Pileus Git - ~andy/gtk/blob - gdk-pixbuf/gdk-pixbuf-loader.c

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*- */
   2 /* GdkPixbuf library - Progressive loader object
   3  *
   4  * Copyright (C) 1999 The Free Software Foundation
   5  *
   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>
  10  *
  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.
  15  *
  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.
  20  *
  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.
  25  */
  26
  27 #include <config.h>
  28 #include <string.h>
  29
  30 #include "gdk-pixbuf-alias.h"
  31 #include "gdk-pixbuf-private.h"
  32 #include "gdk-pixbuf-animation.h"
  33 #include "gdk-pixbuf-io.h"
  34 #include "gdk-pixbuf-loader.h"
  35 #include "gdk-pixbuf-marshal.h"
  36
  37 enum {
  38         SIZE_PREPARED,
  39         AREA_PREPARED,
  40         AREA_UPDATED,
  41         CLOSED,
  42         LAST_SIGNAL
  43 };
  44
  45
  46 static void gdk_pixbuf_loader_class_init    (GdkPixbufLoaderClass   *klass);
  47 static void gdk_pixbuf_loader_init          (GdkPixbufLoader        *loader);
  48 static void gdk_pixbuf_loader_finalize      (GObject                *loader);
  49
  50 static gpointer parent_class = NULL;
  51 static guint    pixbuf_loader_signals[LAST_SIGNAL] = { 0 };
  52
  53 /* Internal data */
  54
  55 #define LOADER_HEADER_SIZE 128
  56
  57 typedef struct
  58 {
  59         GdkPixbufAnimation *animation;
  60         gboolean closed;
  61         gboolean holds_threadlock;
  62         guchar header_buf[LOADER_HEADER_SIZE];
  63         gint header_buf_offset;
  64         GdkPixbufModule *image_module;
  65         gpointer context;
  66         gint width;
  67         gint height;
  68         gboolean size_fixed;
  69         gboolean needs_scale;
  70 } GdkPixbufLoaderPrivate;
  71
  72
  73 /**
  74  * gdk_pixbuf_loader_get_type:
  75  *
  76  * Registers the #GdkPixbufLoader class if necessary, and returns the type ID
  77  * associated to it.
  78  *
  79  * Return value: The type ID of the #GdkPixbufLoader class.
  80  **/
  81 GType
  82 gdk_pixbuf_loader_get_type (void)
  83 {
  84         static GType loader_type = 0;
  85
  86         if (!loader_type)
  87                 {
  88                         static const GTypeInfo loader_info = {
  89                                 sizeof (GdkPixbufLoaderClass),
  90                                 (GBaseInitFunc) NULL,
  91                                 (GBaseFinalizeFunc) NULL,
  92                                 (GClassInitFunc) gdk_pixbuf_loader_class_init,
  93                                 NULL,           /* class_finalize */
  94                                 NULL,           /* class_data */
  95                                 sizeof (GdkPixbufLoader),
  96                                 0,              /* n_preallocs */
  97                                 (GInstanceInitFunc) gdk_pixbuf_loader_init
  98                         };
  99
 100                         loader_type = g_type_register_static (G_TYPE_OBJECT,
 101                                                               "GdkPixbufLoader",
 102                                                               &loader_info,
 103                                                               0);
 104                 }
 105
 106         return loader_type;
 107 }
 108
 109 static void
 110 gdk_pixbuf_loader_class_init (GdkPixbufLoaderClass *class)
 111 {
 112         GObjectClass *object_class;
 113
 114         object_class = (GObjectClass *) class;
 115
 116         parent_class = g_type_class_peek_parent (class);
 117
 118         object_class->finalize = gdk_pixbuf_loader_finalize;
 119
 120         /**
 121          * GdkPixbufLoader::size-prepared:
 122          * @loader: the object which received the signal.
 123          * @width: the original width of the image
 124          * @height: the original height of the image
 125          *
 126          * This signal is emitted when the pixbuf loader has been fed the
 127          * initial amount of data that is required to figure out the size
 128          * of the image that it will create.  Applications can call
 129          * gdk_pixbuf_loader_set_size() in response to this signal to set
 130          * the desired size to which the image should be scaled.
