[SOLVED] [Qt, image-formats, plugins] I do not understand this framework anymore.
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[Qt, image-formats, plugins] I do not understand this framework anymore.
Here is my problem:
How do I publicize the location of a system-wide plugins-directory upon installation of my own application?
And add
... if the directory is anyway a system-wide setting, relative to $QTDIR (the installation-path of the Qt-framework in use)
...
And why should I need this in the first place?
Observation
An application which reads diverse image-formats since 2004, does so in the development environment, but no longer after installation of the only executable in /usr/bin.
One conclusion after some research
The image-formats are handled by plugin libraries which are found in the plugins directory, relative to $QTDIR.
AFAIS, you can set the paths to diverse plugins and plugin-directories programmatically... but why should I? What do I know about the installation-paths on any other computer?
Chances are, my English failed me again, when I was reading the docs. Can you do this in pigeon-english for me, PSE?
TY.
PS.: The application in question is in my blog.
PPS.: DARN.
Last edited by Michael Uplawski; 04-17-2018 at 09:25 AM.
Reason: blog
in 5 there are changes to the core qt system file locations
and some api changes
Thank you John. I am aware of the API changes and they do not frighten me. In fact I had to modify the code at different spots to make it run with Qt5..; now it looks like have not bungled this part.
The “qt system file locations” may have changed, but why should I have to bother? This may be a new obligation, introduced with Qt5 and it appears to be exactly the source of my troubles. More precisely these “plugins” which come from nowhere and suddenly impose that I care for them.
After installation, it seems to me both versions work fine.
I should be nervous, reading that the program may run on one system, maybe many systems, but still fails on my own.
But with respect to all the mess that I have created in my configurations in the past, your observation may just point at yet another one of my own destructive interventions.., that I have lost track of in the meantime.
Thank you norobro. I shall scrutinize my development environment for the glitch.
STOP and Edit: Does the program read and display Tiff-files, PNG, BMP and the like or is it JPEG only?
Last edited by Michael Uplawski; 04-17-2018 at 02:00 PM.
Reason: !JPEG
All QT_INSTALL variables are pointing at /usr, while Qt is installed in /opt.
Without knowing if it can solve anything, I will reinstall the whole framework, as this confusion must originate in the way that Qt had been installed.
Grepping through the divers *.conf files for qmake does not help me find the error. We'll see.
Uninstall / Reinstall... you know. Like in the old times of Windows®.
And YEP! That “solved it”.
While trying to understand a problem is part of the solution-finding and understanding is part of the solution, this time, again, the only thing I learned is: Ask Folks Who Know Stuff!
I still have to set the LD_LIBRARY_PATH to the lib-subdirectory of the installed SDK-version, but the plugins appear to be found and qmake -query knows again, what it is doing.
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