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;
226 g_return_if_fail (GDK_IS_PIXBUF_LOADER (loader));
227 g_return_if_fail (width >= 0 && height >= 0);
229 priv = GDK_PIXBUF_LOADER (loader)->priv;
231 if (!priv->size_fixed)
234 priv->height = height;
239 gdk_pixbuf_loader_size_func (gint *width, gint *height, gpointer loader)
241 GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv;
243 /* allow calling gdk_pixbuf_loader_set_size() before the signal */
244 if (priv->width == -1 && priv->height == -1)
246 priv->width = *width;
247 priv->height = *height;
250 g_signal_emit (loader, pixbuf_loader_signals[SIZE_PREPARED], 0, *width, *height);
251 priv->size_fixed = TRUE;
253 *width = priv->width;
254 *height = priv->height;
258 gdk_pixbuf_loader_prepare (GdkPixbuf *pixbuf,
259 GdkPixbufAnimation *anim,
262 GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv;
263 g_return_if_fail (pixbuf != NULL);
265 if (!priv->size_fixed)
267 /* Defend against lazy loaders which don't call size_func */
268 gint width = gdk_pixbuf_get_width (pixbuf);
269 gint height = gdk_pixbuf_get_height (pixbuf);
271 gdk_pixbuf_loader_size_func (&width, &height, loader);
274 priv->needs_scale = FALSE;
275 if (priv->width > 0 && priv->height > 0 &&
276 (priv->width != gdk_pixbuf_get_width (pixbuf) ||
277 priv->height != gdk_pixbuf_get_height (pixbuf)))
278 priv->needs_scale = TRUE;
283 anim = gdk_pixbuf_non_anim_new (pixbuf);
285 if (priv->needs_scale) {
286 priv->animation = GDK_PIXBUF_ANIMATION (_gdk_pixbuf_scaled_anim_new (anim,
287 (double) priv->width / gdk_pixbuf_get_width (pixbuf),
288 (double) priv->height / gdk_pixbuf_get_height (pixbuf),
290 g_object_unref (anim);
293 priv->animation = anim;
295 if (!priv->needs_scale)
296 g_signal_emit (loader, pixbuf_loader_signals[AREA_PREPARED], 0);
300 gdk_pixbuf_loader_update (GdkPixbuf *pixbuf,
307 GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv;
309 if (!priv->needs_scale)
310 g_signal_emit (loader,
311 pixbuf_loader_signals[AREA_UPDATED],
314 /* sanity check in here. Defend against an errant loader */
315 MIN (width, gdk_pixbuf_animation_get_width (priv->animation)),
316 MIN (height, gdk_pixbuf_animation_get_height (priv->animation)));
319 /* Defense against broken loaders; DO NOT take this as a GError example! */
321 gdk_pixbuf_loader_ensure_error (GdkPixbufLoader *loader,
324 GdkPixbufLoaderPrivate *priv = loader->priv;
326 if (error == NULL || *error != NULL)
329 g_warning ("Bug! loader '%s' didn't set an error on failure",
330 priv->image_module->module_name);
333 GDK_PIXBUF_ERROR_FAILED,
334 _("Internal error: Image loader module '%s' failed to"
335 " complete an operation, but didn't give a reason for"
337 priv->image_module->module_name);
341 gdk_pixbuf_loader_load_module (GdkPixbufLoader *loader,
342 const char *image_type,
345 GdkPixbufLoaderPrivate *priv = loader->priv;
349 priv->image_module = _gdk_pixbuf_get_named_module (image_type,
354 priv->image_module = _gdk_pixbuf_get_module (priv->header_buf,
355 priv->header_buf_offset,
360 if (priv->image_module == NULL)
363 if (!_gdk_pixbuf_load_module (priv->image_module, error))
366 if (priv->image_module->module == NULL)
369 if ((priv->image_module->begin_load == NULL) ||
370 (priv->image_module->stop_load == NULL) ||
371 (priv->image_module->load_increment == NULL))
375 GDK_PIXBUF_ERROR_UNSUPPORTED_OPERATION,
376 _("Incremental loading of image type '%s' is not supported"),
377 priv->image_module->module_name);
382 if (!priv->holds_threadlock) {
383 priv->holds_threadlock = _gdk_pixbuf_lock (priv->image_module);
386 priv->context = priv->image_module->begin_load (gdk_pixbuf_loader_size_func,
387 gdk_pixbuf_loader_prepare,
388 gdk_pixbuf_loader_update,
392 if (priv->context == NULL)
394 gdk_pixbuf_loader_ensure_error (loader, error);
398 if (priv->header_buf_offset
399 && priv->image_module->load_increment (priv->context, priv->header_buf, priv->header_buf_offset, error))
400 return priv->header_buf_offset;
406 gdk_pixbuf_loader_eat_header_write (GdkPixbufLoader *loader,
412 GdkPixbufLoaderPrivate *priv = loader->priv;
414 n_bytes = MIN(LOADER_HEADER_SIZE - priv->header_buf_offset, count);
415 memcpy (priv->header_buf + priv->header_buf_offset, buf, n_bytes);
417 priv->header_buf_offset += n_bytes;
419 if (priv->header_buf_offset >= LOADER_HEADER_SIZE)
421 if (gdk_pixbuf_loader_load_module (loader, NULL, error) == 0)
429 * gdk_pixbuf_loader_write:
430 * @loader: A pixbuf loader.
