Cursor Tracking with Gnome Shell Magnifier on Wayland

[Lee Clark]

Affected version
GNOME 3.36 - 3.40.
Ubuntu 20.04, 20.10, 21.04 and Fedora 34 Beta.
Wayland only.
Bug summary
When running GNOME shell with Wayland, the cursor and focus tracking functionality of the magnifier (a11y feature) do not correctly compute the cursor/focus location. The position is calculated from the top left of the window but the windows position is not included. This causes the magnifier to track the wrong location when the window is not maximiser or is on a second monitor.

I suspect this is related to the way in which wayland is designed. But my experience in this area is minimal. When using X11 this feature works correctly.

The wiki page states that under wayland the cursor and focus tracking work but this information is either out dated or was not tested correctly.

Steps to reproduce
From the Gnome desktop, open a terminal by pressing ctrl + alt + t or by opening the activities overlay and searching for "terminal".
Press super + left arrow key to maximize the terminal window on the left side of the screen.
Activity the magnifier by pressing super + alt + 8.
Type text into the terminal window. The magnified view will move with the text cursor.
Press super + right arrow key to maximize the terminal windows on the right side of the screen.
Type text into the terminal. The magnified view will move but it will not show the text cursor. It will move when text is entered but will focus on the left side of the screen.
What happened
The magnified view does not follow the text/focus cursor correctly.

What did you expect to happen
The magnified view should follow the cursor and show the cursor as it does when the widnows is maximized. The correct behaviour can also be seen in Gnome shell running with X11.

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: gnome-shell 3.38.4-1ubuntu2
ProcVersionSignature: Ubuntu 5.11.0-16.17-generic 5.11.12
Uname: Linux 5.11.0-16-generic x86_64
ApportVersion: 2.20.11-0ubuntu65
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Thu Apr 22 20:55:25 2021
DisplayManager: gdm3
GsettingsChanges:
 b'org.gnome.shell' b'command-history' redacted by apport
 b'org.gnome.desktop.input-sources' b'sources' b"[('xkb', 'gb')]"
 b'org.gnome.desktop.interface' b'gtk-im-module' b"'gtk-im-context-simple'"
 b'org.gnome.desktop.privacy' b'report-technical-problems' b'true'
InstallationDate: Installed on 2021-04-22 (0 days ago)
InstallationMedia: Ubuntu 21.04 "Hirsute Hippo" - Beta amd64 (20210331.1)
RelatedPackageVersions: mutter-common 3.38.4-1ubuntu2
SourcePackage: gnome-shell
UpgradeStatus: No upgrade log present (probably fresh install)

[Lee Clark (lclark125)]

Upstream bug: https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/4112

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.
Ubuntu 21.04 (hirsute) reached end-of-life on January 20, 2022.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test. If you then find the bug is still present in the newer Ubuntu version, please add a comment here telling us which new version it is in.

[Daniel van Vugt (vanvugt)]

Upstream bug gnome-shell#4112 was closed as a duplicate of #5509 which was fixed in gnome-shell 43.0 via !2301