 131          */
 132         pixbuf_loader_signals[SIZE_PREPARED] =
 133                 g_signal_new ("size_prepared",
 134                               G_TYPE_FROM_CLASS (object_class),
 135                               G_SIGNAL_RUN_LAST,
 136                               G_STRUCT_OFFSET (GdkPixbufLoaderClass, size_prepared),
 137                               NULL, NULL,
 138                               _gdk_pixbuf_marshal_VOID__INT_INT,
 139                               G_TYPE_NONE, 2,
 140                               G_TYPE_INT,
 141                               G_TYPE_INT);
 142
 143         /**
 144          * GdkPixbufLoader::area-prepared:
 145          * @loader: the object which received the signal.
 146          *
 147          * This signal is emitted when the pixbuf loader has allocated the
 148          * pixbuf in the desired size.  After this signal is emitted,
 149          * applications can call gdk_pixbuf_loader_get_pixbuf() to fetch
 150          * the partially-loaded pixbuf.
 151          */
 152         pixbuf_loader_signals[AREA_PREPARED] =
 153                 g_signal_new ("area_prepared",
 154                               G_TYPE_FROM_CLASS (object_class),
 155                               G_SIGNAL_RUN_LAST,
 156                               G_STRUCT_OFFSET (GdkPixbufLoaderClass, area_prepared),
 157                               NULL, NULL,
 158                               _gdk_pixbuf_marshal_VOID__VOID,
 159                               G_TYPE_NONE, 0);
 160
 161         /**
 162          * GdkPixbufLoader::area-updated:
 163          * @loader: the object which received the signal.
 164          * @x: X offset of upper-left corner of the updated area.
 165          * @y: Y offset of upper-left corner of the updated area.
 166          * @width: Width of updated area.
 167          * @height: Height of updated area.
 168          *
 169          * This signal is emitted when a significant area of the image being
 170          * loaded has been updated.  Normally it means that a complete
 171          * scanline has been read in, but it could be a different area as
 172          * well.  Applications can use this signal to know when to repaint
 173          * areas of an image that is being loaded.
 174          */
 175         pixbuf_loader_signals[AREA_UPDATED] =
 176                 g_signal_new ("area_updated",
 177                               G_TYPE_FROM_CLASS (object_class),
 178                               G_SIGNAL_RUN_LAST,
 179                               G_STRUCT_OFFSET (GdkPixbufLoaderClass, area_updated),
 180                               NULL, NULL,
 181                               _gdk_pixbuf_marshal_VOID__INT_INT_INT_INT,
 182                               G_TYPE_NONE, 4,
 183                               G_TYPE_INT,
 184                               G_TYPE_INT,
 185                               G_TYPE_INT,
 186                               G_TYPE_INT);
 187
 188         /**
 189          * GdkPixbufLoader::closed:
 190          * @loader: the object which received the signal.
 191          *
 192          * This signal is emitted when gdk_pixbuf_loader_close() is called.
 193          * It can be used by different parts of an application to receive
 194          * notification when an image loader is closed by the code that
 195          * drives it.
 196          */
 197         pixbuf_loader_signals[CLOSED] =
 198                 g_signal_new ("closed",
 199                               G_TYPE_FROM_CLASS (object_class),
 200                               G_SIGNAL_RUN_LAST,
 201                               G_STRUCT_OFFSET (GdkPixbufLoaderClass, closed),
 202                               NULL, NULL,
 203                               _gdk_pixbuf_marshal_VOID__VOID,
 204                               G_TYPE_NONE, 0);
 205 }
 206
 207 static void
 208 gdk_pixbuf_loader_init (GdkPixbufLoader *loader)
 209 {
 210         GdkPixbufLoaderPrivate *priv;
 211
 212         priv = g_new0 (GdkPixbufLoaderPrivate, 1);
 213         priv->width = -1;
 214         priv->height = -1;
 215
 216         loader->priv = priv;
 217 }
 218
 219 static void
 220 gdk_pixbuf_loader_finalize (GObject *object)
 221 {
 222         GdkPixbufLoader *loader;
 223         GdkPixbufLoaderPrivate *priv = NULL;
 224
 225         loader = GDK_PIXBUF_LOADER (object);
 226         priv = loader->priv;
 227
 228         if (!priv->closed) {
 229                 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.");
 230                 if (priv->holds_threadlock) {
 231                         _gdk_pixbuf_unlock (priv->image_module);
 232                 }
 233         }
 234         if (priv->animation)
 235                 g_object_unref (priv->animation);
 236
 237         g_free (priv);
 238
 239         G_OBJECT_CLASS (parent_class)->finalize (object);
 240 }
 241
 242 /**
 243  * gdk_pixbuf_loader_set_size:
 244  * @loader: A pixbuf loader.
