feat(ags4): implement lockscreen

modules/ags/gtk4/widgets/subclasses/overlay.ts

@@ -0,0 +1,49 @@
+import { register } from 'astal';
+import { Gtk } from 'astal/gtk4';
+
+import astalify, { childType, type AstalifyProps, type ConstructProps } from '../astalify';
+
+
+export type OverlayProps = ConstructProps<
+    OverlayClass,
+    Gtk.Overlay.ConstructorProps & AstalifyProps
+>;
+
+@register({ GTypeName: 'Overlay' })
+export class OverlayClass extends astalify(Gtk.Overlay) {
+    constructor({ cssName = 'overlay', ...props }: OverlayProps = {}) {
+        super({ cssName, ...props });
+    }
+
+    getChildren(self: OverlayClass) {
+        const children: Gtk.Widget[] = [];
+        let ch = self.get_first_child();
+
+        while (ch !== null) {
+            children.push(ch);
+            ch = ch.get_next_sibling();
+        }
+
+        return children.filter((child) => child !== self.child);
+    }
+
+    setChildren(self: OverlayClass, children: Gtk.Widget[]) {
+        for (const child of children) {
+            const types = childType in child ?
+                (child[childType] as string).split(/\s+/) :
+                [];
+
+            if (types.includes('overlay')) {
+                self.add_overlay(child);
+            }
+            else {
+                self.set_child(child);
+            }
+
+            self.set_measure_overlay(child, types.includes('measure'));
+            self.set_clip_overlay(child, types.includes('clip'));
+        }
+    }
+}
+
+export const Overlay = (props?: OverlayProps) => new OverlayClass(props);