Fixed removed floating notifications sometimes being rendered for a few ticks

Caused when the notification windows input region is set right after a
notification has been removed, before the AnimatedLists size-allocation
has been re-computed.

Can be reproduced by running this command in sway: `notify-send "test 1"
-u critical; notify-send "test 2" -t 2000; sleep 1; swaymsg "output *
power off"; notify-send "test 3" -t 500; sleep 3; swaymsg "output *
power on"`

Author: ErikReider

src/animatedList/animatedList.vala

@@ -674,17 +674,29 @@ public class AnimatedList : Gtk.Widget, Gtk.Scrollable {
 
         AnimatedListItem ?item = try_get_ancestor (widget);
         if (item == null) {
+            warn_if_reached ();
             return false;
         }
 
         // Will unparent itself when done animating
-        bool result = yield item.removed (transition_children && transition);
+        if (!yield item.removed (transition_children && transition)) {
+            debug ("Skipping extra removal of AnimatedListItem");
+            return false;
+        }
 
         item.unparent ();
         children.remove (item);
         n_children--;
+
+        // Make sure that we don't render/compute the bounds of this destroyed widget.
+        // queue_resize might not finish in-time before iterating the visible children
+        unowned List<unowned AnimatedListItem> visible_item = visible_children.find (item);
+        if (visible_item != null) {
+            visible_children.delete_link (visible_item);
+        }
+
         queue_resize ();
-        return result;
+        return true;
     }
 
     public bool move_to_beginning (Gtk.Widget widget, bool scroll_to) {

src/notificationWindow/notificationWindow.vala

@@ -178,19 +178,26 @@ namespace SwayNotificationCenter {
             }
 
             Cairo.Region region = new Cairo.Region ();
-            foreach (AnimatedListItem item in list.visible_children) {
+            foreach (unowned AnimatedListItem item in list.visible_children) {
+                if (item == null || !(item is Object)) {
+                    critical (
+                        "Could not iter over AnimatedListItem (%p) while setting input region\n",
+                        item);
+                    continue;
+                }
                 if (item.destroying) {
                     continue;
                 }
                 Graphene.Rect out_bounds;
-                item.compute_bounds (this, out out_bounds);
-                Cairo.RectangleInt item_rect = Cairo.RectangleInt () {
-                    x = (int) out_bounds.get_x (),
-                    y = (int) out_bounds.get_y (),
-                    width = (int) out_bounds.get_width (),
-                    height = (int) out_bounds.get_height (),
-                };
-                region.union_rectangle (item_rect);
+                if (item.compute_bounds (this, out out_bounds)) {
+                    Cairo.RectangleInt item_rect = Cairo.RectangleInt () {
+                        x = (int) out_bounds.get_x (),
+                        y = (int) out_bounds.get_y (),
+                        width = (int) out_bounds.get_width (),
+                        height = (int) out_bounds.get_height (),
+                    };
+                    region.union_rectangle (item_rect);
+                }
             }
 
             // The input region should only cover each preview widget