QXcbConnection: XCB error: 8 (BadMatch),

gfxx

the mechanism:

1-qthread with opencv grab from camera...+ v4l.cpp integrted in it for right converting of image....(opencv meke some logical operation on image matrix)
2-matrix2Qimage functon
3-Qimage send to glwidg that use paint event to refresh QImage and convertitin the right dimension (i these way you can use opengl too and you can send multiple image if you wont...)
4-in gui qlabel show qimqge or multiple tranformation from opengl if you want.....

I show glwidg because opencv part use noting of qt part.... only matrix2qimage funcon...... glwidg use painter event ....other part of gui is right tested without glwidg....

Thnks for your help

Regards Giorgio

SGaist

Do you mean that you show the image twice ? Once with a QLabel and once with your QGLWidget ?

gfxx

Real Real Sorry.... no QLabel exist..... GLwidg and opencv calculation is my old application vision system... now I rewamp it in my new interface ... to do that I have copy and paste .ui an .h .cpp file .... I see now that not exist QLabel that now is my custom widget GLwidg.....

I must correct these:

the mechanism:

1-qthread with opencv grab from camera...+ v4l.cpp integrted in it for right converting of image....(opencv meke some logical operation on image matrix)
2-matrix2Qimage functon
3-Qimage send to glwidg that use paint event to refresh QImage and convertitin the right dimension (i these way you can use opengl too and you can send multiple image if you wont...) and show image in gui [stop here]
/// not exist ///4-in gui qlabel show qimqge or multiple tranformation from opengl if you want...../

Any how .....the error is still before the thread that creates the images begin to convey to glwidgt few frames .... I have a button to activate or not the Qthread with opencv capture .... The error occurs just start my application ... reading the link you gave me the error appears to be related to a window that does not open .... I put in /.../ all the code that launches messages or popup windows .... but XBC error remains .....

Please can someone explain to me what does QXcb ??

Regards
Giorgio

gfxx

ok I understand how not works ..... my app is quite large and not can control all in any situation ....

fortunately today I needed to launch a command from my interface .... I made a mistake and the machinery driven by the interface has returned an error to me properly .... just that the pop-up window notifying the error is not seen .. ... so I could verify that the notification window is broken somewhere ...but to some resources it is not available (it could be a font, an icon, an associated variable ... I do not know .... )

mystery solved ... almost ... now I have to see what that is hidden to the system.

regards
Giorgio

SGaist

Check whether you have any path that might be relative in your code.

gfxx

Strange these error .... Finally I found these ....

As I said the problem is a Qdialog ... these dialog is only a Waiting charge dialog with a circular progress bar .... first of insert my openCvWidget the code to start it was:

m_dia2 = new Dia2(this);
            m_dia2->setAttribute(Qt::WA_DeleteOnClose, true);
            m_dia2->setWindowFlags(Qt::Widget | Qt::FramelessWindowHint | Qt::WindowStaysOnTopHint);
            m_dia2->setAttribute(Qt::WA_NoSystemBackground, true);
            m_dia2->setAttribute(Qt::WA_TranslucentBackground, true);
            m_dia2->AutoBmecdia2Value(AutoCount);
            m_dia2->Stepbmecdia2Value(WaitingStep);
            m_dia2->show();

but now with "this" flag I Obtain QXcbConnection:XCB error 8 ......
for solve the error now the code is:

m_dia2 = new Dia2();
            m_dia2->setAttribute(Qt::WA_DeleteOnClose, true);
            m_dia2->setWindowFlags(Qt::Widget | Qt::FramelessWindowHint | Qt::WindowStaysOnTopHint);
            m_dia2->setAttribute(Qt::WA_NoSystemBackground, true);
            m_dia2->setAttribute(Qt::WA_TranslucentBackground, true);
            m_dia2->AutoBmecdia2Value(AutoCount);
            m_dia2->Stepbmecdia2Value(WaitingStep);
            m_dia2->show();

in these way the dialog can exist when myapp is close and not found other solution to close these dialog when my app close .... Why firt to add a new code I can use:

m_dia2 = new Dia2(this);

and after only:

m_dia2 = new Dia2();

???

regards
Giorgio

SGaist

From what widget are you calling this code ?

gfxx

from void in MainWindow .....

regards
Giorgio

SGaist

void is a type, do you mean in a slot from MainWindow ?

gfxx

I call it in c++ style some time from mainwindow slot sometime from qthread with connect signal slot but nevertimre directly every time calling it inside a mainwindows slot....

regards
giorgio

SGaist

How did you connect the signal from that QThread ?

gfxx

i have a slot in mainwindow that start qhread ... inside that slot I have a list of:

connect(mythread, SIGNAL(mysignal1(Qimage)), this, SLOT(mainwindosslot(QImage)), Qt::DirectConnection);

for example....

Ragards
Giorgio

SGaist

Why are you forcing a direct connection ?

This means that the slot will be called in the context of the thread managed by QThread which is not the GUI thread thus you are doing GUI related stuff from another thread which is not allowed.

gfxx

@SGaist ... you are in right .... tanks.

regards
miki