Expose and warn about Node Filters in Scene Tree Dock

Adds "Filter by Type" and "Filter by Group" in the Scene Tree Dock's MenuButton.
Hovering on them displays an useful tooltip.
When selecting these items, the matching parameter is appended to the terms, and the caret is automatically brought to the end.

When typing a filter that cannot be identified, a warning icon is displayed. The reason is explained as a tooltip.

The same options are also quickly available by right-clicking or middle-clicking in the text field.

editor/scene_tree_dock.cpp

@@ -1187,6 +1187,8 @@ void SceneTreeDock::_tool_selected(int p_tool, bool p_confirm_override) {
 		} break;
 
 		default: {
+			_filter_option_selected(p_tool);
+
 			if (p_tool >= EDIT_SUBRESOURCE_BASE) {
 				int idx = p_tool - EDIT_SUBRESOURCE_BASE;
 
@@ -2883,11 +2885,83 @@ void SceneTreeDock::_tree_rmb(const Vector2 &p_menu_pos) {
 
 void SceneTreeDock::_update_tree_menu() {
 	PopupMenu *tree_menu = button_tree_menu->get_popup();
-	tree_menu->set_item_checked(tree_menu->get_item_idx_from_text(TTR("Auto Expand to Selected")), EditorSettings::get_singleton()->get("docks/scene_tree/auto_expand_to_selected"));
+	tree_menu->clear();
+
+	_append_filter_options_to(tree_menu);
+
+	tree_menu->add_separator();
+	tree_menu->add_check_item(TTR("Auto Expand to Selected"), TOOL_AUTO_EXPAND);
+	tree_menu->set_item_checked(tree_menu->get_item_index(TOOL_AUTO_EXPAND), EditorSettings::get_singleton()->get("docks/scene_tree/auto_expand_to_selected"));
+}
+
+void SceneTreeDock::_update_filter_menu() {
+	_append_filter_options_to(filter->get_menu());
 }
 
 void SceneTreeDock::_filter_changed(const String &p_filter) {
 	scene_tree->set_filter(p_filter);
+
+	String warning = scene_tree->get_filter_term_warning();
+	if (!warning.is_empty()) {
+		filter->add_theme_icon_override(SNAME("clear"), get_theme_icon(SNAME("NodeWarning"), SNAME("EditorIcons")));
+		filter->set_tooltip_text(warning);
+	} else {
+		filter->remove_theme_icon_override(SNAME("clear"));
+		filter->set_tooltip_text("");
+	}
+}
+
+void SceneTreeDock::_filter_gui_input(const Ref<InputEvent> &p_event) {
+	Ref<InputEventMouseButton> mb = p_event;
+	if (mb.is_null()) {
+		return;
+	}
+
+	if (mb->is_pressed() && mb->get_button_index() == MouseButton::MIDDLE) {
+		filter_quick_menu->clear();
+
+		_append_filter_options_to(filter_quick_menu, false);
+		filter_quick_menu->set_position(get_screen_position() + get_local_mouse_position());
+		filter_quick_menu->reset_size();
+		filter_quick_menu->popup();
+		filter_quick_menu->grab_focus();
+		accept_event();
+	}
+}
+
+void SceneTreeDock::_filter_option_selected(int p_option) {
+	String filter_parameter;
+	switch (p_option) {
+		case FILTER_BY_TYPE: {
+			filter_parameter = "type";
+		} break;
+		case FILTER_BY_GROUP: {
+			filter_parameter = "group";
+		} break;
+	}
+
+	if (!filter_parameter.is_empty()) {
+		set_filter((get_filter() + " " + filter_parameter + ":").strip_edges());
+		filter->set_caret_column(filter->get_text().length());
+		filter->grab_focus();
+	}
+}
+
+void SceneTreeDock::_append_filter_options_to(PopupMenu *p_menu, bool p_include_separator) {
+	if (p_include_separator) {
+		p_menu->add_separator();
+
+		p_menu->set_item_text(-1, TTR("Filters"));
+		p_menu->set_item_icon(-1, get_theme_icon(SNAME("Search"), SNAME("EditorIcons")));
+		p_menu->set_item_indent(-1, -2);
+	}
+
+	p_menu->add_item(TTR("Filter by Type"), FILTER_BY_TYPE);
+	p_menu->add_item(TTR("Filter by Group"), FILTER_BY_GROUP);
+	p_menu->set_item_icon(p_menu->get_item_index(FILTER_BY_TYPE), get_theme_icon(SNAME("Node"), SNAME("EditorIcons")));
+	p_menu->set_item_icon(p_menu->get_item_index(FILTER_BY_GROUP), get_theme_icon(SNAME("Groups"), SNAME("EditorIcons")));
+	p_menu->set_item_tooltip(p_menu->get_item_index(FILTER_BY_TYPE), TTR("Selects all Nodes of the given type."));
+	p_menu->set_item_tooltip(p_menu->get_item_index(FILTER_BY_GROUP), TTR("Selects all Nodes belonging to the given group.\nIf empty, selects any Node belonging to any group."));
 }
 
