Top of window with "hiddenInset" title bar becomes unresponsive after exiting fullscreen

[javan]

• Output of node_modules/.bin/electron --version: v4.0.1
• Operating System (Platform and Version): macOS 10.14.2

Expected Behavior
The top of the window should continue responding to clicks after exiting from fullscreen.

Actual behavior
The top ~40px stops responding to clicks after exiting from fullscreen.

To Reproduce

1. Clone and run https://github.com/javan/electron-quick-start/tree/hidden-inset-mojave
2. Click the black bar at the top of the window. It should turn purple while the mouse is down.
3. Enter and exit fullscreen.
4. Click the top of the window and note that it no longer turns purple.

$ git clone https://github.com/javan/electron-quick-start.git -b hidden-inset-mojave
$ npm install
$ npm start

Screenshots

Additional Information
This issue is quite similar to #14529.

[olafuria]

We are also seeing this in Tidal update we are working on.

[littlecold233]

I have the same problem！！！

How Could I fix that？It's really strange

[littlecold233]

@javan set the titleBarStyle hidden fix the issue

I just test hidden and hiddenInset for my BrowserWindow and I find hidden works much better then hiddenInset

[nathanlesage]

I second that. Using hidden and having the buttons placed very close to the edge of the frame would require me to overthink my whole toolbar design in Zettlr, which I'd like to avoid. Besides, Chrome, e.g. also uses the hiddenInset way of displaying the traffic lights, but still does not expose the strange unresponsiveness after exiting fullscreen.

Besides, what I noted is that in fullscreen the window uses an extra-high titlebar, which is normally indicative of websites that go in a "fake fullscreen" mode (I'll just call it that, because something different happens there, but I don't know what). Chrome for some time had used this "thick frame" mode as well. Maybe electron is using the same "fake" fullscreen (that is not used anymore in Chrome) as well and that's causing the problems?

To show what I mean: if you put an app into fullscreen mode, e.g. Chrome, or Safari, and go to the very top with your mouse, you'll see a standard-height titlebar:

But compare this to an electron app using hiddenInset:

The titlebar is twice the size, so it seems to be something that happens with the native Window controller on macOS. I'm not a Swift/Apple native programmer so I wouldn't know where to look, but maybe have a look there?

What I also tested and can confirm it does not work:

• Show the window title in fullscreen
• Force-reload the CSS-Stylesheets with the draggable-region directives in them

[nathanlesage]

Some updates. I did some digging into what might be the cause.

1. To achieve the inset traffic lights, Electron uses a Toolbar with no buttons, makes it transparent and click-through.
2. After exiting the fullscreen precisely the area of the toolbar becomes unclickable. Still, it is strange that the hovering still works.
3. Can confirm that Electron 3.1.2 on macOS Mojave 10.14.2 works and buttons stay responsive. I still haven't been able to pinpoint what has changed from 3.1.2 to 4.0.2 what might cause this issue.

[issacgerges]

From some testing with fiddle, this appears to have started in 4.0.0-beta.1 and stops appearing in 5.0.0-beta.1.