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

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
   2
   3 /* GdkPixbuf library - Main header file
   4  *
   5  * Copyright (C) 1999 The Free Software Foundation
   6  *
   7  * Authors: Mark Crichton <crichton@gimp.org>
   8  *          Miguel de Icaza <miguel@gnu.org>
   9  *          Federico Mena-Quintero <federico@gimp.org>
  10  *          Jonathan Blandford <jrb@redhat.com>
  11  *
  12  * This library is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU Library General Public
  14  * License as published by the Free Software Foundation; either
  15  * version 2 of the License, or (at your option) any later version.
  16  *
  17  * This library is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  * Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with this library; if not, write to the
  24  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  25  * Boston, MA 02111-1307, USA.
  26  */
  27
  28 #include <config.h>
  29 #include <gtk/gtksignal.h>
  30 #include "gdk-pixbuf-private.h"
  31 #include "gdk-pixbuf-loader.h"
  32 #include "gdk-pixbuf-io.h"
  33
  34 \f
  35
  36 enum {
  37         AREA_UPDATED,
  38         AREA_PREPARED,
  39         FRAME_DONE,
  40         ANIMATION_DONE,
  41         CLOSED,
  42         LAST_SIGNAL
  43 };
  44
  45 static GtkObjectClass *parent_class;
  46
  47 static void gdk_pixbuf_loader_class_init    (GdkPixbufLoaderClass   *klass);
  48 static void gdk_pixbuf_loader_init          (GdkPixbufLoader        *loader);
  49 static void gdk_pixbuf_loader_destroy       (GtkObject              *loader);
  50 static void gdk_pixbuf_loader_finalize      (GtkObject              *loader);
  51
  52 static guint pixbuf_loader_signals[LAST_SIGNAL] = { 0 };
  53
  54 \f
  55
  56 /* Internal data */
  57
  58 #define LOADER_HEADER_SIZE 128
  59
  60 typedef struct {
  61         GdkPixbuf *pixbuf;
  62         GdkPixbufAnimation *animation;
  63         gboolean closed;
  64         guchar header_buf[LOADER_HEADER_SIZE];
  65         gint header_buf_offset;
  66         GdkPixbufModule *image_module;
  67         gpointer context;
  68 } GdkPixbufLoaderPrivate;
  69
  70 \f
  71
  72 /* our marshaller */
  73 typedef void (* GtkSignal_NONE__INT_INT_INT_INT) (GtkObject *object,
  74                                                   gint arg1, gint arg2, gint arg3, gint arg4,
  75                                                   gpointer user_data);
  76 static void
  77 gtk_marshal_NONE__INT_INT_INT_INT (GtkObject *object, GtkSignalFunc func, gpointer func_data,
  78                                    GtkArg * args)
  79 {
  80         GtkSignal_NONE__INT_INT_INT_INT rfunc;
  81
  82         rfunc = (GtkSignal_NONE__INT_INT_INT_INT) func;
  83         (*rfunc) (object,
  84                   GTK_VALUE_INT (args[0]),
  85                   GTK_VALUE_INT (args[1]),
  86                   GTK_VALUE_INT (args[2]),
  87                   GTK_VALUE_INT (args[3]),
  88                   func_data);
  89 }
  90
  91 \f
  92
  93 /**
  94  * gdk_pixbuf_loader_get_type:
  95  * @void:
  96  *
  97  * Registers the #GdkPixubfLoader class if necessary, and returns the type ID
  98  * associated to it.
  99  *
 100  * Return value: The type ID of the #GdkPixbufLoader class.
