Repositioning a label with mouseevents to anywhere on the screen - c++

Question

I've created a label and used setPixmap to attach a .png image to the label. I've also setWindowFlags to disable the title bar and create a frameless window. Because I've disabled those, it also disables the ability to drag anything around, so I want to create mouseevents (unless there's a better method) to position my label anywhere on the screen exactly like dragging the frame of a window. How would I do that? An example and brief explanation would be greatly appreciated.

Answer 1

reimplement the QMouseEvents you need .... like
void MyLabel::mousePressEvent(QMouseEvent* e)
{
m_moveDatWidget = true;
// so when the mousebutton got pressed, you set something to
// tell your code to move the widget ... consider maybe you
// want to move it only on right button pressed ...
}
void MyLabel::mouseReleaseEvent(QMouseEvent* e)
{
m_moveDatWidget = false;
// after releasing do not forget to reset the movement variable
}
void MyLabel::mouseMoveEvent(QMouseEvent* e)
{
// when in 'moving state' ...
if (m_moveDatWidget)
{
// move your widget around using QWidget::move(qreal,qreal)
}
}
this is only a really basic implementation but it should do well if you calculate the desired movement correct :)

Answer 2

I would implement the label dragging by mouse in the following way:
class Label : public QLabel
{
public:
// Implement the constructor(s)
protected:
void Label::mouseMoveEvent(QMouseEvent* event)
{
if (!m_offset.isNull()) {
move(event->globalPos() - m_offset);
}
QLabel::mouseMoveEvent(event);
}
void Label::mousePressEvent(QMouseEvent* event)
{
// Get the mouse offset in the label's coordinates system.
m_offset = event->globalPos() - pos();
QLabel::mousePressEvent(event);
}
void Notifier::mouseReleaseEvent(QMouseEvent* event)
{
m_offset = QPoint();
QLabel::mouseReleaseEvent(event);
}
private:
// The mouse pointer offset from the top left corner of the label.
QPoint m_offset;
};