gtk/docs/reference/gdk-pixbuf/tmpl/refcounting.sgml

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Reference Counting and Memory Mangement

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Functions for reference counting and memory management on pixbufs.

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  <para>
    #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.
  </para>

  <note>
    <para>
      As #GdkPixbuf is derived from #GObject now, gdk_pixbuf_ref() and
      gdk_pixbuf_unref() are deprecated in favour of g_object_ref()
      and g_object_unref () resp.
    </para>
  </note>

  <para>
    <emphasis>Finalizing</emphasis> 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.
  </para>

  <para>
    As an extension to traditional reference counting, #GdkPixbuf
    structures support defining a handler for the last unref
    operation.  If g_object_unref() is called on a #GdkPixbuf
    structure that has a reference count of 1, i.e. its last
    reference, then the pixbuf's last unref handler function will be
    called.  It is up to this function to determine whether to
    finalize the pixbuf using gdk_pixbuf_finalize() or to just
    continue execution.  This can be used to implement a pixbuf cache
    efficiently; please see the programmer's documentation for
    details.
  </para>

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     the programmer's docs.
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  <para>
    #GdkPixbuf, gdk_pixbuf_new_from_data().
  </para>

<!-- ##### USER_FUNCTION GdkPixbufDestroyNotify ##### -->
  <para>
    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.
  </para>

@pixels: The pixel array of the pixbuf that is being finalized.
@data: User closure data.


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  <para>

  </para>

@pixbuf: 
@Returns: 


<!-- ##### FUNCTION gdk_pixbuf_unref ##### -->
<para>

</para>

@pixbuf: