Synopsis#include <gtk/gtk.h> GtkDrawingArea; GtkWidget* gtk_drawing_area_new (void); void gtk_drawing_area_size (GtkDrawingArea *darea, gint width, gint height); Object HierarchyGObject +----GInitiallyUnowned +----GtkObject +----GtkWidget +----GtkDrawingArea +----GtkCurve Description
The GtkDrawingArea widget is used for creating custom user interface
elements. It's essentially a blank widget; you can draw on
The following code portion demonstrates using a drawing area to display a circle in the normal widget foreground color. Note that GDK automatically clears the exposed area to the background color before sending the expose event, and that drawing is implicitly clipped to the exposed area. Example 45. Simple GtkDrawingArea usage. gboolean expose_event_callback (GtkWidget *widget, GdkEventExpose *event, gpointer data) { gdk_draw_arc (widget->window, widget->style->fg_gc[GTK_WIDGET_STATE (widget)], TRUE, 0, 0, widget->allocation.width, widget->allocation.height, 0, 64 * 360); return TRUE; } [...] GtkWidget *drawing_area = gtk_drawing_area_new (); gtk_widget_set_size_request (drawing_area, 100, 100); g_signal_connect (G_OBJECT (drawing_area), "expose_event", G_CALLBACK (expose_event_callback), NULL);
Expose events are normally delivered when a drawing area first comes
onscreen, or when it's covered by another window and then uncovered
(exposed). You can also force an expose event by adding to the "damage
region" of the drawing area's window;
The available routines for drawing are documented on the GDK Drawing Primitives page.
See also
To receive mouse events on a drawing area, you will need to enable
them with DetailsGtkDrawingAreatypedef struct _GtkDrawingArea GtkDrawingArea; The GtkDrawingArea struct contains private data only, and should be accessed using the functions below. gtk_drawing_area_new ()GtkWidget* gtk_drawing_area_new (void); Creates a new drawing area.
gtk_drawing_area_size ()void gtk_drawing_area_size (GtkDrawingArea *darea, gint width, gint height); Warning
(Use
See Also
Sometimes GtkImage is a useful alternative to a drawing area.
You can put a GdkPixmap in the GtkImage and draw to the GdkPixmap,
calling |