gtk/gdk-pixbuf/gdk-pixbuf-loader.c
Elliot Lee 9d72f811ee Part 2 of previous commit (aka "it compiles now, ma")
Part 2 of previous commit (aka "it compiles now, ma")
2000-07-28 00:16:17 +00:00

575 lines
15 KiB
C

/* 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 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 <string.h>
#include "gdk-pixbuf-private.h"
#include "gdk-pixbuf-loader.h"
#include "gdk-pixbuf-io.h"
#include "gtksignal.h"
enum {
AREA_UPDATED,
AREA_PREPARED,
FRAME_DONE,
ANIMATION_DONE,
CLOSED,
LAST_SIGNAL
};
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 (GObject *loader);
static gpointer parent_class = NULL;
static guint pixbuf_loader_signals[LAST_SIGNAL] = { 0 };
/* Internal data */
#define LOADER_HEADER_SIZE 128
typedef struct
{
GdkPixbuf *pixbuf;
GdkPixbufAnimation *animation;
gboolean closed;
guchar header_buf[LOADER_HEADER_SIZE];
gint header_buf_offset;
GdkPixbufModule *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)
{
GObjectClass *gobject_class;
GtkObjectClass *object_class;
object_class = (GtkObjectClass *) class;
gobject_class = (GObjectClass *) class;
parent_class = gtk_type_class (GTK_TYPE_OBJECT);
pixbuf_loader_signals[AREA_PREPARED] =
gtk_signal_new ("area_prepared",
GTK_RUN_LAST,
GTK_CLASS_TYPE (object_class),
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,
GTK_CLASS_TYPE (object_class),
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[FRAME_DONE] =
gtk_signal_new ("frame_done",
GTK_RUN_LAST,
GTK_CLASS_TYPE (object_class),
GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, frame_done),
gtk_marshal_NONE__POINTER,
GTK_TYPE_NONE, 1,
GTK_TYPE_POINTER);
pixbuf_loader_signals[ANIMATION_DONE] =
gtk_signal_new ("animation_done",
GTK_RUN_LAST,
GTK_CLASS_TYPE (object_class),
GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, animation_done),
gtk_marshal_NONE__NONE,
GTK_TYPE_NONE, 0);
pixbuf_loader_signals[CLOSED] =
gtk_signal_new ("closed",
GTK_RUN_LAST,
GTK_CLASS_TYPE (object_class),
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;
gobject_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 *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->animation)
gdk_pixbuf_animation_unref (priv->animation);
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 (GObject *object)
{
GdkPixbufLoader *loader;
GdkPixbufLoaderPrivate *priv = NULL;
loader = GDK_PIXBUF_LOADER (object);
priv = loader->private;
g_free (priv);
if (G_OBJECT_CLASS (parent_class)->finalize)
G_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]);
}
static void
gdk_pixbuf_loader_update (GdkPixbuf *pixbuf,
guint x,
guint y,
guint width,
guint height,
gpointer loader)
{
GdkPixbufLoaderPrivate *priv = NULL;
priv = GDK_PIXBUF_LOADER (loader)->private;
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 void
gdk_pixbuf_loader_frame_done (GdkPixbufFrame *frame,
gpointer loader)
{
GdkPixbufLoaderPrivate *priv = NULL;
priv = GDK_PIXBUF_LOADER (loader)->private;
priv->pixbuf = NULL;
if (priv->animation == NULL)
{
priv->animation = g_object_new (GDK_TYPE_PIXBUF_ANIMATION, NULL);
priv->animation->n_frames = 0;
priv->animation->width = gdk_pixbuf_get_width (frame->pixbuf) + frame->x_offset;
priv->animation->height = gdk_pixbuf_get_height (frame->pixbuf) + frame->y_offset;
}
else
{
int w, h;
/* update bbox size */
w = gdk_pixbuf_get_width (frame->pixbuf) + frame->x_offset;
h = gdk_pixbuf_get_height (frame->pixbuf) + frame->y_offset;
if (w > priv->animation->width) {
priv->animation->width = w;
}
if (h > priv->animation->height) {
priv->animation->height = h;
}
}
priv->animation->frames = g_list_append (priv->animation->frames, frame);
priv->animation->n_frames++;
gtk_signal_emit (GTK_OBJECT (loader),