 245  * @width: The desired width of the image being loaded.
 246  * @height: The desired height of the image being loaded.
 247  *
 248  * Causes the image to be scaled while it is loaded. The desired
 249  * image size can be determined relative to the original size of
 250  * the image by calling gdk_pixbuf_loader_set_size() from a
 251  * signal handler for the ::size_prepared signal.
 252  *
 253  * Attempts to set the desired image size  are ignored after the
 254  * emission of the ::size_prepared signal.
 255  *
 256  * Since: 2.2
 257  */
 258 void
 259 gdk_pixbuf_loader_set_size (GdkPixbufLoader *loader,
 260                             gint             width,
 261                             gint             height)
 262 {
 263         GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv;
 264         g_return_if_fail (width >= 0 && height >= 0);
 265
 266         if (!priv->size_fixed)
 267                 {
 268                         priv->width = width;
 269                         priv->height = height;
 270                 }
 271 }
 272
 273 static void
 274 gdk_pixbuf_loader_size_func (gint *width, gint *height, gpointer loader)
 275 {
 276         GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv;
 277
 278         /* allow calling gdk_pixbuf_loader_set_size() before the signal */
 279         if (priv->width == -1 && priv->height == -1)
 280                 {
 281                         priv->width = *width;
 282                         priv->height = *height;
 283                 }
 284
 285         g_signal_emit (loader, pixbuf_loader_signals[SIZE_PREPARED], 0, *width, *height);
 286         priv->size_fixed = TRUE;
 287
 288         *width = priv->width;
 289         *height = priv->height;
 290 }
 291
 292 static void
 293 gdk_pixbuf_loader_prepare (GdkPixbuf          *pixbuf,
 294                            GdkPixbufAnimation *anim,
 295                            gpointer            loader)
 296 {
 297         GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv;
 298         g_return_if_fail (pixbuf != NULL);
 299
 300         if (!priv->size_fixed)
 301                 {
 302                         /* Defend against lazy loaders which don't call size_func */
 303                         gint width = gdk_pixbuf_get_width (pixbuf);
 304                         gint height = gdk_pixbuf_get_height (pixbuf);
 305
 306                         gdk_pixbuf_loader_size_func (&width, &height, loader);
 307                 }
 308
 309         priv->needs_scale = FALSE;
 310         if (priv->width > 0 && priv->height > 0 &&
 311             (priv->width != gdk_pixbuf_get_width (pixbuf) ||
 312              priv->height != gdk_pixbuf_get_height (pixbuf)))
 313                 priv->needs_scale = TRUE;
 314
 315         if (anim)
 316                 g_object_ref (anim);
 317         else
 318                 anim = gdk_pixbuf_non_anim_new (pixbuf);
 319
 320         priv->animation = anim;
 321
 322         if (!priv->needs_scale)
 323                 g_signal_emit (loader, pixbuf_loader_signals[AREA_PREPARED], 0);
 324 }
 325
 326 static void
 327 gdk_pixbuf_loader_update (GdkPixbuf *pixbuf,
 328                           gint       x,
 329                           gint       y,
 330                           gint       width,
 331                           gint       height,
 332                           gpointer   loader)
 333 {
 334         GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv;
 335
 336         if (!priv->needs_scale)
 337                 g_signal_emit (loader,
 338                                pixbuf_loader_signals[AREA_UPDATED],
 339                                0,
 340                                x, y,
 341                                /* sanity check in here.  Defend against an errant loader */
 342                                MIN (width, gdk_pixbuf_animation_get_width (priv->animation)),
 343                                MIN (height, gdk_pixbuf_animation_get_height (priv->animation)));
 344 }
 345
 346 static gint
 347 gdk_pixbuf_loader_load_module (GdkPixbufLoader *loader,
 348                                const char      *image_type,
 349                                GError         **error)
 350 {
 351         GdkPixbufLoaderPrivate *priv = loader->priv;
 352
 353         if (image_type)
 354                 {
 355                         priv->image_module = _gdk_pixbuf_get_named_module (image_type,
 356                                                                            error);
 357                 }
 358         else
 359                 {
 360                         priv->image_module = _gdk_pixbuf_get_module (priv->header_buf,
 361                                                                      priv->header_buf_offset,
 362                                                                      NULL,
