Android GodotFragment can't have a transparent background

[lonevox]

Tested versions

• Reproducible in: 4.5-dev4, 4.2.2-stable

System information

Godot v4.2.2.stable.mono - Linux Mint 21.3 (Virginia) - X11 - GLES3 (Compatibility) - AMD Radeon RX 6800 (navi21, LLVM 15.0.7, DRM 3.57, 6.8.0-57-generic) () - AMD Ryzen 5 7600 6-Core Processor (12 Threads)

Issue description

A GodotFragment in an Android app can't be given a transparent background with android:background="@android:color/transparent" as well as having the Godot project allow per-pixel transparency with the following project settings enabled:

• display/window/per_pixel_transparency
• display/window/size/transparent
• rendering/viewport/transparent_background

Running the Godot project from the editor, I correctly get a transparent background on Linux:

However, on Android the background shows as black (I've added an image behind the GodotFragment container so I should be able to see it if Godot's background is transparent):

Steps to reproduce

1. Clone my fork of the GLTF Viewer.
2. In Android Studio, open the project and sync Gradle.
3. Run the apps.gltf_viewer run configuration.
4. Observe that the image of the Godot icon isn't visible behind the GodotFragment, and instead the area that should be transparent is black.

Minimal reproduction project (MRP)

I've modified the GLTF Viewer referenced in the docs with these changes. My fork can be found here.

[llama-nl]

I think this is expected. Do you have any examples application that has functionality like this? And if you want to see your mobile bg you can take device wallpaper using AndroidRuntime and put this in background.

[m4gr3d]

@llama-nl It's a bug as we don't respect the project's transparency flags when we configure the SurfaceView used for rendering and the theme used for the generated app.