Keep image scaled to fit into window

imagescrollarea.cpp

@@ -11,6 +11,7 @@ ImageScrollArea::ImageScrollArea(QWidget *parent) : QScrollArea(parent)
 
 void ImageScrollArea::setImage(const QPixmap &img)
 {
+    m_pixmap = img;
     QPixmap pix = img.scaled(size(), Qt::KeepAspectRatio, Qt::SmoothTransformation);
     m_label->setPixmap(pix);
     m_label->resize(pix.size());
@@ -38,3 +39,10 @@ void ImageScrollArea::mousePressEvent(QMouseEvent *event)
 {
     m_lastPos = event->pos();
 }
+
+void ImageScrollArea::resizeEvent(QResizeEvent *event)
+{
+    m_label->setPixmap(m_pixmap.scaled(event->size(), Qt::KeepAspectRatio, Qt::SmoothTransformation));
+    m_label->resize(event->size());
+    QScrollArea::resizeEvent(event);
+}

imagescrollarea.h

@@ -8,6 +8,7 @@ class ImageScrollArea : public QScrollArea
 {
     QPoint m_lastPos;
     QLabel *m_label;
+    QPixmap m_pixmap;
 public:
     explicit ImageScrollArea(QWidget *parent = 0);
     void setImage(const QPixmap &img);
@@ -16,6 +17,7 @@ protected:
     void keyReleaseEvent(QKeyEvent *event);
     void mouseMoveEvent(QMouseEvent *event);
     void mousePressEvent(QMouseEvent *event);
+    void resizeEvent(QResizeEvent *event);
 };
 
 #endif // IMAGESCROLLAREA_H