matrixion/src/ui/OverlayWidget.cc

#include "OverlayWidget.h"
#include <QEvent>

OverlayWidget::OverlayWidget(QWidget *parent)
    : QWidget(parent)
{
	if (parent) {
		parent->installEventFilter(this);
		setGeometry(overlayGeometry());
		raise();
	}
}

bool OverlayWidget::event(QEvent *event)
{
	if (!parent())
		return QWidget::event(event);

	switch (event->type()) {
	case QEvent::ParentChange: {
		parent()->installEventFilter(this);
		setGeometry(overlayGeometry());
		break;
	}
	case QEvent::ParentAboutToChange: {
		parent()->removeEventFilter(this);
		break;
	}
	default:
		break;
	}

	return QWidget::event(event);
}

bool OverlayWidget::eventFilter(QObject *obj, QEvent *event)
{
	switch (event->type()) {
	case QEvent::Move:
	case QEvent::Resize:
		setGeometry(overlayGeometry());
		break;
	default:
		break;
	}

	return QWidget::eventFilter(obj, event);
}

QRect OverlayWidget::overlayGeometry() const
{
	QWidget *widget = parentWidget();

	if (!widget)
		return QRect();

	return widget->rect();
}