gtk/gdk-pixbuf/gdk-pixbuf-animation.c

/* 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 Lesser 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser 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 <errno.h>
#include "gdk-pixbuf-io.h"
#include "gdk-pixbuf-private.h"

static void gdk_pixbuf_animation_class_init (GdkPixbufAnimationClass *klass);
static void gdk_pixbuf_animation_finalize   (GObject        *object);



static gpointer parent_class;

GType
gdk_pixbuf_animation_get_type (void)
{
        static GType object_type = 0;

        if (!object_type) {
                static const GTypeInfo object_info = {
                        sizeof (GdkPixbufAnimationClass),
                        (GBaseInitFunc) NULL,
                        (GBaseFinalizeFunc) NULL,
                        (GClassInitFunc) gdk_pixbuf_animation_class_init,
                        NULL,           /* class_finalize */
                        NULL,           /* class_data */
                        sizeof (GdkPixbufAnimation),
                        0,              /* n_preallocs */
                        (GInstanceInitFunc) NULL,
                };
      
                object_type = g_type_register_static (G_TYPE_OBJECT,
                                                      "GdkPixbufAnimation",
                                                      &object_info, 0);
        }
  
        return object_type;
}

static void
gdk_pixbuf_animation_class_init (GdkPixbufAnimationClass *klass)
{
        GObjectClass *object_class = G_OBJECT_CLASS (klass);
        
        parent_class = g_type_class_peek_parent (klass);
        
        object_class->finalize = gdk_pixbuf_animation_finalize;
}

static void
gdk_pixbuf_animation_finalize (GObject *object)
{
        GdkPixbufAnimation *animation = GDK_PIXBUF_ANIMATION (object);

        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_OBJECT_CLASS (parent_class)->finalize (object);
}



/**
 * gdk_pixbuf_animation_new_from_file:
 * @filename: Name of file to load.
 * @error: return location for error
 *
 * 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. Possible errors
 * are in the #GDK_PIXBUF_ERROR and #G_FILE_ERROR domains.
 *
 * 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,
                                    GError    **error)
{
	GdkPixbufAnimation *animation;
	int size;
	FILE *f;
	guchar buffer [128];
	GdkPixbufModule *image_module;

	g_return_val_if_fail (filename != NULL, NULL);

	f = fopen (filename, "rb");
	if (!f) {
                g_set_error (error,
                             G_FILE_ERROR,
                             g_file_error_from_errno (errno),
                             _("Failed to open file '%s': %s"),
                             filename, g_strerror (errno));
		return NULL;
        }

	size = fread (&buffer, 1, sizeof (buffer), f);

	if (size == 0) {
                g_set_error (error,
                             GDK_PIXBUF_ERROR,
                             GDK_PIXBUF_ERROR_CORRUPT_IMAGE,
                             _("Image file '%s' contains no data"),
                             filename);
                
		fclose (f);
		return NULL;
	}

	image_module = gdk_pixbuf_get_module (buffer, size, filename, error);
	if (!image_module) {
		fclose (f);
		return NULL;
	}

	if (image_module->module == NULL)
                if (!gdk_pixbuf_load_module (image_module, error)) {
                        fclose (f);
                        return NULL;
                }

	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) {
                        g_set_error (error,
                                     GDK_PIXBUF_ERROR,
                                     GDK_PIXBUF_ERROR_UNSUPPORTED_OPERATION,
                                     _("Don't know how to load the animation in file '%s'"),
                                     filename);                        
			fclose (f);
			return NULL;
		}

		fseek (f, 0, SEEK_SET);
		pixbuf = (* image_module->load) (f, error);
		fclose (f);

                if (pixbuf == NULL && error != NULL && *error == NULL) {
                        /* I don't trust these crufty longjmp()'ing image libs
                         * to maintain proper error invariants, and I don't
                         * want user code to segfault as a result. We need to maintain
                         * the invariant that error gets set if NULL is returned.
                         */
                        
                        g_warning ("Bug! gdk-pixbuf loader '%s' didn't set an error on failure.",
                                   image_module->module_name);
                        g_set_error (error,
                                     GDK_PIXBUF_ERROR,
                                     GDK_PIXBUF_ERROR_FAILED,
                                     _("Failed to load image '%s': reason not known, probably a corrupt image file"),
                                     filename);
                }
                
		if (pixbuf == NULL)
                        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_object_new (GDK_TYPE_PIXBUF_ANIMATION, NULL);

		animation->n_frames = 1;
		animation->frames = g_list_prepend (NULL, frame);
		animation->width = gdk_pixbuf_get_width (pixbuf);
		animation->height = gdk_pixbuf_get_height (pixbuf);
	} else {
		fseek (f, 0, SEEK_SET);
		animation = (* image_module->load_animation) (f, error);

                if (animation == NULL && error != NULL && *error == NULL) {
                        /* I don't trust these crufty longjmp()'ing
                         * image libs to maintain proper error
                         * invariants, and I don't want user code to
                         * segfault as a result. We need to maintain
                         * the invariant that error gets set if NULL
                         * is returned.
                         */
                        