 101  **/
 102 GtkType
 103 gdk_pixbuf_loader_get_type (void)
 104 {
 105         static GtkType loader_type = 0;
 106
 107         if (!loader_type) {
 108                 static const GtkTypeInfo loader_info = {
 109                         "GdkPixbufLoader",
 110                         sizeof (GdkPixbufLoader),
 111                         sizeof (GdkPixbufLoaderClass),
 112                         (GtkClassInitFunc) gdk_pixbuf_loader_class_init,
 113                         (GtkObjectInitFunc) gdk_pixbuf_loader_init,
 114                         /* reserved_1 */ NULL,
 115                         /* reserved_2 */ NULL,
 116                         (GtkClassInitFunc) NULL,
 117                 };
 118
 119                 loader_type = gtk_type_unique (GTK_TYPE_OBJECT, &loader_info);
 120         }
 121
 122         return loader_type;
 123 }
 124
 125 static void
 126 gdk_pixbuf_loader_class_init (GdkPixbufLoaderClass *class)
 127 {
 128         GtkObjectClass *object_class;
 129
 130         object_class = (GtkObjectClass *) class;
 131
 132         parent_class = gtk_type_class (gtk_object_get_type ());
 133
 134         pixbuf_loader_signals[AREA_PREPARED] =
 135                 gtk_signal_new ("area_prepared",
 136                                 GTK_RUN_LAST,
 137                                 parent_class->type,
 138                                 GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, area_prepared),
 139                                 gtk_marshal_NONE__NONE,
 140                                 GTK_TYPE_NONE, 0);
 141
 142         pixbuf_loader_signals[AREA_UPDATED] =
 143                 gtk_signal_new ("area_updated",
 144                                 GTK_RUN_LAST,
 145                                 parent_class->type,
 146                                 GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, area_updated),
 147                                 gtk_marshal_NONE__INT_INT_INT_INT,
 148                                 GTK_TYPE_NONE, 4,
 149                                 GTK_TYPE_INT,
 150                                 GTK_TYPE_INT,
 151                                 GTK_TYPE_INT,
 152                                 GTK_TYPE_INT);
 153
 154         pixbuf_loader_signals[FRAME_DONE] =
 155                 gtk_signal_new ("frame_done",
 156                                 GTK_RUN_LAST,
 157                                 parent_class->type,
 158                                 GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, frame_done),
 159                                 gtk_marshal_NONE__POINTER,
 160                                 GTK_TYPE_NONE, 1,
 161                                 GTK_TYPE_POINTER);
 162
 163         pixbuf_loader_signals[ANIMATION_DONE] =
 164                 gtk_signal_new ("animation_done",
 165                                 GTK_RUN_LAST,
 166                                 parent_class->type,
 167                                 GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, animation_done),
 168                                 gtk_marshal_NONE__NONE,
 169                                 GTK_TYPE_NONE, 0);
 170
 171         pixbuf_loader_signals[CLOSED] =
 172                 gtk_signal_new ("closed",
 173                                 GTK_RUN_LAST,
 174                                 parent_class->type,
 175                                 GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, closed),
 176                                 gtk_marshal_NONE__NONE,
 177                                 GTK_TYPE_NONE, 0);
 178
 179         gtk_object_class_add_signals (object_class, pixbuf_loader_signals, LAST_SIGNAL);
 180
 181         object_class->destroy = gdk_pixbuf_loader_destroy;
 182         object_class->finalize = gdk_pixbuf_loader_finalize;
 183 }
 184
 185 static void
 186 gdk_pixbuf_loader_init (GdkPixbufLoader *loader)
 187 {
 188         GdkPixbufLoaderPrivate *priv;
 189
 190         priv = g_new0 (GdkPixbufLoaderPrivate, 1);
 191         loader->private = priv;
 192 }
 193
 194 static void
 195 gdk_pixbuf_loader_destroy (GtkObject *object)
