]> Pileus Git - ~andy/gtk/blobdiff - gdk-pixbuf/gdk-pixbuf-loader.c
Clarify misleading explanation of rowstride. (#119000)
[~andy/gtk] / gdk-pixbuf / gdk-pixbuf-loader.c
index eecc8a605f72716e5545089b39cfabb68042b656..90635ed62a58d8a3814050f9514a86908d2609b4 100644 (file)
@@ -1,6 +1,5 @@
-/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
-
-/* GdkPixbuf library - Main header file
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*- */
+/* GdkPixbuf library - Progressive loader object
  *
  * Copyright (C) 1999 The Free Software Foundation
  *
  *          Jonathan Blandford <jrb@redhat.com>
  *
  * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Library General Public
+ * 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
- * Library General Public License for more details.
+ * Lesser General Public License for more details.
  *
- * You should have received a copy of the GNU Library General Public
+ * 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 "gdk-pixbuf-loader.h"
-#include "gdk-pixbuf-io.h"
-#include <gtk/gtksignal.h>
+#include <string.h>
 
-\f
+#include "gdk-pixbuf-private.h"
+#include "gdk-pixbuf-animation.h"
+#include "gdk-pixbuf-io.h"
+#include "gdk-pixbuf-loader.h"
+#include "gdk-pixbuf-marshal.h"
 
 enum {
-       AREA_UPDATED,
-       AREA_PREPARED,
-       CLOSED,
-       LAST_SIGNAL
+        SIZE_PREPARED,
+        AREA_PREPARED,
+        AREA_UPDATED,
+        CLOSED,
+        LAST_SIGNAL
 };
 
-static GtkObjectClass *parent_class;
 
 static void gdk_pixbuf_loader_class_init    (GdkPixbufLoaderClass   *klass);
 static void gdk_pixbuf_loader_init          (GdkPixbufLoader        *loader);
-static void gdk_pixbuf_loader_destroy       (GtkObject              *loader);
-static void gdk_pixbuf_loader_finalize      (GtkObject              *loader);
+static void gdk_pixbuf_loader_finalize      (GObject                *loader);
 
-static guint pixbuf_loader_signals[LAST_SIGNAL] = { 0 };
+static gpointer parent_class = NULL;
+static guint    pixbuf_loader_signals[LAST_SIGNAL] = { 0 };
 
-\f
 
 /* Internal data */
 
 #define LOADER_HEADER_SIZE 128
 
-typedef struct {
-       GdkPixbuf *pixbuf;
-       gboolean closed;
-       gchar header_buf[LOADER_HEADER_SIZE];
-       gint header_buf_offset;
-       GdkPixbufModule *image_module;
-       gpointer context;
-} GdkPixbufLoaderPrivate;
-
-\f
-
-/* our marshaller */
-typedef void (* GtkSignal_NONE__INT_INT_INT_INT) (GtkObject *object,
-                                                 gint arg1, gint arg2, gint arg3, gint arg4,
-                                                 gpointer user_data);
-static void
-gtk_marshal_NONE__INT_INT_INT_INT (GtkObject *object, GtkSignalFunc func, gpointer func_data,
-                                  GtkArg * args)
+typedef struct
 {
-       GtkSignal_NONE__INT_INT_INT_INT rfunc;
-
-       rfunc = (GtkSignal_NONE__INT_INT_INT_INT) func;
-       (*rfunc) (object,
-                 GTK_VALUE_INT (args[0]),
-                 GTK_VALUE_INT (args[1]),
-                 GTK_VALUE_INT (args[2]),
-                 GTK_VALUE_INT (args[3]),
-                 func_data);
-}
+        GdkPixbufAnimation *animation;
+        gboolean closed;
+        guchar header_buf[LOADER_HEADER_SIZE];
+        gint header_buf_offset;
+        GdkPixbufModule *image_module;
+        gpointer context;
+        gint width;
+        gint height;
+        gboolean size_fixed;
+        gboolean needs_scale;
+} GdkPixbufLoaderPrivate;
 
