GtkGestureZoom — Zoom gesture
GtkGestureZoom is a GtkGesture implementation able to recognize pinch/zoom gestures, whenever the distance between both tracked sequences changes, the “scale-changed” signal is emitted to report the scale factor.
GtkGesture * gtk_gesture_zoom_new (
Returns a newly created GtkGesture that recognizes zoom in/out gestures (usually known as pinch/zoom).
a newly created GtkGestureZoom
gdouble gtk_gesture_zoom_get_scale_delta (
gesture is active, this function returns the zooming difference since the gesture was recognized (hence the starting point is considered 1:1). If
gesture is not active, 1 is returned.
the scale delta
typedef struct _GtkGestureZoom GtkGestureZoom;
void user_function (GtkGestureZoom *controller, double scale, gpointer user_data)
This signal is emitted whenever the distance between both tracked sequences changes.
the object on which the signal is emitted
Scale delta, taking the initial state as 1:1
user data set when the signal handler was connected.
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