unstable behavior when creating a tabbed window

[shin-kinoshita]

• Electron Version (output of node_modules/.bin/electron --version):
  • v4.0.4
• Operating System (Platform and Version):
  • macOS 10.14.3
• Last known working Electron version (if applicable):
  • v3.1.3

Expected Behavior

be created a tabbed window without any stress.

Actual behavior

it actually works but takes few seconds till complete and the tabbed window would be much unstable, especially making it full screen state.

To Reproduce

import { app, BrowserWindow } from 'electron';
app.on('ready', () => {
  const window = new BrowserWindow();
  window.addTabbedWindow(new BrowserWindow());
});

Additional Information

I found that the code works well with electron v3.1.3.

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[bpasero]

@sofianguy I can reproduce in VSCode and would consider this a blocker for us to update to 4.0.x. It looks like any interaction with tabbed windows takes a very long time in Electron 4.

[codebytere]

Interestingly, this is only true in 4: it's back to normal in v5.0.0 🤔

[zcbenz]

Some observations:

1. The addTabbedWindow() call takes usual time;
2. The CPU usage is normal even though window is lagging;
3. Using TopLevelWindow instead of BrowserWindow still has the problem.

[bpasero]

Confirmed fixed, thanks a lot for the fast turnaround.

[sofianguy]

fixed in #18314