flush draw events

[rbp]

hello,

In my program the user chooses a file with QFileDialog::getOpenFileName() and then a heavy operation gets performed on that file.
My problem is that the dialog is still partly visible during the heavy operation.

What is a good strategy to make sure the dialog is completely hidden before I start the heavy operation? Is there a way to flush all the draw events. Or do I need to wait some milliseconds?

I'm sure this problem is common but I didn't notice anything useful in the QWidget API or this forum.

Richard

[munna]

QFileDialog::getOpenFileName() returns the path to the existing file. The file dialog should be hidden as soon as the path is returned. The operation that you perform on the file should not be the reason for the dialog still being visible.

Can you post the code here for better understanding of the problem?

[rbp]

By partially visible I mean the background widget has not refreshed properly so the dialog is still visible. Do you know a way to flush all pending draw events?

The relevant code:

QString file = QFileDialog::getOpenFileName(this, "Select file");
doHeavyEvent(file);

QString file = QFileDialog::getOpenFileName(this, "Select file");
doHeavyEvent(file);

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[spirit]

try to add qApp->processEvent(); in doHeavyEvent(file); or move "havy operations" in worker thread. first approach is simpler.

[rbp]

thanks spirit. I couldn't easily get a reference to the application variable but fortunately processEvents() is static:

QCoreApplication::processEvents();

QCoreApplication::processEvents();

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[wysota]

The application object is globally available through a "qApp" variable or using QCoreApplication::instance() static call.

[rbp]

oh really, I didn't realize Qt exposed global references. Is there a list available of the global variables in Qt?

[wysota]

Actually in Qt4 qApp is not a global variable but a macro that expands to QCoreApplication::instance() (or QApplication::instance(), depending which header file you included).