Allow to get a list of visible embedded `Window`s

doc/classes/Viewport.xml

@@ -52,6 +52,13 @@
 				Returns an individual bit on the rendering layer mask.
 			</description>
 		</method>
+		<method name="get_embedded_subwindows" qualifiers="const">
+			<return type="Window[]" />
+			<description>
+				Returns a list of the visible embedded [Window]s inside the viewport.
+				[b]Note:[/b] [Window]s inside other viewports will not be listed.
+			</description>
+		</method>
 		<method name="get_final_transform" qualifiers="const">
 			<return type="Transform2D" />
 			<description>

scene/main/viewport.cpp

@@ -2439,6 +2439,7 @@ Window *Viewport::get_base_window() const {
 
 	return w;
 }
+
 void Viewport::_gui_remove_focus_for_window(Node *p_window) {
 	if (get_base_window() == p_window) {
 		gui_release_focus();
@@ -3656,6 +3657,15 @@ bool Viewport::is_embedding_subwindows() const {
 	return gui.embed_subwindows_hint;
 }
 
+TypedArray<Window> Viewport::get_embedded_subwindows() const {
+	TypedArray<Window> windows;
+	for (int i = 0; i < gui.sub_windows.size(); i++) {
+		windows.append(gui.sub_windows[i].window);
+	}
+
+	return windows;
+}
+
 void Viewport::subwindow_set_popup_safe_rect(Window *p_window, const Rect2i &p_rect) {
 	int index = _sub_window_find(p_window);
 	ERR_FAIL_COND(index == -1);
@@ -4384,6 +4394,7 @@ void Viewport::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("set_embedding_subwindows", "enable"), &Viewport::set_embedding_subwindows);
 	ClassDB::bind_method(D_METHOD("is_embedding_subwindows"), &Viewport::is_embedding_subwindows);
+	ClassDB::bind_method(D_METHOD("get_embedded_subwindows"), &Viewport::get_embedded_subwindows);
 
 	ClassDB::bind_method(D_METHOD("set_canvas_cull_mask", "mask"), &Viewport::set_canvas_cull_mask);
 	ClassDB::bind_method(D_METHOD("get_canvas_cull_mask"), &Viewport::get_canvas_cull_mask);

scene/main/viewport.h

@@ -653,6 +653,7 @@ public:
 
 	void set_embedding_subwindows(bool p_embed);
 	bool is_embedding_subwindows() const;
+	TypedArray<Window> get_embedded_subwindows() const;
 	void subwindow_set_popup_safe_rect(Window *p_window, const Rect2i &p_rect);
 	Rect2i subwindow_get_popup_safe_rect(Window *p_window) const;