Qt setMask and resizing

[bunjee]

Are you sure there is no simpler way ?

Anybody reimplemented the resize window algorithm on a QWidget ?

[jpn]

Are you sure there is no simpler way ?

What's more simple than placing a QSizeGrip into each corner (possibly with help of QGridLayout) and voilá? Optionally you can subclass QSizeGrip and reimplement its paintEvent() handler to draw nothing. I mean, QSizeGrip provides resizing functionality into each direction out of the box.

[jpn]

Give it a try:

// main.cpp
#include <QtGui>
 
class MaskWindow : public QWidget
{
public:
	MaskWindow()
	{
		QGridLayout* grid = new QGridLayout(this);
		grid->addWidget(new QSizeGrip(this), 0, 0, Qt::AlignTop | Qt::AlignLeft);
		grid->addWidget(new QSizeGrip(this), 0, 2, Qt::AlignTop | Qt::AlignRight);
		grid->addWidget(new QSizeGrip(this), 2, 0, Qt::AlignBottom | Qt::AlignLeft);
		grid->addWidget(new QSizeGrip(this), 2, 2, Qt::AlignBottom | Qt::AlignRight);
		grid->addWidget(new QLabel("Content", this), 1, 1, Qt::AlignCenter);
		grid->setSpacing(0);
		grid->setMargin(0);
	}
 
protected:
	void resizeEvent(QResizeEvent* event)
	{
		QWidget::resizeEvent(event);
		setMask(rect());
	} 
};
 
int main(int argc, char *argv[])
{
	QApplication a(argc, argv);
	MaskWindow w;
	w.show();
	return a.exec();
}

// main.cpp
#include <QtGui>

class MaskWindow : public QWidget
{
public:
	MaskWindow()
	{
		QGridLayout* grid = new QGridLayout(this);
		grid->addWidget(new QSizeGrip(this), 0, 0, Qt::AlignTop | Qt::AlignLeft);
		grid->addWidget(new QSizeGrip(this), 0, 2, Qt::AlignTop | Qt::AlignRight);
		grid->addWidget(new QSizeGrip(this), 2, 0, Qt::AlignBottom | Qt::AlignLeft);
		grid->addWidget(new QSizeGrip(this), 2, 2, Qt::AlignBottom | Qt::AlignRight);
		grid->addWidget(new QLabel("Content", this), 1, 1, Qt::AlignCenter);
		grid->setSpacing(0);
		grid->setMargin(0);
	}

protected:
	void resizeEvent(QResizeEvent* event)
	{
		QWidget::resizeEvent(event);
		setMask(rect());
	} 
};

int main(int argc, char *argv[])
{
	QApplication a(argc, argv);
	MaskWindow w;
	w.show();
	return a.exec();
}

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[bunjee]

That's exactly what I just coded .

But,
It's only working for the corners of the widget, not for the sides.

So there is more work to do to completely emulate the window's behaviour.

[jpn]

But,
It's only working for the corners of the widget, not for the sides.

So there is more work to do to completely emulate the window's behaviour.

That's right. You might want to take a peek into QSizeGrip sources for implementation tips.