431 * @buf: Pointer to image data.
432 * @count: Length of the @buf buffer in bytes.
433 * @error: return location for errors
435 * This will cause a pixbuf loader to parse the next @count bytes of
436 * an image. It will return %TRUE if the data was loaded successfully,
437 * and %FALSE if an error occurred. In the latter case, the loader
438 * will be closed, and will not accept further writes. If %FALSE is
439 * returned, @error will be set to an error from the #GDK_PIXBUF_ERROR
440 * or #G_FILE_ERROR domains.
442 * Return value: %TRUE if the write was successful, or %FALSE if the loader
443 * cannot parse the buffer.
446 gdk_pixbuf_loader_write (GdkPixbufLoader *loader,
451 GdkPixbufLoaderPrivate *priv;
453 g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), FALSE);
455 g_return_val_if_fail (buf != NULL, FALSE);
456 g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
460 /* we expect it's not to be closed */
461 g_return_val_if_fail (priv->closed == FALSE, FALSE);
463 if (count > 0 && priv->image_module == NULL)
467 eaten = gdk_pixbuf_loader_eat_header_write (loader, buf, count, error);
475 if (count > 0 && priv->image_module->load_increment)
477 if (!priv->image_module->load_increment (priv->context, buf, count,
485 gdk_pixbuf_loader_ensure_error (loader, error);
486 gdk_pixbuf_loader_close (loader, NULL);
492 * gdk_pixbuf_loader_new:
494 * Creates a new pixbuf loader object.
496 * Return value: A newly-created pixbuf loader.
499 gdk_pixbuf_loader_new (void)
501 return g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
505 * gdk_pixbuf_loader_new_with_type:
506 * @image_type: name of the image format to be loaded with the image
507 * @error: (allow-none): return location for an allocated #GError, or %NULL to ignore errors
509 * Creates a new pixbuf loader object that always attempts to parse
510 * image data as if it were an image of type @image_type, instead of
511 * identifying the type automatically. Useful if you want an error if
512 * the image isn't the expected type, for loading image formats
513 * that can't be reliably identified by looking at the data, or if
514 * the user manually forces a specific type.
516 * The list of supported image formats depends on what image loaders
517 * are installed, but typically "png", "jpeg", "gif", "tiff" and
518 * "xpm" are among the supported formats. To obtain the full list of
519 * supported image formats, call gdk_pixbuf_format_get_name() on each
520 * of the #GdkPixbufFormat structs returned by gdk_pixbuf_get_formats().
522 * Return value: A newly-created pixbuf loader.
525 gdk_pixbuf_loader_new_with_type (const char *image_type,
528 GdkPixbufLoader *retval;
530 g_return_val_if_fail (error == NULL || *error == NULL, NULL);
532 retval = g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
535 gdk_pixbuf_loader_load_module (retval, image_type, &tmp);
538 g_propagate_error (error, tmp);
539 gdk_pixbuf_loader_close (retval, NULL);
540 g_object_unref (retval);
548 * gdk_pixbuf_loader_new_with_mime_type:
549 * @mime_type: the mime type to be loaded
550 * @error: (allow-none): return location for an allocated #GError, or %NULL to ignore errors
552 * Creates a new pixbuf loader object that always attempts to parse
553 * image data as if it were an image of mime type @mime_type, instead of
554 * identifying the type automatically. Useful if you want an error if
555 * the image isn't the expected mime type, for loading image formats
556 * that can't be reliably identified by looking at the data, or if
557 * the user manually forces a specific mime type.
559 * The list of supported mime types depends on what image loaders
560 * are installed, but typically "image/png", "image/jpeg", "image/gif",
561 * "image/tiff" and "image/x-xpixmap" are among the supported mime types.
562 * To obtain the full list of supported mime types, call
563 * gdk_pixbuf_format_get_mime_types() on each of the #GdkPixbufFormat
564 * structs returned by gdk_pixbuf_get_formats().
566 * Return value: A newly-created pixbuf loader.
