1844226 - [Wayland] PIP window has no opaque region

Status: NEW

(Core :: Widget: Gtk, defect, P3)

Description

[Jan Alexander Steffens [:heftig]]

Picture-in-picture windows are rectangular and have no transparent parts, not even a drop shadow.

Enabling GNOME Shell's opaque region debugging marks Picture-in-Picture windows as potentially transparent (tinted purple). However, given the above, they should get marked entirely opaque (tinted green).

Not having a correct opaque region increases the cost of compositing PIP windows.

Comment 1

[Martin Stránský [:stransky] (ni? me)]

Jan, do you mind to investigate it more?

PIP window should not be transparent:
https://searchfox.org/mozilla-central/rev/907db2c22743f1b24496198b10a3dca4085cfb08/widget/gtk/nsWindow.cpp#5946

so I wonder where the transparency come from. May it be related to utility window type?
https://searchfox.org/mozilla-central/rev/907db2c22743f1b24496198b10a3dca4085cfb08/widget/gtk/nsWindow.cpp#5997

Comment 2

[Jan Alexander Steffens [:heftig]]

Disabling widget.transparent-windows fixes PIP windows but breaks popup menus. Since this just affects the app-paintable property, it looks like we're seeing GtkWindow's default opaque region.