YACReader
[MacOS] White line on top of the screen in fullscreen mode
MacOS Version used: 11.7.10 (Macbook Air 13" 2018)
Versions tested: 9.15.0 (Intel version) and the two versions prior.
There is a white line with inconsistent behavior that pops into view in fullscreen mode, with semi erratic behavior.
See video:
https://www.youtube.com/watch?v=poQsGTlhdBA
Here is the behavior of the white line.
With hardware acceleration this triggers on every page move. With hardware acceleration off, this triggers on every forth or so page move.
With hardware acceleration on, the line stays on screen almost always. With hardware acceleration off, it often vanishes within a second, but sometimes stays on screen without vanishing.
The line can be triggered to show, by using the arrow keys, or the space bar.
The line often vanishes, then you move the mouse.
The line ALWAYS vanishes, when you click on the image.
Desired behavior:
Make the line go away!
Similar issues afair once were related to older Mac Versions an youtube fullscreen mode in chrome (with HW acceleration enabled), which is why I instantly tried disabling HW acceleration.
Comic images in the video are not zoomed, but same behavior with zoom to fit, height, custom zoom and so on settings. (Its not zoom. ;) )
Even when activating the magnifying glass with Z did not trigger the line, moving it across the screen triggers it. :)
While you are seeing the white line, can you try pressing H in the keyboard (this hides/shows the top bar) I wonder if the problem is that.
Tried that, nope its not that. Its more likely this:
https://bugzilla.mozilla.org/show_bug.cgi?id=1700211
:)
edit: Actually --- dark mode doesnt solve the issue, so its likely not that either.
The only really interesting behavior change is, that disabling hardware accelleration makes the problem occur 10x less frequently. Although the line will still draw.
I wonder if it might be rounding error related. So that the HW accelerated "view" rounds height values somehow differently... Dont know - I'm stumped. :)
On this OS version I have no issues with other programs, showing this behavior (not chrome, not firefox, not youtube (because those are other common search results for similar issues on macos having crept up).
Zoom in (systemwide zoom) on the Mac shows the white pixel bar appearing underneath the YAC topbar, if its made visible using H in fullscreen mode. If thats helpful. :)