* #GisCallback objects are used for custom drawing functions. A common example
* of this would be to render something which does not easily fit into a normal
* object. For instance, a Heads-Up-Display overlay.
+ *
+ * Callbacks are an alternate to extending GisObject with a new class and
+ * should be used when only once instance of the object will be needed.
*/
#include <config.h>
#include "gis-callback.h"
-/* GisCallback */
-G_DEFINE_TYPE(GisCallback, gis_callback, GIS_TYPE_OBJECT);
-static void gis_callback_init(GisCallback *cb)
-{
-}
-
-static void gis_callback_class_init(GisCallbackClass *klass)
-{
-}
-
/**
* gis_callback_new:
* @callback: the function to call to draw the object
*
* Returns: the new #GisCallback
*/
-GisCallback *gis_callback_new(GisCallbackFunc callback, gpointer user_data)
+GisCallback *gis_callback_new(GisCallbackFunc draw_cb, gpointer user_data)
{
GisCallback *cb = g_object_new(GIS_TYPE_CALLBACK, NULL);
- cb->callback = callback;
+ cb->draw = draw_cb;
cb->user_data = user_data;
return cb;
}
+
+/* Proxy class methods to per-object methods */
+static void proxy_draw(GisObject *_cb, GisOpenGL *opengl)
+{
+ GisCallback *cb = GIS_CALLBACK(_cb);
+ if (cb->draw)
+ cb->draw(cb, opengl, cb->user_data);
+}
+
+/* GisCallback */
+G_DEFINE_TYPE(GisCallback, gis_callback, GIS_TYPE_OBJECT);
+static void gis_callback_init(GisCallback *cb)
+{
+}
+
+static void gis_callback_class_init(GisCallbackClass *klass)
+{
+ GisObjectClass *object_class = GIS_OBJECT_CLASS(klass);
+ object_class->draw = proxy_draw;
+}