GDScript: Add "Quick Fix" to create function stub matching signal connection

core/object/editor_language.h

@@ -194,6 +194,74 @@ class EditorLanguage {
 	 */
 	virtual void format_code(String &r_code, uint32_t p_from_line, uint32_t p_to_line) const {}
 
+	/* CODE ACTIONS */
+	/**
+	 * @brief Specifies a series of text edits to make to a particular document.
+	 */
+	struct DocumentEditOperation {
+		String file_path;
+		LocalVector<TextEdit> edits;
+	};
+
+	/**
+	 * @brief Specifies a code action that the user can perform, in the form of
+	 * the description or title presented to the user, and the set of underlying
+	 * document edits that the code action will perform.
+	 */
+	struct CodeActionOperation {
+		String description;
+		LocalVector<DocumentEditOperation> document_edits;
+	};
+
+	/**
+	 * @brief Specifies a group of code actions, so they can be displayed together
+	 * in Godot's built-in script editor. For example, if a line has the `UNTYPED_DECLARATION`
+	 * and `UNUSED_VARIABLE` warnings, the quick fix menu will display:
+	 * ```text
+	 * -- UNTYPED_DECLARATION --
+	 * Add type specifier "String"
+	 * Ignore "UNTYPED_DECLARATION"
+	 *
+	 * -- UNUSED_VARIABLE --
+	 * Add underscore to variable name
+	 * Remove variable declaration
+	 * Ignore "UNUSED_VARIABLE"
+	 * ```
+	 *
+	 * Note that the LSP does not support groups like this, so external IDEs will display
+	 * all actions in one continuous list.
+	 *
+	 * This chart demonstrates an example of what a `CodeActionGroup` for an `UNTYPED_DECLARATION`
+	 * warning might look like:
+	 * ```text
+	 * CodeActionGroup
+	 * ├─ title = "UNTYPED_DECLARATION"
+	 * └─ actions
+	 *    ├─ actions[0]
+	 *    │  ├─ description = "Add type specifier \"String\""
+	 *    │  └─ edits
+	 *    │     └─ edits[0]
+	 *    │        ├─ new_text = ": String"
+	 *    │        ├─ start_line = 4
+	 *    │        ├─ start_column = 5
+	 *    │        ├─ end_line = 4
+	 *    │        └─ end_column = 5
+	 *    └─ actions[1]
+	 *       ├─ description = "Ignore \"UNTYPED_DECLARATION\""
+	 *       └─ edits
+	 *          └─ edits[0]
+	 *             ├─ new_text = "@warning_ignore('untyped_declaration')"
+	 *             ├─ start_line = 3
+	 *             ├─ start_column = 0
+	 *             ├─ end_line = 3
+	 *             └─ end_column = 0
+	 * ```
+	 */
+	struct CodeActionGroup {
+		String title;
+		LocalVector<CodeActionOperation> actions;
+	};
+
 	struct Warning {
 		/// One-based.
 		int start_line = 0;
@@ -205,6 +273,7 @@ class EditorLanguage {
 
 		String string_code;
 		String message;
+		CodeActionGroup code_actions;
 	};
 
 	struct ScriptError {
@@ -215,6 +284,7 @@ class EditorLanguage {
 		int end_line = -1;
 		int end_column = -1;
 		String message;
+		CodeActionGroup code_actions;
 	};
 