 363                                                                      error);
 364                 }
 365
 366         if (priv->image_module == NULL)
 367                 return 0;
 368
 369         if (priv->image_module->module == NULL)
 370                 if (!_gdk_pixbuf_load_module (priv->image_module, error))
 371                         return 0;
 372
 373         if (priv->image_module->module == NULL)
 374                 return 0;
 375
 376         if ((priv->image_module->begin_load == NULL) ||
 377             (priv->image_module->stop_load == NULL) ||
 378             (priv->image_module->load_increment == NULL))
 379                 {
 380                         g_set_error (error,
 381                                      GDK_PIXBUF_ERROR,
 382                                      GDK_PIXBUF_ERROR_UNSUPPORTED_OPERATION,
 383                                      _("Incremental loading of image type '%s' is not supported"),
 384                                      priv->image_module->module_name);
 385
 386                         return 0;
 387                 }
 388
 389         if (!priv->holds_threadlock) {
 390                 priv->holds_threadlock = _gdk_pixbuf_lock (priv->image_module);
 391         }
 392
 393         priv->context = priv->image_module->begin_load (gdk_pixbuf_loader_size_func,
 394                                                         gdk_pixbuf_loader_prepare,
 395                                                         gdk_pixbuf_loader_update,
 396                                                         loader,
 397                                                         error);
 398
 399         if (priv->context == NULL)
 400                 {
 401                         /* Defense against broken loaders; DO NOT take this as a GError
 402                          * example
 403                          */
 404                         if (error && *error == NULL)
 405                                 {
 406                                         g_warning ("Bug! loader '%s' didn't set an error on failure",
 407                                                    priv->image_module->module_name);
 408                                         g_set_error (error,
 409                                                      GDK_PIXBUF_ERROR,
 410                                                      GDK_PIXBUF_ERROR_FAILED,
 411                                                      _("Internal error: Image loader module '%s'"
 412                                                        " failed to begin loading an image, but didn't"
 413                                                        " give a reason for the failure"),
 414                                                      priv->image_module->module_name);
 415
 416                                 }
 417
 418                         return 0;
 419                 }
 420
 421         if (priv->header_buf_offset
 422             && priv->image_module->load_increment (priv->context, priv->header_buf, priv->header_buf_offset, error))
 423                 return priv->header_buf_offset;
 424
 425         return 0;
 426 }
 427
 428 static int
 429 gdk_pixbuf_loader_eat_header_write (GdkPixbufLoader *loader,
 430                                     const guchar    *buf,
 431                                     gsize            count,
 432                                     GError         **error)
 433 {
 434         gint n_bytes;
 435         GdkPixbufLoaderPrivate *priv = loader->priv;
 436
 437         n_bytes = MIN(LOADER_HEADER_SIZE - priv->header_buf_offset, count);
 438         memcpy (priv->header_buf + priv->header_buf_offset, buf, n_bytes);
 439
 440         priv->header_buf_offset += n_bytes;
 441
 442         if (priv->header_buf_offset >= LOADER_HEADER_SIZE)
 443                 {
 444                         if (gdk_pixbuf_loader_load_module (loader, NULL, error) == 0)
 445                                 return 0;
 446                 }
 447
 448         return n_bytes;
 449 }
 450
 451 /**
 452  * gdk_pixbuf_loader_write:
 453  * @loader: A pixbuf loader.
 454  * @buf: Pointer to image data.
 455  * @count: Length of the @buf buffer in bytes.
 456  * @error: return location for errors
 457  *
 458  * This will cause a pixbuf loader to parse the next @count bytes of
 459  * an image.  It will return %TRUE if the data was loaded successfully,
 460  * and %FALSE if an error occurred.  In the latter case, the loader
 461  * will be closed, and will not accept further writes. If %FALSE is
 462  * returned, @error will be set to an error from the #GDK_PIXBUF_ERROR
 463  * or #G_FILE_ERROR domains.
 464  *
 465  * Return value: %TRUE if the write was successful, or %FALSE if the loader
 466  * cannot parse the buffer.
