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

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<!-- ##### SECTION Title ##### -->
Image Data in Memory
<!-- ##### SECTION Short_Description ##### -->
Creating a pixbuf from image data that is already in memory.
<!-- ##### SECTION Long_Description ##### -->
<para>
The most basic way to create a pixbuf is to wrap an existing pixel
buffer with a #GdkPixbuf structure. You can use the
gdk_pixbuf_new_from_data() function to do this You need to specify
the destroy notification function that will be called when the
data buffer needs to be freed; this will happen when a #GdkPixbuf
is finalized by the reference counting functions If you have a
chunk of static data compiled into your application, you can pass
in #NULL as the destroy notification function so that the data
will not be freed.
</para>
<para>
The gdk_pixbuf_new() function can be used as a convenience to
create a pixbuf with an empty buffer. This is equivalent to
allocating a data buffer using malloc() and then wrapping it with
gdk_pixbuf_new_from_data(). The gdk_pixbuf_new() function will
compute an optimal rowstride so that rendering can be performed
with an efficient algorithm.
</para>
<para>
As a special case, you can use the gdk_pixbuf_new_from_xpm_data()
function to create a pixbuf from inline XPM image data.
</para>
<para>
You can also copy an existing pixbuf with the gdk_pixbuf_copy()
function. This is not the same as just doing a gdk_pixbuf_ref()
on the old pixbuf; the copy function will actually duplicate the
pixel data in memory and create a new #GdkPixbuf structure for it.
</para>
Your eyes are bloodshot. Your eyes are bloodshot. Your mouth starts to foam. Your hands are shaking. You know your need your fix. NEED MORE ABSTRACTION! 2000-04-12 Federico Mena Quintero <federico@helixcode.com> This comes from an excellent idea by Tim Janik (timj@gtk.org) to hook to the last unref operation. * gdk-pixbuf/gdk-pixbuf.c (gdk_pixbuf_set_last_unref_handler): New function to set the last unref handler for a pixbuf. (gdk_pixbuf_finalize): New function to actually finalize a pixbuf. It calls the pixbuf's destroy notification function and frees the GdkPixbuf structure itself. (gdk_pixbuf_unref): Use the last unref function of the pixbuf if available. * gdk-pixbuf/gdk-pixbuf-private.h (struct _GdkPixbuf): New fields for the last unref handler and its user data. * gdk-pixbuf/gdk-pixbuf-data.c (gdk_pixbuf_new_from_data): Use g_new0() to allocate the pixbuf. * gdk-pixbuf/gdk-pixbuf-loader.c (gdk_pixbuf_loader_class_init): Fixed the call to gtk_signal_new() for the "frame_done" signal; it was not specifying the `frame' argument. * gdk-pixbuf/gdk-pixbuf-animation.c (gdk_pixbuf_animation_get_width): Fixed docstring. (gdk_pixbuf_animation_get_height): Likewise. (gdk_pixbuf_animation_get_num_frames): Likewise. (gdk_pixbuf_animation_get_frames): Likewise. * doc/gdk-pixbuf-sections.txt: Updated with the new functions and types. * doc/tmpl/gdk-pixbuf.sgml: Added the description for GdkColorspace. * doc/tmpl/scaling.sgml: Added the description for GdkInterpType. * doc/tmpl/refcounting.sgml: Updated with the information about the last unref handler. * doc/tmpl/*.sgml: Markup tweaks. * gdk-pixbuf/Makefile.am (libgnomecanvaspixbuf_la_LDFLAGS): Sigh, update the libtool version number for libgnomecanvaspixbuf as well. (libpixbufloader_*_la_LDFLAGS): The loaders need to be versioned as well, or the old ones won't work with the new stuff. Also, renamed the modules as follows. * gdk-pixbuf/gdk-pixbuf-io.c (gdk_pixbuf_load_module): Now the modules are called "libpixbufloader-<format>.so" instead of "libpixbuf-<format>.so". They needed renaming so that the new loaders won't overwrite the old ones; even with the versioning stuff, the new .so symlink to the .so.1.0.0 would overwrite the old real .so file.