                        g_warning ("Bug! gdk-pixbuf loader '%s' didn't set an error on failure.",
                                   image_module->module_name);
                        g_set_error (error,
                                     GDK_PIXBUF_ERROR,
                                     GDK_PIXBUF_ERROR_FAILED,
                                     _("Failed to load animation '%s': reason not known, probably a corrupt animation file"),
                                     filename);
                }
                
		fclose (f);
	}

	return animation;
}

/**
 * gdk_pixbuf_animation_ref:
 * @animation: An animation.
 *
 * Adds a reference to an animation. Deprecated; use
 * g_object_ref(). The reference must be released afterwards using
 * g_object_unref().
 *
 * Return value: The same as the @animation argument.
 **/
GdkPixbufAnimation *
gdk_pixbuf_animation_ref (GdkPixbufAnimation *animation)
{
        return (GdkPixbufAnimation*) g_object_ref (G_OBJECT (animation));
}

/**
 * gdk_pixbuf_animation_unref:
 * @animation: An animation.
 * 
 * Removes a reference from an animation. Deprecated; use g_object_unref().
 **/
void
gdk_pixbuf_animation_unref (GdkPixbufAnimation *animation)
{
        g_object_unref (G_OBJECT (animation));
}

/**
 * gdk_pixbuf_animation_get_width:
 * @animation: An animation.
 *
 * Queries the width of the bounding box of a pixbuf animation.
 * 
 * Return value: Width of the bounding box of the animation.
 **/
int
gdk_pixbuf_animation_get_width (GdkPixbufAnimation *animation)
{
	g_return_val_if_fail (animation != NULL, -1);

	return animation->width;
}

/**
 * gdk_pixbuf_animation_get_height:
 * @animation: An animation.
 *
 * Queries the height of the bounding box of a pixbuf animation.
 * 
 * Return value: Height of the bounding box of the animation.
 **/
int
gdk_pixbuf_animation_get_height (GdkPixbufAnimation *animation)
{
	g_return_val_if_fail (animation != NULL, -1);

	return animation->height;
}

/**
 * gdk_pixbuf_animation_get_num_frames:
 * @animation: An animation.
 *
 * Queries the number of frames in a pixbuf animation.
 * 
 * Return value: Number of frames in the animation.
 **/
int
gdk_pixbuf_animation_get_num_frames (GdkPixbufAnimation *animation)
{
	g_return_val_if_fail (animation != NULL, -1);

	return animation->n_frames;
}

/**
 * gdk_pixbuf_animation_get_frames:
 * @animation: An animation.
 *
 * Queries the list of frames of an animation.
 * 
 * Return value: List of frames in the animation; this is a #GList of
 * #GdkPixbufFrame structures.
 **/
GList *
gdk_pixbuf_animation_get_frames (GdkPixbufAnimation *animation)
{
	g_return_val_if_fail (animation != NULL, NULL);

	return animation->frames;
}



/**
 * gdk_pixbuf_frame_get_pixbuf:
 * @frame: A pixbuf animation frame.
 * 
 * Queries the pixbuf of an animation frame.
 * 
 * Return value: A pixbuf.
 **/
GdkPixbuf *
gdk_pixbuf_frame_get_pixbuf (GdkPixbufFrame *frame)
{
	g_return_val_if_fail (frame != NULL, NULL);

	return frame->pixbuf;
}

/**
 * gdk_pixbuf_frame_get_x_offset:
 * @frame: A pixbuf animation frame.
 * 
 * Queries the X offset of an animation frame.
 * 
 * Return value: X offset from the top left corner of the animation.
 **/
int
gdk_pixbuf_frame_get_x_offset (GdkPixbufFrame *frame)
{
	g_return_val_if_fail (frame != NULL, -1);

	return frame->x_offset;
}

/**
 * gdk_pixbuf_frame_get_y_offset:
 * @frame: A pixbuf animation frame.
 * 
 * Queries the Y offset of an animation frame.
 * 
 * Return value: Y offset from the top left corner of the animation.
 **/
int
gdk_pixbuf_frame_get_y_offset (GdkPixbufFrame *frame)
{
	g_return_val_if_fail (frame != NULL, -1);

	return frame->y_offset;
}

/**
 * gdk_pixbuf_frame_get_delay_time:
 * @frame: A pixbuf animation frame.
 * 
 * Queries the delay time in milliseconds of an animation frame.
 * 
 * Return value: Delay time in milliseconds.
 **/
int
gdk_pixbuf_frame_get_delay_time (GdkPixbufFrame *frame)
{
	g_return_val_if_fail (frame != NULL, -1);

	return frame->delay_time;
}

/**
 * gdk_pixbuf_frame_get_action:
 * @frame: A pixbuf animation frame.
 * 
 * Queries the overlay action of an animation frame.
 * 
 * Return value: Overlay action for this frame.
 **/
GdkPixbufFrameAction
gdk_pixbuf_frame_get_action (GdkPixbufFrame *frame)
{
	g_return_val_if_fail (frame != NULL, GDK_PIXBUF_FRAME_RETAIN);

	return frame->action;
}