Introduce a CanvasActor

lib/CanvasActor.vala

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2024 elementary, Inc. (https://elementary.io)
+ * SPDX-License-Identifier: LGPL-2.0-or-later
+ */
+
+public class Gala.CanvasActor : Clutter.Actor {
+    private Clutter.Canvas canvas;
+
+    construct {
+        canvas = new Clutter.Canvas ();
+        content = canvas;
+        canvas.draw.connect ((ctx, width, height) => {
+            draw (ctx, width, height);
+            return true;
+        });
+    }
+
+    public override void resource_scale_changed () {
+        canvas.set_scale_factor (get_resource_scale ());
+    }
+
+    public override void allocate (Clutter.ActorBox box) {
+        base.allocate (box);
+        canvas.set_size ((int)box.get_width (), (int)box.get_height ());
+        canvas.set_scale_factor (get_resource_scale ());
+    }
+
+    protected virtual void draw (Cairo.Context canvas, int width, int height) { }
+}

lib/meson.build

@@ -4,6 +4,7 @@ gala_lib_sources = files(
     'AppCache.vala',
     'AppSystem.vala',
     'BackgroundManager.vala',
+    'CanvasActor.vala',
     'CloseButton.vala',
     'Constants.vala',
     'DragDropAction.vala',

plugins/pip/SelectionArea.vala

@@ -15,7 +15,7 @@
 //  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
-public class Gala.Plugins.PIP.SelectionArea : Clutter.Actor {
+public class Gala.Plugins.PIP.SelectionArea : CanvasActor {
     public signal void captured (int x, int y, int width, int height);
     public signal void selected (int x, int y);
     public signal void closed ();
@@ -42,13 +42,6 @@ public class Gala.Plugins.PIP.SelectionArea : Clutter.Actor {
         wm.get_display ().get_size (out screen_width, out screen_height);
         width = screen_width;
         height = screen_height;
-
-        var canvas = new Clutter.Canvas ();
-        canvas.set_size (screen_width, screen_height);
-        canvas.draw.connect (draw_area);
-        set_content (canvas);
-
-        canvas.invalidate ();
     }
 
 #if HAS_MUTTER45
@@ -159,7 +152,7 @@ public class Gala.Plugins.PIP.SelectionArea : Clutter.Actor {
         height = (start_point.y - end_point.y).abs ();
     }
 
-    private bool draw_area (Cairo.Context ctx) {
+    protected override void draw (Cairo.Context ctx, int width, int height) {
         ctx.save ();
 
         ctx.set_operator (Cairo.Operator.CLEAR);
@@ -168,7 +161,7 @@ public class Gala.Plugins.PIP.SelectionArea : Clutter.Actor {
         ctx.restore ();
 
         if (!dragging) {
-            return true;
+            return;
         }
 
         int x, y, w, h;
@@ -182,7 +175,5 @@ public class Gala.Plugins.PIP.SelectionArea : Clutter.Actor {
         ctx.set_source_rgb (0.7, 0.7, 0.7);
         ctx.set_line_width (1.0);
         ctx.stroke ();
-
-        return true;
     }
 }

src/Widgets/IconGroup.vala

@@ -10,7 +10,7 @@ namespace Gala {
      * It also decides whether to draw the container shape, a plus sign or an ellipsis.
      * Lastly it also includes the drawing code for the active highlight.
      */
-    public class IconGroup : Clutter.Actor {
+    public class IconGroup : CanvasActor {
         public const int SIZE = 64;
 
         private const int PLUS_SIZE = 6;
@@ -47,7 +47,7 @@ namespace Gala {
             set {
                 if (value != _scale_factor) {
                     _scale_factor = value;
-                    resize_canvas ();
+                    resize ();
                 }
             }
         }
@@ -62,10 +62,6 @@ namespace Gala {
         construct {
             reactive = true;
 
-            var canvas = new Clutter.Canvas ();
-            canvas.draw.connect (draw);
-            content = canvas;
-
             drag_action = new DragDropAction (DragDropActionType.SOURCE | DragDropActionType.DESTINATION, "multitaskingview-window");
             drag_action.actor_clicked.connect (() => selected ());
             drag_action.drag_begin.connect (drag_begin);
@@ -80,7 +76,7 @@ namespace Gala {
 
             add_child (icon_container);
 