2000-04-13 01:18:41 +00:00
<!-- ##### SECTION See_Also ##### -->
<para>
gdk_pixbuf_finalize().
</para>
<!-- ##### FUNCTION gdk_pixbuf_new ##### -->
<para>
</para>
@colorspace:
@has_alpha:
@bits_per_sample:
@width:
@height:
@Returns:
<!-- ##### FUNCTION gdk_pixbuf_new_from_data ##### -->
<para>
</para>
@data:
@colorspace:
@has_alpha:
@bits_per_sample:
@width:
@height:
@rowstride:
@destroy_fn:
@destroy_fn_data:
@Returns:
<!-- ##### FUNCTION gdk_pixbuf_new_from_xpm_data ##### -->
<para>
</para>
@data:
@Returns:
doh, this was broken beyond believe. Tue Dec 12 23:46:44 2000 Tim Janik <timj@gtk.org> * gtk/stock-icons/Makefile.am: doh, this was broken beyond believe. * gtk/gtkbox.c: change property types from (u)long to (u)int for ::position and ::padding. * gtk/gtkcontainer.c: make ::border_width an INT property. * gtk/gtkpacker.c: make ::position an INT property. * gtk/gtkscrolledwindow.c (gtk_scrolled_window_adjustment_changed): guard against NULL h/v scrollbars, since this is used at construction time. * gtk/gtkclist.[hc]: nuked gtk_clist_construct(), implemented internal gtk_clist_constructor(). * gtk/gtkctree.[hc]: nuked gtk_ctree_construct(), implemented gtk_ctree_constructor(). * gtk/gtkprogressbar.c (gtk_progress_bar_class_init): property ::pulse_step should use ARG_PULSE_STEP, not ARG_FRACTION. * docs/reference/Makefile.am: fun stuff, disabled docs generation again, gtk-scan.c needs to introspec paramspecs, not GtkAgs. * gtk/gtkwidget.[hc]: removed gtk_widget_setv(), gtk_widget_getv(), gtk_widget_newv() and gtk_widget_get(). (gtk_widget_new): use g_object_new_valist(). (gtk_widget_set): use g_object_set_valist(). * gtk/gtkobject.[hc]: removed gtk_object_arg_get_info(), gtk_object_getv(), gtk_object_query_args(), gtk_object_newv(), gtk_object_class_add_signals(), gtk_object_class_user_signal_new(), gtk_object_class_user_signal_newv(), gtk_object_arg_set(), gtk_object_arg_get(), gtk_object_args_collect(), gtk_object_default_construct(), gtk_object_constructed(), GTK_CONSTRUCTED and GTK_OBJECT_CONSTRUCTED(). removed nsignals, signals and n_args members from GtkObjectClass. (gtk_object_new): use g_object_new_valist(). (gtk_object_set): use g_object_set_valist(). (gtk_object_get): use g_object_get_valist(). * gtk/gtkcompat.h: define gtk_object_default_construct(). * gtk/gtktypeutils.c (gtk_type_new): create constructed objects via g_object_new(). * gtk/*.c: removed gtk_object_class_add_signals() from class_init() fucntions, cleaned up method assignments (make sure your structures are setup properly before calling out). removed all GTK_CONSTRUCTED hacks ;)
2000-12-13 01:34:41 +00:00
<!-- ##### FUNCTION gdk_pixbuf_new_subpixbuf ##### -->
<para>
</para>
@src_pixbuf:
@src_x:
@src_y:
@width:
@height:
@Returns:
<!-- ##### FUNCTION gdk_pixbuf_copy ##### -->
<para>
</para>
@pixbuf:
@Returns: <!--
Local variables:
mode: sgml
sgml-parent-document: ("../gdk-pixbuf.sgml" "book" "refsect2" "")
End:
-->