signal-desktop/app/SystemTrayService.ts
2021-10-26 14:15:33 -05:00

247 lines
7.1 KiB
TypeScript

// Copyright 2017-2021 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
import { join } from 'path';
import type { BrowserWindow, NativeImage } from 'electron';
import { Menu, Tray, app, nativeImage } from 'electron';
import * as log from '../ts/logging/log';
import type { LocaleMessagesType } from '../ts/types/I18N';
/**
* A class that manages an [Electron `Tray` instance][0]. It's responsible for creating
* and destroying a `Tray`, and listening to the associated `BrowserWindow`'s visibility
* state.
*
* [0]: https://www.electronjs.org/docs/api/tray
*/
export class SystemTrayService {
private browserWindow?: BrowserWindow;
private readonly messages: LocaleMessagesType;
private tray?: Tray;
private isEnabled = false;
private unreadCount = 0;
private boundRender: typeof SystemTrayService.prototype.render;
constructor({ messages }: Readonly<{ messages: LocaleMessagesType }>) {
log.info('System tray service: created');
this.messages = messages;
this.boundRender = this.render.bind(this);
}
/**
* Update or clear the associated `BrowserWindow`. This is used for the hide/show
* functionality. It attaches event listeners to the window to manage the hide/show
* toggle in the tray's context menu.
*/
setMainWindow(newBrowserWindow: undefined | BrowserWindow): void {
const oldBrowserWindow = this.browserWindow;
if (oldBrowserWindow === newBrowserWindow) {
return;
}
log.info(
`System tray service: updating main window. Previously, there was ${
oldBrowserWindow ? '' : 'not '
}a window, and now there is${newBrowserWindow ? '' : ' not'}`
);
if (oldBrowserWindow) {
oldBrowserWindow.off('show', this.boundRender);
oldBrowserWindow.off('hide', this.boundRender);
}
if (newBrowserWindow) {
newBrowserWindow.on('show', this.boundRender);
newBrowserWindow.on('hide', this.boundRender);
}
this.browserWindow = newBrowserWindow;
this.render();
}
/**
* Enable or disable the tray icon. Note: if there is no associated browser window (see
* `setMainWindow`), the tray icon will not be shown, even if enabled.
*/
setEnabled(isEnabled: boolean): void {
if (this.isEnabled === isEnabled) {
return;
}
log.info(`System tray service: ${isEnabled ? 'enabling' : 'disabling'}`);
this.isEnabled = isEnabled;
this.render();
}
/**
* Update the unread count, which updates the tray icon if it's visible.
*/
setUnreadCount(unreadCount: number): void {
if (this.unreadCount === unreadCount) {
return;
}
log.info(`System tray service: setting unread count to ${unreadCount}`);
this.unreadCount = unreadCount;
this.render();
}
private render(): void {
if (this.isEnabled && this.browserWindow) {
this.renderEnabled();
return;
}
this.renderDisabled();
}
private renderEnabled() {
log.info('System tray service: rendering the tray');
this.tray = this.tray || this.createTray();
const { browserWindow, tray } = this;
try {
tray.setImage(getIcon(this.unreadCount));
} catch (err: unknown) {
log.warn(
'System tray service: failed to set preferred image. Falling back...'
);
tray.setImage(getDefaultIcon());
}
// NOTE: we want to have the show/hide entry available in the tray icon
// context menu, since the 'click' event may not work on all platforms.
// For details please refer to:
// https://github.com/electron/electron/blob/master/docs/api/tray.md.
tray.setContextMenu(
Menu.buildFromTemplate([
{
id: 'toggleWindowVisibility',
...(browserWindow?.isVisible()
? {
label: this.messages.hide.message,
click: () => {
log.info(
'System tray service: hiding the window from the context menu'
);
// We re-fetch `this.browserWindow` here just in case the browser window
// has changed while the context menu was open. Same applies in the
// "show" case below.
this.browserWindow?.hide();
},
}
: {
label: this.messages.show.message,
click: () => {
log.info(
'System tray service: showing the window from the context menu'
);
if (this.browserWindow) {
this.browserWindow.show();
forceOnTop(this.browserWindow);
}
},
}),
},
{
id: 'quit',
label: this.messages.quit.message,
click: () => {
log.info(
'System tray service: quitting the app from the context menu'
);
app.quit();
},
},
])
);
}
private renderDisabled() {
log.info('System tray service: rendering no tray');
if (!this.tray) {
return;
}
this.tray.destroy();
this.tray = undefined;
}
private createTray(): Tray {
log.info('System tray service: creating the tray');
// This icon may be swiftly overwritten.
const result = new Tray(getDefaultIcon());
// Note: "When app indicator is used on Linux, the click event is ignored." This
// doesn't mean that the click event is always ignored on Linux; it depends on how
// the app indicator is set up.
//
// See <https://github.com/electron/electron/blob/v13.1.3/docs/api/tray.md#class-tray>.
result.on('click', () => {
const { browserWindow } = this;
if (!browserWindow) {
return;
}
if (!browserWindow.isVisible()) {
browserWindow.show();
}
forceOnTop(browserWindow);
});
result.setToolTip(this.messages.signalDesktop.message);
return result;
}
/**
* This is exported for testing, because Electron doesn't have any easy way to hook
* into the existing tray instances. It should not be used by "real" code.
*/
_getTray(): undefined | Tray {
return this.tray;
}
}
function getIcon(unreadCount: number) {
let iconSize: string;
switch (process.platform) {
case 'darwin':
iconSize = '16';
break;
case 'win32':
iconSize = '32';
break;
default:
iconSize = '256';
break;
}
if (unreadCount > 0) {
const filename = `${String(unreadCount >= 10 ? 10 : unreadCount)}.png`;
return join(__dirname, '..', 'images', 'alert', iconSize, filename);
}
return join(__dirname, '..', 'images', `icon_${iconSize}.png`);
}
let defaultIcon: undefined | NativeImage;
function getDefaultIcon(): NativeImage {
defaultIcon ??= nativeImage.createFromPath(getIcon(0));
return defaultIcon;
}
function forceOnTop(browserWindow: BrowserWindow) {
// On some versions of GNOME the window may not be on top when restored.
// This trick should fix it.
// Thanks to: https://github.com/Enrico204/Whatsapp-Desktop/commit/6b0dc86b64e481b455f8fce9b4d797e86d000dc1
browserWindow.setAlwaysOnTop(true);
browserWindow.focus();
browserWindow.setAlwaysOnTop(false);
}