1798147 - Mouse position offset without title bar

Status: UNCONFIRMED

(Core :: Widget: Gtk, defect)

Description

[Yichao Yu]

User Agent: Mozilla/5.0 (X11; Linux aarch64; rv:106.0) Gecko/20100101 Firefox/106.0

Steps to reproduce:

Regression from version 104.
ArchLinuxARM on aarch64.
Tested with clean profile.

• Disable title bar
• Resize the window to ~half screen (not sure what size exactly is the threshold)
• A blank area would appear on the left of the list of tabs.

Actual results:

All the mouse events are shifted by roughly the size of that blank area to the left. It's as if that blank area shifted where the top left corner of the window is. The coordinate shift happens across the whole window, including the web page and the browser UI.

Expected results:

The mouse event (hover, click) should happen to the UI element under the mouse.

Comment 1

[Yichao Yu]

Actually this is not related to that blank area directly but only happen when the window was tiled to the side of the screen.

Comment 2

[Yichao Yu]

Attachment: Screenshot showing the blank area and the offset in mouse position detection.

Comment 3

[Yichao Yu]

Actually this seems to be a gtk issue or at least bad interaction with kwin and gtk3/4.

I've tested a few other programs with client side decoration.

• One using qt6 doesn't have this problem.
• Chromium (gtk3) has this problem for the UI but not for the webpage.
• Firefox (gtk3) has this problem for UI and webpage
• gedit (gtk4) has this problem for the whole app

Comment 4

[Yichao Yu]

(correction: gedit was gtk3)

Comment 5

[Yichao Yu]

And somehow I can’t reproduce on x86 archlinux

Comment 6

[Emilio Cobos Álvarez [:emilio]]

If this repros on other GTK apps, it's unlikely to be a Firefox bug...