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 (priv->image_module->module == NULL)
360 if (!_gdk_pixbuf_load_module (priv->image_module, error))
363 if (priv->image_module->module == NULL)
366 if ((priv->image_module->begin_load == NULL) ||
367 (priv->image_module->stop_load == NULL) ||
368 (priv->image_module->load_increment == NULL))
372 GDK_PIXBUF_ERROR_UNSUPPORTED_OPERATION,
373 _("Incremental loading of image type '%s' is not supported"),
374 priv->image_module->module_name);
379 if (!priv->holds_threadlock) {
380 priv->holds_threadlock = _gdk_pixbuf_lock (priv->image_module);
383 priv->context = priv->image_module->begin_load (gdk_pixbuf_loader_size_func,
384 gdk_pixbuf_loader_prepare,
385 gdk_pixbuf_loader_update,
389 if (priv->context == NULL)
391 gdk_pixbuf_loader_ensure_error (loader, error);
395 if (priv->header_buf_offset
396 && priv->image_module->load_increment (priv->context, priv->header_buf, priv->header_buf_offset, error))
397 return priv->header_buf_offset;
403 gdk_pixbuf_loader_eat_header_write (GdkPixbufLoader *loader,
409 GdkPixbufLoaderPrivate *priv = loader->priv;
411 n_bytes = MIN(LOADER_HEADER_SIZE - priv->header_buf_offset, count);
412 memcpy (priv->header_buf + priv->header_buf_offset, buf, n_bytes);
414 priv->header_buf_offset += n_bytes;
416 if (priv->header_buf_offset >= LOADER_HEADER_SIZE)
418 if (gdk_pixbuf_loader_load_module (loader, NULL, error) == 0)
426 * gdk_pixbuf_loader_write:
427 * @loader: A pixbuf loader.
428 * @buf: Pointer to image data.
429 * @count: Length of the @buf buffer in bytes.
430 * @error: return location for errors
432 * This will cause a pixbuf loader to parse the next @count bytes of
433 * an image. It will return %TRUE if the data was loaded successfully,
434 * and %FALSE if an error occurred. In the latter case, the loader
435 * will be closed, and will not accept further writes. If %FALSE is
436 * returned, @error will be set to an error from the #GDK_PIXBUF_ERROR
437 * or #G_FILE_ERROR domains.
439 * Return value: %TRUE if the write was successful, or %FALSE if the loader
440 * cannot parse the buffer.
443 gdk_pixbuf_loader_write (GdkPixbufLoader *loader,
448 GdkPixbufLoaderPrivate *priv;
450 g_return_val_if_fail (loader != NULL, FALSE);
451 g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), FALSE);
453 g_return_val_if_fail (buf != NULL, FALSE);
454 g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
458 /* we expect it's not to be closed */
459 g_return_val_if_fail (priv->closed == FALSE, FALSE);
461 if (count > 0 && priv->image_module == NULL)
465 eaten = gdk_pixbuf_loader_eat_header_write (loader, buf, count, error);
473 if (count > 0 && priv->image_module->load_increment)
475 if (!priv->image_module->load_increment (priv->context, buf, count,
483 gdk_pixbuf_loader_ensure_error (loader, error);
484 gdk_pixbuf_loader_close (loader, NULL);
490 * gdk_pixbuf_loader_new:
492 * Creates a new pixbuf loader object.
494 * Return value: A newly-created pixbuf loader.
497 gdk_pixbuf_loader_new (void)
499 return g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
503 * gdk_pixbuf_loader_new_with_type:
504 * @image_type: name of the image format to be loaded with the image
505 * @error: return location for an allocated #GError, or %NULL to ignore errors
507 * Creates a new pixbuf loader object that always attempts to parse
508 * image data as if it were an image of type @image_type, instead of
509 * identifying the type automatically. Useful if you want an error if
510 * the image isn't the expected type, for loading image formats
511 * that can't be reliably identified by looking at the data, or if
512 * the user manually forces a specific type.