 467  **/
 468 gboolean
 469 gdk_pixbuf_loader_write (GdkPixbufLoader *loader,
 470                          const guchar    *buf,
 471                          gsize            count,
 472                          GError         **error)
 473 {
 474         GdkPixbufLoaderPrivate *priv;
 475
 476         g_return_val_if_fail (loader != NULL, FALSE);
 477         g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), FALSE);
 478
 479         g_return_val_if_fail (buf != NULL, FALSE);
 480         g_return_val_if_fail (count >= 0, FALSE);
 481         g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
 482
 483         priv = loader->priv;
 484
 485         /* we expect it's not to be closed */
 486         g_return_val_if_fail (priv->closed == FALSE, FALSE);
 487
 488         if (priv->image_module == NULL)
 489                 {
 490                         gint eaten;
 491
 492                         eaten = gdk_pixbuf_loader_eat_header_write (loader, buf, count, error);
 493                         if (eaten <= 0)
 494                                 return FALSE;
 495
 496                         count -= eaten;
 497                         buf += eaten;
 498                 }
 499
 500         if (count > 0 && priv->image_module->load_increment)
 501                 {
 502                         gboolean retval;
 503                         retval = priv->image_module->load_increment (priv->context, buf, count,
 504                                                                      error);
 505                         if (!retval && error && *error == NULL)
 506                                 {
 507                                         /* Fix up busted image loader */
 508                                         g_warning ("Bug! loader '%s' didn't set an error on failure",
 509                                                    priv->image_module->module_name);
 510                                         g_set_error (error,
 511                                                      GDK_PIXBUF_ERROR,
 512                                                      GDK_PIXBUF_ERROR_FAILED,
 513                                                      _("Internal error: Image loader module '%s'"
 514                                                        " failed to begin loading an image, but didn't"
 515                                                        " give a reason for the failure"),
 516                                                      priv->image_module->module_name);
 517                                 }
 518
 519                         return retval;
 520                 }
 521
 522         return TRUE;
 523 }
 524
 525 /**
 526  * gdk_pixbuf_loader_new:
 527  *
 528  * Creates a new pixbuf loader object.
 529  *
 530  * Return value: A newly-created pixbuf loader.
 531  **/
 532 GdkPixbufLoader *
 533 gdk_pixbuf_loader_new (void)
 534 {
 535         return g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
 536 }
 537
 538 /**
 539  * gdk_pixbuf_loader_new_with_type:
 540  * @image_type: name of the image format to be loaded with the image
 541  * @error: return location for an allocated #GError, or %NULL to ignore errors
 542  *
 543  * Creates a new pixbuf loader object that always attempts to parse
 544  * image data as if it were an image of type @image_type, instead of
 545  * identifying the type automatically. Useful if you want an error if
 546  * the image isn't the expected type, for loading image formats
 547  * that can't be reliably identified by looking at the data, or if
 548  * the user manually forces a specific type.
 549  *
 550  * Return value: A newly-created pixbuf loader.
 551  **/
 552 GdkPixbufLoader *
 553 gdk_pixbuf_loader_new_with_type (const char *image_type,
 554                                  GError    **error)
 555 {
 556         GdkPixbufLoader *retval;
 557         GError *tmp;
 558         g_return_val_if_fail (error == NULL || *error == NULL, NULL);
 559
 560         retval = g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
 561
 562         tmp = NULL;
 563         gdk_pixbuf_loader_load_module (retval, image_type, &tmp);
 564         if (tmp != NULL)
 565                 {
 566                         g_propagate_error (error, tmp);
 567                         g_object_unref (retval);
 568                         return NULL;
 569                 }
 570
 571         return retval;
 572 }
 573
 574 /**
 575  * gdk_pixbuf_loader_new_with_mime_type:
 576  * @mime_type: the mime type to be loaded
 577  * @error: return location for an allocated #GError, or %NULL to ignore errors
 578  *
 579  * Creates a new pixbuf loader object that always attempts to parse
 580  * image data as if it were an image of mime type @mime_type, instead of
 581  * identifying the type automatically. Useful if you want an error if
 582  * the image isn't the expected mime type, for loading image formats
 583  * that can't be reliably identified by looking at the data, or if
 584  * the user manually forces a specific mime type.