570 gdk_pixbuf_loader_new_with_mime_type (const char *mime_type,
573 const char * image_type = NULL;
576 GdkPixbufLoader *retval;
580 GdkPixbufFormat *info;
583 formats = gdk_pixbuf_get_formats ();
584 length = g_slist_length (formats);
586 for (i = 0; i < length && image_type == NULL; i++) {
587 info = (GdkPixbufFormat *)g_slist_nth_data (formats, i);
588 mimes = info->mime_types;
590 for (j = 0; mimes[j] != NULL; j++)
591 if (g_ascii_strcasecmp (mimes[j], mime_type) == 0) {
592 image_type = info->name;
597 g_slist_free (formats);
599 retval = g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
602 gdk_pixbuf_loader_load_module (retval, image_type, &tmp);
605 g_propagate_error (error, tmp);
606 gdk_pixbuf_loader_close (retval, NULL);
607 g_object_unref (retval);
615 * gdk_pixbuf_loader_get_pixbuf:
616 * @loader: A pixbuf loader.
618 * Queries the #GdkPixbuf that a pixbuf loader is currently creating.
619 * In general it only makes sense to call this function after the
620 * "area-prepared" signal has been emitted by the loader; this means
621 * that enough data has been read to know the size of the image that
622 * will be allocated. If the loader has not received enough data via
623 * gdk_pixbuf_loader_write(), then this function returns %NULL. The
624 * returned pixbuf will be the same in all future calls to the loader,
625 * so simply calling g_object_ref() should be sufficient to continue
626 * using it. Additionally, if the loader is an animation, it will
627 * return the "static image" of the animation
628 * (see gdk_pixbuf_animation_get_static_image()).
630 * Return value: The #GdkPixbuf that the loader is creating, or %NULL if not
631 * enough data has been read to determine how to create the image buffer.
634 gdk_pixbuf_loader_get_pixbuf (GdkPixbufLoader *loader)
636 GdkPixbufLoaderPrivate *priv;
638 g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
643 return gdk_pixbuf_animation_get_static_image (priv->animation);
649 * gdk_pixbuf_loader_get_animation:
650 * @loader: A pixbuf loader
652 * Queries the #GdkPixbufAnimation that a pixbuf loader is currently creating.
653 * In general it only makes sense to call this function after the "area-prepared"
654 * signal has been emitted by the loader. If the loader doesn't have enough
655 * bytes yet (hasn't emitted the "area-prepared" signal) this function will
658 * Return value: The #GdkPixbufAnimation that the loader is loading, or %NULL if
659 not enough data has been read to determine the information.
662 gdk_pixbuf_loader_get_animation (GdkPixbufLoader *loader)
664 GdkPixbufLoaderPrivate *priv;
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: (allow-none): 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 (GDK_IS_PIXBUF_LOADER (loader), TRUE);
699 g_return_val_if_fail (error == NULL || *error == NULL, TRUE);
706 /* We have less the LOADER_HEADER_SIZE bytes in the image.
707 * Flush it, and keep going.
709 if (priv->image_module == NULL)
712 gdk_pixbuf_loader_load_module (loader, NULL, &tmp);
715 g_propagate_error (error, tmp);
720 if (priv->image_module && priv->image_module->stop_load && priv->context)
723 if (!priv->image_module->stop_load (priv->context, &tmp) || tmp)
725 /* don't call gdk_pixbuf_loader_ensure_error()
726 * here, since we might not get an error in the
727 * gdk_pixbuf_get_file_info() case
730 if (error && *error == NULL)
731 g_propagate_error (error, tmp);
740 if (priv->image_module && priv->holds_threadlock) {
741 _gdk_pixbuf_unlock (priv->image_module);
742 priv->holds_threadlock = FALSE;
745 if (priv->needs_scale)
748 g_signal_emit (loader, pixbuf_loader_signals[AREA_PREPARED], 0);
749 g_signal_emit (loader, pixbuf_loader_signals[AREA_UPDATED], 0,
750 0, 0, priv->width, priv->height);
754 g_signal_emit (loader, pixbuf_loader_signals[CLOSED], 0);
760 * gdk_pixbuf_loader_get_format:
761 * @loader: A pixbuf loader.
763 * Obtains the available information about the format of the
764 * currently loading image file.
766 * Returns: A #GdkPixbufFormat or %NULL. The return value is owned
767 * by GdkPixbuf and should not be freed.
772 gdk_pixbuf_loader_get_format (GdkPixbufLoader *loader)
774 GdkPixbufLoaderPrivate *priv;
776 g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
780 if (priv->image_module)
781 return _gdk_pixbuf_get_format (priv->image_module);
787 #define __GDK_PIXBUF_LOADER_C__
788 #include "gdk-pixbuf-aliasdef.c"