Receiving QMousePressEvents above QPushButton in the parrent widget

[marcel]

Well, not necessarily block them. Just acknowledge them. Think of it as a way for the frameless widget to know that mouse was pressed or moved somewhere inside it.
So there is no need to block them, just let them pass through, but also do something specific: move the widget.

The mouse coordinates can be extracted from the event itself, so you need only a function in the frameless widget that moves it. You can call it from the event filter for every mouse move event that you get. As for the rest, just call the base class version of eventFilter, don't interfere with the events.

[aMan]

BinCalc::BinCalc(QWidget *parent)  {
	..
	pushButton_0->installEventFilter(this);
}
 
bool BinCalc::eventFilter(QObject* watched, QEvent* event) //BinCalc is the frameless widget
{	
	if(event->type()==QEvent::MouseButtonPress) {
		QPoint posInPushButton=dynamic_cast<QMouseEvent*>(event)->pos();
		QPoint posOfPushButton=dynamic_cast<QWidget*>(watched)->pos();
		m_moveStartPos=posInPushButton+posOfPushButton;
	}
 
	return QWidget::eventFilter(watched, event);
}

BinCalc::BinCalc(QWidget *parent)  {
	..
	pushButton_0->installEventFilter(this);
}

bool BinCalc::eventFilter(QObject* watched, QEvent* event) //BinCalc is the frameless widget
{	
	if(event->type()==QEvent::MouseButtonPress) {
		QPoint posInPushButton=dynamic_cast<QMouseEvent*>(event)->pos();
		QPoint posOfPushButton=dynamic_cast<QWidget*>(watched)->pos();
		m_moveStartPos=posInPushButton+posOfPushButton;
	}
	
	return QWidget::eventFilter(watched, event);
}

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This code works but is very slow (It flickers when moving. This doesn't happen when moving with the line edit.) Is there a possibility to make it faster?

edit: I've noticed, that the button isn't activated (it doesn't get the event). So it doesn't work
edit2: it is activated, but it has no animation

[marcel]

I'm not sure.
Can you post the part where you move the widget and how do you call it?

[aMan]

Sure

void BinCalc::mouseMoveEvent(QMouseEvent* event) {
	move(event->globalX()-m_moveStartPos.x(),
		  event->globalY()-m_moveStartPos.y());
}
 
void BinCalc::mousePressEvent(QMouseEvent* event) {
	m_moveStartPos = event->pos();
	QWidget::mousePressEvent(event);
}

void BinCalc::mouseMoveEvent(QMouseEvent* event) {
	move(event->globalX()-m_moveStartPos.x(),
		  event->globalY()-m_moveStartPos.y());
}

void BinCalc::mousePressEvent(QMouseEvent* event) {
	m_moveStartPos = event->pos();
	QWidget::mousePressEvent(event);
}

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[marcel]

You're moving the widget for every move event.
try adding a boolean flag in your class. Set it to true when the mouse button is pressed and to false on release.

In mouse move event, move the widget only if the flag is true.

edit: I've noticed, that the button isn't activated (it doesn't get the event). So it doesn't work
edit2: it is activated, but it has no animation

That's not normal. It should get the events and behave normal.

[aMan]

You're moving the widget for every move event.
try adding a boolean flag in your class. Set it to true when the mouse button is pressed and to false on release.

In mouse move event, move the widget only if the flag is true.

Are you sure? If mouse tracking is of, mouseMoveEvent is only called if the button is pressed.

[marcel]

I don't trust mouse tracking . Well of course it gets called only when the button is press, I just forget that.

Anyway, you get flicker because you m_moveStartPos is in local widget coordinates. It should also be in global coordinates.

Somewhere in the QWidget documentation it is stated that when performing moves, the passed coordinates should be global, to avoid flicker.

[aMan]

Thank you for you help, problem solved. I had to add the mouse move event to the filter too.

bool BinCalc::eventFilter(QObject* watched, QEvent* event)
{
	if(event->type()==QEvent::MouseButtonPress) {
		QPoint posInPushButton=dynamic_cast<QMouseEvent*>(event)->pos();
		QPoint posOfPushButton=dynamic_cast<QWidget*>(watched)->pos();
		m_moveStartPos=posInPushButton+posOfPushButton;
	}
	else if(event->type()==QEvent::MouseMove) {
		mouseMoveEvent(dynamic_cast<QMouseEvent*>(event));
	}
 
	return QWidget::eventFilter(watched, event);
}

bool BinCalc::eventFilter(QObject* watched, QEvent* event)
{
	if(event->type()==QEvent::MouseButtonPress) {
		QPoint posInPushButton=dynamic_cast<QMouseEvent*>(event)->pos();
		QPoint posOfPushButton=dynamic_cast<QWidget*>(watched)->pos();
		m_moveStartPos=posInPushButton+posOfPushButton;
	}
	else if(event->type()==QEvent::MouseMove) {
		mouseMoveEvent(dynamic_cast<QMouseEvent*>(event));
	}
	
	return QWidget::eventFilter(watched, event);
}

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