 585  *
 586  * Return value: A newly-created pixbuf loader.
 587  * Since: 2.4
 588  **/
 589 GdkPixbufLoader *
 590 gdk_pixbuf_loader_new_with_mime_type (const char *mime_type,
 591                                       GError    **error)
 592 {
 593         const char * image_type = NULL;
 594         char ** mimes;
 595
 596         GdkPixbufLoader *retval;
 597         GError *tmp;
 598
 599         GSList * formats;
 600         GdkPixbufFormat *info;
 601         int i, j, length;
 602
 603         formats = gdk_pixbuf_get_formats ();
 604         length = g_slist_length (formats);
 605
 606         for (i = 0; i < length && image_type == NULL; i++) {
 607                 info = (GdkPixbufFormat *)g_slist_nth_data (formats, i);
 608                 mimes = info->mime_types;
 609
 610                 for (j = 0; mimes[j] != NULL; j++)
 611                         if (g_ascii_strcasecmp (mimes[j], mime_type) == 0) {
 612                                 image_type = info->name;
 613                                 break;
 614                         }
 615         }
 616
 617         g_slist_free (formats);
 618
 619         retval = g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL);
 620
 621         tmp = NULL;
 622         gdk_pixbuf_loader_load_module(retval, image_type, &tmp);
 623         if (tmp != NULL)
 624                 {
 625                         g_propagate_error (error, tmp);
 626                         g_object_unref (retval);
 627                         return NULL;
 628                 }
 629
 630         return retval;
 631 }
 632
 633 /**
 634  * gdk_pixbuf_loader_get_pixbuf:
 635  * @loader: A pixbuf loader.
 636  *
 637  * Queries the #GdkPixbuf that a pixbuf loader is currently creating.
 638  * In general it only makes sense to call this function after the
 639  * "area_prepared" signal has been emitted by the loader; this means
 640  * that enough data has been read to know the size of the image that
 641  * will be allocated.  If the loader has not received enough data via
 642  * gdk_pixbuf_loader_write(), then this function returns %NULL.  The
 643  * returned pixbuf will be the same in all future calls to the loader,
 644  * so simply calling g_object_ref() should be sufficient to continue
 645  * using it.  Additionally, if the loader is an animation, it will
 646  * return the "static image" of the animation
 647  * (see gdk_pixbuf_animation_get_static_image()).
 648  *
 649  * Return value: The #GdkPixbuf that the loader is creating, or %NULL if not
 650  * enough data has been read to determine how to create the image buffer.
 651  **/
 652 GdkPixbuf *
 653 gdk_pixbuf_loader_get_pixbuf (GdkPixbufLoader *loader)
 654 {
 655         GdkPixbufLoaderPrivate *priv;
 656
 657         g_return_val_if_fail (loader != NULL, NULL);
 658         g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
 659
 660         priv = loader->priv;
 661
 662         if (priv->animation)
 663                 return gdk_pixbuf_animation_get_static_image (priv->animation);
 664         else
 665                 return NULL;
 666 }
 667
 668 /**
 669  * gdk_pixbuf_loader_get_animation:
 670  * @loader: A pixbuf loader
 671  *
 672  * Queries the #GdkPixbufAnimation that a pixbuf loader is currently creating.
 673  * In general it only makes sense to call this function after the "area_prepared"
 674  * signal has been emitted by the loader. If the loader doesn't have enough
 675  * bytes yet (hasn't emitted the "area_prepared" signal) this function will
 676  * return %NULL.
 677  *
 678  * Return value: The #GdkPixbufAnimation that the loader is loading, or %NULL if
 679  not enough data has been read to determine the information.
 680 **/
 681 GdkPixbufAnimation *
 682 gdk_pixbuf_loader_get_animation (GdkPixbufLoader *loader)
 683 {
 684         GdkPixbufLoaderPrivate *priv;
 685
 686         g_return_val_if_fail (loader != NULL, NULL);
 687         g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
 688
 689         priv = loader->priv;
 690
 691         return priv->animation;
 692 }
 693
 694 /**
 695  * gdk_pixbuf_loader_close:
 696  * @loader: A pixbuf loader.
