godot/scene/gui/menu_button.cpp

/*************************************************************************/
/*  menu_button.cpp                                                      */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
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#include "menu_button.h"

#include "core/os/keyboard.h"
#include "scene/main/window.h"

void MenuButton::shortcut_input(const Ref<InputEvent> &p_event) {
	ERR_FAIL_COND(p_event.is_null());

	if (!_is_focus_owner_in_shortcut_context()) {
		return;
	}

	if (disable_shortcuts) {
		return;
	}

	if (p_event->is_pressed() && !p_event->is_echo() && !is_disabled() && is_visible_in_tree() && popup->activate_item_by_event(p_event, false)) {
		accept_event();
		return;
	}

	Button::shortcut_input(p_event);
}

void MenuButton::_popup_visibility_changed(bool p_visible) {
	set_pressed(p_visible);

	if (!p_visible) {
		set_process_internal(false);
		return;
	}

	if (switch_on_hover) {
		Window *window = Object::cast_to<Window>(get_viewport());
		if (window) {
			mouse_pos_adjusted = window->get_position();

			if (window->is_embedded()) {
				Window *window_parent = Object::cast_to<Window>(window->get_parent()->get_viewport());
				while (window_parent) {
					if (!window_parent->is_embedded()) {
						mouse_pos_adjusted += window_parent->get_position();
						break;
					}

					window_parent = Object::cast_to<Window>(window_parent->get_parent()->get_viewport());
				}
			}

			set_process_internal(true);
		}
	}
}

void MenuButton::pressed() {
	if (popup->is_visible()) {
		popup->hide();
		return;
	}

	show_popup();
}

PopupMenu *MenuButton::get_popup() const {
	return popup;
}

void MenuButton::show_popup() {
	if (!get_viewport()) {
		return;
	}

	emit_signal(SNAME("about_to_popup"));
	Size2 size = get_size() * get_viewport()->get_canvas_transform().get_scale();

	popup->set_size(Size2(size.width, 0));
	Point2 gp = get_screen_position();
	gp.y += size.y;
	if (is_layout_rtl()) {
		gp.x += size.width - popup->get_size().width;
	}
	popup->set_position(gp);
	popup->set_parent_rect(Rect2(Point2(gp - popup->get_position()), size));

	// If not triggered by the mouse, start the popup with its first enabled item focused.
	if (!_was_pressed_by_mouse()) {
		for (int i = 0; i < popup->get_item_count(); i++) {
			if (!popup->is_item_disabled(i)) {
				popup->set_focused_item(i);
				break;
			}
		}
	}

	popup->popup();
}

void MenuButton::set_switch_on_hover(bool p_enabled) {
	switch_on_hover = p_enabled;
}

bool MenuButton::is_switch_on_hover() {
	return switch_on_hover;
}

void MenuButton::set_item_count(int p_count) {
	ERR_FAIL_COND(p_count < 0);

	if (popup->get_item_count() == p_count) {
		return;
	}

	popup->set_item_count(p_count);
	notify_property_list_changed();
}

int MenuButton::get_item_count() const {
	return popup->get_item_count();
}

void MenuButton::_notification(int p_what) {
	switch (p_what) {
		case NOTIFICATION_LAYOUT_DIRECTION_CHANGED: {
			popup->set_layout_direction((Window::LayoutDirection)get_layout_direction());
		} break;

		case NOTIFICATION_VISIBILITY_CHANGED: {
			if (!is_visible_in_tree()) {
				popup->hide();
			}
		} break;

		case NOTIFICATION_INTERNAL_PROCESS: {
			Vector2i mouse_pos = DisplayServer::get_singleton()->mouse_get_position() - mouse_pos_adjusted;
			MenuButton *menu_btn_other = Object::cast_to<MenuButton>(get_viewport()->gui_find_control(mouse_pos));

			if (menu_btn_other && menu_btn_other != this && menu_btn_other->is_switch_on_hover() && !menu_btn_other->is_disabled() &&
					(get_parent()->is_ancestor_of(menu_btn_other) || menu_btn_other->get_parent()->is_ancestor_of(popup))) {
				popup->hide();

				menu_btn_other->pressed();
				// As the popup wasn't triggered by a mouse click, the item focus needs to be removed manually.
				menu_btn_other->get_popup()->set_focused_item(-1);
			}
		} break;
	}
}

