[qt5] repainting qwidget

[zodiac]

Hello.

void dUpload::show( Qt::WindowFlags flags )
{
	//setWindowFlags( flags );
 
	setAttribute(Qt::WA_NoSystemBackground, true);
 
	show();
}

void dUpload::show( Qt::WindowFlags flags )
{
	//setWindowFlags( flags );

	setAttribute(Qt::WA_NoSystemBackground, true);

	show();
}

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After call setAttribute function from this code my qwidget doesn't repaint (i.e. I see artefacts from child widgets), but when I resize that widget, then it repaints.

Is it bug in qt5 or I do something wrong?

OS: win7 + msvs 2010.

[wysota]

What does your paint event look like?

[zodiac]

Firstly (when I created this topic) I didn't use paintEvent.
Now it is:

void dUpload::paintEvent( QPaintEvent *event )
{
	QPainter p(this);
	p.setCompositionMode(QPainter::CompositionMode_Clear);
	p.fillRect(0, 0, width(), height(), Qt::BrushStyle::SolidPattern);
}

void dUpload::paintEvent( QPaintEvent *event )
{
	QPainter p(this);
	p.setCompositionMode(QPainter::CompositionMode_Clear);
	p.fillRect(0, 0, width(), height(), Qt::BrushStyle::SolidPattern);
}

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and this resolved my problem (artefacts goes away). But I think it's just hack

[wysota]

So why are you using the NoSystemBackground attribute?

[zodiac]

So why are you using the NoSystemBackground attribute?

I need to make my widget glass-styled (windows 7), and for that I use this code:

void dUpload::show( Qt::WindowFlags flags )
{
	setWindowFlags( flags );
 
	//setAttribute(Qt::WA_NoSystemBackground, true); // 1
	setAttribute(Qt::WA_TranslucentBackground, true); // 2
 
	if ( QtWin::isCompositionEnabled() )
		QtWin::extendFrameIntoClientArea( this );
 
	show();
}

void dUpload::show( Qt::WindowFlags flags )
{
	setWindowFlags( flags );

	//setAttribute(Qt::WA_NoSystemBackground, true); // 1
	setAttribute(Qt::WA_TranslucentBackground, true); // 2

	if ( QtWin::isCompositionEnabled() )
		QtWin::extendFrameIntoClientArea( this );

	show();
}

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1 and 2 are equal, i.e. widget will be glassed, but not repainted.

UPD: screenshot when it doesn't repaint:

[wysota]

They are definitely not equal. (1) is wrong, (2) is correct.

[zodiac]

They are definitely not equal. (1) is wrong, (2) is correct.

But widget also doesn't automatically repaint when (2) is activated.

[wysota]

It does repaint. It just doesn't paint its background.

[zodiac]

It does repaint. It just doesn't paint its background.

Do you mean this is normal behaviour? But in qt4 I didn't see any artefacts.

[wysota]

Qt5 is still pre-beta, so I would expect glitches.

[zodiac]

Qt5 is still pre-beta, so I would expect glitches.

Ok, I thought such bugs can't be in beta.

[wysota]

It's not beta, it's pre-beta. Besides I don't know if what you experience is a glitch or not. I'm just saying glitches are expected.