pixbuf_loader_signals[FRAME_DONE],
frame);
}
static void
gdk_pixbuf_loader_animation_done (GdkPixbuf *pixbuf,
gpointer loader)
{
GdkPixbufLoaderPrivate *priv = NULL;
GdkPixbufFrame *frame;
GList *current = NULL;
gint h, w;
priv = GDK_PIXBUF_LOADER (loader)->private;
priv->pixbuf = NULL;
current = gdk_pixbuf_animation_get_frames (priv->animation);
while (current)
{
frame = (GdkPixbufFrame *) current->data;
/* update bbox size */
w = gdk_pixbuf_get_width (frame->pixbuf) + frame->x_offset;
h = gdk_pixbuf_get_height (frame->pixbuf) + frame->y_offset;
if (w > priv->animation->width)
priv->animation->width = w;
if (h > priv->animation->height)
priv->animation->height = h;
current = current->next;
}
gtk_signal_emit (GTK_OBJECT (loader), pixbuf_loader_signals[ANIMATION_DONE]);
}
static gint
gdk_pixbuf_loader_load_module (GdkPixbufLoader *loader, const char *image_type)
{
GdkPixbufLoaderPrivate *priv = loader->private;
if(image_type)
priv->image_module = gdk_pixbuf_get_named_module (image_type);
else
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 (G_STRLOC ": 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,
gdk_pixbuf_loader_frame_done,
gdk_pixbuf_loader_animation_done,
loader);
if (priv->context == NULL)
{
g_warning (G_STRLOC ": Failed to begin progressive load");
return 0;
}
if (priv->header_buf_offset
&& 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 guchar *buf,
gsize count)
{
gint n_bytes;
GdkPixbufLoaderPrivate *priv = loader->private;
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) == 0)
return 0;
}
return n_bytes;
}
/**
* gdk_pixbuf_loader_write:
* @loader: A pixbuf loader.
* @buf: Pointer to image data.
* @count: Length of the @buf buffer in bytes.
*
* 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.
*
* 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)
{
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)
{
gint 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;
}
/**
* gdk_pixbuf_loader_new:
*
* Creates a new pixbuf loader object.
*
* Return value: A newly-created pixbuf loader.
**/
GdkPixbufLoader *
gdk_pixbuf_loader_new (void)
{
return g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
}
/**
* gdk_pixbuf_loader_new_with_type:
*
* Creates a new pixbuf loader object.
*
* Return value: A newly-created pixbuf loader.
**/
GdkPixbufLoader *
gdk_pixbuf_loader_new_with_type (const char *image_type)
{
GdkPixbufLoader *retval;
retval = g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
gdk_pixbuf_loader_load_module(retval, image_type);
return retval;
}
/**
* gdk_pixbuf_loader_get_pixbuf:
* @loader: A pixbuf loader.
*
* Queries the GdkPixbuf that a pixbuf loader is currently creating. In general
* it only makes sense to call this function afer 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 gdk_pixbuf_ref() should be sufficient to continue using it.
*
* 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;
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 afer the "area_prepared"
* signal has been emitted by the loader. If the image is not an animation,
* then it 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->private;
return priv->animation;
}
/**
* gdk_pixbuf_loader_close:
* @loader: A pixbuf loader.
*
* Informs a pixbuf loader that no further writes with gdk_pixbuf_load_write()
* will occur, so that it can free its internal loading structures.
**/
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)
gdk_pixbuf_loader_load_module (loader, NULL);
if (priv->image_module && priv->image_module->stop_load)
priv->image_module->stop_load (priv->context);
priv->closed = TRUE;
gtk_signal_emit (GTK_OBJECT (loader), pixbuf_loader_signals[CLOSED]);
}