Added TransitionControl and plot rewinding.

New component overlays main view and handles middle clicks/drags
to performing rewinding. Also sports smooth transitioning back to
current projection whenever the mouse button is lifted.

Next up, the same kind of transitions in the displayed values.

1 files changed, 41 insertions, 0 deletions

diff --git a/transitioncontrol.h b/transitioncontrol.h
new file mode 100644
index 0000000..ac84786
--- /dev/null
+++ b/transitioncontrol.h
@@ -0,0 +1,41 @@
+#ifndef TRANSITIONCONTROL_H
+#define TRANSITIONCONTROL_H
+
+#include <QQuickItem>
+
+/*
+ * This component emits signals indicating how far from its left edge is the
+ * mouse since the mouse button was pressed (starting from t == 1.0 with 0.0
+ * being exactly at the left edge). As the mouse is released, it emits periodic
+ * signals incrementing the value until it is restored to the default.
+ */
+class TransitionControl :
+    public QQuickItem
+{
+    Q_OBJECT
+public:
+    TransitionControl();
+    double t() const { return m_t; }
+
+signals:
+    void tChanged(double t) const;
+
+public slots:
+    void setT(double t);
+
+protected:
+    void mousePressEvent(QMouseEvent *event);
+    void mouseMoveEvent(QMouseEvent *event);
+    void mouseReleaseEvent(QMouseEvent *event);
+
+private:
+    double m_t;
+
+    // The x pos where interaction started
+    int m_startPos;
+
+    // Controls the smooth rewind transition
+    QThread *m_rewindThread;
+};
+
+#endif // TRANSITIONCONTROL_H