 String SceneTreeDock::get_filter() {
@@ -3399,14 +3473,22 @@ SceneTreeDock::SceneTreeDock(Node *p_scene_root, EditorSelection *p_editor_selec
 	button_instance->set_tooltip_text(TTR("Instantiate a scene file as a Node. Creates an inherited scene if no root node exists."));
 	button_instance->set_shortcut(ED_GET_SHORTCUT("scene_tree/instance_scene"));
 	filter_hbc->add_child(button_instance);
-
 	vbc->add_child(filter_hbc);
+
+	// The "Filter Nodes" text input above the Scene Tree Editor.
 	filter = memnew(LineEdit);
 	filter->set_h_size_flags(SIZE_EXPAND_FILL);
 	filter->set_placeholder(TTR("Filter Nodes"));
 	filter_hbc->add_child(filter);
 	filter->add_theme_constant_override("minimum_character_width", 0);
 	filter->connect("text_changed", callable_mp(this, &SceneTreeDock::_filter_changed));
+	filter->connect("gui_input", callable_mp(this, &SceneTreeDock::_filter_gui_input));
+	filter->get_menu()->connect("about_to_popup", callable_mp(this, &SceneTreeDock::_update_filter_menu));
+	filter->get_menu()->connect("id_pressed", callable_mp(this, &SceneTreeDock::_filter_option_selected));
+
+	filter_quick_menu = memnew(PopupMenu);
+	filter_quick_menu->connect("id_pressed", callable_mp(this, &SceneTreeDock::_filter_option_selected));
+	filter->add_child(filter_quick_menu);
 
 	button_create_script = memnew(Button);
 	button_create_script->set_flat(true);
@@ -3430,7 +3512,6 @@ SceneTreeDock::SceneTreeDock(Node *p_scene_root, EditorSelection *p_editor_selec
 	filter_hbc->add_child(button_tree_menu);
 
 	PopupMenu *tree_menu = button_tree_menu->get_popup();
-	tree_menu->add_check_item(TTR("Auto Expand to Selected"), TOOL_AUTO_EXPAND);
 	tree_menu->connect("id_pressed", callable_mp(this, &SceneTreeDock::_tool_selected).bind(false));
 
 	button_hb = memnew(HBoxContainer);

editor/scene_tree_dock.h

@@ -160,7 +160,13 @@ class SceneTreeDock : public VBoxContainer {
 	EditorQuickOpen *quick_open = nullptr;
 	EditorFileDialog *new_scene_from_dialog = nullptr;
 
+	enum FilterMenuItems {
+		FILTER_BY_TYPE = 64, // Used in the same menus as the Tool enum.
+		FILTER_BY_GROUP,
+	};
+
 	LineEdit *filter = nullptr;
+	PopupMenu *filter_quick_menu = nullptr;
 	TextureRect *filter_icon = nullptr;
 
 	PopupMenu *menu = nullptr;
@@ -243,8 +249,12 @@ class SceneTreeDock : public VBoxContainer {
 
 	void _tree_rmb(const Vector2 &p_menu_pos);
 	void _update_tree_menu();
+	void _update_filter_menu();
 
 	void _filter_changed(const String &p_filter);
+	void _filter_gui_input(const Ref<InputEvent> &p_event);
+	void _filter_option_selected(int option);
+	void _append_filter_options_to(PopupMenu *p_menu, bool p_include_separator = true);
 
 	void _perform_instantiate_scenes(const Vector<String> &p_files, Node *parent, int p_pos);
 	void _replace_with_branch_scene(const String &p_file, Node *base);

editor/scene_tree_editor.cpp

@@ -612,6 +612,7 @@ void SceneTreeEditor::_update_tree(bool p_scroll_to_selected) {
 bool SceneTreeEditor::_update_filter(TreeItem *p_parent, bool p_scroll_to_selected) {
 	if (!p_parent) {
 		p_parent = tree->get_root();
+		filter_term_warning.clear();
 	}
 
 	if (!p_parent) {
@@ -704,8 +705,8 @@ bool SceneTreeEditor::_item_matches_all_terms(TreeItem *p_item, PackedStringArra
 						return false;
 					}
 				}
-			} else {
-				WARN_PRINT(vformat(TTR("Special Node filter \"%s\" is not recognised. Available filters include \"type\" and \"group\"."), parameter));
+			} else if (filter_term_warning.is_empty()) {
+				filter_term_warning = vformat(TTR("\"%s\" is not a known filter."), parameter);
 				continue;
 			}
 		} else {
@@ -1029,6 +1030,10 @@ String SceneTreeEditor::get_filter() const {
 	return filter;
 }
 
+String SceneTreeEditor::get_filter_term_warning() {
+	return filter_term_warning;
+}
+
 void SceneTreeEditor::set_undo_redo(Ref<EditorUndoRedoManager> p_undo_redo) {
 	undo_redo = p_undo_redo;
 }

editor/scene_tree_editor.h

@@ -62,6 +62,7 @@ class SceneTreeEditor : public Control {
 	ObjectID instance_node;
 
 	String filter;
+	String filter_term_warning;
 
 	AcceptDialog *error = nullptr;
 	AcceptDialog *warning = nullptr;
@@ -142,6 +143,7 @@ public:
 
 	void set_filter(const String &p_filter);
 	String get_filter() const;
+	String get_filter_term_warning();
 
 	void set_undo_redo(Ref<EditorUndoRedoManager> p_undo_redo);
 	void set_display_foreign_nodes(bool p_display);