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Reference Counting and Memory MangementReference Counting and Memory Mangement — Functions for reference counting and memory management on pixbufs. |
GdkPixbuf structures are reference counted. This means that an
application can share a single pixbuf among many parts of the
code. When a piece of the program needs to keep a pointer to a
pixbuf, it should add a reference to it by calling g_object_ref().
When it no longer needs the pixbuf, it should subtract a reference
by calling g_object_unref(). The pixbuf will be destroyed when
its reference count drops to zero. Newly-created GdkPixbuf
structures start with a reference count of one.
As GdkPixbuf is derived from GObject now,
gdk_pixbuf_ref()andgdk_pixbuf_unref()are deprecated in favour ofg_object_ref()andg_object_unref()resp.
Finalizing a pixbuf means to free its pixel
data and to free the GdkPixbuf structure itself. Most of the
library functions that create GdkPixbuf structures create the
pixel data by themselves and define the way it should be freed;
you do not need to worry about those. The only function that lets
you specify how to free the pixel data is
gdk_pixbuf_new_from_data(). Since you pass it a pre-allocated
pixel buffer, you must also specify a way to free that data. This
is done with a function of type GdkPixbufDestroyNotify. When a
pixbuf created with gdk_pixbuf_new_from_data() is finalized, your
destroy notification function will be called, and it is its
responsibility to free the pixel array.
GdkPixbuf *
gdk_pixbuf_ref (GdkPixbuf *pixbuf);
gdk_pixbuf_ref has been deprecated since version 2.0 and should not be used in newly-written code.
Use g_object_ref().
Adds a reference to a pixbuf.
void
gdk_pixbuf_unref (GdkPixbuf *pixbuf);
gdk_pixbuf_unref has been deprecated since version 2.0 and should not be used in newly-written code.
Use g_object_unref().
Removes a reference from a pixbuf.
void (*GdkPixbufDestroyNotify) (guchar *pixels,gpointer data);
A function of this type is responsible for freeing the pixel array
of a pixbuf. The gdk_pixbuf_new_from_data() function lets you
pass in a pre-allocated pixel array so that a pixbuf can be
created from it; in this case you will need to pass in a function
of GdkPixbufDestroyNotify so that the pixel data can be freed
when the pixbuf is finalized.