1
/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*- */
2
/* GdkPixbuf library - Progressive loader object
4
* Copyright (C) 1999 The Free Software Foundation
6
* Authors: Mark Crichton <crichton@gimp.org>
7
* Miguel de Icaza <miguel@gnu.org>
8
* Federico Mena-Quintero <federico@gimp.org>
9
* Jonathan Blandford <jrb@redhat.com>
11
* This library is free software; you can redistribute it and/or
12
* modify it under the terms of the GNU Lesser General Public
13
* License as published by the Free Software Foundation; either
14
* version 2 of the License, or (at your option) any later version.
16
* This library is distributed in the hope that it will be useful,
17
* but WITHOUT ANY WARRANTY; without even the implied warranty of
18
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19
* Lesser General Public License for more details.
21
* You should have received a copy of the GNU Lesser General Public
22
* License along with this library; if not, write to the
23
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
24
* Boston, MA 02111-1307, USA.
30
#include "gdk-pixbuf-private.h"
31
#include "gdk-pixbuf-animation.h"
32
#include "gdk-pixbuf-scaled-anim.h"
33
#include "gdk-pixbuf-io.h"
34
#include "gdk-pixbuf-loader.h"
35
#include "gdk-pixbuf-marshal.h"
36
#include "gdk-pixbuf-alias.h"
47
static void gdk_pixbuf_loader_finalize (GObject *loader);
49
static guint pixbuf_loader_signals[LAST_SIGNAL] = { 0 };
53
#define LOADER_HEADER_SIZE 1024
57
GdkPixbufAnimation *animation;
59
gboolean holds_threadlock;
60
guchar header_buf[LOADER_HEADER_SIZE];
61
gint header_buf_offset;
62
GdkPixbufModule *image_module;
68
} GdkPixbufLoaderPrivate;
70
G_DEFINE_TYPE (GdkPixbufLoader, gdk_pixbuf_loader, G_TYPE_OBJECT)
73
gdk_pixbuf_loader_class_init (GdkPixbufLoaderClass *class)
75
GObjectClass *object_class;
77
object_class = (GObjectClass *) class;
79
object_class->finalize = gdk_pixbuf_loader_finalize;
82
* GdkPixbufLoader::size-prepared:
83
* @loader: the object which received the signal.
84
* @width: the original width of the image
85
* @height: the original height of the image
87
* This signal is emitted when the pixbuf loader has been fed the
88
* initial amount of data that is required to figure out the size
89
* of the image that it will create. Applications can call
90
* gdk_pixbuf_loader_set_size() in response to this signal to set
91
* the desired size to which the image should be scaled.
93
pixbuf_loader_signals[SIZE_PREPARED] =
94
g_signal_new ("size-prepared",
95
G_TYPE_FROM_CLASS (object_class),
97
G_STRUCT_OFFSET (GdkPixbufLoaderClass, size_prepared),
99
_gdk_pixbuf_marshal_VOID__INT_INT,
105
* GdkPixbufLoader::area-prepared:
106
* @loader: the object which received the signal.
108
* This signal is emitted when the pixbuf loader has allocated the
109
* pixbuf in the desired size. After this signal is emitted,
110
* applications can call gdk_pixbuf_loader_get_pixbuf() to fetch
111
* the partially-loaded pixbuf.
113
pixbuf_loader_signals[AREA_PREPARED] =
114
g_signal_new ("area-prepared",
115
G_TYPE_FROM_CLASS (object_class),
117
G_STRUCT_OFFSET (GdkPixbufLoaderClass, area_prepared),
119
_gdk_pixbuf_marshal_VOID__VOID,
123
* GdkPixbufLoader::area-updated:
124
* @loader: the object which received the signal.
125
* @x: X offset of upper-left corner of the updated area.
126
* @y: Y offset of upper-left corner of the updated area.
127
* @width: Width of updated area.
128
* @height: Height of updated area.
130
* This signal is emitted when a significant area of the image being
131
* loaded has been updated. Normally it means that a complete
132
* scanline has been read in, but it could be a different area as
133
* well. Applications can use this signal to know when to repaint
134
* areas of an image that is being loaded.