 697  * @error: return location for a #GError, or %NULL to ignore errors
 698  *
 699  * Informs a pixbuf loader that no further writes with
 700  * gdk_pixbuf_loader_write() will occur, so that it can free its
 701  * internal loading structures. Also, tries to parse any data that
 702  * hasn't yet been parsed; if the remaining data is partial or
 703  * corrupt, an error will be returned.  If %FALSE is returned, @error
 704  * will be set to an error from the #GDK_PIXBUF_ERROR or #G_FILE_ERROR
 705  * domains. If you're just cancelling a load rather than expecting it
 706  * to be finished, passing %NULL for @error to ignore it is
 707  * reasonable.
 708  *
 709  * Returns: %TRUE if all image data written so far was successfully
 710             passed out via the update_area signal
 711  **/
 712 gboolean
 713 gdk_pixbuf_loader_close (GdkPixbufLoader *loader,
 714                          GError         **error)
 715 {
 716         GdkPixbufLoaderPrivate *priv;
 717         gboolean retval = TRUE;
 718
 719         g_return_val_if_fail (loader != NULL, TRUE);
 720         g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), TRUE);
 721         g_return_val_if_fail (error == NULL || *error == NULL, TRUE);
 722
 723         priv = loader->priv;
 724
 725         /* we expect it's not closed */
 726         g_return_val_if_fail (priv->closed == FALSE, TRUE);
 727
 728         /* We have less the 128 bytes in the image.  Flush it, and keep going. */
 729         if (priv->image_module == NULL)
 730                 {
 731                         GError *tmp = NULL;
 732                         gdk_pixbuf_loader_load_module (loader, NULL, &tmp);
 733                         if (tmp != NULL)
 734                                 {
 735                                         g_propagate_error (error, tmp);
 736                                         retval = FALSE;
 737                                 }
 738                 }
 739
 740         if (priv->image_module && priv->image_module->stop_load && priv->context)
 741                 {
 742                         if (!priv->image_module->stop_load (priv->context, error))
 743                                 retval = FALSE;
 744                 }
 745
 746         priv->closed = TRUE;
 747         if (priv->image_module && priv->holds_threadlock) {
 748                 _gdk_pixbuf_unlock (priv->image_module);
 749                 priv->holds_threadlock = FALSE;
 750         }
 751
 752         if (priv->needs_scale)
 753                 {
 754                         GdkPixbuf *tmp, *pixbuf;
 755
 756                         tmp = gdk_pixbuf_animation_get_static_image (priv->animation);
 757                         g_object_ref (tmp);
 758                         pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, tmp->has_alpha, 8, priv->width, priv->height);
 759                         g_object_unref (priv->animation);
 760                         priv->animation = gdk_pixbuf_non_anim_new (pixbuf);
 761                         g_object_unref (pixbuf);
 762                         g_signal_emit (loader, pixbuf_loader_signals[AREA_PREPARED], 0);
 763                         gdk_pixbuf_scale (tmp, pixbuf, 0, 0, priv->width, priv->height, 0, 0,
 764                                           (double) priv->width / tmp->width,
 765                                           (double) priv->height / tmp->height,
 766                                           GDK_INTERP_BILINEAR);
 767                         g_object_unref (tmp);
 768
 769                         g_signal_emit (loader, pixbuf_loader_signals[AREA_UPDATED], 0,
 770                                        0, 0, priv->width, priv->height);
 771                 }
 772
 773
 774         g_signal_emit (loader, pixbuf_loader_signals[CLOSED], 0);
 775
 776         return retval;
 777 }
 778
 779 /**
 780  * gdk_pixbuf_loader_get_format:
 781  * @loader: A pixbuf loader.
 782  *
 783  * Obtains the available information about the format of the
 784  * currently loading image file.
 785  *
 786  * Returns: A #GdkPixbufFormat or %NULL. The return value is owned
 787  * by GdkPixbuf and should not be freed.
 788  *
 789  * Since: 2.2
 790  */
 791 GdkPixbufFormat *
 792 gdk_pixbuf_loader_get_format (GdkPixbufLoader *loader)
 793 {
 794         GdkPixbufLoaderPrivate *priv;
 795
 796         g_return_val_if_fail (loader != NULL, NULL);
 797         g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
 798
 799         priv = loader->priv;
 800
 801         if (priv->image_module)
 802                 return _gdk_pixbuf_get_format (priv->image_module);
 803         else
 804                 return NULL;
 805 }
 806
 807
 808
 809