forked from AuroraMiddleware/gtk
407 lines
10 KiB
C
407 lines
10 KiB
C
/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
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/* GdkPixbuf library - Main header file
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*
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* Copyright (C) 1999 The Free Software Foundation
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*
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* Authors: Mark Crichton <crichton@gimp.org>
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* Miguel de Icaza <miguel@gnu.org>
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* Federico Mena-Quintero <federico@gimp.org>
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* Jonathan Blandford <jrb@redhat.com>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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#include "gdk-pixbuf-loader.h"
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#include "gdk-pixbuf-io.h"
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#include <gtk/gtksignal.h>
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enum {
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AREA_UPDATED,
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AREA_PREPARED,
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CLOSED,
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LAST_SIGNAL
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};
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static GtkObjectClass *parent_class;
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static void gdk_pixbuf_loader_class_init (GdkPixbufLoaderClass *klass);
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static void gdk_pixbuf_loader_init (GdkPixbufLoader *loader);
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static void gdk_pixbuf_loader_destroy (GtkObject *loader);
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static void gdk_pixbuf_loader_finalize (GtkObject *loader);
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static guint pixbuf_loader_signals[LAST_SIGNAL] = { 0 };
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/* Internal data */
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#define LOADER_HEADER_SIZE 128
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typedef struct {
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GdkPixbuf *pixbuf;
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gboolean closed;
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gchar header_buf[LOADER_HEADER_SIZE];
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gint header_buf_offset;
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GdkPixbufModule *image_module;
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gpointer context;
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} GdkPixbufLoaderPrivate;
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/* our marshaller */
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typedef void (* GtkSignal_NONE__INT_INT_INT_INT) (GtkObject *object,
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gint arg1, gint arg2, gint arg3, gint arg4,
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gpointer user_data);
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static void
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gtk_marshal_NONE__INT_INT_INT_INT (GtkObject *object, GtkSignalFunc func, gpointer func_data,
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GtkArg * args)
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{
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GtkSignal_NONE__INT_INT_INT_INT rfunc;
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rfunc = (GtkSignal_NONE__INT_INT_INT_INT) func;
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(*rfunc) (object,
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GTK_VALUE_INT (args[0]),
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GTK_VALUE_INT (args[1]),
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GTK_VALUE_INT (args[2]),
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GTK_VALUE_INT (args[3]),
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func_data);
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}
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/**
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* gdk_pixbuf_loader_get_type:
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* @void:
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*
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* Registers the #GdkPixubfLoader class if necessary, and returns the type ID
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* associated to it.
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*
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* Return value: The type ID of the #GdkPixbufLoader class.
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**/
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GtkType
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gdk_pixbuf_loader_get_type (void)
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{
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static GtkType loader_type = 0;
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if (!loader_type) {
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static const GtkTypeInfo loader_info = {
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"GdkPixbufLoader",
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sizeof (GdkPixbufLoader),
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sizeof (GdkPixbufLoaderClass),
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(GtkClassInitFunc) gdk_pixbuf_loader_class_init,
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(GtkObjectInitFunc) gdk_pixbuf_loader_init,
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/* reserved_1 */ NULL,
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/* reserved_2 */ NULL,
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(GtkClassInitFunc) NULL,
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};
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loader_type = gtk_type_unique (GTK_TYPE_OBJECT, &loader_info);
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}
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return loader_type;
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}
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static void
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gdk_pixbuf_loader_class_init (GdkPixbufLoaderClass *class)
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{
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GtkObjectClass *object_class;
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object_class = (GtkObjectClass *) class;
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parent_class = gtk_type_class (gtk_object_get_type ());
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pixbuf_loader_signals[AREA_PREPARED] =
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gtk_signal_new ("area_prepared",
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GTK_RUN_LAST,
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parent_class->type,