136
pixbuf_loader_signals[AREA_UPDATED] =
137
g_signal_new ("area-updated",
138
G_TYPE_FROM_CLASS (object_class),
140
G_STRUCT_OFFSET (GdkPixbufLoaderClass, area_updated),
142
_gdk_pixbuf_marshal_VOID__INT_INT_INT_INT,
150
* GdkPixbufLoader::closed:
151
* @loader: the object which received the signal.
153
* This signal is emitted when gdk_pixbuf_loader_close() is called.
154
* It can be used by different parts of an application to receive
155
* notification when an image loader is closed by the code that
158
pixbuf_loader_signals[CLOSED] =
159
g_signal_new ("closed",
160
G_TYPE_FROM_CLASS (object_class),
162
G_STRUCT_OFFSET (GdkPixbufLoaderClass, closed),
164
_gdk_pixbuf_marshal_VOID__VOID,
169
gdk_pixbuf_loader_init (GdkPixbufLoader *loader)
171
GdkPixbufLoaderPrivate *priv;
173
priv = g_new0 (GdkPixbufLoaderPrivate, 1);
181
gdk_pixbuf_loader_finalize (GObject *object)
183
GdkPixbufLoader *loader;
184
GdkPixbufLoaderPrivate *priv = NULL;
186
loader = GDK_PIXBUF_LOADER (object);
190
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.");
191
if (priv->holds_threadlock) {
192
_gdk_pixbuf_unlock (priv->image_module);
196
g_object_unref (priv->animation);
200
G_OBJECT_CLASS (gdk_pixbuf_loader_parent_class)->finalize (object);
204
* gdk_pixbuf_loader_set_size:
205
* @loader: A pixbuf loader.
206
* @width: The desired width of the image being loaded.
207
* @height: The desired height of the image being loaded.
209
* Causes the image to be scaled while it is loaded. The desired
210
* image size can be determined relative to the original size of
211
* the image by calling gdk_pixbuf_loader_set_size() from a
212
* signal handler for the ::size-prepared signal.
214
* Attempts to set the desired image size are ignored after the
215
* emission of the ::size-prepared signal.
220
gdk_pixbuf_loader_set_size (GdkPixbufLoader *loader,
224
GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv;
225
g_return_if_fail (width >= 0 && height >= 0);
227
if (!priv->size_fixed)
230
priv->height = height;
235
gdk_pixbuf_loader_size_func (gint *width, gint *height, gpointer loader)
237
GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv;
239
/* allow calling gdk_pixbuf_loader_set_size() before the signal */
240
if (priv->width == -1 && priv->height == -1)
242
priv->width = *width;
243
priv->height = *height;
246
g_signal_emit (loader, pixbuf_loader_signals[SIZE_PREPARED], 0, *width, *height);
247
priv->size_fixed = TRUE;
249
*width = priv->width;
250
*height = priv->height;
254
gdk_pixbuf_loader_prepare (GdkPixbuf *pixbuf,
255
GdkPixbufAnimation *anim,
258
GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv;
259
g_return_if_fail (pixbuf != NULL);
261
if (!priv->size_fixed)
263
/* Defend against lazy loaders which don't call size_func */
264
gint width = gdk_pixbuf_get_width (pixbuf);
265
gint height = gdk_pixbuf_get_height (pixbuf);
267
gdk_pixbuf_loader_size_func (&width, &height, loader);
270
priv->needs_scale = FALSE;
271
if (priv->width > 0 && priv->height > 0 &&
272
(priv->width != gdk_pixbuf_get_width (pixbuf) ||
273
priv->height != gdk_pixbuf_get_height (pixbuf)))
274
priv->needs_scale = TRUE;
279
anim = gdk_pixbuf_non_anim_new (pixbuf);
281
if (priv->needs_scale) {
282
priv->animation = GDK_PIXBUF_ANIMATION (_gdk_pixbuf_scaled_anim_new (anim,
283
(double) priv->width / gdk_pixbuf_get_width (pixbuf),
284
(double) priv->height / gdk_pixbuf_get_height (pixbuf),
286
g_object_unref (anim);
289
priv->animation = anim;
291
if (!priv->needs_scale)
292
g_signal_emit (loader, pixbuf_loader_signals[AREA_PREPARED], 0);
296
gdk_pixbuf_loader_update (GdkPixbuf *pixbuf,
303
GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv;
305
if (!priv->needs_scale)
306
g_signal_emit (loader,
307
pixbuf_loader_signals[AREA_UPDATED],
310
/* sanity check in here. Defend against an errant loader */