-\f
 
 /**
  * gdk_pixbuf_loader_get_type:
- * @void: 
- * 
- * Registers the &GdkPixubfLoader class if necessary, and returns the type ID
+ * @void:
+ *
+ * Registers the #GdkPixbufLoader class if necessary, and returns the type ID
  * associated to it.
- * 
- * Return value: The type ID of the &GdkPixbufLoader class.
+ *
+ * Return value: The type ID of the #GdkPixbufLoader class.
  **/
-GtkType
+GType
 gdk_pixbuf_loader_get_type (void)
 {
-       static GtkType loader_type = 0;
-
-       if (!loader_type) {
-               static const GtkTypeInfo loader_info = {
-                       "GdkPixbufLoader",
-                       sizeof (GdkPixbufLoader),
-                       sizeof (GdkPixbufLoaderClass),
-                       (GtkClassInitFunc) gdk_pixbuf_loader_class_init,
-                       (GtkObjectInitFunc) gdk_pixbuf_loader_init,
-                       /* reserved_1 */ NULL,
-                       /* reserved_2 */ NULL,
-                       (GtkClassInitFunc) NULL,
-               };
-
-               loader_type = gtk_type_unique (GTK_TYPE_OBJECT, &loader_info);
-       }
-
-       return loader_type;
+        static GType loader_type = 0;
+  
+        if (!loader_type)
+                {
+                        static const GTypeInfo loader_info = {
+                                sizeof (GdkPixbufLoaderClass),
+                                (GBaseInitFunc) NULL,
+                                (GBaseFinalizeFunc) NULL,
+                                (GClassInitFunc) gdk_pixbuf_loader_class_init,
+                                NULL,           /* class_finalize */
+                                NULL,           /* class_data */
+                                sizeof (GdkPixbufLoader),
+                                0,              /* n_preallocs */
+                                (GInstanceInitFunc) gdk_pixbuf_loader_init
+                        };
+      
+                        loader_type = g_type_register_static (G_TYPE_OBJECT,
+                                                              "GdkPixbufLoader",
+                                                              &loader_info,
+                                                              0);
+                }
+  
+        return loader_type;
 }
 
 static void
 gdk_pixbuf_loader_class_init (GdkPixbufLoaderClass *class)
 {
-       GtkObjectClass *object_class;
-
-       object_class = (GtkObjectClass *) class;
-
-       parent_class = gtk_type_class (gtk_object_get_type ());
-
-       pixbuf_loader_signals[AREA_PREPARED] =
-               gtk_signal_new ("area_prepared",
-                               GTK_RUN_LAST,
-                               parent_class->type,
-                               GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, area_prepared),
-                               gtk_marshal_NONE__NONE,
-                               GTK_TYPE_NONE, 0);
-
-       pixbuf_loader_signals[AREA_UPDATED] =
-               gtk_signal_new ("area_updated",
-                               GTK_RUN_LAST,
-                               parent_class->type,
-                               GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, area_updated),
-                               gtk_marshal_NONE__INT_INT_INT_INT,
-                               GTK_TYPE_NONE, 4,
-                               GTK_TYPE_INT,
-                               GTK_TYPE_INT,
-                               GTK_TYPE_INT,
-                               GTK_TYPE_INT);
-
-       pixbuf_loader_signals[CLOSED] =
-               gtk_signal_new ("closed",
-                               GTK_RUN_LAST,
-                               parent_class->type,
-                               GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, closed),
-                               gtk_marshal_NONE__NONE,
-                               GTK_TYPE_NONE, 0);
-
-       gtk_object_class_add_signals (object_class, pixbuf_loader_signals, LAST_SIGNAL);
-
-       object_class->destroy = gdk_pixbuf_loader_destroy;
-       object_class->finalize = gdk_pixbuf_loader_finalize;
+        GObjectClass *object_class;
+  
+        object_class = (GObjectClass *) class;
+  
+        parent_class = g_type_class_peek_parent (class);
+  
+        object_class->finalize = gdk_pixbuf_loader_finalize;
+
+        pixbuf_loader_signals[SIZE_PREPARED] =
+                g_signal_new ("size_prepared",
+                              G_TYPE_FROM_CLASS (object_class),
+                              G_SIGNAL_RUN_LAST,
+                              G_STRUCT_OFFSET (GdkPixbufLoaderClass, size_prepared),
+                              NULL, NULL,
+                              gdk_pixbuf_marshal_VOID__INT_INT,
+                              G_TYPE_NONE, 2, 
+                              G_TYPE_INT,
+                              G_TYPE_INT);
+  
+        pixbuf_loader_signals[AREA_PREPARED] =
+                g_signal_new ("area_prepared",
+                              G_TYPE_FROM_CLASS (object_class),
+                              G_SIGNAL_RUN_LAST,
+                              G_STRUCT_OFFSET (GdkPixbufLoaderClass, area_prepared),
+                              NULL, NULL,
+                              gdk_pixbuf_marshal_VOID__VOID,
+                              G_TYPE_NONE, 0);
+  
+        pixbuf_loader_signals[AREA_UPDATED] =
+                g_signal_new ("area_updated",
+                              G_TYPE_FROM_CLASS (object_class),
+                              G_SIGNAL_RUN_LAST,
+                              G_STRUCT_OFFSET (GdkPixbufLoaderClass, area_updated),
+                              NULL, NULL,
+                              gdk_pixbuf_marshal_VOID__INT_INT_INT_INT,
+                              G_TYPE_NONE, 4,
+                              G_TYPE_INT,
+                              G_TYPE_INT,
+                              G_TYPE_INT,
+                              G_TYPE_INT);
+  
+        pixbuf_loader_signals[CLOSED] =
+                g_signal_new ("closed",
+                              G_TYPE_FROM_CLASS (object_class),
+                              G_SIGNAL_RUN_LAST,
+                              G_STRUCT_OFFSET (GdkPixbufLoaderClass, closed),
+                              NULL, NULL,
+                              gdk_pixbuf_marshal_VOID__VOID,
+                              G_TYPE_NONE, 0);
 }
 
