[Viewer] Using Alt + Tab to switch programs in Windows when using the viewer in full screen, the text is adjusted as it was not in full screen

[Jonatan Nyberg]

Using Alt+Tab to switch programs in Windows when using the viewer in full screen, the text is adjusted as it was not in full screen but the window is shown in full screen.

Steps to reproduce:
1. Open viewer
2. Switch to full screen
3. Use Alt+Tab to switch to another program
4. Use Alt+Tab to switch back to the viewer

[Kovid Goyal (kovid)]

I spent some time looking into this, and on my windows system it is
difficult to reproduce, seems to happen once every 5-6 times and that
too only when switching to certain applications. As far as I can tell,
its a bug in Qt WebEgine on windows. Nothing I can do about that. When
it did happen on my system I could recover by simply scrolling the book
a page.

 status invalid

[Jim de Graff (rjdegraff)]

It happens every time I switch between virtual desktops. As you say, it
recovers my position by scrolling so it's not a big deal. If its in Qt
then it's an SEP (someone else's problem).

Jim

On 2021-04-08 06:17, Kovid Goyal wrote:
> I spent some time looking into this, and on my windows system it is
> difficult to reproduce, seems to happen once every 5-6 times and that
> too only when switching to certain applications. As far as I can tell,
> its a bug in Qt WebEgine on windows. Nothing I can do about that. When
> it did happen on my system I could recover by simply scrolling the book
> a page.
>
> status invalid
>
> ** Changed in: calibre
> Status: New => Invalid
>

[Kovid Goyal (kovid)]

Well I had a brainwave and realized that the issue is basically fixed by forcing a re-render. So I can detect the switch back in fullscreen mode event and force a re-render, working around the Qt bug.

[Kovid Goyal (kovid)]

Fixed in branch master. The fix will be in the next release. calibre is usually released every alternate Friday.

 status fixreleased