QDrag pixmap changes between Qt 6.4 and 6.10?
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Recently recompiled a Qt6 C++ application that had been running in Ubuntu 24.04 Qt 6.4.2, to Ubuntu 26.04, Qt 6.10.2. (x86_64,GNOME Wayland) Everything worked, except the visual feedback during a drag operation using QDrag (structured like the example code, and confined to a QFrame within the application main window).
With the older binary, the drag pixmap,which is set to an image of a small QLabel, being dragged, was clearly visible during the drag operation. In the new binary, the apparent object being dragged appears as just a cursor (a '+' with arrows on all ends) and the pixmap is never visible. The drag and drop action still works in the new environment, but the lack of the pixmap as feedback during the drag is a problem for users.
My quick scan of the release notes between versions did not reveal whatever change might explain this. I can run the old application in the newer Ubuntu 26.04 (by importing libraries) and the desired pixmap appears during drag operations. Any suggestions?
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Hi and welcome to devnet,
Are you in both cases using the distribution provided Qt ?
Can you check with a more recent version to see if it's still acting up ?
Did you check, when launching from the terminal, if there's any system generated message about the pixmap ?Interested in AI ? www.idiap.ch
Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct -
Hi and welcome to devnet,
Are you in both cases using the distribution provided Qt ?
Can you check with a more recent version to see if it's still acting up ?
Did you check, when launching from the terminal, if there's any system generated message about the pixmap ?@SGaist said in QDrag pixmap changes between Qt 6.4 and 6.10?:
Are you in both cases using the distribution provided Qt ?
Yes, these are the last two LTS releases of Ubuntu btw.
Did you check, when launching from the terminal, if there's any system generated message about the pixmap ?
No messages observed.
Can you check with a more recent version to see if it's still acting up ?
This was a shrewd suggestion, if a bit tedious to test: The expected drag behavior was restored in version 6.11.1 !
I know this is not the Qt package management forum, but am I correct in guessing that patches are unlikely to get backported to a 6.10 branch? Unless there is some application code workaround, likely I will need to look into snaps, flatpaks, and appimages etc to cover the expected runtime environments...
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@SGaist said in QDrag pixmap changes between Qt 6.4 and 6.10?:
Are you in both cases using the distribution provided Qt ?
Yes, these are the last two LTS releases of Ubuntu btw.
Did you check, when launching from the terminal, if there's any system generated message about the pixmap ?
No messages observed.
Can you check with a more recent version to see if it's still acting up ?
This was a shrewd suggestion, if a bit tedious to test: The expected drag behavior was restored in version 6.11.1 !
I know this is not the Qt package management forum, but am I correct in guessing that patches are unlikely to get backported to a 6.10 branch? Unless there is some application code workaround, likely I will need to look into snaps, flatpaks, and appimages etc to cover the expected runtime environments...
@Squeeqt said in QDrag pixmap changes between Qt 6.4 and 6.10?:
am I correct in guessing that patches are unlikely to get backported to a 6.10 branch?
Yes, Qt 6.10 will not receive any further releases.
likely I will need to look into snaps, flatpaks, and appimages etc to cover the expected runtime environments...
This might help: https://github.com/probonopd/linuxdeployqt
