Hi, I am using Elementary OS Juno which is based on Ubuntu 18.04 LTS. I downloaded the Moodle Desktop AppImage (22.214.171.1242) from https://download.moodle.org/desktop. But when I open it, I can only 'see' a transparent window. I can see it in the dock, I can Alt+Tab to it and it gets focus when I do that (I can see it if I use my screenshot tool to capture active window). However the window remains transparent.
Elementary OS Juno x64
elementary GTK+ theme (default)
Steps to reproduce
- Double-click the AppImage
- Run Once / Integrate and Run
These are the output when I run the AppImage via terminal:
Hotfixes that worked for me
- Switching GTK+ theme to anything else
- I can switch back to elementary without issues once the window appears.
- It seems that switching theme redraws the window.
- However on the Arc and Adwaita theme, the issue does occur at all. The window loads fine on first run.
- The error messages are shown even for the Arc/Adwaita theme where the issue does not occur.
2. Un-maximizing the window (I have hot corners enabled. Thus, I could toggle maximise eventhough the window is invisible)
- This seems to redraw the window as well.
- Ran the Moodle Desktop AppImage using different GTK+ themes
Works: Arc, Adwaita
Does not work: Elementary, High Contrast
2. Built the Moodle Desktop app from [source|https://github.com/moodlehq/moodlemobile2] as a Debian package as well as AppImage. Both of them failed to open (invisible) when using GTK+ themes from above.The hotfixes worked for both.
3. Tested on a fresh user with and without AppImageLauncher installed. The issue remains the same. And the hotfixes work.
The issue seems to only affect certain GTK+ themes but since we cannot control what themes users will use, I suppose we should force a redraw through Electron?
I sort of fixed it by commenting out line 57 in desktop/electron.js
I'm not sure if there would be any repercussions from doing that but I'd be happy to test any other possible fixes.