splash-screen.ts

/*
MIT License

Copyright (c) 2017 Troy McKinnon

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
// Copied from https://raw.githubusercontent.com/trodi/electron-splashscreen/2f5052a133be021cbf9a438d0ef4719cd1796b75/index.ts

/**
 * Module handles configurable splashscreen to show while app is loading.
 */

import { Event } from '@theia/core/lib/common/event';
import { BrowserWindow } from 'electron';

/**
 * When splashscreen was shown.
 * @ignore
 */
let splashScreenTimestamp = 0;
/**
 * Splashscreen is loaded and ready to show.
 * @ignore
 */
let splashScreenReady = false;
/**
 * Main window has been loading for a min amount of time.
 * @ignore
 */
let slowStartup = false;
/**
 * True when expected work is complete and we've closed splashscreen, else user prematurely closed splashscreen.
 * @ignore
 */
let done = false;
/**
 * Show splashscreen if criteria are met.
 * @ignore
 */
const showSplash = () => {
  if (splashScreen && splashScreenReady && slowStartup) {
    splashScreen.show();
    splashScreenTimestamp = Date.now();
  }
};
/**
 * Close splashscreen / show main screen. Ensure screen is visible for a min amount of time.
 * @ignore
 */
const closeSplashScreen = (main: Electron.BrowserWindow, min: number): void => {
  if (splashScreen) {
    const timeout = min - (Date.now() - splashScreenTimestamp);
    setTimeout(() => {
      done = true;
      if (splashScreen) {
        splashScreen.isDestroyed() || splashScreen.close(); // Avoid `Error: Object has been destroyed` (#19)
        splashScreen = null;
      }
      if (!main.isDestroyed()) {
        main.show();
      }
    }, timeout);
  }
};
/** `electron-splashscreen` config object. */
export interface Config {
  /** Options for the window that is loading and having a splashscreen tied to. */
  windowOpts: Electron.BrowserWindowConstructorOptions;
  /**
   * URL to the splashscreen template. This is the path to an `HTML` or `SVG` file.
   * If you want to simply show a `PNG`, wrap it in an `HTML` file.
   */
  templateUrl: string;

  /**
   * Full set of browser window options for the splashscreen. We override key attributes to
   * make it look & feel like a splashscreen; the rest is up to you!
   */
  splashScreenOpts: Electron.BrowserWindowConstructorOptions;
  /** Number of ms the window will load before splashscreen appears (default: 500ms). */
  delay?: number;
  /** Minimum ms the splashscreen will be visible (default: 500ms). */
  minVisible?: number;
  /** Close window that is loading if splashscreen is closed by user (default: true). */
  closeWindow?: boolean;
}
/**
 * The actual splashscreen browser window.
 * @ignore
 */
let splashScreen: Electron.BrowserWindow | null;
/**
 * Initializes a splashscreen that will show/hide smartly (and handle show/hiding of main window).
 * @param config - Configures splashscreen
 * @returns {BrowserWindow} the main browser window ready for loading
 */
export const initSplashScreen = async (
  config: Config,
  windowFactory: (
    options: Electron.BrowserViewConstructorOptions
  ) => Promise<BrowserWindow>,
  onCloseRequested?: Event<void>
): Promise<BrowserWindow> => {
  const xConfig: Required<Config> = {
    windowOpts: config.windowOpts,
    templateUrl: config.templateUrl,
    splashScreenOpts: config.splashScreenOpts,
    delay: config.delay ?? 500,
    minVisible: config.minVisible ?? 500,
    closeWindow: config.closeWindow ?? true,
  };
  xConfig.splashScreenOpts.center = true;
  xConfig.splashScreenOpts.frame = false;
  xConfig.windowOpts.show = false;
  const window = await windowFactory(xConfig.windowOpts);
  splashScreen = new BrowserWindow(xConfig.splashScreenOpts);
  splashScreen.loadURL(`file://${xConfig.templateUrl}`);
  xConfig.closeWindow &&
    splashScreen.on('close', () => {
      done || window.close();
    });
  // Splashscreen is fully loaded and ready to view.
  splashScreen.webContents.on('did-finish-load', () => {
    splashScreenReady = true;
    showSplash();
  });
  // Startup is taking enough time to show a splashscreen.
  setTimeout(() => {
    slowStartup = true;
    showSplash();
  }, xConfig.delay);
  if (onCloseRequested) {
    onCloseRequested(() => closeSplashScreen(window, xConfig.minVisible));
  } else {
    window.webContents.on('did-finish-load', () => {
      closeSplashScreen(window, xConfig.minVisible);
    });
  }
  window.on('closed', () => closeSplashScreen(window, 0)); // XXX: close splash when main window is closed
  return window;
};