 	/**

doc/classes/EditorSettings.xml

@@ -1503,6 +1503,9 @@
 		<member name="text_editor/appearance/whitespace/line_spacing" type="int" setter="" getter="">
 			The space to add between lines (in pixels). Greater line spacing can help improve readability at the cost of displaying fewer lines on screen. Negative values allow for even more compact text, but may look broken with certain fonts.
 		</member>
+		<member name="text_editor/behavior/code_actions/show_code_actions_button" type="bool" setter="" getter="">
+			If [code]true[/code], the script editor displays a lightbulb button when the caret is on a line with code actions available. Clicking the lightbulb button shows available code actions. Code actions can perform automated edits to code that address warnings or fix errors. If [code]false[/code], code actions are only available through the "Show Code Actions" shortcut.
+		</member>
 		<member name="text_editor/behavior/diagnostics/enable_tooltips" type="bool" setter="" getter="">
 			If [code]true[/code], warning and error messages will appear in tooltips when hovering over code.
 		</member>

editor/gui/code_editor.cpp

@@ -940,6 +940,11 @@ void CodeTextEditor::_text_editor_gui_input(const Ref<InputEvent> &p_event) {
 	Ref<InputEventMouseButton> mb = p_event;
 
 	if (mb.is_valid()) {
+		if (show_code_actions && mb->is_pressed() && mb->get_button_index() == MouseButton::LEFT && _get_code_action_button_inline_rect().has_point(mb->get_position())) {
+			popup_code_actions(text_editor->get_caret_line());
+			accept_event();
+			return;
+		}
 		if (mb->is_pressed() && mb->is_command_or_control_pressed()) {
 			if (mb->get_button_index() == MouseButton::WHEEL_UP) {
 				_zoom_in();
@@ -963,6 +968,18 @@ void CodeTextEditor::_text_editor_gui_input(const Ref<InputEvent> &p_event) {
 	}
 #endif
 
+	Ref<InputEventMouseMotion> mm = p_event;
+
+	if (show_code_actions && mm.is_valid() && mm->get_button_mask().is_empty()) {
+		if (_get_code_action_button_inline_rect().has_point(mm->get_position()) && code_actions_exist_for_line(text_editor->get_caret_line())) {
+			text_editor->set_default_cursor_shape(Control::CURSOR_POINTING_HAND);
+			text_editor->set_symbol_tooltip_on_hover_enabled(false);
+		} else {
+			text_editor->set_default_cursor_shape(Control::CURSOR_IBEAM);
+			text_editor->set_symbol_tooltip_on_hover_enabled(true);
+		}
+	}
+
 	Ref<InputEventKey> k = p_event;
 
 	if (k.is_valid()) {
@@ -982,6 +999,11 @@ void CodeTextEditor::_text_editor_gui_input(const Ref<InputEvent> &p_event) {
 				accept_event();
 				return;
 			}
+			if (ED_IS_SHORTCUT("script_editor/code_actions", p_event)) {
+				popup_code_actions(text_editor->get_caret_line(), true);
+				accept_event();
+				return;
+			}
 		}
 	}
 }
@@ -1009,6 +1031,9 @@ void CodeTextEditor::_line_col_changed() {
 }
 
 void CodeTextEditor::_text_changed() {
+	code_actions.clear();
+	ungrouped_current_code_actions.clear();
+
 	if (code_complete_enabled && text_editor->is_insert_text_operation()) {
 		code_complete_timer_line = text_editor->get_caret_line();
 		code_complete_timer->start();
@@ -1160,6 +1185,16 @@ void CodeTextEditor::update_editor_settings() {
 	text_editor->set_auto_indent_enabled(EDITOR_GET("text_editor/behavior/indent/auto_indent"));
 	text_editor->set_indent_wrapped_lines(EDITOR_GET("text_editor/behavior/indent/indent_wrapped_lines"));
 