 static void
 gdk_pixbuf_loader_init (GdkPixbufLoader *loader)
 {
-       GdkPixbufLoaderPrivate *priv;
-
-       priv = g_new0 (GdkPixbufLoaderPrivate, 1);
-       loader->private = priv;
+        GdkPixbufLoaderPrivate *priv;
+  
+        priv = g_new0 (GdkPixbufLoaderPrivate, 1);
+        loader->priv = priv;
 }
 
 static void
-gdk_pixbuf_loader_destroy (GtkObject *object)
+gdk_pixbuf_loader_finalize (GObject *object)
 {
-       GdkPixbufLoader *loader;
-       GdkPixbufLoaderPrivate *priv = NULL;
-
-       g_return_if_fail (object != NULL);
-       g_return_if_fail (GDK_IS_PIXBUF_LOADER (object));
-
-       loader = GDK_PIXBUF_LOADER (object);
-       priv = loader->private;
-
-       if (!priv->closed)
-               gdk_pixbuf_loader_close (loader);
-
-       if (priv->pixbuf)
-               gdk_pixbuf_unref (priv->pixbuf);
+        GdkPixbufLoader *loader;
+        GdkPixbufLoaderPrivate *priv = NULL;
+  
+        loader = GDK_PIXBUF_LOADER (object);
+        priv = loader->priv;
+
+        if (!priv->closed)
+                g_warning ("GdkPixbufLoader finalized without calling gdk_pixbuf_loader_close() - this is not allowed. You must explicitly end the data stream to the loader before dropping the last reference.");
+  
+        if (priv->animation)
+                g_object_unref (priv->animation);
+  
+        g_free (priv);
+  
+        G_OBJECT_CLASS (parent_class)->finalize (object);
+}
 
-       if (GTK_OBJECT_CLASS (parent_class)->destroy)
-               (* GTK_OBJECT_CLASS (parent_class)->destroy) (object);
+/**
+ * gdk_pixbuf_loader_set_size:
+ * @loader: A pixbuf loader.
+ * @width: The desired width of the image being loaded.
+ * @height: The desired height of the image being loaded.
+ *
+ * Causes the image to be scaled while it is loaded. The desired
+ * image size can be determined relative to the original size of
+ * the image by calling gdk_pixbuf_loader_set_size() from a
+ * signal handler for the ::size_prepared signal.
+ *
+ * Attempts to set the desired image size  are ignored after the 
+ * emission of the ::size_prepared signal.
+ *
+ * Since: 2.2
+ */
+void 
+gdk_pixbuf_loader_set_size (GdkPixbufLoader *loader,
+                           gint             width,
+                           gint             height)
+{
+        GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv;
+        g_return_if_fail (width > 0 && height > 0);
+
+        if (!priv->size_fixed) 
+                {
+                        priv->width = width;
+                        priv->height = height;
+                }
 }
 
 static void
-gdk_pixbuf_loader_finalize (GtkObject *object)
+gdk_pixbuf_loader_size_func (gint *width, gint *height, gpointer loader)
 {
-       GdkPixbufLoader *loader;
-       GdkPixbufLoaderPrivate *priv = NULL;
+        GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv;
 
-       loader = GDK_PIXBUF_LOADER (object);
-       priv = loader->private;
+        /* allow calling gdk_pixbuf_loader_set_size() before the signal */
+        if (priv->width == 0 && priv->height == 0) 
+                {
+                        priv->width = *width;
+                        priv->height = *height;
+                }
 
-       g_free (priv);
+        g_signal_emit (loader, pixbuf_loader_signals[SIZE_PREPARED], 0, *width, *height);
+        priv->size_fixed = TRUE;
 
