: Option<&W::Id>, change: SizeChange) {
         if self.columns.is_empty() {
             return;
         }
 
-        let col = &mut self.columns[self.active_column_idx];
-        col.set_column_width(change, None, true);
+        let (col, tile_idx) = if let Some(window) = window {
+            self.columns
+                .iter_mut()
+                .find_map(|col| {
+                    col.tiles
+                        .iter()
+                        .position(|tile| tile.window().id() == window)
+                        .map(|tile_idx| (col, Some(tile_idx)))
+                })
+                .unwrap()
+        } else {
+            (&mut self.columns[self.active_column_idx], None)
+        };
+
+        col.set_column_width(change, tile_idx, true);
 
         cancel_resize_for_column(&mut self.interactive_resize, col);
     }

src/layout/workspace.rs

@@ -998,7 +998,17 @@ impl<W: LayoutElement> Workspace<W> {
         if self.floating_is_active.get() {
             self.floating.set_window_width(None, change, true);
         } else {
-            self.scrolling.set_column_width(change);
+            self.scrolling.set_window_width(None, change);
+        }
+    }
+
+    pub fn set_window_width(&mut self, window: Option<&W::Id>, change: SizeChange) {
+        if window.map_or(self.floating_is_active.get(), |id| {
+            self.floating.has_window(id)
+        }) {
+            self.floating.set_window_width(window, change, true);
+        } else {
+            self.scrolling.set_window_width(window, change);
         }
     }