514 * The list of supported image formats depends on what image loaders
515 * are installed, but typically "png", "jpeg", "gif", "tiff" and
516 * "xpm" are among the supported formats. To obtain the full list of
517 * supported image formats, call gdk_pixbuf_format_get_name() on each
518 * of the #GdkPixbufFormat structs returned by gdk_pixbuf_get_formats().
520 * Return value: A newly-created pixbuf loader.
523 gdk_pixbuf_loader_new_with_type (const char *image_type,
526 GdkPixbufLoader *retval;
528 g_return_val_if_fail (error == NULL || *error == NULL, NULL);
530 retval = g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
533 gdk_pixbuf_loader_load_module (retval, image_type, &tmp);
536 g_propagate_error (error, tmp);
537 gdk_pixbuf_loader_close (retval, NULL);
538 g_object_unref (retval);
546 * gdk_pixbuf_loader_new_with_mime_type:
547 * @mime_type: the mime type to be loaded
548 * @error: return location for an allocated #GError, or %NULL to ignore errors
550 * Creates a new pixbuf loader object that always attempts to parse
551 * image data as if it were an image of mime type @mime_type, instead of
552 * identifying the type automatically. Useful if you want an error if
553 * the image isn't the expected mime type, for loading image formats
554 * that can't be reliably identified by looking at the data, or if
555 * the user manually forces a specific mime type.
557 * The list of supported mime types depends on what image loaders
558 * are installed, but typically "image/png", "image/jpeg", "image/gif",
559 * "image/tiff" and "image/x-xpixmap" are among the supported mime types.
560 * To obtain the full list of supported mime types, call
561 * gdk_pixbuf_format_get_mime_types() on each of the #GdkPixbufFormat
562 * structs returned by gdk_pixbuf_get_formats().
564 * Return value: A newly-created pixbuf loader.
568 gdk_pixbuf_loader_new_with_mime_type (const char *mime_type,
571 const char * image_type = NULL;
574 GdkPixbufLoader *retval;
578 GdkPixbufFormat *info;
581 formats = gdk_pixbuf_get_formats ();
582 length = g_slist_length (formats);
584 for (i = 0; i < length && image_type == NULL; i++) {
585 info = (GdkPixbufFormat *)g_slist_nth_data (formats, i);
586 mimes = info->mime_types;
588 for (j = 0; mimes[j] != NULL; j++)
589 if (g_ascii_strcasecmp (mimes[j], mime_type) == 0) {
590 image_type = info->name;
595 g_slist_free (formats);
597 retval = g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
600 gdk_pixbuf_loader_load_module (retval, image_type, &tmp);
603 g_propagate_error (error, tmp);
604 gdk_pixbuf_loader_close (retval, NULL);
605 g_object_unref (retval);
613 * gdk_pixbuf_loader_get_pixbuf:
614 * @loader: A pixbuf loader.
616 * Queries the #GdkPixbuf that a pixbuf loader is currently creating.
617 * In general it only makes sense to call this function after the
618 * "area-prepared" signal has been emitted by the loader; this means
619 * that enough data has been read to know the size of the image that
620 * will be allocated. If the loader has not received enough data via
621 * gdk_pixbuf_loader_write(), then this function returns %NULL. The
622 * returned pixbuf will be the same in all future calls to the loader,
623 * so simply calling g_object_ref() should be sufficient to continue
624 * using it. Additionally, if the loader is an animation, it will
625 * return the "static image" of the animation
626 * (see gdk_pixbuf_animation_get_static_image()).
628 * Return value: The #GdkPixbuf that the loader is creating, or %NULL if not
629 * enough data has been read to determine how to create the image buffer.