-       if (GTK_OBJECT_CLASS (parent_class)->finalize)
-               (* GTK_OBJECT_CLASS (parent_class)->finalize) (object);
+        *width = priv->width;
+        *height = priv->height;
 }
 
 static void
-gdk_pixbuf_loader_prepare (GdkPixbuf *pixbuf, gpointer loader)
+gdk_pixbuf_loader_prepare (GdkPixbuf          *pixbuf,
+                           GdkPixbufAnimation *anim,
+                          gpointer            loader)
 {
-       GdkPixbufLoaderPrivate *priv = NULL;
-
-       priv = GDK_PIXBUF_LOADER (loader)->private;
-       gdk_pixbuf_ref (pixbuf);
-       g_assert (priv->pixbuf == NULL);
-
-       priv->pixbuf = pixbuf;
-       gtk_signal_emit (GTK_OBJECT (loader), pixbuf_loader_signals[AREA_PREPARED]);
+        GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv;
+        g_return_if_fail (pixbuf != NULL);
+
+        if (!priv->size_fixed) 
+                {
+                        /* Defend against lazy loaders which don't call size_func */
+                        gint width = gdk_pixbuf_get_width (pixbuf);
+                        gint height = gdk_pixbuf_get_height (pixbuf);
+                        
+                        gdk_pixbuf_loader_size_func (&width, &height, loader);
+                }
+
+        priv->needs_scale = FALSE;
+        if (priv->width > 0 && priv->height > 0 &&
+            (priv->width != gdk_pixbuf_get_width (pixbuf) ||
+             priv->height != gdk_pixbuf_get_height (pixbuf)))
+                priv->needs_scale = TRUE;
+
+        if (anim)
+                g_object_ref (anim);
+        else
+                anim = gdk_pixbuf_non_anim_new (pixbuf);
+  
+        priv->animation = anim;
+  
+        if (!priv->needs_scale)
+                g_signal_emit (loader, pixbuf_loader_signals[AREA_PREPARED], 0);
 }
 
 static void
-gdk_pixbuf_loader_update (GdkPixbuf *pixbuf, gpointer loader, guint x, guint y, guint width, guint height)
+gdk_pixbuf_loader_update (GdkPixbuf *pixbuf,
+                         gint       x,
+                         gint       y,
+                         gint       width,
+                         gint       height,
+                         gpointer   loader)
 {
-       GdkPixbufLoaderPrivate *priv = NULL;
+        GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv;
+  
+        if (!priv->needs_scale)
+                g_signal_emit (loader,
+                               pixbuf_loader_signals[AREA_UPDATED],
+                               0,
+                               x, y,
+                               /* sanity check in here.  Defend against an errant loader */
+                               MIN (width, gdk_pixbuf_animation_get_width (priv->animation)),
+                               MIN (height, gdk_pixbuf_animation_get_height (priv->animation)));
+}
 
-       priv = GDK_PIXBUF_LOADER (loader)->private;
+static gint
+gdk_pixbuf_loader_load_module (GdkPixbufLoader *loader,
+                               const char      *image_type,
+                               GError         **error)
+{
+        GdkPixbufLoaderPrivate *priv = loader->priv;
+
+        if (image_type)
+                {
+                        priv->image_module = _gdk_pixbuf_get_named_module (image_type,
+                                                                           error);
+                }
+        else
+                {
+                        priv->image_module = _gdk_pixbuf_get_module (priv->header_buf,
+                                                                     priv->header_buf_offset,
+                                                                     NULL,
+                                                                     error);
+                }
+  
+        if (priv->image_module == NULL)
+                return 0;
+  
+        if (priv->image_module->module == NULL)
+                if (!_gdk_pixbuf_load_module (priv->image_module, error))
+                        return 0;
+  
+        if (priv->image_module->module == NULL)
+                return 0;
+  
+        if ((priv->image_module->begin_load == NULL) ||
+            (priv->image_module->stop_load == NULL) ||
+            (priv->image_module->load_increment == NULL))
+                {
+                        g_set_error (error,
+                                     GDK_PIXBUF_ERROR,
+                                     GDK_PIXBUF_ERROR_UNSUPPORTED_OPERATION,
+                                     _("Incremental loading of image type '%s' is not supported"),
+                                     priv->image_module->module_name);
+
+                        return 0;
+                }
+
+        priv->context = priv->image_module->begin_load (gdk_pixbuf_loader_size_func,
+                                                        gdk_pixbuf_loader_prepare,
+                                                        gdk_pixbuf_loader_update,
+                                                        loader,
+                                                        error);
+  
+        if (priv->context == NULL)
+                {
+                        /* Defense against broken loaders; DO NOT take this as a GError
+                         * example
+                         */
+                        if (error && *error == NULL)
+                                {
+                                        g_warning ("Bug! loader '%s' didn't set an error on failure",
+                                                   priv->image_module->module_name);
+                                        g_set_error (error,
+                                                     GDK_PIXBUF_ERROR,
+                                                     GDK_PIXBUF_ERROR_FAILED,
+                                                     _("Internal error: Image loader module '%s'"
+                                                       " failed to begin loading an image, but didn't"
+                                                       " give a reason for the failure"),
+                                                     priv->image_module->module_name);
+
+                                }
+      
+                        return 0;
+                }
+  
+        if (priv->header_buf_offset
+            && priv->image_module->load_increment (priv->context, priv->header_buf, priv->header_buf_offset, error))
+                return priv->header_buf_offset;
+  
+        return 0;
+}
 
