app_menu.js

const Lang = imports.lang;
const Main = imports.ui.main;
const Mainloop = imports.mainloop;
const Shell = imports.gi.Shell;
const St = imports.gi.St;
const Clutter = imports.gi.Clutter;

const ExtensionUtils = imports.misc.extensionUtils;
const Me = ExtensionUtils.getCurrentExtension();
const Util = Me.imports.util;

function LOG(message) {
	// log("[pixel-saver]: " + message);
}

function WARN(message) {
	log("[pixel-saver]: " + message);
}

let appMenu = null;

/**
 * AppMenu synchronization
 */
function updateAppMenu() {
	let win = global.display.focus_window;
	if (!win) {
		return false;
	}
	
	let title = win.title;
	
	// Not the topmost maximized window.
	if (win !== Util.getWindow()) {
		let app = Shell.WindowTracker.get_default().get_window_app(win);
		title = app.get_name();
	}
	
	if (title.length > 64) {
                title = title.substr(0, 62) + '...';
        }
	title = title.replace(/\n/g, " ");

	LOG('Override title ' + title);
	appMenu._label.set_text(title);
	tooltip.text = title;
	
	return false;
}

/**
 * Track the focused window's title
 */
let activeWindow = null;
let awCallbackID = 0;
function changeActiveWindow(win) {
	if (win === activeWindow) {
		return;
	}
	
	if (activeWindow) {
		activeWindow.disconnect(awCallbackID);
	}
	
	activeWindow = win;
	
	if (win) {
		awCallbackID = win.connect('notify::title', updateAppMenu);
		updateAppMenu();
	}
}

/**
 * Focus change
 */
function onFocusChange() {
	let input_mode_check = (global.stage_input_mode === undefined)
		? true
		: global.stage_input_mode == Shell.StageInputMode.FOCUSED;
	if (!Shell.WindowTracker.get_default().focus_app && input_mode_check) {
		// If the app has just lost focus to the panel, pretend
		// nothing happened; otherwise you can't keynav to the
		// app menu.
		return false;
	}
	
	changeActiveWindow(global.display.focus_window);
	return false;
}

/**
 * tooltip
 */
let tooltip = null;
let showTooltip = false;

let SHOW_DELAY = 350;
let SHOW_DURATION = 0.15;
let HIDE_DURATION = 0.1;

let tooltipDelayCallbackID = 0;
let menuCallbackID = 0;

function resetMenuCallback() {
	if (menuCallbackID) {
		appMenu.menu.disconnect(menuCallbackID);
		menuCallbackID = 0;
	}
}

function onAppMenuHover(actor) {
	let hover = actor.get_hover();
	if (showTooltip === hover) {
		return false;
	}
	
	// We are not in the right state, let's fix that.
	showTooltip = hover;
	
	if (showTooltip) {
		tooltipDelayCallbackID = Mainloop.timeout_add(SHOW_DELAY, function() {
			if (!showTooltip) {
				WARN('showTooltip is false and delay callback ran.');
			}
			
			// Something wants us to stop.
			if (tooltipDelayCallbackID === 0) {
				return false;
			}
			
			let label = appMenu._label;
			if (label == null || !label.get_clutter_text().get_layout().is_ellipsized()) {
				// Do not need to hide.
				tooltipDelayCallbackID = 0;
				return false;
			}
			
			Main.uiGroup.add_actor(tooltip);
			
			resetMenuCallback();
			menuCallbackID = appMenu.menu.connect('open-state-changed', function(menu, open) {
				if (open) {
					Main.uiGroup.remove_actor(tooltip);
				} else {
					Main.uiGroup.add_actor(tooltip);
				}
			});
			
			[px, py] = Main.panel.actor.get_transformed_position();
			[bx, by] = label.get_transformed_position();
			[w, h] = label.get_transformed_size();
			
			let y = py + Main.panel.actor.get_height() + 3;
			let x = bx - Math.round((tooltip.get_width() - w)/2);
			tooltip.opacity = 0;
			tooltip.set_position(x, y);
			
			LOG('show title tooltip');
			
			tooltip.remove_all_transitions();
			tooltip.ease({
				opacity: 255,
				time: SHOW_DURATION,
				transition: Clutter.AnimationMode.EASE_OUT_QUAD,
			});
			
			return false;
		});
	} else if (tooltipDelayCallbackID > 0) {
		// If the event ran, then we hide.
		LOG('hide title tooltip');
		
		resetMenuCallback();
		
		tooltip.remove_all_transitions();
		tooltip.ease({
			opacity: 0,
			time: HIDE_DURATION,
			transition: Clutter.AnimationMode.EASE_OUT_QUAD,
			onComplete: function() {
				Main.uiGroup.remove_actor(tooltip);
			}
		});
		
		tooltipDelayCallbackID = 0;
	}
	
	return false;
}

/**
 * Subextension hooks
 */
function init() {}

let wmCallbackIDs = [];
let focusCallbackID = 0;
let tooltipCallbackID = 0;

function enable() {
	appMenu = Main.panel.statusArea.appMenu;
	
	tooltip = new St.Label({
		style_class: 'tooltip dash-label',
		text: '',
		opacity: 0
	});
	
	wmCallbackIDs = wmCallbackIDs.concat(Util.onSizeChange(updateAppMenu));
	
	focusCallbackID = global.display.connect('notify::focus-window', onFocusChange);
	tooltipCallbackID = appMenu.actor.connect('notify::hover', onAppMenuHover);
}

function disable() {
	wmCallbackIDs.forEach(function(id) {
		global.window_manager.disconnect(id);
	});
	
	wmCallbackIDs = [];
	
	global.display.disconnect(focusCallbackID);
	focusCallbackID = 0;
	
	appMenu.actor.disconnect(tooltipCallbackID);
	tooltipCallbackID = 0;
	
	if (activeWindow) {
		activeWindow.disconnect(awCallbackID);
		awCallbackID = 0;
		activeWindow = null;
	}
	
	if (tooltipDelayCallbackID) {
		Mainloop.source_remove(tooltipDelayCallbackID);
		tooltipDelayCallbackID = 0;
	}
	
	resetMenuCallback();
	
	tooltip.destroy();
	tooltip = null;
}