311
MIN (width, gdk_pixbuf_animation_get_width (priv->animation)),
312
MIN (height, gdk_pixbuf_animation_get_height (priv->animation)));
315
/* Defense against broken loaders; DO NOT take this as a GError example! */
317
gdk_pixbuf_loader_ensure_error (GdkPixbufLoader *loader,
320
GdkPixbufLoaderPrivate *priv = loader->priv;
322
if (error == NULL || *error != NULL)
325
g_warning ("Bug! loader '%s' didn't set an error on failure",
326
priv->image_module->module_name);
329
GDK_PIXBUF_ERROR_FAILED,
330
_("Internal error: Image loader module '%s' failed to"
331
" complete an operation, but didn't give a reason for"
333
priv->image_module->module_name);
337
gdk_pixbuf_loader_load_module (GdkPixbufLoader *loader,
338
const char *image_type,
341
GdkPixbufLoaderPrivate *priv = loader->priv;
345
priv->image_module = _gdk_pixbuf_get_named_module (image_type,
350
priv->image_module = _gdk_pixbuf_get_module (priv->header_buf,
351
priv->header_buf_offset,
356
if (priv->image_module == NULL)
359
if (!_gdk_pixbuf_load_module (priv->image_module, error))
362
if (priv->image_module->module == NULL)
365
if ((priv->image_module->begin_load == NULL) ||
366
(priv->image_module->stop_load == NULL) ||
367
(priv->image_module->load_increment == NULL))
371
GDK_PIXBUF_ERROR_UNSUPPORTED_OPERATION,
372
_("Incremental loading of image type '%s' is not supported"),
373
priv->image_module->module_name);
378
if (!priv->holds_threadlock) {
379
priv->holds_threadlock = _gdk_pixbuf_lock (priv->image_module);
382
priv->context = priv->image_module->begin_load (gdk_pixbuf_loader_size_func,
383
gdk_pixbuf_loader_prepare,
384
gdk_pixbuf_loader_update,
388
if (priv->context == NULL)
390
gdk_pixbuf_loader_ensure_error (loader, error);
394
if (priv->header_buf_offset
395
&& priv->image_module->load_increment (priv->context, priv->header_buf, priv->header_buf_offset, error))
396
return priv->header_buf_offset;
402
gdk_pixbuf_loader_eat_header_write (GdkPixbufLoader *loader,
408
GdkPixbufLoaderPrivate *priv = loader->priv;
410
n_bytes = MIN(LOADER_HEADER_SIZE - priv->header_buf_offset, count);
411
memcpy (priv->header_buf + priv->header_buf_offset, buf, n_bytes);
413
priv->header_buf_offset += n_bytes;
415
if (priv->header_buf_offset >= LOADER_HEADER_SIZE)
417
if (gdk_pixbuf_loader_load_module (loader, NULL, error) == 0)
425
* gdk_pixbuf_loader_write:
426
* @loader: A pixbuf loader.
427
* @buf: Pointer to image data.
428
* @count: Length of the @buf buffer in bytes.
429
* @error: return location for errors
431
* This will cause a pixbuf loader to parse the next @count bytes of
432
* an image. It will return %TRUE if the data was loaded successfully,
433
* and %FALSE if an error occurred. In the latter case, the loader
434
* will be closed, and will not accept further writes. If %FALSE is
435
* returned, @error will be set to an error from the #GDK_PIXBUF_ERROR
436
* or #G_FILE_ERROR domains.
438
* Return value: %TRUE if the write was successful, or %FALSE if the loader
439
* cannot parse the buffer.
442
gdk_pixbuf_loader_write (GdkPixbufLoader *loader,
447
GdkPixbufLoaderPrivate *priv;
449
g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), FALSE);
451
g_return_val_if_fail (buf != NULL, FALSE);
452
g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
456
/* we expect it's not to be closed */
457
g_return_val_if_fail (priv->closed == FALSE, FALSE);
459
if (count > 0 && priv->image_module == NULL)
463
eaten = gdk_pixbuf_loader_eat_header_write (loader, buf, count, error);
471
if (count > 0 && priv->image_module->load_increment)
473
if (!priv->image_module->load_increment (priv->context, buf, count,
481
gdk_pixbuf_loader_ensure_error (loader, error);
482
gdk_pixbuf_loader_close (loader, NULL);
488
* gdk_pixbuf_loader_new:
490
* Creates a new pixbuf loader object.