-       gtk_signal_emit (GTK_OBJECT (loader),
-                        pixbuf_loader_signals[AREA_UPDATED],
-                        x, y,
-                        /* sanity check in here.  Defend against an errant loader */
-                        MIN (width, gdk_pixbuf_get_width (priv->pixbuf)),
-                        MIN (height, gdk_pixbuf_get_height (priv->pixbuf)));
+static int
+gdk_pixbuf_loader_eat_header_write (GdkPixbufLoader *loader,
+                                   const guchar    *buf,
+                                   gsize            count,
+                                    GError         **error)
+{
+        gint n_bytes;
+        GdkPixbufLoaderPrivate *priv = loader->priv;
+  
+        n_bytes = MIN(LOADER_HEADER_SIZE - priv->header_buf_offset, count);
+        memcpy (priv->header_buf + priv->header_buf_offset, buf, n_bytes);
+  
+        priv->header_buf_offset += n_bytes;
+  
+        if (priv->header_buf_offset >= LOADER_HEADER_SIZE)
+                {
+                        if (gdk_pixbuf_loader_load_module (loader, NULL, error) == 0)
+                                return 0;
+                }
+  
+        return n_bytes;
 }
 
-\f
+/**
+ * gdk_pixbuf_loader_write:
+ * @loader: A pixbuf loader.
+ * @buf: Pointer to image data.
+ * @count: Length of the @buf buffer in bytes.
+ * @error: return location for errors
+ *
+ * This will cause a pixbuf loader to parse the next @count bytes of
+ * an image.  It will return %TRUE if the data was loaded successfully,
+ * and %FALSE if an error occurred.  In the latter case, the loader
+ * will be closed, and will not accept further writes. If %FALSE is
+ * returned, @error will be set to an error from the #GDK_PIXBUF_ERROR
+ * or #G_FILE_ERROR domains.
+ *
+ * Return value: %TRUE if the write was successful, or %FALSE if the loader
+ * cannot parse the buffer.
+ **/
+gboolean
+gdk_pixbuf_loader_write (GdkPixbufLoader *loader,
+                        const guchar    *buf,
+                        gsize            count,
+                         GError         **error)
+{
+        GdkPixbufLoaderPrivate *priv;
+  
+        g_return_val_if_fail (loader != NULL, FALSE);
+        g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), FALSE);
+  
+        g_return_val_if_fail (buf != NULL, FALSE);
+        g_return_val_if_fail (count >= 0, FALSE);
+        g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
+  
+        priv = loader->priv;
+
+        /* we expect it's not to be closed */
+        g_return_val_if_fail (priv->closed == FALSE, FALSE);
+  
+        if (priv->image_module == NULL)
+                {
+                        gint eaten;
+      
+                        eaten = gdk_pixbuf_loader_eat_header_write (loader, buf, count, error);
+                        if (eaten <= 0)
+                                return FALSE;
+      
+                        count -= eaten;
+                        buf += eaten;
+                }
+  
+        if (count > 0 && priv->image_module->load_increment)
+                {
+                        gboolean retval;
+                        retval = priv->image_module->load_increment (priv->context, buf, count,
+                                                                     error);
+                        if (!retval && error && *error == NULL)
+                                {
+                                        /* Fix up busted image loader */
+                                        g_warning ("Bug! loader '%s' didn't set an error on failure",
+                                                   priv->image_module->module_name);
+                                        g_set_error (error,
+                                                     GDK_PIXBUF_ERROR,
+                                                     GDK_PIXBUF_ERROR_FAILED,
+                                                     _("Internal error: Image loader module '%s'"
+                                                       " failed to begin loading an image, but didn't"
+                                                       " give a reason for the failure"),
+                                                     priv->image_module->module_name);
+                                }
+
+                        return retval;
+                }
+      
+        return TRUE;
+}
 
 /**
  * gdk_pixbuf_loader_new:
- * @void: 
- * 
+ *
  * Creates a new pixbuf loader object.
- * 
+ *
  * Return value: A newly-created pixbuf loader.
  **/
 GdkPixbufLoader *
 gdk_pixbuf_loader_new (void)
 {
-       return gtk_type_new (gdk_pixbuf_loader_get_type ());
+        return g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
 }
 