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GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, area_prepared),
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gtk_marshal_NONE__NONE,
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GTK_TYPE_NONE, 0);
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pixbuf_loader_signals[AREA_UPDATED] =
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gtk_signal_new ("area_updated",
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GTK_RUN_LAST,
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parent_class->type,
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GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, area_updated),
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gtk_marshal_NONE__INT_INT_INT_INT,
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GTK_TYPE_NONE, 4,
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GTK_TYPE_INT,
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GTK_TYPE_INT,
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GTK_TYPE_INT,
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GTK_TYPE_INT);
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pixbuf_loader_signals[CLOSED] =
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gtk_signal_new ("closed",
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GTK_RUN_LAST,
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parent_class->type,
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GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, closed),
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gtk_marshal_NONE__NONE,
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GTK_TYPE_NONE, 0);
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gtk_object_class_add_signals (object_class, pixbuf_loader_signals, LAST_SIGNAL);
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object_class->destroy = gdk_pixbuf_loader_destroy;
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object_class->finalize = gdk_pixbuf_loader_finalize;
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}
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static void
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gdk_pixbuf_loader_init (GdkPixbufLoader *loader)
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{
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GdkPixbufLoaderPrivate *priv;
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priv = g_new0 (GdkPixbufLoaderPrivate, 1);
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loader->private = priv;
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}
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static void
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gdk_pixbuf_loader_destroy (GtkObject *object)
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{
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GdkPixbufLoader *loader;
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GdkPixbufLoaderPrivate *priv = NULL;
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g_return_if_fail (object != NULL);
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g_return_if_fail (GDK_IS_PIXBUF_LOADER (object));
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loader = GDK_PIXBUF_LOADER (object);
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priv = loader->private;
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if (!priv->closed)
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gdk_pixbuf_loader_close (loader);
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if (priv->pixbuf)
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gdk_pixbuf_unref (priv->pixbuf);
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if (GTK_OBJECT_CLASS (parent_class)->destroy)
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(* GTK_OBJECT_CLASS (parent_class)->destroy) (object);
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}
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static void
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gdk_pixbuf_loader_finalize (GtkObject *object)
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{
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GdkPixbufLoader *loader;
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GdkPixbufLoaderPrivate *priv = NULL;
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loader = GDK_PIXBUF_LOADER (object);
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priv = loader->private;
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g_free (priv);
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if (GTK_OBJECT_CLASS (parent_class)->finalize)
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(* GTK_OBJECT_CLASS (parent_class)->finalize) (object);
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}
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static void
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gdk_pixbuf_loader_prepare (GdkPixbuf *pixbuf, gpointer loader)
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{
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GdkPixbufLoaderPrivate *priv = NULL;
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priv = GDK_PIXBUF_LOADER (loader)->private;
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gdk_pixbuf_ref (pixbuf);
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g_assert (priv->pixbuf == NULL);
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priv->pixbuf = pixbuf;
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gtk_signal_emit (GTK_OBJECT (loader), pixbuf_loader_signals[AREA_PREPARED]);
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}
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static void
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gdk_pixbuf_loader_update (GdkPixbuf *pixbuf, gpointer loader, guint x, guint y, guint width, guint height)
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{
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GdkPixbufLoaderPrivate *priv = NULL;
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priv = GDK_PIXBUF_LOADER (loader)->private;
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gtk_signal_emit (GTK_OBJECT (loader),
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pixbuf_loader_signals[AREA_UPDATED],
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x, y,
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/* sanity check in here. Defend against an errant loader */
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MIN (width, gdk_pixbuf_get_width (priv->pixbuf)),
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MIN (height, gdk_pixbuf_get_height (priv->pixbuf)));
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}
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/**
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* gdk_pixbuf_loader_new:
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* @void:
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*
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* Creates a new pixbuf loader object.
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*
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* Return value: A newly-created pixbuf loader.