+	// Behavior: Code Actions
+	show_code_actions = EDITOR_GET("text_editor/behavior/code_actions/show_code_actions_button");
+	if (text_editor->is_connected(SceneStringName(draw), callable_mp(this, &CodeTextEditor::_on_text_editor_draw))) {
+		if (!show_code_actions) {
+			text_editor->disconnect(SceneStringName(draw), callable_mp(this, &CodeTextEditor::_on_text_editor_draw));
+		}
+	} else if (show_code_actions) {
+		text_editor->connect(SceneStringName(draw), callable_mp(this, &CodeTextEditor::_on_text_editor_draw));
+	}
+
 	// Completion
 	text_editor->set_auto_brace_completion_enabled(EDITOR_GET("text_editor/completion/auto_brace_complete"));
 	text_editor->set_code_hint_draw_below(EDITOR_GET("text_editor/completion/put_callhint_tooltip_below_current_line"));
@@ -1669,6 +1704,9 @@ void CodeTextEditor::_update_text_editor_theme() {
 	warning_button->set_button_icon(get_editor_theme_icon(SNAME("NodeWarning")));
 	warning_button->add_theme_color_override(SceneStringName(font_color), warning_color);
 
+	code_action_dropdown_icon = get_editor_theme_icon(SNAME("CodeActionDropdown"));
+	code_action_icon = get_editor_theme_icon(SNAME("CodeAction"));
+
 	const int child_count = status_bar->get_child_count();
 	for (int i = 0; i < child_count; i++) {
 		Control *child = Object::cast_to<Control>(status_bar->get_child(i));
@@ -1951,6 +1989,7 @@ void CodeTextEditor::_bind_methods() {
 	ADD_SIGNAL(MethodInfo("show_goto_popup"));
 	ADD_SIGNAL(MethodInfo("navigation_preview_ended"));
 	ADD_SIGNAL(MethodInfo("zoomed", PropertyInfo(Variant::FLOAT, "zoom_factor")));
+	ADD_SIGNAL(MethodInfo("document_edits_requested", PropertyInfo(Variant::ARRAY, "edits")));
 	ADD_SIGNAL(MethodInfo("_request_save_new_history", PropertyInfo(Variant::DICTIONARY, "state")));
 }
 
@@ -1959,15 +1998,160 @@ void CodeTextEditor::set_code_complete_func(CodeTextEditorCodeCompleteFunc p_cod
 	code_complete_ud = p_ud;
 }
 
