lookingGlass: Draw a red border around target actor

js/ui/lookingGlass.js

@@ -230,6 +230,14 @@ LookingGlass.prototype = {
             let displayText = new Clutter.Text({ color: MATRIX_GREEN,
                                                  font_name: MATRIX_FONT, text: '' });
             eventHandler.append(displayText, Big.BoxPackFlags.EXPAND);
+
+            let borderPaintTarget = null;
+            let borderPaintId = null;
+            eventHandler.connect('destroy', Lang.bind(this, function() {
+                if (borderPaintTarget != null)
+                    borderPaintTarget.disconnect(borderPaintId);
+            }));
+
             eventHandler.connect('button-press-event', Lang.bind(this, function (actor, event) {
                 let global = Shell.Global.get();
                 Clutter.ungrab_pointer(eventHandler);
@@ -246,6 +254,7 @@ LookingGlass.prototype = {
                 global.stage.set_key_focus(this._entry);
                 return true;
             }));
+
             eventHandler.connect('motion-event', Lang.bind(this, function (actor, event) {
                 let global = Shell.Global.get();
                 let [stageX, stageY] = event.get_coords();
@@ -253,6 +262,10 @@ LookingGlass.prototype = {
                                                            stageX,
                                                            stageY);
                 displayText.text = '<inspect x: ' + stageX + ' y: ' + stageY + '> ' + target;
+                if (borderPaintTarget != null)
+                    borderPaintTarget.disconnect(borderPaintId);
+                borderPaintTarget = target;
+                borderPaintId = Shell.add_hook_paint_red_border(target);
                 return true;
             }));
             Clutter.grab_pointer(eventHandler);

src/shell-drawing.c

@@ -178,3 +178,38 @@ shell_draw_glow (ClutterCairoTexture *texture,
   cairo_pattern_destroy (gradient);
   cairo_destroy (cr);
 }
+
+static void
+hook_paint_red_border (ClutterActor  *actor,
+                       gpointer       user_data)
+{
+  CoglColor color;
+  ClutterGeometry geom;
+  float width = 2;
+  float x2;
+  float y2;
+
+  cogl_color_set_from_4ub (&color, 0xff, 0, 0, 0xc4);
+  cogl_set_source_color (&color);
+
+  clutter_actor_get_allocation_geometry (actor, &geom);
+  x2 = geom.x + geom.width;
+  y2 = geom.y + geom.height;
+
+  /** clockwise order **/
+  cogl_rectangle (geom.x, geom.y,
+                  x2, geom.y + width);
+  cogl_rectangle (x2 - width, geom.y + width,
+                  x2, y2);
+  cogl_rectangle (x2 - width, y2,
+                  geom.x, y2 - width);
+  cogl_rectangle (geom.x + width, y2 - width,
+                  geom.x, geom.y + width);
+}
+
+guint
+shell_add_hook_paint_red_border (ClutterActor *actor)
+{
+  return g_signal_connect_after (G_OBJECT (actor), "paint",
+                                 G_CALLBACK (hook_paint_red_border), NULL);
+}

src/shell-drawing.h

@@ -23,6 +23,8 @@ void shell_draw_glow (ClutterCairoTexture *texture,
                       double green,
                       double alpha);
 
+guint shell_add_hook_paint_red_border (ClutterActor *actor);
+
 G_END_DECLS
 
 #endif /* __SHELL_GLOBAL_H__ */