-static int
-gdk_pixbuf_loader_load_module(GdkPixbufLoader *loader)
-{
-       GdkPixbufLoaderPrivate *priv = loader->private;
-
-       priv->image_module = gdk_pixbuf_get_module (priv->header_buf, priv->header_buf_offset);
-
-       if (priv->image_module == NULL)
-               return 0;
-
-       if (priv->image_module->module == NULL)
-               gdk_pixbuf_load_module (priv->image_module);
-
-       if (priv->image_module->module == NULL)
-               return 0;
-
-       if ((priv->image_module->begin_load == NULL) ||
-           (priv->image_module->stop_load == NULL) ||
-           (priv->image_module->load_increment == NULL)) {
-               g_warning ("module %s does not support incremental loading.\n",
-                          priv->image_module->module_name);
-               return 0;
-       }
-
-       priv->context = (*priv->image_module->begin_load) (gdk_pixbuf_loader_prepare, gdk_pixbuf_loader_update, loader);
-
-       if (priv->context == NULL) {
-               g_warning("Failed to begin progressive load");
-               return 0;
-       }
-
-       if( (* priv->image_module->load_increment) (priv->context, priv->header_buf, priv->header_buf_offset) )
-               return priv->header_buf_offset;
-       return 0;
-}
-
-static int
-gdk_pixbuf_loader_eat_header_write (GdkPixbufLoader *loader, const gchar *buf, size_t count)
+/**
+ * gdk_pixbuf_loader_new_with_type:
+ * @image_type: name of the image format to be loaded with the image
+ * @error: return location for an allocated #GError, or %NULL to ignore errors
+ *
+ * Creates a new pixbuf loader object that always attempts to parse
+ * image data as if it were an image of type @image_type, instead of
+ * identifying the type automatically. Useful if you want an error if
+ * the image isn't the expected type, for loading image formats
+ * that can't be reliably identified by looking at the data, or if
+ * the user manually forces a specific type.
+ *
+ * Return value: A newly-created pixbuf loader.
+ **/
+GdkPixbufLoader *
+gdk_pixbuf_loader_new_with_type (const char *image_type,
+                                 GError    **error)
 {
-       int nbytes;
-       GdkPixbufLoaderPrivate *priv = loader->private;
-
-       nbytes = MIN(LOADER_HEADER_SIZE - priv->header_buf_offset, count);
-       memcpy (priv->header_buf + priv->header_buf_offset, buf, nbytes);
-           
-       priv->header_buf_offset += nbytes;
-           
-       if(priv->header_buf_offset >= LOADER_HEADER_SIZE)
-               gdk_pixbuf_loader_load_module(loader);
-
-       return nbytes;
+        GdkPixbufLoader *retval;
+        GError *tmp;
+        g_return_val_if_fail (error == NULL || *error == NULL, NULL);
+  
+        retval = g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
+
+        tmp = NULL;
+        gdk_pixbuf_loader_load_module (retval, image_type, &tmp);
+        if (tmp != NULL)
+                {
+                        g_propagate_error (error, tmp);
+                        g_object_unref (retval);
+                        return NULL;
+                }
+
+        return retval;
 }
 
 /**
- * gdk_pixbuf_loader_write:
- * @loader: A pixbuf loader.
- * @buf: The image data.
- * @count: The length of @buf in bytes.
+ * gdk_pixbuf_loader_new_with_mime_type:
+ * @mime_type: the mime type to be loaded 
+ * @error: return location for an allocated #GError, or %NULL to ignore errors
  *
- * This will load the next @size bytes of the image.  It will return TRUE if the
- * data was loaded successfully, and FALSE if an error occurred. In this case,
- * the loader will be closed, and will not accept further writes.
+ * Creates a new pixbuf loader object that always attempts to parse
+ * image data as if it were an image of mime type @mime_type, instead of
+ * identifying the type automatically. Useful if you want an error if
+ * the image isn't the expected mime type, for loading image formats
+ * that can't be reliably identified by looking at the data, or if
+ * the user manually forces a specific mime type.
  *
- * Return value: Returns TRUE if the write was successful -- FALSE if the loader
- * cannot parse the buf.
+ * Return value: A newly-created pixbuf loader.
+ * Since: 2.4
  **/
-gboolean
-gdk_pixbuf_loader_write (GdkPixbufLoader *loader, const gchar *buf, size_t count)
+GdkPixbufLoader *
+gdk_pixbuf_loader_new_with_mime_type (const char *mime_type,
+                                      GError    **error)
 {
-       GdkPixbufLoaderPrivate *priv;
-
-       g_return_val_if_fail (loader != NULL, FALSE);
-       g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), FALSE);
-
-       g_return_val_if_fail (buf != NULL, FALSE);
-       g_return_val_if_fail (count >= 0, FALSE);
-
-       priv = loader->private;
-
-       /* we expect it's not to be closed */
-       g_return_val_if_fail (priv->closed == FALSE, FALSE);
-
-       if (priv->image_module == NULL) {
-               int eaten;
-
-               eaten = gdk_pixbuf_loader_eat_header_write(loader, buf, count);
-               if (eaten <= 0)
-                       return FALSE;
-
-               count -= eaten;
-               buf += eaten;
-       }
-
-       if (count > 0 && priv->image_module->load_increment)
-               return (* priv->image_module->load_increment) (priv->context, buf, count);
-
-       return TRUE;
+        const char * image_type = NULL;
+        char ** mimes;
+
+        GdkPixbufLoader *retval;
+        GError *tmp;
+  
+        GSList * formats;
+        GdkPixbufFormat *info;
+        int i, j, length;
+
+        formats = gdk_pixbuf_get_formats ();
+        length = g_slist_length (formats);
+
+        for (i = 0; i < length && image_type == NULL; i++) {
+                info = (GdkPixbufFormat *)g_slist_nth_data (formats, i);
+                mimes = info->mime_types;
+                
+                for (j = 0; mimes[j] != NULL; j++)
+                        if (g_ascii_strcasecmp (mimes[i], mime_type)) {
+                                image_type = info->name;
+                                break;
+                        }
+        }
+
+        g_slist_free (formats);
+
+        retval = g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
+
+        tmp = NULL;
+        gdk_pixbuf_loader_load_module(retval, image_type, &tmp);
+        if (tmp != NULL)
+                {
+                        g_propagate_error (error, tmp);
+                        g_object_unref (retval);
+                        return NULL;
+                }
+
+        return retval;
 }
 