+Rect2 CodeTextEditor::_get_code_action_button_inline_rect() const {
+	const int line = text_editor->get_caret_line();
+	const int indent_level = text_editor->get_indent_level(line);
+
+	const int line_spacing = text_editor->get_theme_constant("line_spacing");
+	const int row_height = text_editor->get_line_height() - line_spacing;
+	Size2 icon_size(row_height, row_height);
+
+	Rect2i rect = text_editor->get_rect_at_line_column(line, 0);
+	if (rect.position == Point2i(-1, -1)) {
+		return Rect2i();
+	}
+
+	Point2 icon_position = rect.position;
+	icon_position.x = text_editor->get_total_gutter_width();
+	icon_position.y = icon_position.y + (row_height / 2.0) - (icon_size.y / 2.0) + (line_spacing / 2.0);
+
+	// If the current line doesn't have indentation, then the button will cover
+	// the beginning of the line, so we need to find a better place for it.
+	if (text_editor->get_line_width(line) > 0 && indent_level < 4) {
+		// If there is a line above, and it has space for the button, we can put it there.
+		if (line > 0 && (text_editor->get_indent_level(line - 1) >= 4 || text_editor->get_line_width(line - 1) == 0)) {
+			icon_position.y -= text_editor->get_line_height();
+		}
+
+		// If this is the last line, or the line below has space for the button, we can put it there.
+		else if (line == text_editor->get_line_count() - 1 || text_editor->get_indent_level(line + 1) >= 4 || text_editor->get_line_width(line + 1) == 0) {
+			icon_position.y += text_editor->get_line_height() * (1 + text_editor->get_line_wrap_count(line));
+		}
+	}
+
+	icon_position = icon_position.round();
+
+	return Rect2(icon_position, icon_size);
+}
+
+void CodeTextEditor::_on_text_editor_draw() const {
+	if (!code_action_dropdown_icon.is_valid() || !code_actions_exist_for_line(text_editor->get_caret_line())) {
+		return;
+	}
+
+	RID ci = text_editor->get_text_canvas_item();
+	Rect2 inline_rect = _get_code_action_button_inline_rect();
+	if (inline_rect.position == Point2i()) {
+		return;
+	}
+	code_action_dropdown_icon->draw_rect(ci, inline_rect);
+}
+
+void CodeTextEditor::_on_code_action_id_pressed(int p_id) {
+	EditorLanguage::CodeActionOperation ca = ungrouped_current_code_actions[p_id];
+	Array document_edits_arr;
+	for (const EditorLanguage::DocumentEditOperation &doc_edit : ca.document_edits) {
+		Dictionary de_dict;
+		de_dict["file_path"] = doc_edit.file_path;
+
+		Array edits_arr;
+		for (const EditorLanguage::TextEdit &edit : doc_edit.edits) {
+			Dictionary te_dict;
+			te_dict["start_line"] = edit.start_line;
+			te_dict["start_column"] = edit.start_column;
+			te_dict["end_line"] = edit.end_line;
+			te_dict["end_column"] = edit.end_column;
+			te_dict["new_text"] = edit.new_text;
+			edits_arr.append(te_dict);
+		}
+		de_dict["edits"] = edits_arr;
+		document_edits_arr.append(de_dict);
+	}
+	emit_signal(SNAME("document_edits_requested"), document_edits_arr);
+}
+
+void CodeTextEditor::popup_code_actions(int p_line, bool p_from_shortcut) {
+	if (code_action_popup == nullptr) {
+		code_action_popup = memnew(PopupMenu);
+		code_action_popup->connect(SceneStringName(id_pressed), callable_mp(this, &CodeTextEditor::_on_code_action_id_pressed));
+		add_child(code_action_popup);
+	}
+	code_action_popup->clear();
+
+	ungrouped_current_code_actions.clear();
+	int action_index = 0;
+
+	if (!code_actions.has(p_line)) {
+		return;
+	}
+
+	for (const EditorLanguage::CodeActionGroup &group : code_actions[p_line]) {
+		code_action_popup->add_separator(group.title, -1);
+		for (const EditorLanguage::CodeActionOperation &action : group.actions) {
+			code_action_popup->add_icon_item(code_action_icon, action.description, action_index);
+			ungrouped_current_code_actions.push_back(action);
+			action_index++;
+		}
+	}
+
+	if (action_index == 0) {
+		return;
+	}
+
+	if (p_from_shortcut) {
+		if (!text_editor->is_caret_visible()) {
+			text_editor->adjust_viewport_to_caret();
+		}
+		callable_mp(this, &CodeTextEditor::_deferred_popup_code_actions).call_deferred();
+		return;
+	}
+
+	// Accessing from the button, so we should just use the button's position
+	// to determine where to place the popup.
+	Rect2 button_rect = _get_code_action_button_inline_rect();
+	Point2 pos = button_rect.position;
+	pos.y += button_rect.size.y;
+	pos = text_editor->get_global_transform_with_canvas().xform(pos);
+
+	pos += get_window()->get_position();
+	code_action_popup->popup(Rect2i(pos, Size2i()));
+	code_action_popup->set_focused_item(1); // The item at index 0 will be the first section's header.
+}
+
+void CodeTextEditor::_deferred_popup_code_actions() {
+	// This method is necessary because adjust_viewport_to_caret doesn't take effect until the next frame,
+	// so if we try to call get_rect_at_line_column() immediately after it, we get invalid data.
+	int l = text_editor->get_caret_line();
+	int c = text_editor->get_caret_column();
+
+	Rect2 line_rect = text_editor->get_rect_at_line_column(l, c);
+	Point2 pos = text_editor->get_global_transform_with_canvas().xform(line_rect.position);
+	pos.y += line_rect.size.y;
+
+	pos += get_window()->get_position();
+	code_action_popup->popup(Rect2i(pos, Size2i()));
+	code_action_popup->set_focused_item(1); // The item at index 0 will be the first section's header.
+}
+
+String CodeTextEditor::get_tooltip(const Point2 &p_pos) const {
+	if (show_code_actions && _get_code_action_button_inline_rect().has_point(p_pos) && code_actions_exist_for_line(text_editor->get_caret_line())) {
+		return TTRC("Show Code Actions") + vformat(" (%s)", ED_GET_SHORTCUT("script_editor/code_actions")->get_as_text());
+	} else {
+		return "";
+	}
+}
+
 CodeTextEditor::CodeTextEditor() {
 	code_complete_func = nullptr;
 	ED_SHORTCUT("script_editor/zoom_in", TTRC("Zoom In"), KeyModifierMask::CMD_OR_CTRL | Key::EQUAL);
 	ED_SHORTCUT("script_editor/zoom_out", TTRC("Zoom Out"), KeyModifierMask::CMD_OR_CTRL | Key::MINUS);
 	ED_SHORTCUT_ARRAY("script_editor/reset_zoom", TTRC("Reset Zoom"),
 			{ int32_t(KeyModifierMask::CMD_OR_CTRL | Key::KEY_0), int32_t(KeyModifierMask::CMD_OR_CTRL | Key::KP_0) });
+	ED_SHORTCUT("script_editor/code_actions", TTRC("Show Code Actions"), KeyModifierMask::CMD_OR_CTRL | Key::APOSTROPHE);
 
