gtk2/gdk-pixbuf/gdk-pixbuf-loader.c
Federico Mena Quintero 23b0f15ee8 Return a GdkPixbufLoader, not a GtkObject.
1999-10-27  Federico Mena Quintero  <federico@redhat.com>

	* src/gdk-pixbuf-loader.c (gdk_pixbuf_loader_new): Return a
	GdkPixbufLoader, not a GtkObject.
	(gtk_marshal_NONE__INT_INT_INT_INT): Made static.
	(gdk_pixbuf_loader_get_type): Documented.
	(gdk_pixbuf_loader_class_init): Initialize the parent class
	correctly.
	(gdk_pixbuf_loader_destroy): Added sanity checks. Call the parent
	class destroy function.
	(gdk_pixbuf_loader_new): Documented.
	(gdk_pixbuf_loader_finalize): Call the parent class finalize
	function.
	(gdk_pixbuf_loader_write): Use size_t for count.
1999-10-27 17:31:07 +00:00

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/* GdkPixbuf library - Main header file
*
* Copyright (C) 1999 The Free Software Foundation
*
* Authors: Mark Crichton <crichton@gimp.org>
* Miguel de Icaza <miguel@gnu.org>
* Federico Mena-Quintero <federico@gimp.org>
* 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
* 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 "gdk-pixbuf-loader.h"
#include "gdk-pixbuf-io.h"
#include <gtk/gtksignal.h>
enum {
AREA_UPDATED,
AREA_PREPARED,
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 guint pixbuf_loader_signals[LAST_SIGNAL] = { 0 };
/* Internal data */
typedef struct {
GdkPixbuf *pixbuf;
gboolean closed;
gchar buf[128];
gint buf_offset;
ModuleType *image_module;
gpointer context;
} GdkPixbufLoaderPrivate;
/* 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)
{
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);
}
/**
* gdk_pixbuf_loader_get_type:
* @void:
*
* Registers the &GdkPixubfLoader class if necessary, and returns the type ID
* associated to it.
*
* Return value: The type ID of the &GdkPixbufLoader class.
**/
GtkType
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 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;
}
static void
gdk_pixbuf_loader_init (GdkPixbufLoader *loader)
{
GdkPixbufLoaderPrivate *priv;
priv = g_new0 (GdkPixbufLoaderPrivate, 1);
loader->private = priv;
}
static void
gdk_pixbuf_loader_destroy (GtkObject *loader)
{
GdkPixbufLoaderPrivate *priv = NULL;
g_return_if_fail (loader != NULL);
g_return_if_fail (GDK_IS_PIXBUF_LOADER (loader));
priv = GDK_PIXBUF_LOADER (loader)->private;
if (!priv->closed)
gdk_pixbuf_loader_close (GDK_PIXBUF_LOADER (loader));
if (priv->pixbuf)
gdk_pixbuf_unref (priv->pixbuf);
if (GTK_OBJECT_CLASS (parent_class)->destroy)
(* GTK_OBJECT_CLASS (parent_class)->destroy) (object);
}
static void
gdk_pixbuf_loader_finalize (GtkObject *loader)
{
GdkPixbufLoaderPrivate *priv = NULL;
priv = GDK_PIXBUF_LOADER (loader)->private;
g_free (priv);
if (GTK_OBJECT_CLASS (parent_class)->finalize)
(* GTK_OBJECT_CLASS (parent_class)->finalize) (object);
}
static void
gdk_pixbuf_loader_prepare (GdkPixbuf *pixbuf, 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]);
}
/**
* 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 ());
}
/**
* gdk_pixbuf_loader_write:
* @loader: A pixbuf loader.
* @buf: The image data.
* @count: The length of @buf in bytes.
*
* 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.
*
* Return value: Returns TRUE if the write was successful -- FALSE if the loader
* cannot parse the buf.
**/
gboolean
gdk_pixbuf_loader_write (GdkPixbufLoader *loader, guchar *buf, size_t count)
{
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) {
gboolean retval = TRUE;
memcpy (priv->buf + priv->buf_offset,
buf,
(priv->buf_offset + count > 128) ? (128 - priv->buf_offset) : count);
if (priv->buf_offset + count >= 128) {
/* We have enough data to start doing something with the image */
priv->image_module = gdk_pixbuf_get_module (priv->buf, 128);
if (priv->image_module == NULL)
return FALSE;
else 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 FALSE;
} else {
priv->context = (*priv->image_module->begin_load) (
gdk_pixbuf_loader_prepare, loader);
if (priv->context == NULL) {
g_warning("Failed to begin progressive load");
return FALSE;
}
retval = (* priv->image_module->load_increment) (
priv->context, priv->buf, 128);
/* if we had more then 128 bytes total, we want
* to send the rest of the buffer.
*/
if (retval && (priv->buf_offset + count) >= 128) {
retval = (* priv->image_module->load_increment) (
priv->context,
buf,
count + priv->buf_offset - 128);
}
}
} else
priv->buf_offset += count;
return retval;
}
if (priv->image_module->load_increment)
return (* priv->image_module->load_increment) (priv->context, buf, count);
return (FALSE);
}
/**
* 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.
**/
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;
return priv->pixbuf;
}
/**
* gdk_pixbuf_loader_close:
* @loader: A pixbuf loader.
*
* Tells the loader to stop accepting writes.
**/
void
gdk_pixbuf_loader_close (GdkPixbufLoader *loader)
{
GdkPixbufLoaderPrivate *priv;
g_return_if_fail (loader != NULL);
g_return_if_fail (GDK_IS_PIXBUF_LOADER (loader));
priv = loader->private;
/* 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) {
priv->image_module = gdk_pixbuf_get_module (priv->buf, priv->buf_offset);
if (priv->image_module &&
((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);
} else if (priv->image_module) {
g_print ("module loaded: name is %s\n", priv->image_module->module_name);
priv->context = (* priv->image_module->begin_load) (
gdk_pixbuf_loader_prepare, loader);
(* priv->image_module->load_increment) (priv->context,
priv->buf, priv->buf_offset);
}
}
if (priv->image_module && priv->image_module->stop_load)
(* priv->image_module->stop_load) (priv->context);
priv->closed = TRUE;
}