 /**
  * gdk_pixbuf_loader_get_pixbuf:
  * @loader: A pixbuf loader.
  *
- * Gets the GdkPixbuf that the loader is currently loading.  If the loader
- * hasn't been enough data via gdk_pixbuf_loader_write, then NULL is returned.
- * Any application using this function should check for this value when it is
- * used.  The pixbuf returned will be the same in all future calls to the
- * loader, so simply calling a gdk_pixbuf_ref() should be sufficient to continue
- * using it.
- *
- * Return value: The GdkPixbuf that the loader is loading.
+ * Queries the #GdkPixbuf that a pixbuf loader is currently creating.
+ * In general it only makes sense to call this function after the
+ * "area_prepared" signal has been emitted by the loader; this means
+ * that enough data has been read to know the size of the image that
+ * will be allocated.  If the loader has not received enough data via
+ * gdk_pixbuf_loader_write(), then this function returns %NULL.  The
+ * returned pixbuf will be the same in all future calls to the loader,
+ * so simply calling g_object_ref() should be sufficient to continue
+ * using it.  Additionally, if the loader is an animation, it will
+ * return the "static image" of the animation
+ * (see gdk_pixbuf_animation_get_static_image()).
+ * 
+ * Return value: The #GdkPixbuf that the loader is creating, or %NULL if not
+ * enough data has been read to determine how to create the image buffer.
  **/
 GdkPixbuf *
 gdk_pixbuf_loader_get_pixbuf (GdkPixbufLoader *loader)
 {
-       GdkPixbufLoaderPrivate *priv;
-
-       g_return_val_if_fail (loader != NULL, NULL);
-       g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
-
-       priv = loader->private;
+        GdkPixbufLoaderPrivate *priv;
+  
+        g_return_val_if_fail (loader != NULL, NULL);
+        g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
+  
+        priv = loader->priv;
+
+        if (priv->animation)
+                return gdk_pixbuf_animation_get_static_image (priv->animation);
+        else
+                return NULL;
+}
 
-       return priv->pixbuf;
+/**
+ * gdk_pixbuf_loader_get_animation:
+ * @loader: A pixbuf loader
+ *
+ * Queries the #GdkPixbufAnimation that a pixbuf loader is currently creating.
+ * In general it only makes sense to call this function after the "area_prepared"
+ * signal has been emitted by the loader. If the loader doesn't have enough
+ * bytes yet (hasn't emitted the "area_prepared" signal) this function will 
+ * return %NULL.
+ *
+ * Return value: The #GdkPixbufAnimation that the loader is loading, or %NULL if
+ not enough data has been read to determine the information.
+**/
+GdkPixbufAnimation *
+gdk_pixbuf_loader_get_animation (GdkPixbufLoader *loader)
+{
+        GdkPixbufLoaderPrivate *priv;
+  
+        g_return_val_if_fail (loader != NULL, NULL);
+        g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
+  
+        priv = loader->priv;
+  
+        return priv->animation;
 }
 
