Gtk.Widget.Add_Tick_Callback_User_Data

Entities

Generic formal parameters

Access Types

Subprograms

Description

Add_Tick_Callback

function Add_Tick_Callback
   (Widget    : not null access Gtk.Widget.Gtk_Widget_Record'Class;
    Callback  : Gtk_Tick_Callback;
    User_Data : User_Data_Type) return Guint

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 Gtk.Label.Gtk_Label), then you will have to call Gtk.Widget.Queue_Resize or Gtk.Widget.Queue_Draw_Area 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 Gdk.Frame_Clock.Gdk_Frame_Clock::update signal of Gdk.Frame_Clock.Gdk_Frame_Clock, since you don't have to worry about when a Gdk.Frame_Clock.Gdk_Frame_Clock is assigned to a widget. Since: gtk+ 3.8

Parameters
Widget
Callback

function to call for updating animations

User_Data

data to pass to Callback

Return Value

an id for the connection of this callback. Remove the callback by passing it to Gtk.Widget.Remove_Tick_Callback

Destroy

procedure Destroy (Data : in out User_Data_Type)
Parameters
Data

Gtk_Tick_Callback

type Gtk_Tick_Callback is access function
  (Widget      : not null access Gtk.Widget.Gtk_Widget_Record'Class;
   Frame_Clock : not null access Gdk.Frame_Clock.Gdk_Frame_Clock_Record'Class;
   User_Data   : User_Data_Type) return Boolean;

Callback type for adding a function to update animations. See Gtk.Widget.Add_Tick_Callback. Since: gtk+ 3.8

Parameters
Widget

the widget

Frame_Clock

the frame clock for the widget (same as calling gtk_widget_get_frame_clock)

User_Data

user data passed to Gtk.Widget.Add_Tick_Callback.

Return Value

G_SOURCE_CONTINUE if the tick callback should continue to be called, G_SOURCE_REMOVE if the tick callback should be removed.

User_Data_Type

type User_Data_Type (<>) is private;