QDialog don't show widgets, when method show() calling

[Vinod Kuntoji]

@oBOXPOH ,

Are you showing dialog inside thread?

[oBOXPOH]

I used Sleep() as example. If instead of Sleep() I want compute something during showing dialog, what can I do?

[SGaist]

Except that you will block the main thread and thus your dialog will not show until its too late.

If you have a long computational process running you should consider maybe using QtConcurrent and wire that properly with your GUI.

[oBOXPOH]

@Vinod-Kuntoji said in QDialog don't show widgets, when method show() calling:

@oBOXPOH ,

Are you showing dialog inside thread?

I show dialog, when something button was clicked. During this dialog some computing task must execute. When this task finish, this dialog must close.

[Vinod Kuntoji]

@oBOXPOH ,

Are you talking about progressbar?

[oBOXPOH]

@Vinod-Kuntoji said in QDialog don't show widgets, when method show() calling:

@oBOXPOH ,

Are you talking about progressbar?

Just about some dialog with text without any buttons. If it easier for you, yes, about progressbar.

[mrjj]

Hi

• Just about some dialog with text without any buttons. If it easier for you, yes, about progressbar.

Its not so much about being easier.
Its a concrete class
http://doc.qt.io/qt-5/qprogressbar.html

Also
WaitingDialog *dlg = new WaitingDialog;
dlg->show();
Sleep(10000); <<< here u lag all of application. nothing can be drawn and u will first see dialog after 10 secs.

Sleep cannot be used to simulate a workload.

[oBOXPOH]

@mrjj said in QDialog don't show widgets, when method show() calling:

Hi

• Just about some dialog with text without any buttons. If it easier for you, yes, about progressbar.

Its not so much about being easier.
Its a concrete class
http://doc.qt.io/qt-5/qprogressbar.html

Also
WaitingDialog *dlg = new WaitingDialog;
dlg->show();
Sleep(10000); <<< here u lag all of application. nothing can be drawn and u will first see dialog after 10 secs.

Sleep cannot be used to simulate a workload.

I know! I wrote Sleep() only for example. But even in this case dlg->show() doesn't show content of the dialog, shows only title and window.

[mrjj]

@oBOXPOH

Ok, but you description of your issue , sounds 100% when a poster loop/sleep the main thread and
other windows shows up as empty becuase there is no time to draw the child widgets.

dlg->show() doesn't show content of the dialog, shows only title and window.

Well do you call a loop or something else after you open the dialog ?

Clearly
WaitingDialog *dlg = new WaitingDialog;
dlg->show();

must work and i assume the widget IN the dialog is made with UI file so all should be ok ?

There is something you are not telling :)

[Vinod Kuntoji]

@oBOXPOH ,

WaitingDialog *dlg = new WaitingDialog;
dlg->exec();

connect(dlg,SIGNAL(aborted()),dlg,SLOT(stopDialog()));
connect(yourWidget,SIGNAL(executionComplete()),dlg,SLOT(stopDialog()));

void WaitingDialog::stopDialog() {
this->close();
emit aborted();
}

[oBOXPOH]

@Vinod-Kuntoji said in QDialog don't show widgets, when method show() calling:

@oBOXPOH ,

WaitingDialog *dlg = new WaitingDialog;
dlg->exec();

connect(dlg,SIGNAL(aborted()),dlg,SLOT(stopDialog()));
connect(yourWidget,SIGNAL(executionComplete()),dlg,SLOT(stopDialog()));

void WaitingDialog::stopDialog() {
this->close();
emit aborted();
}

It seems logical. I'll try. Thanks!

[VRonin]

I'll say what everybody else is afraid to say. Because this is not the solution Gotham deserves but it's the one it needs right now:
just add QApplication::processEvents(); after dlg.show();

[mrjj]

@VRonin
hehe first time i seen the evil QApplication::processEvents() served with a batman quote :))

[oBOXPOH]

@VRonin said in QDialog don't show widgets, when method show() calling:

I'll say what everybody else is afraid to say. Because this is not the solution Gotham deserves but it's the one it need right now:
just add QApplication::processEvents(); after dlg.show();

It's working! Thanks a lot! Great!