-            resize_canvas ();
+            resize ();
 
 #if HAS_MUTTER46
             icon_container.child_removed.connect_after (redraw);
@@ -97,13 +93,11 @@ namespace Gala {
 #endif
         }
 
-        private bool resize_canvas () {
+        private void resize () {
             var size = InternalUtils.scale_to_int (SIZE, scale_factor);
 
             width = size;
             height = size;
-
-            return ((Clutter.Canvas) content).set_size (size, size);
         }
 
         /**
@@ -206,16 +200,14 @@ namespace Gala {
          * Trigger a redraw
          */
         public void redraw () {
-            if (!resize_canvas ()) {
-                content.invalidate ();
-            }
+            content.invalidate ();
         }
 
         /**
          * Draw the background or plus sign and do layouting. We won't lose performance here
          * by relayouting in the same function, as it's only ever called when we invalidate it.
          */
-        private bool draw (Cairo.Context cr) {
+        protected override void draw (Cairo.Context cr, int cr_width, int cr_height) {
             clear_effects ();
             cr.set_operator (Cairo.Operator.CLEAR);
             cr.paint ();
@@ -228,7 +220,7 @@ namespace Gala {
                 var icon = (WindowIconActor) icon_container.get_child_at_index (0);
                 icon.place (0, 0, 64, scale_factor);
 
-                return false;
+                return;
             }
 
             // more than one => we need a folder
@@ -289,7 +281,7 @@ namespace Gala {
             if (n_windows < 1) {
                 if (!Meta.Prefs.get_dynamic_workspaces ()
                     || workspace_index != manager.get_n_workspaces () - 1)
-                    return false;
+                    return;
 
                 var buffer = new Drawing.BufferSurface (scaled_size, scaled_size);
                 var offset = scaled_size / 2 - InternalUtils.scale_to_int (PLUS_WIDTH, scale_factor) / 2;
@@ -330,7 +322,7 @@ namespace Gala {
                 cr.set_source_surface (buffer.surface, 0, 0);
                 cr.paint ();
 
-                return false;
+                return;
             }
 
             int size;
@@ -391,7 +383,7 @@ namespace Gala {
                 }
             }
 
-            return false;
+            return;
         }
 
         private Clutter.Actor? drag_begin (float click_x, float click_y) {

src/Widgets/SelectionArea.vala

@@ -16,7 +16,7 @@
 //
 
 namespace Gala {
-    public class SelectionArea : Clutter.Actor {
+    public class SelectionArea : CanvasActor {
         public signal void closed ();
 
         public WindowManager wm { get; construct; }
@@ -43,13 +43,6 @@ namespace Gala {
             wm.get_display ().get_size (out screen_width, out screen_height);
             width = screen_width;
             height = screen_height;
-
-            var canvas = new Clutter.Canvas ();
-            canvas.set_size (screen_width, screen_height);
-            canvas.draw.connect (draw_area);
-            set_content (canvas);
-
-            canvas.invalidate ();
         }
 
 #if HAS_MUTTER45
@@ -155,7 +148,7 @@ namespace Gala {
             }.expand (end_point);
         }
 
-        private bool draw_area (Cairo.Context ctx) {
+        protected override void draw (Cairo.Context ctx, int width, int height) {
             ctx.save ();
 
             ctx.set_operator (Cairo.Operator.CLEAR);
@@ -164,7 +157,7 @@ namespace Gala {
             ctx.restore ();
 
             if (!dragging) {
-                return true;
+                return;
             }
 
             ctx.translate (0.5, 0.5);
@@ -178,8 +171,6 @@ namespace Gala {
             ctx.set_source_rgb (0.7, 0.7, 0.7);
             ctx.set_line_width (1.0);
             ctx.stroke ();
-
-            return true;
         }
     }
 }

src/Widgets/Tooltip.vala

@@ -7,16 +7,11 @@
 /**
  * Clutter actor to display text in a tooltip-like component.
  */
-public class Gala.Tooltip : Clutter.Actor {
+public class Gala.Tooltip : CanvasActor {
     private static Clutter.Color text_color;
     private static Gtk.Border padding;
     private static Gtk.StyleContext style_context;
 
