Does a qt5 virtual framebuffer exist?
Ok, so i'm totally new to Qt and am trying to get up to speed for a new embedded project that I'm going to be working on. I have both Qt4 and Qt5 installed on my host machine (running Fedora). I can successfully create a Qt5 Widget Application that runs from Qt Creator. I can also compile and run my app using qmake-qt5 and make.
But now I would like to see what the app would look like on a monochrome display so I thought i could run it with -platform linuxfb while running the Qt Virtual Framebuffer from Qt4. However, when i do this, the virtual frame buffer runs just fine (with a blank screen obviously) but my app shows the following errors:
Unable to figure out framebuffer device. Specify it manually.
linuxfb: Failed to initialize screen
no screens available, assuming 24-bit color
Cannot create window: no screens available
Abort (core dumped)
The error implies that I need to tell it which display to actually use but I am not sure how to do that. I have tried various things, such as using -display QVFb:0 as described here:
But that didn't seem to work.
I feel like I am missing something fundamental here. Can i run a Qt 5 application against a Virtual Framebuffer or is that not supported?
Thanks in advance for any help you can give me.
Hi and welcome to devnet,
AFAIK, QVfb is a Qt 4 only feature
@SGaist Ok thanks for the response!
Out of curiosity, why monochrome ?
@SGaist not my choice :-) Our hardware / business team has price targets they need to meet. I guess they feel that color is too expensive!
Depending on your device you should directly work with it like e.g. the Raspberry Pi
@SGaist yes i plan to do that eventually... i'm just waiting on co-worker to provide me the proper toolchain / deployment mechanism for our custom board. I was hoping to jumpstart my development using the virtual framebuffer capabilities. Maybe i should just do my app in QT4? Is there any benefit to QT5 that I'd be missing... as you can imagine the GUI will be a very simple monochrome display with no touch screen or mouse. The end product is a desk phone so the input is just buttons.
Thanks for your time! I appreciate it.
To jumpstart you can indeed go with Qt 4 and the virtual frame buffer. Be aware however that Qt 4 will only see one more patch release (AFAIK) but no more minor release. Once you have your board, you can always go on Qt 5
@SGaist Do you have any idea why they dropped support for the virtual framebuffer in Qt5?
No, I don't know that. You can try asking in the #qt IRC channel on freenode or the interest mailing list