Added selection history. Hit escape key to go back to last selected area

sleepyhead/Graphs/gGraphView.cpp

@@ -1574,6 +1574,13 @@ void gGraphView::mouseReleaseEvent(QMouseEvent *event)
         m_button_down = false;
         m_metaselect = event->modifiers() & Qt::ShiftModifier;
 
+        const int max_history = 20;
+
+        history.push_front(SelectionHistoryItem(m_minx, m_maxx));
+        if (history.size() > max_history) {
+            history.pop_back();
+        }
+
         if (m_metaselect) {
             m_point_released = event->pos();
         } else {
@@ -1592,6 +1599,15 @@ void gGraphView::keyReleaseEvent(QKeyEvent *event)
         m_metaselect = false;
         timedRedraw(50);
     }
+    if (event->key() == Qt::Key_Escape) {
+        if (history.size() > 0) {
+            SelectionHistoryItem h = history.takeFirst();
+            SetXBounds(h.minx, h.maxx);
+        } else {
+
+        }
+        return;
+    }
 #ifdef BROKEN_OPENGL_BUILD
         QWidget::keyReleaseEvent(event);
 #else

sleepyhead/Graphs/gGraphView.h

@@ -152,6 +152,23 @@ class gToolTip : public QObject
     void timerDone();
 };
 
+struct SelectionHistoryItem {
+    SelectionHistoryItem() {
+        minx=maxx=0;
+    }
+    SelectionHistoryItem(quint64 m1, quint64 m2) {
+        minx=m1;
+        maxx=m2;
+    }
+
+    SelectionHistoryItem(const SelectionHistoryItem & copy) {
+        minx = copy.minx;
+        maxx = copy.maxx;
+    }
+    quint64 minx;
+    quint64 maxx;
+};
+
 /*! \class gGraphView
     \brief Main OpenGL Graph Area, derived from QGLWidget
 
@@ -446,6 +463,8 @@ class gGraphView
     bool m_showsplitter;
 
     qint64 m_minx, m_maxx;
+
+    QList<SelectionHistoryItem> history;
     float print_scaleX, print_scaleY;
 
     QPixmap previous_day_snapshot;