 196 {
 197         GdkPixbufLoader *loader;
 198         GdkPixbufLoaderPrivate *priv = NULL;
 199
 200         g_return_if_fail (object != NULL);
 201         g_return_if_fail (GDK_IS_PIXBUF_LOADER (object));
 202
 203         loader = GDK_PIXBUF_LOADER (object);
 204         priv = loader->private;
 205
 206         if (!priv->closed)
 207                 gdk_pixbuf_loader_close (loader);
 208
 209         if (priv->animation)
 210                 gdk_pixbuf_animation_unref (priv->animation);
 211         if (priv->pixbuf)
 212                 gdk_pixbuf_unref (priv->pixbuf);
 213
 214         if (GTK_OBJECT_CLASS (parent_class)->destroy)
 215                 (* GTK_OBJECT_CLASS (parent_class)->destroy) (object);
 216 }
 217
 218 static void
 219 gdk_pixbuf_loader_finalize (GtkObject *object)
 220 {
 221         GdkPixbufLoader *loader;
 222         GdkPixbufLoaderPrivate *priv = NULL;
 223
 224         loader = GDK_PIXBUF_LOADER (object);
 225         priv = loader->private;
 226
 227         g_free (priv);
 228
 229         if (GTK_OBJECT_CLASS (parent_class)->finalize)
 230                 (* GTK_OBJECT_CLASS (parent_class)->finalize) (object);
 231 }
 232
 233 static void
 234 gdk_pixbuf_loader_prepare (GdkPixbuf *pixbuf, gpointer loader)
 235 {
 236         GdkPixbufLoaderPrivate *priv = NULL;
 237
 238         priv = GDK_PIXBUF_LOADER (loader)->private;
 239         gdk_pixbuf_ref (pixbuf);
 240         g_assert (priv->pixbuf == NULL);
 241
 242         priv->pixbuf = pixbuf;
 243         gtk_signal_emit (GTK_OBJECT (loader), pixbuf_loader_signals[AREA_PREPARED]);
 244 }
 245
 246 static void
 247 gdk_pixbuf_loader_update (GdkPixbuf *pixbuf, guint x, guint y, guint width, guint height, gpointer loader)
 248 {
 249         GdkPixbufLoaderPrivate *priv = NULL;
 250
 251         priv = GDK_PIXBUF_LOADER (loader)->private;
 252
 253         gtk_signal_emit (GTK_OBJECT (loader),
 254                          pixbuf_loader_signals[AREA_UPDATED],
 255                          x, y,
 256                          /* sanity check in here.  Defend against an errant loader */
 257                          MIN (width, gdk_pixbuf_get_width (priv->pixbuf)),
 258                          MIN (height, gdk_pixbuf_get_height (priv->pixbuf)));
 259 }
 260
 261 static void
 262 gdk_pixbuf_loader_frame_done (GdkPixbufFrame *frame, gpointer loader)
 263 {
 264         GdkPixbufLoaderPrivate *priv = NULL;
 265
 266         priv = GDK_PIXBUF_LOADER (loader)->private;
 267
 268         priv->pixbuf = NULL;
 269
 270         if (priv->animation == NULL) {
 271                 priv->animation = g_new0 (GdkPixbufAnimation, 1);
 272                 priv->animation->n_frames = 0;
 273                 priv->animation->ref_count = 1;
 274                 priv->animation->width  = gdk_pixbuf_get_width  (frame->pixbuf);
 275                 priv->animation->height = gdk_pixbuf_get_height (frame->pixbuf);
 276         } else {
 277                 int w, h;
 278
 279                 /* update bbox size */
 280                 w = gdk_pixbuf_get_width (frame->pixbuf);
 281                 h = gdk_pixbuf_get_height (frame->pixbuf);
 282
 283                 if (w > priv->animation->width) {
 284                         priv->animation->width = h;
 285                 }
 286                 if (h > priv->animation->height) {
 287                         priv->animation->height = h;
 288                 }
 289         }
 290
 291         priv->animation->frames = g_list_append (priv->animation->frames, frame);
 292         priv->animation->n_frames ++;
 293         gtk_signal_emit (GTK_OBJECT (loader),
 294                          pixbuf_loader_signals[FRAME_DONE],
 295                          frame);
 296 }
 297
 298 static void
 299 gdk_pixbuf_loader_animation_done (GdkPixbuf *pixbuf, gpointer loader)
 300 {
 301         gtk_signal_emit (GTK_OBJECT (loader),
 302                          pixbuf_loader_signals[ANIMATION_DONE]);
 303 }
 304
 305 \f
 306
 307 /**
 308  * gdk_pixbuf_loader_new:
 309  *
 310  * Creates a new pixbuf loader object.
