Raspberry and QT: application not visible on VNC
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Hi, I added "-v" as run argument. But I don't understand how this could show if the xcb support is missing.
I mean, I'm not using or calling nothing that uses xcb.. Only if I add "-platform xcb" I'm specifying that.So I tried to add both: -v -platform xcb
but the result is the same, the application crashes at boot and in the output I can see this:
Can someone explain me how to install xcb that is obviously missing? Should be installed in the target (RPi) or in the developemnt VM (Ubuntu)?
@Andreagugu I was talking about adding -v to configure command you can find in Qt source code...
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Not sure to understand what you mean sorry. I'm not an expert of QT..
@jsulm said in Raspberry and QT: application not visible on VNC:
adding -v to configure command you can find in Qt source code...
for me this tell me nothing.
I tried to find the file "libqxcb.so" and I placed it into plugins/platforms/ folder and it is recognized somehow because calling the app with argument "-platform xcb" still not working but xcb is into the list.. maybe copy&paste doesn't mean correctly installed.
Any help?
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Not sure to understand what you mean sorry. I'm not an expert of QT..
@jsulm said in Raspberry and QT: application not visible on VNC:
adding -v to configure command you can find in Qt source code...
for me this tell me nothing.
I tried to find the file "libqxcb.so" and I placed it into plugins/platforms/ folder and it is recognized somehow because calling the app with argument "-platform xcb" still not working but xcb is into the list.. maybe copy&paste doesn't mean correctly installed.
Any help?
@Andreagugu said in Raspberry and QT: application not visible on VNC:
adding -v to configure command you can find in Qt source code...
Did you cross-compile Qt yourself?
If so, at some point you run command like this on your host PC:./configure -release -opengl es2 -device ...
in that case, @jsulm is asking you to run the command below and provide its output:
./configure -v
you can also get same information by looking at file config.opt in that same folder where you configured/built Qt framework
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I'm not cross-compile Qt by myself.
I installed Qt on Ubuntu, I configured device inside options.. when I run the application I simply press on Debug button!
What do you mean with cross-compile by yourself?!I found something like you speak about inside the folder "device" in the installation path:

this is something that can help?
I try to ask it again: if I need xcb plugin platform, there is a way to install? all tentative was not successful.
the problem is in the Ubuntu installation or raspberry in your opinion? at which level this xcb should work?in my understanding, based on the fact that having a program build I should add argument "-platform xcb" and should work
means simply that on raspberry the plugin is missing, right? -
I'm not cross-compile Qt by myself.
I installed Qt on Ubuntu, I configured device inside options.. when I run the application I simply press on Debug button!
What do you mean with cross-compile by yourself?!I found something like you speak about inside the folder "device" in the installation path:

this is something that can help?
I try to ask it again: if I need xcb plugin platform, there is a way to install? all tentative was not successful.
the problem is in the Ubuntu installation or raspberry in your opinion? at which level this xcb should work?in my understanding, based on the fact that having a program build I should add argument "-platform xcb" and should work
means simply that on raspberry the plugin is missing, right?@Andreagugu Looks like we need to clarify some things:
- Do you build your app on your Raspberry Pi or on a host machine?
- How did you install Qt for your Raspberry Pi?
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I build the application in the host machine (Ubuntu).
I followed some guide on the web.. after some tentatives :-P I found the way to make it working.
Basically I configure the device as remove device linux with his IP address, etc.. and then Qt could build and deploy the application built. I could also debug, breakpoints, etc.. it works quite well.

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I build the application in the host machine (Ubuntu).
I followed some guide on the web.. after some tentatives :-P I found the way to make it working.
Basically I configure the device as remove device linux with his IP address, etc.. and then Qt could build and deploy the application built. I could also debug, breakpoints, etc.. it works quite well.

@Andreagugu Glad to hear this!
Please mark your thread as solved then. -
Sorry but.. what I solved??
From the first post I wrote that the tool chain is working.
Is not this the problem! I can run the application shown on the physical display HDMI but not on VNC as I need finally.The problem that I still having is that the visualization is shown as framebuffers and I'm not able to show my application in
the standard display :0 !!The question is: developing an application with QT5 on Ubuntu deployed on Raspberry, could show the result in the display :0?
If yes... good, please explain how because searching on the web I'm not able to find the way. -
Sorry but.. what I solved??
From the first post I wrote that the tool chain is working.
Is not this the problem! I can run the application shown on the physical display HDMI but not on VNC as I need finally.The problem that I still having is that the visualization is shown as framebuffers and I'm not able to show my application in
the standard display :0 !!The question is: developing an application with QT5 on Ubuntu deployed on Raspberry, could show the result in the display :0?
If yes... good, please explain how because searching on the web I'm not able to find the way.@Andreagugu "I'm not cross-compile Qt by myself." - then how do you build your app on Ubuntu host machine for raspberry Pi?!
You need a cross compiled Qt to do so.
http://wiki.qt.io/Raspberry_Pi_Beginners_Guide -
I build the application on Qt installed on Ubuntu. So I write the code.. I click on "Build button" and then I press "Run" or "Start debugging F5" and magically the application on Raspberry starts.
As already wrote many times the tool chain is working. From my side is not clear what does it mean "....by myself" it seems I have to call some script or launch commands manually.. by myself...
What do it mean for you?
Sorry but I installed the tool chain for the first time it was easy to configure following most probably the guide you linked, I don't remember which one, you can find many on the web.But again the tool chain is working!! Have you understood what is the problem? Then we can try to find a solution.
When I wrote "no, I'm not cross-compiling by myself" is because for example the command "./configure bla bla bla..." I haven't to call, simply F5.. RUN.Maybe is more easy if you answer my question first.. if the answer is no we have done.