Pileus Git - ~andy/gtk/blob - gtk/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) + frame->x_offset;
 275                 priv->animation->height = gdk_pixbuf_get_height (frame->pixbuf) + frame->y_offset;
 276         } else {
 277                 int w, h;
 278
 279                 /* update bbox size */
 280                 w = gdk_pixbuf_get_width (frame->pixbuf) + frame->x_offset;
 281                 h = gdk_pixbuf_get_height (frame->pixbuf) + frame->y_offset;
 282
 283                 if (w > priv->animation->width) {
 284                         priv->animation->width = w;
 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         GdkPixbufLoaderPrivate *priv = NULL;
 302         GdkPixbufFrame    *frame;
 303         GList *current = NULL;
 304         gint h, w;
 305
 306         priv = GDK_PIXBUF_LOADER (loader)->private;
 307         priv->pixbuf = NULL;
 308
 309         current = gdk_pixbuf_animation_get_frames (priv->animation);
 310
 311         while (current) {
 312                 frame = (GdkPixbufFrame *) current->data;
 313
 314                 /* update bbox size */
 315                 w = gdk_pixbuf_get_width (frame->pixbuf) + frame->x_offset;
 316                 h = gdk_pixbuf_get_height (frame->pixbuf) + frame->y_offset;
 317
 318                 if (w > priv->animation->width) {
 319                         priv->animation->width = w;
 320                 }
 321                 if (h > priv->animation->height) {
 322                         priv->animation->height = h;
 323                 }
 324                 current = current->next;
 325         }
 326
 327         gtk_signal_emit (GTK_OBJECT (loader),
 328                          pixbuf_loader_signals[ANIMATION_DONE]);
 329 }
 330
 331 \f
 332
 333 /**
 334  * gdk_pixbuf_loader_new:
 335  *
 336  * Creates a new pixbuf loader object.
 337  *
 338  * Return value: A newly-created pixbuf loader.
 339  **/
 340 GdkPixbufLoader *
 341 gdk_pixbuf_loader_new (void)
 342 {
 343         return gtk_type_new (gdk_pixbuf_loader_get_type ());
 344 }
 345
 346 static int
 347 gdk_pixbuf_loader_load_module(GdkPixbufLoader *loader)
 348 {
 349         GdkPixbufLoaderPrivate *priv = loader->private;
 350
 351         priv->image_module = gdk_pixbuf_get_module (priv->header_buf, priv->header_buf_offset);
 352
 353         if (priv->image_module == NULL)
 354                 return 0;
 355
 356         if (priv->image_module->module == NULL)
 357                 gdk_pixbuf_load_module (priv->image_module);
 358
 359         if (priv->image_module->module == NULL)
 360                 return 0;
 361
 362         if ((priv->image_module->begin_load == NULL) ||
 363             (priv->image_module->stop_load == NULL) ||
 364             (priv->image_module->load_increment == NULL)) {
 365                 g_warning ("module %s does not support incremental loading.\n",
 366                            priv->image_module->module_name);
 367                 return 0;
 368         }
 369
 370         priv->context = (*priv->image_module->begin_load) (gdk_pixbuf_loader_prepare,
 371                                                            gdk_pixbuf_loader_update,
 372                                                            gdk_pixbuf_loader_frame_done,
 373                                                            gdk_pixbuf_loader_animation_done,
 374                                                            loader);
 375
 376         if (priv->context == NULL) {
 377                 g_warning("Failed to begin progressive load");
 378                 return 0;
 379         }
 380
 381         if( (* priv->image_module->load_increment) (priv->context, priv->header_buf, priv->header_buf_offset) )
 382                 return priv->header_buf_offset;
 383
 384         return 0;
 385 }
 386
 387 static int
 388 gdk_pixbuf_loader_eat_header_write (GdkPixbufLoader *loader, const guchar *buf, size_t count)
 389 {
 390         int nbytes;
 391         GdkPixbufLoaderPrivate *priv = loader->private;
 392
 393         nbytes = MIN(LOADER_HEADER_SIZE - priv->header_buf_offset, count);
 394         memcpy (priv->header_buf + priv->header_buf_offset, buf, nbytes);
 395
 396         priv->header_buf_offset += nbytes;
 397
 398         if(priv->header_buf_offset >= LOADER_HEADER_SIZE) {
 399                 if (gdk_pixbuf_loader_load_module(loader) == 0)
 400                         return 0;
 401         }
 402         return nbytes;
 403 }
 404
 405 /**
 406  * gdk_pixbuf_loader_write:
 407  * @loader: A pixbuf loader.
 408  * @buf: Pointer to image data.
 409  * @count: Length of the @buf buffer in bytes.
 410  *
 411  * This will cause a pixbuf loader to parse the next @count bytes of an image.