 311  *
 312  * Return value: A newly-created pixbuf loader.
 313  **/
 314 GdkPixbufLoader *
 315 gdk_pixbuf_loader_new (void)
 316 {
 317         return gtk_type_new (gdk_pixbuf_loader_get_type ());
 318 }
 319
 320 static int
 321 gdk_pixbuf_loader_load_module(GdkPixbufLoader *loader)
 322 {
 323         GdkPixbufLoaderPrivate *priv = loader->private;
 324
 325         priv->image_module = gdk_pixbuf_get_module (priv->header_buf, priv->header_buf_offset);
 326
 327         if (priv->image_module == NULL)
 328                 return 0;
 329
 330         if (priv->image_module->module == NULL)
 331                 gdk_pixbuf_load_module (priv->image_module);
 332
 333         if (priv->image_module->module == NULL)
 334                 return 0;
 335
 336         if ((priv->image_module->begin_load == NULL) ||
 337             (priv->image_module->stop_load == NULL) ||
 338             (priv->image_module->load_increment == NULL)) {
 339                 g_warning ("module %s does not support incremental loading.\n",
 340                            priv->image_module->module_name);
 341                 return 0;
 342         }
 343
 344         priv->context = (*priv->image_module->begin_load) (gdk_pixbuf_loader_prepare,
 345                                                            gdk_pixbuf_loader_update,
 346                                                            gdk_pixbuf_loader_frame_done,
 347                                                            gdk_pixbuf_loader_animation_done,
 348                                                            loader);
 349
 350         if (priv->context == NULL) {
 351                 g_warning("Failed to begin progressive load");
 352                 return 0;
 353         }
 354
 355         if( (* priv->image_module->load_increment) (priv->context, priv->header_buf, priv->header_buf_offset) )
 356                 return priv->header_buf_offset;
 357
 358         return 0;
 359 }
 360
 361 static int
 362 gdk_pixbuf_loader_eat_header_write (GdkPixbufLoader *loader, const guchar *buf, size_t count)
 363 {
 364         int nbytes;
 365         GdkPixbufLoaderPrivate *priv = loader->private;
 366
 367         nbytes = MIN(LOADER_HEADER_SIZE - priv->header_buf_offset, count);
 368         memcpy (priv->header_buf + priv->header_buf_offset, buf, nbytes);
 369
 370         priv->header_buf_offset += nbytes;
 371
 372         if(priv->header_buf_offset >= LOADER_HEADER_SIZE) {
 373                 if (gdk_pixbuf_loader_load_module(loader) == 0)
 374                         return 0;
 375         }
 376         return nbytes;
 377 }
 378
 379 /**
 380  * gdk_pixbuf_loader_write:
 381  * @loader: A pixbuf loader.
 382  * @buf: Pointer to image data.
 383  * @count: Length of the @buf buffer in bytes.
 384  *
 385  * This will cause a pixbuf loader to parse the next @count bytes of an image.
 386  * It will return TRUE if the data was loaded successfully, and FALSE if an
 387  * error occurred.  In the latter case, the loader will be closed, and will not
 388  * accept further writes.
 389  *
 390  * Return value: #TRUE if the write was successful, or #FALSE if the loader
 391  * cannot parse the buffer.