632 gdk_pixbuf_loader_get_pixbuf (GdkPixbufLoader *loader)
634 GdkPixbufLoaderPrivate *priv;
636 g_return_val_if_fail (loader != NULL, NULL);
637 g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
642 return gdk_pixbuf_animation_get_static_image (priv->animation);
648 * gdk_pixbuf_loader_get_animation:
649 * @loader: A pixbuf loader
651 * Queries the #GdkPixbufAnimation that a pixbuf loader is currently creating.
652 * In general it only makes sense to call this function after the "area-prepared"
653 * signal has been emitted by the loader. If the loader doesn't have enough
654 * bytes yet (hasn't emitted the "area-prepared" signal) this function will
657 * Return value: The #GdkPixbufAnimation that the loader is loading, or %NULL if
658 not enough data has been read to determine the information.
661 gdk_pixbuf_loader_get_animation (GdkPixbufLoader *loader)
663 GdkPixbufLoaderPrivate *priv;
665 g_return_val_if_fail (loader != NULL, NULL);
666 g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
670 return priv->animation;
674 * gdk_pixbuf_loader_close:
675 * @loader: A pixbuf loader.
676 * @error: return location for a #GError, or %NULL to ignore errors
678 * Informs a pixbuf loader that no further writes with
679 * gdk_pixbuf_loader_write() will occur, so that it can free its
680 * internal loading structures. Also, tries to parse any data that
681 * hasn't yet been parsed; if the remaining data is partial or
682 * corrupt, an error will be returned. If %FALSE is returned, @error
683 * will be set to an error from the #GDK_PIXBUF_ERROR or #G_FILE_ERROR
684 * domains. If you're just cancelling a load rather than expecting it
685 * to be finished, passing %NULL for @error to ignore it is
688 * Returns: %TRUE if all image data written so far was successfully
689 passed out via the update_area signal
692 gdk_pixbuf_loader_close (GdkPixbufLoader *loader,
695 GdkPixbufLoaderPrivate *priv;
696 gboolean retval = TRUE;
698 g_return_val_if_fail (loader != NULL, TRUE);
699 g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), TRUE);
700 g_return_val_if_fail (error == NULL || *error == NULL, TRUE);
707 /* We have less the LOADER_HEADER_SIZE bytes in the image.
708 * Flush it, and keep going.
710 if (priv->image_module == NULL)
713 gdk_pixbuf_loader_load_module (loader, NULL, &tmp);
716 g_propagate_error (error, tmp);
721 if (priv->image_module && priv->image_module->stop_load && priv->context)
724 if (!priv->image_module->stop_load (priv->context, &tmp) || tmp)
726 /* don't call gdk_pixbuf_loader_ensure_error()
727 * here, since we might not get an error in the
728 * gdk_pixbuf_get_file_info() case
731 g_propagate_error (error, tmp);
737 if (priv->image_module && priv->holds_threadlock) {
738 _gdk_pixbuf_unlock (priv->image_module);
739 priv->holds_threadlock = FALSE;
742 if (priv->needs_scale)
745 g_signal_emit (loader, pixbuf_loader_signals[AREA_PREPARED], 0);
746 g_signal_emit (loader, pixbuf_loader_signals[AREA_UPDATED], 0,
747 0, 0, priv->width, priv->height);
751 g_signal_emit (loader, pixbuf_loader_signals[CLOSED], 0);
757 * gdk_pixbuf_loader_get_format:
758 * @loader: A pixbuf loader.
760 * Obtains the available information about the format of the
761 * currently loading image file.
763 * Returns: A #GdkPixbufFormat or %NULL. The return value is owned
764 * by GdkPixbuf and should not be freed.
769 gdk_pixbuf_loader_get_format (GdkPixbufLoader *loader)
771 GdkPixbufLoaderPrivate *priv;
773 g_return_val_if_fail (loader != NULL, NULL);
774 g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
778 if (priv->image_module)
779 return _gdk_pixbuf_get_format (priv->image_module);
785 #define __GDK_PIXBUF_LOADER_C__
786 #include "gdk-pixbuf-aliasdef.c"