Move BottomMargin into a separate file and clean it up (#461)

Co-authored-by: Danielle Foré <[email protected]>

Author: lenemter

src/BottomMargin.vala

@@ -0,0 +1,30 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0
+ * SPDX-FileCopyrightText: 2025 elementary, Inc. (https://elementary.io)
+ */
+
+public class BottomMargin : Gtk.Widget {
+    private static GLib.List<unowned BottomMargin> instances = new GLib.List<unowned BottomMargin> ();
+
+    class construct {
+        set_css_name ("bottom-margin");
+    }
+
+    construct {
+        instances.append (this);
+    }
+
+    ~BottomMargin () {
+        instances.remove (this);
+    }
+
+    public new static int get_size () {
+        foreach (var instance in instances) {
+            if (instance.get_realized ()) {
+                return instance.get_height ();
+            }
+        }
+
+        return 0;
+    }
+}

src/MainWindow.vala

@@ -10,12 +10,6 @@ public class Dock.MainWindow : Gtk.ApplicationWindow {
         }
     }
 
-    private class BottomMargin : Gtk.Widget {
-        class construct {
-            set_css_name ("bottom-margin");
-        }
-    }
-
     // Matches top margin in Launcher.css
     private const int TOP_MARGIN = 64;
     private const int BORDER_RADIUS = 9;
@@ -29,7 +23,6 @@ public class Dock.MainWindow : Gtk.ApplicationWindow {
     private Gtk.Box main_box;
 
     private WindowDragManager window_drag_manager;
-    private BottomMargin bottom_margin;
     private bool initialized_blur = false;
 
     class construct {
@@ -53,11 +46,9 @@ public class Dock.MainWindow : Gtk.ApplicationWindow {
         size_group.add_widget (overlay.child);
         size_group.add_widget (launcher_manager);
 
-        bottom_margin = new BottomMargin ();
-
         main_box = new Gtk.Box (VERTICAL, 0);
         main_box.append (overlay);
-        main_box.append (bottom_margin);
+        main_box.append (new BottomMargin ());
         child = main_box;
 
         remove_css_class ("background");
@@ -141,13 +132,10 @@ public class Dock.MainWindow : Gtk.ApplicationWindow {
                 return;
             }
 
-            Graphene.Rect bounds;
-            bottom_margin.compute_bounds (bottom_margin, out bounds);
-
             initialized_blur = true;
 
             if (panel != null) {
-                panel.add_blur (0, 0, 0, (int) bounds.get_height (), BORDER_RADIUS);
+                panel.add_blur (0, 0, 0, BottomMargin.get_size (), BORDER_RADIUS);
             } else {
                 update_panel_x11 ();
             }
@@ -183,9 +171,7 @@ public class Dock.MainWindow : Gtk.ApplicationWindow {
             var value = "anchor=8:hide-mode=%d:restore-previous-region=1:visible-in-multitasking-view=1".printf (settings.get_enum ("autohide-mode"));
 
             if (initialized_blur) {
-                Graphene.Rect bounds;
-                bottom_margin.compute_bounds (bottom_margin, out bounds);
-                value += ":blur=0,0,0,%d,%d".printf ((int) bounds.get_height (), BORDER_RADIUS);
+                value += ":blur=0,0,0,%d,%d".printf (BottomMargin.get_size (), BORDER_RADIUS);
             }
 
             xdisplay.change_property (window, prop, X.XA_STRING, 8, 0, (uchar[]) value, value.length);

src/meson.build

@@ -2,6 +2,7 @@ sources = [
     'Application.vala',
     'BaseIconGroup.vala',
     'BaseItem.vala',
+    'BottomMargin.vala',
     'ItemManager.vala',
     'MainWindow.vala',
     'AppSystem' / 'App.vala',