 392  **/
 393 gboolean
 394 gdk_pixbuf_loader_write (GdkPixbufLoader *loader, const guchar *buf, size_t count)
 395 {
 396         GdkPixbufLoaderPrivate *priv;
 397
 398         g_return_val_if_fail (loader != NULL, FALSE);
 399         g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), FALSE);
 400
 401         g_return_val_if_fail (buf != NULL, FALSE);
 402         g_return_val_if_fail (count >= 0, FALSE);
 403
 404         priv = loader->private;
 405
 406         /* we expect it's not to be closed */
 407         g_return_val_if_fail (priv->closed == FALSE, FALSE);
 408
 409         if (priv->image_module == NULL) {
 410                 int eaten;
 411
 412                 eaten = gdk_pixbuf_loader_eat_header_write(loader, buf, count);
 413                 if (eaten <= 0)
 414                         return FALSE;
 415
 416                 count -= eaten;
 417                 buf += eaten;
 418         }
 419
 420         if (count > 0 && priv->image_module->load_increment)
 421                 return (* priv->image_module->load_increment) (priv->context, buf, count);
 422
 423         return TRUE;
 424 }
 425
 426 /**
 427  * gdk_pixbuf_loader_get_pixbuf:
 428  * @loader: A pixbuf loader.
 429  *
 430  * Queries the GdkPixbuf that a pixbuf loader is currently creating.  In general
 431  * it only makes sense to call this function afer the "area_prepared" signal has
 432  * been emitted by the loader; this means that enough data has been read to know
 433  * the size of the image that will be allocated.  If the loader has not received
 434  * enough data via gdk_pixbuf_loader_write(), then this function returns NULL.
 435  * The returned pixbuf will be the same in all future calls to the loader, so
 436  * simply calling gdk_pixbuf_ref() should be sufficient to continue using it.
 437  *
 438  * Return value: The GdkPixbuf that the loader is creating, or NULL if not
 439  * enough data has been read to determine how to create the image buffer.
 440  **/
 441 GdkPixbuf *
 442 gdk_pixbuf_loader_get_pixbuf (GdkPixbufLoader *loader)
 443 {
 444         GdkPixbufLoaderPrivate *priv;
 445
 446         g_return_val_if_fail (loader != NULL, NULL);
 447         g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
 448
 449         priv = loader->private;
 450
 451         return priv->pixbuf;
 452 }
 453
 454 /**
 455  * gdk_pixbuf_loader_get_animation:
 456  * @loader: A pixbuf loader
 457  *
 458  * Queries the GdkPixbufAnimation that a pixbuf loader is currently creating.
 459  * In general it only makes sense to call this function afer the "area_prepared"
 460  * signal has been emitted by the loader.  If the image is not an animation,
 461  * then it will return NULL.
 462  *
 463  * Return value: The GdkPixbufAnimation that the loader is loading, or NULL if
 464  not enough data has been read to determine the information.
 465  **/
 466 GdkPixbufAnimation *
 467 gdk_pixbuf_loader_get_animation (GdkPixbufLoader *loader)
 468 {
 469         GdkPixbufLoaderPrivate *priv;
 470
 471         g_return_val_if_fail (loader != NULL, NULL);
 472         g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
 473
 474         priv = loader->private;
 475
 476         return priv->animation;
 477 }
 478
 479 /**
 480  * gdk_pixbuf_loader_close:
 481  * @loader: A pixbuf loader.
 482  *
 483  * Informs a pixbuf loader that no further writes with gdk_pixbuf_load_write()
 484  * will occur, so that it can free its internal loading structures.
 485  **/
 486 void
 487 gdk_pixbuf_loader_close (GdkPixbufLoader *loader)
 488 {
 489         GdkPixbufLoaderPrivate *priv;
 490
 491         g_return_if_fail (loader != NULL);
 492         g_return_if_fail (GDK_IS_PIXBUF_LOADER (loader));
 493
 494         priv = loader->private;
 495
 496         /* we expect it's not closed */
 497         g_return_if_fail (priv->closed == FALSE);
 498
 499         /* We have less the 128 bytes in the image.  Flush it, and keep going. */
 500         if (priv->image_module == NULL)
 501                 gdk_pixbuf_loader_load_module (loader);
 502
 503         if (priv->image_module && priv->image_module->stop_load)
 504                 (* priv->image_module->stop_load) (priv->context);
 505
 506         priv->closed = TRUE;
 507
 508         gtk_signal_emit (GTK_OBJECT (loader),
 509                          pixbuf_loader_signals[CLOSED]);
 510 }
 511