I want to use aspect ratio (for example, 1:3) when make a selection with rubberBand. How can i do it? By default it make selection with 1:1 ratio... in function mouseMoveEvent.

mywidget.h:

Qt Code: 
  1. #include <QtGui>
  2.  
  3. class MyWidget : public QWidget
  4. {
  5.     Q_OBJECT
  6.     public:
  7.         MyWidget (QWidget* parent = 0);
  8.     protected:
  9.         void mouseMoveEvent(QMouseEvent *event);
  10.         void mousePressEvent(QMouseEvent *event);
  11.         void mouseReleaseEvent(QMouseEvent *event);
  12.     private:
  13.         QLabel* m_pixmapLabel;
  14.         QRubberBand* rubberBand;
  15.         QPoint origin;
  16. };
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main.cpp:

Qt Code: 
  1. #include <QApplication>
  2. #include <QtGui>
  3. #include "mywidget.h"
  4.  
  5. MyWidget::MyWidget(QWidget* parent): QWidget(parent)
  6. {
  7.      m_pixmapLabel = new QLabel;
  8.      rubberBand = new QRubberBand(QRubberBand::Rectangle, this);
  9.      QVBoxLayout* mainLayout = new QVBoxLayout;
  10.      QPixmap pm;
  11.      pm.load("image.jpg");
  12.      m_pixmapLabel->setPixmap(pm);
  13.      mainLayout->addWidget(m_pixmapLabel);
  14.      setLayout(mainLayout);
  15.  
  16. }
  17.  
  18. void MyWidget::mouseMoveEvent(QMouseEvent *event)
  19. {
  20.    rubberBand->setGeometry(QRect(origin, event->pos()).normalized());
  21.  
  22. }
  23.  
  24. void MyWidget::mousePressEvent(QMouseEvent *event)
  25. {
  26.      origin = event->pos();
  27.      rubberBand->setGeometry(QRect(origin, QSize()));
  28.      rubberBand->show();
  29. }
  30.  
  31. void MyWidget::mouseReleaseEvent(QMouseEvent *event)
  32. {
  33.     rubberBand->hide();
  34.  
  35. }
  36.  
  37.  
  38. int main(int argc, char *argv[])
  39. {
  40.     QApplication application(argc, argv);
  41.     MyWidget window;
  42.     window.show();
  43.     return application.exec();
  44. }
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