Window state

createWindowState keeps where each window stood, so it opens there again: its size, its place, and whether it was maximized or in full screen. The app chooses the key a window is kept under, such as main, or the project a window shows.

import { createWindowState, fileStorage } from '@basmilius/desktop-shell';

const windowState = createWindowState({
    storage: fileStorage(join(app.getPath('userData'), 'window-state.json')),
    displays: () => screen.getAllDisplays(),
    defaults: { width: 1440, height: 900 }
});

const createWindow = (): BrowserWindow => {
    const window = new BrowserWindow({ ...windowState.bounds('main'), minWidth: 800, minHeight: 500, show: false });
    windowState.track('main', window);
    window.once('ready-to-show', () => window.show());
    return window;
};

app.on('before-quit', () => windowState.flush());

bounds goes into the constructor. track follows the window from then on; call it right after constructing the window, before it is shown, since it maximizes the window or puts it in full screen again once the window is ready to show.

When it writes

Half a second after a window stops moving or resizing, at once when it closes, and on flush, for the moment the app quits. The bounds are always the window's normal ones, so a window that was maximized comes back maximized, and at its own size once a person unmaximizes it.

Displays that changed

A display that was unplugged or rearranged would leave saved bounds off screen. fitBounds keeps them only while a display still shows enough of the window to grab its title bar (VISIBLE_EDGE), moves it fully onto that display and shrinks it to the display's work area. Otherwise the window opens at its default size, which Electron centers.

Storage

fileStorage writes one JSON file through a file beside it, so a crash halfway leaves the last whole one. A file that does not parse, from another version, or with an entry that is not whole pixels is read as far as it holds; the rest opens at the default.