 412  * It will return TRUE if the data was loaded successfully, and FALSE if an
 413  * error occurred.  In the latter case, the loader will be closed, and will not
 414  * accept further writes.
 415  *
 416  * Return value: #TRUE if the write was successful, or #FALSE if the loader
 417  * cannot parse the buffer.
 418  **/
 419 gboolean
 420 gdk_pixbuf_loader_write (GdkPixbufLoader *loader, const guchar *buf, size_t count)
 421 {
 422         GdkPixbufLoaderPrivate *priv;
 423
 424         g_return_val_if_fail (loader != NULL, FALSE);
 425         g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), FALSE);
 426
 427         g_return_val_if_fail (buf != NULL, FALSE);
 428         g_return_val_if_fail (count >= 0, FALSE);
 429
 430         priv = loader->private;
 431
 432         /* we expect it's not to be closed */
 433         g_return_val_if_fail (priv->closed == FALSE, FALSE);
 434
 435         if (priv->image_module == NULL) {
 436                 int eaten;
 437
 438                 eaten = gdk_pixbuf_loader_eat_header_write(loader, buf, count);
 439                 if (eaten <= 0)
 440                         return FALSE;
 441
 442                 count -= eaten;
 443                 buf += eaten;
 444         }
 445
 446         if (count > 0 && priv->image_module->load_increment)
 447                 return (* priv->image_module->load_increment) (priv->context, buf, count);
 448
 449         return TRUE;
 450 }
 451
 452 /**
 453  * gdk_pixbuf_loader_get_pixbuf:
 454  * @loader: A pixbuf loader.
 455  *
 456  * Queries the GdkPixbuf that a pixbuf loader is currently creating.  In general
 457  * it only makes sense to call this function afer the "area_prepared" signal has
 458  * been emitted by the loader; this means that enough data has been read to know
 459  * the size of the image that will be allocated.  If the loader has not received
 460  * enough data via gdk_pixbuf_loader_write(), then this function returns NULL.
 461  * The returned pixbuf will be the same in all future calls to the loader, so
 462  * simply calling gdk_pixbuf_ref() should be sufficient to continue using it.
 463  *
 464  * Return value: The GdkPixbuf that the loader is creating, or NULL if not
 465  * enough data has been read to determine how to create the image buffer.
 466  **/
 467 GdkPixbuf *
 468 gdk_pixbuf_loader_get_pixbuf (GdkPixbufLoader *loader)
 469 {
 470         GdkPixbufLoaderPrivate *priv;
 471
 472         g_return_val_if_fail (loader != NULL, NULL);
 473         g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
 474
 475         priv = loader->private;
 476
 477         return priv->pixbuf;
 478 }
 479
 480 /**
 481  * gdk_pixbuf_loader_get_animation:
 482  * @loader: A pixbuf loader
 483  *
 484  * Queries the GdkPixbufAnimation that a pixbuf loader is currently creating.
 485  * In general it only makes sense to call this function afer the "area_prepared"
 486  * signal has been emitted by the loader.  If the image is not an animation,
 487  * then it will return NULL.
 488  *
 489  * Return value: The GdkPixbufAnimation that the loader is loading, or NULL if
 490  not enough data has been read to determine the information.
 491  **/
 492 GdkPixbufAnimation *
 493 gdk_pixbuf_loader_get_animation (GdkPixbufLoader *loader)
 494 {
 495         GdkPixbufLoaderPrivate *priv;
 496
 497         g_return_val_if_fail (loader != NULL, NULL);
 498         g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
 499
 500         priv = loader->private;
 501
 502         return priv->animation;
 503 }
 504
 505 /**
 506  * gdk_pixbuf_loader_close:
 507  * @loader: A pixbuf loader.
 508  *
 509  * Informs a pixbuf loader that no further writes with gdk_pixbuf_load_write()
 510  * will occur, so that it can free its internal loading structures.
 511  **/
 512 void
 513 gdk_pixbuf_loader_close (GdkPixbufLoader *loader)
 514 {
 515         GdkPixbufLoaderPrivate *priv;
 516
 517         g_return_if_fail (loader != NULL);
 518         g_return_if_fail (GDK_IS_PIXBUF_LOADER (loader));
 519
 520         priv = loader->private;
 521
 522         /* we expect it's not closed */
 523         g_return_if_fail (priv->closed == FALSE);
 524
 525         /* We have less the 128 bytes in the image.  Flush it, and keep going. */
 526         if (priv->image_module == NULL)
 527                 gdk_pixbuf_loader_load_module (loader);
 528
 529         if (priv->image_module && priv->image_module->stop_load)
 530                 (* priv->image_module->stop_load) (priv->context);
 531
 532         priv->closed = TRUE;
 533
 534         gtk_signal_emit (GTK_OBJECT (loader),
 535                          pixbuf_loader_signals[CLOSED]);
 536 }
 537