KDE/Wayland: Backintime has a Wayland icon in the taskbar

[parrenin]

When run under KDE/Wayland, Backintime does not have its proper icon in the taskbar.
Instead, it has a Wayland icon.

[aryoda]

Which version of BiT did you use? The commonly rolled-out 1.2.1 or a newer one (eg. from here at github)?

[parrenin]

I use 1.3.2 from debian testing.

[aryoda]

May be related to https://bugs.kde.org/show_bug.cgi?id=447845 and there-in linked further bug reports: App ID does not match desktop file name so the icon is not found on Wayland (but works on X11)...

[parrenin]

I got a similar problem with Gnumeric, which was fixed:
https://gitlab.gnome.org/GNOME/gnumeric/-/issues/677
So I was wondering if anything can be learned from the Gnumeric's case.
I ran backintime-qt with WAYLAND_DEBUG=1 and I got set_app_id("python3").
So I guess the app_id is wrong, it should be "backintime-qt".
Fixing this is beyond my skills, but if somebody fixes it, I will be happy.

[aryoda]

We are using Qt5 for the GUI and the challenge will be to find a python API in Qt5 that does always work (not only on Wayland).

I just saw a python example which sets the app id but uses a Wayland window class (not Qt5):
https://github.com/sde1000/python-wayland/blob/b017596de0d550aabfc24a26554a22e43ceb7861/demo.py#L127

Edit: It looks like it could work by setting QGuiApplication::setDesktopFileName(QStringLiteral("libreoffice-startcenter.desktop")); correctly (found in this diff). QGuiApplication is contained in PyQt5.QtGui

BiT does instantiate a QApplication (to use QtWidgets) instead of a QGuiApplication (uses QML) but the setter is also available and could be added to

backintime/qt/qttools.py

Lines 153 to 168 in b4dd2d1

	def createQApplication(app_name = 'Back In Time'):
	global qapp
	try:
	return qapp
	except NameError:
	pass
	if Version(QT_VERSION_STR) >= Version('5.6') and \
	hasattr(Qt, 'AA_EnableHighDpiScaling'):
	QApplication.setAttribute(Qt.AA_EnableHighDpiScaling)
	qapp = QApplication(sys.argv)
	qapp.setApplicationName(app_name)
	if os.geteuid() == 0 and \
	qapp.style().objectName().lower() == 'windows' and \
	'GTK+' in QStyleFactory.keys():
	qapp.setStyle('GTK+')
	return qapp

eg.

    qapp = QApplication(sys.argv)
    qapp.setDesktopFileName("backintime-qt") # TODO find the right app id and protect with "try" since the setter exists only since v5.7

Edit 2: "backintime-qt" works for the non-root GUI in Manjaro KDE Plasma with Wayland. As root still the Wayland icon is shown (I'll do some more testing...)

[aryoda]

BTW: Setting the App ID to identify the related .desktop file is not only important for displaying the correct icon:

https://nicolasfella.de/posts/importance-of-desktop-file-mapping/

[aryoda]

@parrenin I have just opened the PR #1336 to fix this. It would be great if you could test this fix on your machine.

You can clone and test the fixed version from my clone https://github.com/aryoda/backintime/tree/issue/1244_wrong_icon_on_wayland or the PR itself:

git clone https://github.com/aryoda/backintime.git
git switch issue/122_wrong_icon_on_wayland
cd backintime/common
./configure
make
make test
sudo make install
cd ../qt
./configure
make
sudo make install

I think you have to go through all the configure/make/make test/make install machinery of common and qt so there is some risk doing this on a non-testing machine (up to you).

I have tested this on a Manjaro KDE Plasma VM with Wayland.

[parrenin]

Sorry, but I get an error:

# git switch issue/122_wrong_icon_on_wayland
fatal: référence invalide : issue/122_wrong_icon_on_wayland

[parrenin]

I patched by hand and it works, thanks!

By the way, make install installs directly in /usr/bin/.
I would suggest to install in /usr/local/bin by default, to not override the distro package.

[aryoda]

I patched by hand and it works, thanks!

Thanks a lot for backtesting!

By the way, make install installs directly in /usr/bin/.
I would suggest to install in /usr/local/bin by default, to not override the distro package.

Thanks for this hint! Yes, for testing purposes it would be great to do a parallel installation and I have used
make install here (which is the official way of installation - package maintainers also use this)
because we currently have no other make target for installing a separate release candidate.

I will discuss this with the team.

[buhtz]

By the way, make install installs directly in /usr/bin/.
I would suggest to install in /usr/local/bin by default,

I see it the same. See the SO-answer to compare the different bin folders.

to not override the distro package.

No matter if we install in /usr/bin or /usr/local/bin the question is if we should do this at all. Maybe the make-file should check for the existence of a bit installation and avoid installation?

[aryoda]

@buhtzz I'd say let's discuss this in our email news group to keep the issue clean and don't mix topics here

[emtiu]

Fixed by merging #1336. Thanks, everyone!

[emtiu]

Re-opening until the problem mentioned in #1336 (comment) is resolved.