 /**
  * gdk_pixbuf_loader_close:
  * @loader: A pixbuf loader.
+ * @error: return location for a #GError, or %NULL to ignore errors
+ *
+ * Informs a pixbuf loader that no further writes with
+ * gdk_pixbuf_loader_write() will occur, so that it can free its
+ * internal loading structures. Also, tries to parse any data that
+ * hasn't yet been parsed; if the remaining data is partial or
+ * corrupt, an error will be returned.  If %FALSE is returned, @error
+ * will be set to an error from the #GDK_PIXBUF_ERROR or #G_FILE_ERROR
+ * domains. If you're just cancelling a load rather than expecting it
+ * to be finished, passing %NULL for @error to ignore it is
+ * reasonable.
  *
- * Tells the loader to stop accepting writes.
+ * Returns: %TRUE if all image data written so far was successfully
+            passed out via the update_area signal
  **/
-void
-gdk_pixbuf_loader_close (GdkPixbufLoader *loader)
+gboolean
+gdk_pixbuf_loader_close (GdkPixbufLoader *loader,
+                         GError         **error)
 {
-       GdkPixbufLoaderPrivate *priv;
-
-       g_return_if_fail (loader != NULL);
-       g_return_if_fail (GDK_IS_PIXBUF_LOADER (loader));
+        GdkPixbufLoaderPrivate *priv;
+        gboolean retval = TRUE;
+  
+        g_return_val_if_fail (loader != NULL, TRUE);
+        g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), TRUE);
+        g_return_val_if_fail (error == NULL || *error == NULL, TRUE);
+  
+        priv = loader->priv;
+  
+        /* we expect it's not closed */
+        g_return_val_if_fail (priv->closed == FALSE, TRUE);
+  
+        /* We have less the 128 bytes in the image.  Flush it, and keep going. */
+        if (priv->image_module == NULL)
+                {
+                        GError *tmp = NULL;
+                        gdk_pixbuf_loader_load_module (loader, NULL, &tmp);
+                        if (tmp != NULL)
+                                {
+                                        g_propagate_error (error, tmp);
+                                        retval = FALSE;
+                                }
+                }  
+
+        if (priv->image_module && priv->image_module->stop_load && priv->context) 
+                {
+                        if (!priv->image_module->stop_load (priv->context, error))
+                                retval = FALSE;
+                }
+  
+        priv->closed = TRUE;
+
+        if (priv->needs_scale) 
+                {
+                        GdkPixbuf *tmp, *pixbuf;
+                        
+                        tmp = gdk_pixbuf_animation_get_static_image (priv->animation);
+                        g_object_ref (tmp);
+                        pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, tmp->has_alpha, 8, priv->width, priv->height);
+                        g_object_unref (priv->animation);
+                        priv->animation = gdk_pixbuf_non_anim_new (pixbuf);
+                        g_object_unref (pixbuf);
+                        g_signal_emit (loader, pixbuf_loader_signals[AREA_PREPARED], 0);
+                        gdk_pixbuf_scale (tmp, pixbuf, 0, 0, priv->width, priv->height, 0, 0,
+                                          (double) priv->width / tmp->width,
+                                          (double) priv->height / tmp->height,
+                                          GDK_INTERP_BILINEAR); 
+                        g_object_unref (tmp);
+                        
+                        g_signal_emit (loader, pixbuf_loader_signals[AREA_UPDATED], 0, 
+                                       0, 0, priv->width, priv->height);
+                }
+
+        
+        g_signal_emit (loader, pixbuf_loader_signals[CLOSED], 0);
+
+        return retval;
+}
 
-       priv = loader->private;
+/**
+ * gdk_pixbuf_loader_get_format:
+ * @loader: A pixbuf loader.
+ *
+ * Obtains the available information about the format of the 
+ * currently loading image file.
+ *
+ * Returns: A #GdkPixbufFormat or %NULL. The return value is owned 
+ * by GdkPixbuf and should not be freed.
+ * 
+ * Since: 2.2
+ */
+GdkPixbufFormat *
+gdk_pixbuf_loader_get_format (GdkPixbufLoader *loader)
+{
+        GdkPixbufLoaderPrivate *priv;
+  
+        g_return_val_if_fail (loader != NULL, NULL);
+        g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
+  
+        priv = loader->priv;
+
+        if (priv->image_module)
+                return _gdk_pixbuf_get_format (priv->image_module);
+        else
+                return NULL;
+}
 
-       /* we expect it's not closed */
-       g_return_if_fail (priv->closed == FALSE);
 
-       /* We have less the 128 bytes in the image.  Flush it, and keep going. */
-       if (priv->image_module == NULL)
-               gdk_pixbuf_loader_load_module (loader);
 
-       if (priv->image_module && priv->image_module->stop_load)
-               (* priv->image_module->stop_load) (priv->context);
 
-       priv->closed = TRUE;
-}