Method

Gtk.Widget.add_tick_callback

Declaration [src]

guint
gtk_widget_add_tick_callback (
  GtkWidget* widget,
  GtkTickCallback callback,
  gpointer user_data,
  GDestroyNotify notify
)

Description [src]

Queues an animation frame update and adds a callback to be called before each frame.

Until the tick callback is removed, it will be called frequently (usually at the frame rate of the output device or as quickly as the application can be repainted, whichever is slower). For this reason, is most suitable for handling graphics that change every frame or every few frames. The tick callback does not automatically imply a relayout or repaint. If you want a repaint or relayout, and aren’t changing widget properties that would trigger that (for example, changing the text of a GtkLabel), then you will have to call gtk_widget_queue_resize() or gtk_widget_queue_draw() yourself.

gdk_frame_clock_get_frame_time() should generally be used for timing continuous animations and gdk_frame_timings_get_predicted_presentation_time() if you are trying to display isolated frames at particular times.

This is a more convenient alternative to connecting directly to the GdkFrameClock::update signal of GdkFrameClock, since you don’t have to worry about when a GdkFrameClock is assigned to a widget.

Parameters

callback GtkTickCallback
 

function to call for updating animations

user_data gpointer
 

data to pass to callback

notify GDestroyNotify
 

function to call to free user_data when the callback is removed.

Return value

Returns: guint

an id for the connection of this callback. Remove the callback by passing the id returned from this function to gtk_widget_remove_tick_callback()