492
* Return value: A newly-created pixbuf loader.
495
gdk_pixbuf_loader_new (void)
497
return g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
501
* gdk_pixbuf_loader_new_with_type:
502
* @image_type: name of the image format to be loaded with the image
503
* @error: (allow-none): return location for an allocated #GError, or %NULL to ignore errors
505
* Creates a new pixbuf loader object that always attempts to parse
506
* image data as if it were an image of type @image_type, instead of
507
* identifying the type automatically. Useful if you want an error if
508
* the image isn't the expected type, for loading image formats
509
* that can't be reliably identified by looking at the data, or if
510
* the user manually forces a specific type.
512
* The list of supported image formats depends on what image loaders
513
* are installed, but typically "png", "jpeg", "gif", "tiff" and
514
* "xpm" are among the supported formats. To obtain the full list of
515
* supported image formats, call gdk_pixbuf_format_get_name() on each
516
* of the #GdkPixbufFormat structs returned by gdk_pixbuf_get_formats().
518
* Return value: A newly-created pixbuf loader.
521
gdk_pixbuf_loader_new_with_type (const char *image_type,
524
GdkPixbufLoader *retval;
526
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
528
retval = g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
531
gdk_pixbuf_loader_load_module (retval, image_type, &tmp);
534
g_propagate_error (error, tmp);
535
gdk_pixbuf_loader_close (retval, NULL);
536
g_object_unref (retval);
544
* gdk_pixbuf_loader_new_with_mime_type:
545
* @mime_type: the mime type to be loaded
546
* @error: (allow-none): return location for an allocated #GError, or %NULL to ignore errors
548
* Creates a new pixbuf loader object that always attempts to parse
549
* image data as if it were an image of mime type @mime_type, instead of
550
* identifying the type automatically. Useful if you want an error if
551
* the image isn't the expected mime type, for loading image formats
552
* that can't be reliably identified by looking at the data, or if
553
* the user manually forces a specific mime type.
555
* The list of supported mime types depends on what image loaders
556
* are installed, but typically "image/png", "image/jpeg", "image/gif",
557
* "image/tiff" and "image/x-xpixmap" are among the supported mime types.
558
* To obtain the full list of supported mime types, call
559
* gdk_pixbuf_format_get_mime_types() on each of the #GdkPixbufFormat
560
* structs returned by gdk_pixbuf_get_formats().
562
* Return value: A newly-created pixbuf loader.
566
gdk_pixbuf_loader_new_with_mime_type (const char *mime_type,
569
const char * image_type = NULL;
572
GdkPixbufLoader *retval;
576
GdkPixbufFormat *info;
579
formats = gdk_pixbuf_get_formats ();
580
length = g_slist_length (formats);
582
for (i = 0; i < length && image_type == NULL; i++) {
583
info = (GdkPixbufFormat *)g_slist_nth_data (formats, i);
584
mimes = info->mime_types;
586
for (j = 0; mimes[j] != NULL; j++)
587
if (g_ascii_strcasecmp (mimes[j], mime_type) == 0) {
588
image_type = info->name;
593
g_slist_free (formats);
595
retval = g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
598
gdk_pixbuf_loader_load_module (retval, image_type, &tmp);
601
g_propagate_error (error, tmp);
602
gdk_pixbuf_loader_close (retval, NULL);
603
g_object_unref (retval);
611
* gdk_pixbuf_loader_get_pixbuf:
612
* @loader: A pixbuf loader.
614
* Queries the #GdkPixbuf that a pixbuf loader is currently creating.
615
* In general it only makes sense to call this function after the
616
* "area-prepared" signal has been emitted by the loader; this means
617
* that enough data has been read to know the size of the image that
618
* will be allocated. If the loader has not received enough data via
619
* gdk_pixbuf_loader_write(), then this function returns %NULL. The
620
* returned pixbuf will be the same in all future calls to the loader,
621
* so simply calling g_object_ref() should be sufficient to continue
622
* using it. Additionally, if the loader is an animation, it will
623
* return the "static image" of the animation
624
* (see gdk_pixbuf_animation_get_static_image()).
