gtk2/gdk-pixbuf/gdk-pixbuf-animation.c
Jonathan Blandford 84c85a1a11 Added progressive animation loading. Added progressive animation loading.
2000-01-07  Jonathan Blandford  <jrb@redhat.com>

	* gdk-pixbuf/gdk-pixbuf-io.c: Added progressive animation loading.
	* gdk-pixbuf/gdk-pixbuf-io.h: Added progressive animation loading.
	* gdk-pixbuf/gdk-pixbuf-loader.c: Added progressive animation
	loading.
	* gdk-pixbuf/gdk-pixbuf-loader.h: Added progressive animation
	loading.
	* gdk-pixbuf/io-gif.c (image_load_increment): I think the
	ref-counting mess is finally fixed.  Added progressive animation
	loading.

I think progressive animation loading all works now.  It's all
documented too, if anyone wants to play with it.
2000-01-07 18:29:13 +00:00

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/* GdkPixbuf library - Simple animation support
*
* Copyright (C) 1999 The Free Software Foundation
*
* Authors: Jonathan Blandford <jrb@redhat.com>
* Havoc Pennington <hp@redhat.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <config.h>
#include "gdk-pixbuf-io.h"
/**
* gdk_pixbuf_animation_new_from_file:
* @filename: Name of file to load.
*
* Creates a new animation by loading it from a file. The file format is
* detected automatically. If the file's format does not support multi-frame
* images, then an animation with a single frame will be created.
*
* Return value: A newly created animation with a reference count of 1, or NULL
* if any of several error conditions ocurred: the file could not be opened,
* there was no loader for the file's format, there was not enough memory to
* allocate the image buffer, or the image file contained invalid data.
**/
GdkPixbufAnimation *
gdk_pixbuf_animation_new_from_file (const char *filename)
{
GdkPixbufAnimation *animation;
int size;
FILE *f;
guchar buffer [128];
GdkPixbufModule *image_module;
g_return_val_if_fail (filename != NULL, NULL);
f = fopen (filename, "r");
if (!f)
return NULL;
size = fread (&buffer, 1, sizeof (buffer), f);
if (size == 0) {
fclose (f);
return NULL;
}
image_module = gdk_pixbuf_get_module (buffer, size);
if (!image_module) {
g_warning ("Unable to find handler for file: %s", filename);
fclose (f);
return NULL;
}
if (image_module->module == NULL)
gdk_pixbuf_load_module (image_module);
if (image_module->load_animation == NULL) {
GdkPixbuf *pixbuf;
GdkPixbufFrame *frame;
/* Keep this logic in sync with gdk_pixbuf_new_from_file() */
if (image_module->load == NULL) {
fclose (f);
return NULL;
}
fseek (f, 0, SEEK_SET);
pixbuf = (* image_module->load) (f);
fclose (f);
if (pixbuf)
g_assert (pixbuf->ref_count > 0);
else
return NULL;
frame = g_new (GdkPixbufFrame, 1);
frame->pixbuf = pixbuf;
frame->x_offset = 0;
frame->y_offset = 0;
frame->delay_time = -1;
frame->action = GDK_PIXBUF_FRAME_RETAIN;
animation = g_new0 (GdkPixbufAnimation, 1);
animation->ref_count = 1;
animation->n_frames = 1;
animation->frames = g_list_prepend (NULL, frame);
} else {
fseek (f, 0, SEEK_SET);
animation = (* image_module->load_animation) (f);
fclose (f);
}
return animation;
}
/**
* gdk_pixbuf_animation_ref:
* @animation: An animation.
*
* Adds a reference to an animation. It must be released afterwards using
* gdk_pixbuf_animation_unref().
**/
void
gdk_pixbuf_animation_ref (GdkPixbufAnimation *animation)
{
g_return_if_fail (animation != NULL);
g_return_if_fail (animation->ref_count > 0);
animation->ref_count++;
}
/**
* gdk_pixbuf_animation_unref:
* @animation: An animation.
*
* Removes a reference from an animation. It will be destroyed when the
* reference count drops to zero. At that point, all the frames in the
* animation will be freed and their corresponding pixbufs will be unreferenced.
**/
void
gdk_pixbuf_animation_unref (GdkPixbufAnimation *animation)
{
g_return_if_fail (animation != NULL);
g_return_if_fail (animation->ref_count > 0);
animation->ref_count--;
if (animation->ref_count == 0) {
GList *l;
GdkPixbufFrame *frame;
for (l = animation->frames; l; l = l->next) {
frame = l->data;
gdk_pixbuf_unref (frame->pixbuf);
g_free (frame);
}
g_list_free (animation->frames);
g_free (animation);
}
}