+ /** computes the timeline frame (sample) of an event whose coordinates
+ * are in canvas units (pixels, scroll offset included).
+ */
+ framepos_t canvas_event_frame (GdkEvent const *, double* px = 0, double* py = 0) const;
+
+ /** computes the timeline frame (sample) of an event whose coordinates
+ * are in window units (pixels, no scroll offset).
+ */
+ framepos_t window_event_frame (GdkEvent const *, double* px = 0, double* py = 0) const;