# HG changeset patch
# User Hasan Yavuz ÖZDERYA <hy@ozderya.net>
# Date 2017-04-22 12:57:22
# Node ID c9d4060942ac8161894633ca65e910e98e855da9
# Parent  ebae6e42a84a9d8cc303365c13c7caa732e84d2f

added panning when ctrl is pressed

diff --git a/src/zoomer.cpp b/src/zoomer.cpp
--- a/src/zoomer.cpp
+++ b/src/zoomer.cpp
@@ -21,9 +21,13 @@
 #include <qwt_plot.h>
 #include <QtDebug>
 
+#include <QMouseEvent>
+
 Zoomer::Zoomer(QWidget* widget, bool doReplot) :
     ScrollZoomer(widget)
 {
+    is_panning = false;
+
     // set corner widget between the scrollbars with default background color
     auto cornerWidget = new QWidget();
     auto bgColor = cornerWidget->palette().color(QPalette::Window).name();
@@ -95,3 +99,43 @@ QRegion Zoomer::rubberBandMask() const
     const QRect r = QRect(pa.first(), pa.last()).normalized().adjusted(0, 0, 1, 1);
     return QRegion(r);
 }
+
+void Zoomer::widgetMousePressEvent(QMouseEvent* mouseEvent)
+{
+    if (mouseEvent->modifiers() & Qt::ControlModifier)
+    {
+        is_panning = true;
+        pan_point = invTransform(mouseEvent->pos());
+    }
+    else
+    {
+        ScrollZoomer::widgetMousePressEvent(mouseEvent);
+    }
+}
+
+void Zoomer::widgetMouseMoveEvent(QMouseEvent* mouseEvent)
+{
+    if (is_panning)
+    {
+        auto cur_point = invTransform(mouseEvent->pos());
+        auto delta = cur_point - pan_point;
+        moveBy(-delta.x(), -delta.y());
+        pan_point = invTransform(mouseEvent->pos());
+    }
+    else
+    {
+        ScrollZoomer::widgetMouseMoveEvent(mouseEvent);
+    }
+}
+
+void Zoomer::widgetMouseReleaseEvent(QMouseEvent* mouseEvent)
+{
+    if (is_panning)
+    {
+        is_panning = false;
+    }
+    else
+    {
+        ScrollZoomer::widgetMouseReleaseEvent(mouseEvent);
+    }
+}
diff --git a/src/zoomer.h b/src/zoomer.h
--- a/src/zoomer.h
+++ b/src/zoomer.h
@@ -41,6 +41,16 @@ protected:
     void drawRubberBand(QPainter* painter) const;
     /// Re-implemented for alpha background (masking is basically disabled)
     QRegion rubberBandMask() const;
+    /// Overloaded for panning
+    void widgetMousePressEvent(QMouseEvent* mouseEvent);
+    /// Overloaded for panning
+    void widgetMouseReleaseEvent(QMouseEvent* mouseEvent);
+    /// Overloaded for panning
+    void widgetMouseMoveEvent(QMouseEvent* mouseEvent);
+
+private:
+    bool is_panning;
+    QPointF pan_point;
 };
 
 #endif // ZOOMER_H