Defined in:Sets the track task callback function for a viewport widget.
void SetTrackTaskCallback(TrackTaskCallback *callback, void *cookie = nullptr);
||A pointer to the track task callback function.|
||A user-defined pointer that is passed to the callback function.|
SetTrackTaskCallbackfunction installs a callback function that is called once per frame after a mouse down event has occurred inside a viewport widget and before a mouse up event occurs. The
callbackparameter should point to a function having the following prototype.
The first parameter passed to the callback function is the mouse position in local viewport coordinates, and the second parameter is a pointer to the viewport inside which a mouse event occurred. The last parameter receives the pointer specified by the
typedef void TrackTaskCallback(const Point2D&, ViewportWidget *, void *);
The current track task callback function is called when the viewport widget's
Widget::TrackTaskfunction is called by the Interface Manager.
nullptr, then any currently installed track task callback function is removed.