bool MenuButton::_set(const StringName &p_name, const Variant &p_value) {
	Vector<String> components = String(p_name).split("/", true, 2);
	if (components.size() >= 2 && components[0] == "popup") {
		bool valid;
		popup->set(String(p_name).trim_prefix("popup/"), p_value, &valid);
		return valid;
	}
	return false;
}

bool MenuButton::_get(const StringName &p_name, Variant &r_ret) const {
	Vector<String> components = String(p_name).split("/", true, 2);
	if (components.size() >= 2 && components[0] == "popup") {
		bool valid;
		r_ret = popup->get(String(p_name).trim_prefix("popup/"), &valid);
		return valid;
	}
	return false;
}

void MenuButton::_get_property_list(List<PropertyInfo> *p_list) const {
	for (int i = 0; i < popup->get_item_count(); i++) {
		p_list->push_back(PropertyInfo(Variant::STRING, vformat("popup/item_%d/text", i)));

		PropertyInfo pi = PropertyInfo(Variant::OBJECT, vformat("popup/item_%d/icon", i), PROPERTY_HINT_RESOURCE_TYPE, "Texture2D");
		pi.usage &= ~(popup->get_item_icon(i).is_null() ? PROPERTY_USAGE_STORAGE : 0);
		p_list->push_back(pi);

		pi = PropertyInfo(Variant::INT, vformat("popup/item_%d/checkable", i), PROPERTY_HINT_ENUM, "No,As Checkbox,As Radio Button");
		pi.usage &= ~(!popup->is_item_checkable(i) ? PROPERTY_USAGE_STORAGE : 0);
		p_list->push_back(pi);

		pi = PropertyInfo(Variant::BOOL, vformat("popup/item_%d/checked", i));
		pi.usage &= ~(!popup->is_item_checked(i) ? PROPERTY_USAGE_STORAGE : 0);
		p_list->push_back(pi);

		pi = PropertyInfo(Variant::INT, vformat("popup/item_%d/id", i), PROPERTY_HINT_RANGE, "0,10,1,or_greater");
		p_list->push_back(pi);

		pi = PropertyInfo(Variant::BOOL, vformat("popup/item_%d/disabled", i));
		pi.usage &= ~(!popup->is_item_disabled(i) ? PROPERTY_USAGE_STORAGE : 0);
		p_list->push_back(pi);

		pi = PropertyInfo(Variant::BOOL, vformat("popup/item_%d/separator", i));
		pi.usage &= ~(!popup->is_item_separator(i) ? PROPERTY_USAGE_STORAGE : 0);
		p_list->push_back(pi);
	}
}

void MenuButton::_bind_methods() {
	ClassDB::bind_method(D_METHOD("get_popup"), &MenuButton::get_popup);
	ClassDB::bind_method(D_METHOD("show_popup"), &MenuButton::show_popup);
	ClassDB::bind_method(D_METHOD("set_switch_on_hover", "enable"), &MenuButton::set_switch_on_hover);
	ClassDB::bind_method(D_METHOD("is_switch_on_hover"), &MenuButton::is_switch_on_hover);
	ClassDB::bind_method(D_METHOD("set_disable_shortcuts", "disabled"), &MenuButton::set_disable_shortcuts);

	ClassDB::bind_method(D_METHOD("set_item_count", "count"), &MenuButton::set_item_count);
	ClassDB::bind_method(D_METHOD("get_item_count"), &MenuButton::get_item_count);

	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "switch_on_hover"), "set_switch_on_hover", "is_switch_on_hover");
	ADD_ARRAY_COUNT("Items", "item_count", "set_item_count", "get_item_count", "popup/item_");

	ADD_SIGNAL(MethodInfo("about_to_popup"));
}

void MenuButton::set_disable_shortcuts(bool p_disabled) {
	disable_shortcuts = p_disabled;
}

MenuButton::MenuButton(const String &p_text) :
		Button(p_text) {
	set_flat(true);
	set_toggle_mode(true);
	set_disable_shortcuts(false);
	set_process_shortcut_input(true);
	set_focus_mode(FOCUS_NONE);
	set_action_mode(ACTION_MODE_BUTTON_PRESS);

	popup = memnew(PopupMenu);
	popup->hide();
	add_child(popup, false, INTERNAL_MODE_FRONT);
	popup->connect("about_to_popup", callable_mp(this, &MenuButton::_popup_visibility_changed).bind(true));
	popup->connect("popup_hide", callable_mp(this, &MenuButton::_popup_visibility_changed).bind(false));
}

MenuButton::~MenuButton() {
}