-    /**
-     * Canvas to draw the Tooltip background.
-     */
-    private Clutter.Canvas background_canvas;
-
     /**
      * Actor to display the Tooltip text.
      */
@@ -38,11 +33,7 @@ public class Gala.Tooltip : Clutter.Actor {
         text = "";
         max_width = 200;
 
-        background_canvas = new Clutter.Canvas ();
-        background_canvas.draw.connect (draw_background);
-        content = background_canvas;
-
-        draw ();
+        resize ();
     }
 
     private static void create_gtk_objects () {
@@ -79,19 +70,19 @@ public class Gala.Tooltip : Clutter.Actor {
         text = new_text;
 
         if (redraw) {
-            draw ();
+            resize ();
         }
     }
 
     public void set_max_width (float new_max_width, bool redraw = true) {
         max_width = new_max_width;
 
         if (redraw) {
-            draw ();
+            resize ();
         }
     }
 
-    private void draw () {
+    private void resize () {
         visible = (text.length != 0);
 
         if (!visible) {
@@ -120,13 +111,12 @@ public class Gala.Tooltip : Clutter.Actor {
         // Adjust the size of the tooltip to the text
         width = text_actor.width + padding.left + padding.right;
         height = text_actor.height + padding.top + padding.bottom;
-        background_canvas.set_size ((int) width, (int) height);
 
-        // And paint the background
-        background_canvas.invalidate ();
+        //Failsafe that if by accident the size doesn't change we still redraw
+        content.invalidate ();
     }
 
-    private static bool draw_background (Cairo.Context ctx, int width, int height) {
+    protected override void draw (Cairo.Context ctx, int width, int height) {
         if (style_context == null) {
             create_gtk_objects ();
         }
@@ -141,7 +131,5 @@ public class Gala.Tooltip : Clutter.Actor {
         style_context.render_background (ctx, 0, 0, width, height);
 
         ctx.restore ();
-
-        return false;
     }
 }

src/Widgets/WindowClone.vala

@@ -866,17 +866,11 @@ public class Gala.WindowClone : Clutter.Actor {
     /**
      * Border to show around the selected window when using keyboard navigation.
      */
-    private class ActiveShape : Clutter.Actor {
+    private class ActiveShape : CanvasActor {
         private static int border_radius = -1;
         private const double COLOR_OPACITY = 0.8;
 
-        private Clutter.Canvas background_canvas;
-
         construct {
-            background_canvas = new Clutter.Canvas ();
-            background_canvas.draw.connect (draw_background);
-            content = background_canvas;
-
             notify["opacity"].connect (invalidate);
         }
 
@@ -896,16 +890,16 @@ public class Gala.WindowClone : Clutter.Actor {
         }
 
         public void invalidate () {
-            background_canvas.invalidate ();
+            content.invalidate ();
         }
 
-        private bool draw_background (Cairo.Context cr, int width, int height) {
+        protected override void draw (Cairo.Context cr, int width, int height) {
             if (border_radius == -1) {
                 create_gtk_objects ();
             }
 
             if (!visible || opacity == 0) {
-                return Clutter.EVENT_PROPAGATE;
+                return;
             }
 
             var color = InternalUtils.get_theme_accent_color ();
@@ -918,15 +912,6 @@ public class Gala.WindowClone : Clutter.Actor {
             Drawing.Utilities.cairo_rounded_rectangle (cr, 0, 0, width, height, border_radius);
             cr.set_source_rgba (color.red, color.green, color.blue, COLOR_OPACITY);
             cr.fill ();
-
-            return Clutter.EVENT_PROPAGATE;
-        }
-
-        public override void allocate (Clutter.ActorBox box) {
-            base.allocate (box);
-
-            background_canvas.set_size ((int) box.get_width (), (int) box.get_height ());
-            invalidate ();
         }
     }
 }