Universalize draw-over API for EditorPlugins

- Now it is usable from both `CanvasItem` and `Spatial` editors.
- `EditorPlugin` API changes:
 - `forward_draw_over_canvas()` becomes `forward_draw_over_viewport()`.
 - `update_canvas()` becomes `update_overlays()`, which now triggers the update of every overlay on top of any 2D or 3D viewports present. Also now it returns the number of such viewports, which is useful whenever you need to know the number of draw-over calls you'll get.
 - New: `[set/is]_force_draw_over_forwarding_enabled()` to force overlaying regardless it handles the current object type, in a similar fashion as `[set/is]_input_event_forwarding_always_enabled`. This kind of overlay is also on top of those for regular handled node types.
 - New: `forward_force_draw_over_canvas()`, which is the callback that gets called for plugins that enable forced overlaying.

1 files changed, 39 insertions, 7 deletions

diff --git a/editor/editor_plugin.cpp b/editor/editor_plugin.cpp
index 38e8b301b7..c1fbcde6ac 100644
--- a/editor/editor_plugin.cpp
+++ b/editor/editor_plugin.cpp
@@ -375,6 +375,12 @@ void EditorPlugin::set_input_event_forwarding_always_enabled() {
 	always_input_forwarding_list->add_plugin(this);
 }
 
+void EditorPlugin::set_force_draw_over_forwarding_enabled() {
+	force_draw_over_forwarding_enabled = true;
+	EditorPluginList *always_draw_over_forwarding_list = EditorNode::get_singleton()->get_editor_plugins_force_over();
+	always_draw_over_forwarding_list->add_plugin(this);
+}
+
 void EditorPlugin::notify_scene_changed(const Node *scn_root) {
 	if (scn_root == NULL) return;
 	emit_signal("scene_changed", scn_root);
@@ -410,15 +416,38 @@ bool EditorPlugin::forward_canvas_gui_input(const Ref<InputEvent> &p_event) {
 	return false;
 }
 
-void EditorPlugin::forward_draw_over_canvas(Control *p_canvas) {
+void EditorPlugin::forward_draw_over_viewport(Control *p_overlay) {
 
-	if (get_script_instance() && get_script_instance()->has_method("forward_draw_over_canvas")) {
-		get_script_instance()->call("forward_draw_over_canvas", p_canvas);
+	if (get_script_instance() && get_script_instance()->has_method("forward_draw_over_viewport")) {
+		get_script_instance()->call("forward_draw_over_viewport", p_overlay);
 	}
 }
 
-void EditorPlugin::update_canvas() {
-	CanvasItemEditor::get_singleton()->get_viewport_control()->update();
+void EditorPlugin::forward_force_draw_over_viewport(Control *p_overlay) {
+
+	if (get_script_instance() && get_script_instance()->has_method("forward_force_draw_over_viewport")) {
+		get_script_instance()->call("forward_force_draw_over_viewport", p_overlay);
+	}
+}
+
+// Updates the overlays of the 2D viewport or, if in 3D mode, of every 3D viewport.
+int EditorPlugin::update_overlays() const {
+
+	if (SpatialEditor::get_singleton()->is_visible()) {
+		int count = 0;
+		for (int i = 0; i < SpatialEditor::VIEWPORTS_COUNT; i++) {
+			SpatialEditorViewport *vp = SpatialEditor::get_singleton()->get_editor_viewport(i);
+			if (vp->is_visible()) {
+				vp->update_surface();
+				count++;
+			}
+		}
+		return count;
+	} else {
+		// This will update the normal viewport itself as well
+		CanvasItemEditor::get_singleton()->get_viewport_control()->update();
+		return 1;
+	}
 }
 
 bool EditorPlugin::forward_spatial_gui_input(Camera *p_camera, const Ref<InputEvent> &p_event) {
@@ -590,7 +619,7 @@ void EditorPlugin::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("add_custom_type", "type", "base", "script", "icon"), &EditorPlugin::add_custom_type);
 	ClassDB::bind_method(D_METHOD("remove_custom_type", "type"), &EditorPlugin::remove_custom_type);
 
-	ClassDB::bind_method(D_METHOD("update_canvas"), &EditorPlugin::update_canvas);
+	ClassDB::bind_method(D_METHOD("update_overlays"), &EditorPlugin::update_overlays);
 
 	ClassDB::bind_method(D_METHOD("make_bottom_panel_item_visible", "item"), &EditorPlugin::make_bottom_panel_item_visible);
 	ClassDB::bind_method(D_METHOD("hide_bottom_panel"), &EditorPlugin::hide_bottom_panel);
@@ -602,11 +631,13 @@ void EditorPlugin::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("add_export_plugin", "exporter"), &EditorPlugin::add_export_plugin);
 	ClassDB::bind_method(D_METHOD("remove_export_plugin", "exporter"), &EditorPlugin::remove_export_plugin);
 	ClassDB::bind_method(D_METHOD("set_input_event_forwarding_always_enabled"), &EditorPlugin::set_input_event_forwarding_always_enabled);
+	ClassDB::bind_method(D_METHOD("set_force_draw_over_forwarding_enabled"), &EditorPlugin::set_force_draw_over_forwarding_enabled);
 
 	ClassDB::bind_method(D_METHOD("get_editor_interface"), &EditorPlugin::get_editor_interface);
 
 	ClassDB::add_virtual_method(get_class_static(), MethodInfo(Variant::BOOL, "forward_canvas_gui_input", PropertyInfo(Variant::TRANSFORM2D, "canvas_xform"), PropertyInfo(Variant::OBJECT, "event", PROPERTY_HINT_RESOURCE_TYPE, "InputEvent")));
-	ClassDB::add_virtual_method(get_class_static(), MethodInfo("forward_draw_over_canvas", PropertyInfo(Variant::TRANSFORM2D, "canvas_xform"), PropertyInfo(Variant::OBJECT, "canvas", PROPERTY_HINT_RESOURCE_TYPE, "Control")));
+	ClassDB::add_virtual_method(get_class_static(), MethodInfo("forward_draw_over_viewport", PropertyInfo(Variant::OBJECT, "overlay", PROPERTY_HINT_RESOURCE_TYPE, "Control")));
+	ClassDB::add_virtual_method(get_class_static(), MethodInfo("forward_force_draw_over_viewport", PropertyInfo(Variant::OBJECT, "overlay", PROPERTY_HINT_RESOURCE_TYPE, "Control")));
 	ClassDB::add_virtual_method(get_class_static(), MethodInfo(Variant::BOOL, "forward_spatial_gui_input", PropertyInfo(Variant::OBJECT, "camera", PROPERTY_HINT_RESOURCE_TYPE, "Camera"), PropertyInfo(Variant::OBJECT, "event", PROPERTY_HINT_RESOURCE_TYPE, "InputEvent")));
 	MethodInfo gizmo = MethodInfo(Variant::OBJECT, "create_spatial_gizmo", PropertyInfo(Variant::OBJECT, "for_spatial", PROPERTY_HINT_RESOURCE_TYPE, "Spatial"));
 	gizmo.return_val.hint = PROPERTY_HINT_RESOURCE_TYPE;
@@ -653,6 +684,7 @@ void EditorPlugin::_bind_methods() {
 EditorPlugin::EditorPlugin() {
 	undo_redo = NULL;
 	input_event_forwarding_always_enabled = false;
+	force_draw_over_forwarding_enabled = false;
 	last_main_screen_name = "";
 }