626
* Return value: The #GdkPixbuf that the loader is creating, or %NULL if not
627
* enough data has been read to determine how to create the image buffer.
630
gdk_pixbuf_loader_get_pixbuf (GdkPixbufLoader *loader)
632
GdkPixbufLoaderPrivate *priv;
634
g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
639
return gdk_pixbuf_animation_get_static_image (priv->animation);
645
* gdk_pixbuf_loader_get_animation:
646
* @loader: A pixbuf loader
648
* Queries the #GdkPixbufAnimation that a pixbuf loader is currently creating.
649
* In general it only makes sense to call this function after the "area-prepared"
650
* signal has been emitted by the loader. If the loader doesn't have enough
651
* bytes yet (hasn't emitted the "area-prepared" signal) this function will
654
* Return value: The #GdkPixbufAnimation that the loader is loading, or %NULL if
655
not enough data has been read to determine the information.
658
gdk_pixbuf_loader_get_animation (GdkPixbufLoader *loader)
660
GdkPixbufLoaderPrivate *priv;
662
g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
666
return priv->animation;
670
* gdk_pixbuf_loader_close:
671
* @loader: A pixbuf loader.
672
* @error: (allow-none): return location for a #GError, or %NULL to ignore errors
674
* Informs a pixbuf loader that no further writes with
675
* gdk_pixbuf_loader_write() will occur, so that it can free its
676
* internal loading structures. Also, tries to parse any data that
677
* hasn't yet been parsed; if the remaining data is partial or
678
* corrupt, an error will be returned. If %FALSE is returned, @error
679
* will be set to an error from the #GDK_PIXBUF_ERROR or #G_FILE_ERROR
680
* domains. If you're just cancelling a load rather than expecting it
681
* to be finished, passing %NULL for @error to ignore it is
684
* Returns: %TRUE if all image data written so far was successfully
685
passed out via the update_area signal
688
gdk_pixbuf_loader_close (GdkPixbufLoader *loader,
691
GdkPixbufLoaderPrivate *priv;
692
gboolean retval = TRUE;
694
g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), TRUE);
695
g_return_val_if_fail (error == NULL || *error == NULL, TRUE);
702
/* We have less the LOADER_HEADER_SIZE bytes in the image.
703
* Flush it, and keep going.
705
if (priv->image_module == NULL)
708
gdk_pixbuf_loader_load_module (loader, NULL, &tmp);
711
g_propagate_error (error, tmp);
716
if (priv->image_module && priv->image_module->stop_load && priv->context)
719
if (!priv->image_module->stop_load (priv->context, &tmp) || tmp)
721
/* don't call gdk_pixbuf_loader_ensure_error()
722
* here, since we might not get an error in the
723
* gdk_pixbuf_get_file_info() case
726
if (error && *error == NULL)
727
g_propagate_error (error, tmp);
736
if (priv->image_module && priv->holds_threadlock) {
737
_gdk_pixbuf_unlock (priv->image_module);
738
priv->holds_threadlock = FALSE;
741
if (priv->needs_scale)
744
g_signal_emit (loader, pixbuf_loader_signals[AREA_PREPARED], 0);
745
g_signal_emit (loader, pixbuf_loader_signals[AREA_UPDATED], 0,
746
0, 0, priv->width, priv->height);
750
g_signal_emit (loader, pixbuf_loader_signals[CLOSED], 0);
756
* gdk_pixbuf_loader_get_format:
757
* @loader: A pixbuf loader.
759
* Obtains the available information about the format of the
760
* currently loading image file.
762
* Returns: A #GdkPixbufFormat or %NULL. The return value is owned
763
* by GdkPixbuf and should not be freed.
768
gdk_pixbuf_loader_get_format (GdkPixbufLoader *loader)
770
GdkPixbufLoaderPrivate *priv;
772
g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
776
if (priv->image_module)
777
return _gdk_pixbuf_get_format (priv->image_module);
783
#define __GDK_PIXBUF_LOADER_C__
784
#include "gdk-pixbuf-aliasdef.c"
added
removed
gdk-pixbuf/gdk-pixbuf-loader.c