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**/
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GdkPixbufLoader *
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gdk_pixbuf_loader_new (void)
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{
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return gtk_type_new (gdk_pixbuf_loader_get_type ());
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}
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static int
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gdk_pixbuf_loader_load_module(GdkPixbufLoader *loader)
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{
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GdkPixbufLoaderPrivate *priv = loader->private;
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priv->image_module = gdk_pixbuf_get_module (priv->header_buf, priv->header_buf_offset);
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if (priv->image_module == NULL)
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return 0;
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if (priv->image_module->module == NULL)
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gdk_pixbuf_load_module (priv->image_module);
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if (priv->image_module->module == NULL)
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return 0;
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if ((priv->image_module->begin_load == NULL) ||
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(priv->image_module->stop_load == NULL) ||
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(priv->image_module->load_increment == NULL)) {
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g_warning ("module %s does not support incremental loading.\n",
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priv->image_module->module_name);
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return 0;
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}
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priv->context = (*priv->image_module->begin_load) (gdk_pixbuf_loader_prepare, gdk_pixbuf_loader_update, loader);
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if (priv->context == NULL) {
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g_warning("Failed to begin progressive load");
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return 0;
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}
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if( (* priv->image_module->load_increment) (priv->context, priv->header_buf, priv->header_buf_offset) )
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return priv->header_buf_offset;
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return 0;
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}
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static int
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gdk_pixbuf_loader_eat_header_write (GdkPixbufLoader *loader, const gchar *buf, size_t count)
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{
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int nbytes;
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GdkPixbufLoaderPrivate *priv = loader->private;
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nbytes = MIN(LOADER_HEADER_SIZE - priv->header_buf_offset, count);
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memcpy (priv->header_buf + priv->header_buf_offset, buf, nbytes);
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priv->header_buf_offset += nbytes;
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if(priv->header_buf_offset >= LOADER_HEADER_SIZE)
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gdk_pixbuf_loader_load_module(loader);
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return nbytes;
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}
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/**
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* gdk_pixbuf_loader_write:
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* @loader: A pixbuf loader.
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* @buf: The image data.
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* @count: The length of @buf in bytes.
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*
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* This will load the next @size bytes of the image. It will return TRUE if the
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* data was loaded successfully, and FALSE if an error occurred. In this case,
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* the loader will be closed, and will not accept further writes.
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*
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* Return value: Returns TRUE if the write was successful -- FALSE if the loader
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* cannot parse the buf.
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**/
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gboolean
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gdk_pixbuf_loader_write (GdkPixbufLoader *loader, const gchar *buf, size_t count)
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{
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GdkPixbufLoaderPrivate *priv;
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g_return_val_if_fail (loader != NULL, FALSE);
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g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), FALSE);
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g_return_val_if_fail (buf != NULL, FALSE);
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g_return_val_if_fail (count >= 0, FALSE);
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priv = loader->private;
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/* we expect it's not to be closed */
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g_return_val_if_fail (priv->closed == FALSE, FALSE);
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if (priv->image_module == NULL) {
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int eaten;
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eaten = gdk_pixbuf_loader_eat_header_write(loader, buf, count);
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if (eaten <= 0)
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return FALSE;
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count -= eaten;
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buf += eaten;
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}
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if (count > 0 && priv->image_module->load_increment)
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return (* priv->image_module->load_increment) (priv->context, buf, count);
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return TRUE;
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}
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/**
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* gdk_pixbuf_loader_get_pixbuf:
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* @loader: A pixbuf loader.
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*
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* Gets the GdkPixbuf that the loader is currently loading. If the loader
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* hasn't been enough data via gdk_pixbuf_loader_write, then NULL is returned.
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* Any application using this function should check for this value when it is
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* used. The pixbuf returned will be the same in all future calls to the
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* loader, so simply calling a gdk_pixbuf_ref() should be sufficient to continue
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* using it.
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*
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* Return value: The GdkPixbuf that the loader is loading.
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**/
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GdkPixbuf *
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gdk_pixbuf_loader_get_pixbuf (GdkPixbufLoader *loader)
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{
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GdkPixbufLoaderPrivate *priv;
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g_return_val_if_fail (loader != NULL, NULL);
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g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
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priv = loader->private;
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return priv->pixbuf;
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}
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/**
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* gdk_pixbuf_loader_close:
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* @loader: A pixbuf loader.
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*
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* Tells the loader to stop accepting writes.
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**/
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void
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gdk_pixbuf_loader_close (GdkPixbufLoader *loader)
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{
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GdkPixbufLoaderPrivate *priv;
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g_return_if_fail (loader != NULL);
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g_return_if_fail (GDK_IS_PIXBUF_LOADER (loader));
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priv = loader->private;
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/* we expect it's not closed */
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g_return_if_fail (priv->closed == FALSE);
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/* We have less the 128 bytes in the image. Flush it, and keep going. */
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if (priv->image_module == NULL)
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gdk_pixbuf_loader_load_module (loader);
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if (priv->image_module && priv->image_module->stop_load)
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(* priv->image_module->stop_load) (priv->context);
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priv->closed = TRUE;
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}
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