Multiple windows

An Application can own several BrowserWindow instances. All of them share the same native event loop and JavaScript event pump.

const windows = new Map();

function openWindow(id, url) {
  const existing = windows.get(id);
  if (existing && !existing.win.isDisposed()) {
    existing.win.show();
    return existing;
  }

  const win = app.createBrowserWindow({ title: id, width: 900, height: 600 });
  const webview = win.createWebview({ url });
  const handles = { win, webview };
  windows.set(id, handles);

  win.on('close', () => windows.delete(id));
  return handles;
}

openWindow('docs', 'https://webview.js.org');
openWindow('reference', 'https://nodejs.org');
app.run();

The map keeps JavaScript references to the wrappers while the application uses them. A normal allowed close disposes a window and its webviews, so remove that entry from the registry. If a window should be reusable after the close button is pressed, call event.preventDefault() synchronously and then win.hide(); see Application lifecycle.

Child windowsCopy Anchor Link

app.createChildBrowserWindow() creates a child-marked native window. Check win.isChild to identify it. This is distinct from WebviewOptions.child, which positions a webview within its parent window.

const dialog = app.createChildBrowserWindow({
  title: 'Settings',
  width: 420,
  height: 320,
});
const dialogView = dialog.createWebview({
  html: '<main><h1>Settings</h1></main>',
});

When WebviewOptions.child is true, x, y, width, and height define the webview rectangle in logical pixels relative to its containing window. With the default child: false, an unbounded webview fills the window.

Track closure and exitCopy Anchor Link

Listen on each window's close event for per-window state. app's window-close-requested and application-close-requested events do not include a window wrapper. The application emits application-close-requested after the last native window is destroyed, including after direct win.close() or win.dispose(); explicit app.exit() suppresses it.

app.on('application-close-requested', () => {
  // The final native window has been destroyed.
  // The application is already finalizing its native resources.
});

See Application lifecycle for close prevention, hide(), dispose(), and exit() semantics. Runnable examples: multiple windows and multiple webviews.