 	text_editor = memnew(CodeEdit);
 	add_child(text_editor);
+	text_editor->set_mouse_filter(Control::MOUSE_FILTER_PASS);
 	text_editor->set_v_size_flags(SIZE_EXPAND_FILL);
 	text_editor->set_structured_text_bidi_override(TextServer::STRUCTURED_TEXT_GDSCRIPT);
 	text_editor->set_draw_bookmarks_gutter(true);

editor/gui/code_editor.h

@@ -223,6 +223,23 @@ class CodeTextEditor : public VBoxContainer {
 	void _zoom_popup_id_pressed(int p_idx);
 
 protected:
+	virtual String get_tooltip(const Point2 &p_pos) const override;
+
+	bool show_code_actions = true;
+	PopupMenu *code_action_popup = nullptr;
+	void _on_code_action_id_pressed(int p_id);
+	void popup_code_actions(int p_line, bool p_from_shortcut = false);
+	void _deferred_popup_code_actions();
+
+	AHashMap<int, LocalVector<EditorLanguage::CodeActionGroup>> code_actions;
+	LocalVector<EditorLanguage::CodeActionOperation> ungrouped_current_code_actions;
+
+	Rect2 _get_code_action_button_inline_rect() const;
+	void _on_text_editor_draw() const;
+
+	Ref<Texture2D> code_action_dropdown_icon;
+	Ref<Texture2D> code_action_icon;
+
 	void _text_changed_idle_timeout();
 	void _code_complete_timer_timeout();
 	void _text_changed();
@@ -292,6 +309,21 @@ class CodeTextEditor : public VBoxContainer {
 	void goto_next_bookmark();
 	void goto_prev_bookmark();
 	void remove_all_bookmarks();
+	void clear_code_action_groups() {
+		code_actions.clear();
+	}
+	void add_code_action_group_for_line(int p_line, const EditorLanguage::CodeActionGroup &p_action) {
+		if (!code_actions.has(p_line)) {
+			code_actions.insert(p_line, LocalVector<EditorLanguage::CodeActionGroup>());
+		}
+		code_actions[p_line].push_back(p_action);
+	}
+	bool code_actions_exist_for_line(int p_line) const {
+		if (!code_actions.has(p_line)) {
+			return false;
+		}
+		return !code_actions[p_line].is_empty();
+	}
 
 	void set_zoom_factor(float p_zoom_factor);
 	float get_zoom_factor();