libview/ev-page-cache.c

   1 #include <config.h>
   2 #include "ev-page-cache.h"
   3 #include "ev-document-thumbnails.h"
   4 #include "ev-page.h"
   5 #include <stdlib.h>
   6 #include <string.h>
   7
   8 #define THUMBNAIL_WIDTH 100
   9
  10 typedef struct _EvPageCacheInfo
  11 {
  12         double width;
  13         double height;
  14 } EvPageCacheInfo;
  15
  16 typedef struct _EvPageThumbsInfo
  17 {
  18         gint width;
  19         gint height;
  20 } EvPageThumbsInfo;
  21
  22 struct _EvPageCache
  23 {
  24         GObject parent;
  25
  26         gint current_page;
  27         int n_pages;
  28         char *title;
  29         char **page_labels;
  30
  31         gint max_label_chars;
  32         gboolean has_labels;
  33         gboolean uniform;
  34         gboolean dual_even_left;
  35
  36         double uniform_width;
  37         double uniform_height;
  38
  39         double  max_width;
  40         double  max_height;
  41
  42         double* height_to_page;
  43         double* dual_height_to_page;
  44
  45         int rotation;
  46
  47         EvPageCacheInfo *size_cache;
  48         EvDocumentInfo *page_info;
  49
  50         /* Thumbnail dimensions */
  51         gboolean thumbs_uniform;
  52         gint thumbs_uniform_width;
  53         gint thumbs_uniform_height;
  54         gint thumbs_max_width;
  55         gint thumbs_max_height;
  56         EvPageThumbsInfo *thumbs_size_cache;
  57 };
  58
  59 struct _EvPageCacheClass
  60 {
  61         GObjectClass parent_class;
  62
  63         void (* page_changed) (EvPageCache *page_cache, gint page);
  64         void (* history_changed) (EvPageCache *page_cache, gint page);
  65 };
  66
  67 enum
  68 {
  69         PAGE_CHANGED,
  70         HISTORY_CHANGED,
  71         N_SIGNALS,
  72 };
  73
  74 static guint signals[N_SIGNALS] = {0, };
  75
  76 static void ev_page_cache_init       (EvPageCache      *page_cache);
  77 static void ev_page_cache_class_init (EvPageCacheClass *page_cache);
  78 static void ev_page_cache_finalize   (GObject *object);
  79
  80 G_DEFINE_TYPE (EvPageCache, ev_page_cache, G_TYPE_OBJECT)
  81
  82 static void
  83 ev_page_cache_init (EvPageCache *page_cache)
  84 {
  85         page_cache->current_page = -1;
  86         page_cache->max_label_chars = 0;
  87 }
  88
  89 static void
  90 ev_page_cache_class_init (EvPageCacheClass *class)
  91 {
  92         GObjectClass *object_class;
  93
  94         object_class = G_OBJECT_CLASS (class);
  95
  96         object_class->finalize = ev_page_cache_finalize;
  97
  98         signals [PAGE_CHANGED] =
  99                 g_signal_new ("page-changed",
 100                               EV_TYPE_PAGE_CACHE,
 101                               G_SIGNAL_RUN_LAST,
 102                               G_STRUCT_OFFSET (EvPageCacheClass, page_changed),
 103                               NULL, NULL,
 104                               g_cclosure_marshal_VOID__INT,
 105                               G_TYPE_NONE, 1,
 106                               G_TYPE_INT);
 107
 108         signals [HISTORY_CHANGED] =
 109                 g_signal_new ("history-changed",
 110                               EV_TYPE_PAGE_CACHE,
 111                               G_SIGNAL_RUN_LAST,
 112                               G_STRUCT_OFFSET (EvPageCacheClass, history_changed),
 113                               NULL, NULL,
 114                               g_cclosure_marshal_VOID__INT,
 115                               G_TYPE_NONE, 1,
 116                               G_TYPE_INT);
 117
 118 }
 119
 120 static void
 121 ev_page_cache_finalize (GObject *object)
 122 {
 123         EvPageCache *page_cache;
 124
 125         page_cache = EV_PAGE_CACHE (object);
 126
 127         if (page_cache->title) {
 128                 g_free (page_cache->title);
 129                 page_cache->title = NULL;
 130         }
 131
 132         if (page_cache->size_cache) {
 133                 g_free (page_cache->size_cache);
 134                 page_cache->size_cache = NULL;
 135         }
 136
 137         if (page_cache->thumbs_size_cache) {
 138                 g_free (page_cache->thumbs_size_cache);
 139                 page_cache->thumbs_size_cache = NULL;
 140         }
 141
 142         if (page_cache->height_to_page) {
 143                 g_free (page_cache->height_to_page);
 144                 page_cache->height_to_page = NULL;
 145         }
 146
 147         if (page_cache->dual_height_to_page) {
 148                 g_free (page_cache->dual_height_to_page);
 149                 page_cache->dual_height_to_page = NULL;
 150         }
 151
 152         if (page_cache->page_labels) {
 153                 gint i;
 154
 155                 for (i = 0; i < page_cache->n_pages; i++) {
 156                         if (page_cache->page_labels[i])
 157                                 g_free (page_cache->page_labels[i]);
 158                 }
 159                 g_free (page_cache->page_labels);
 160                 page_cache->page_labels = NULL;
 161         }
 162
 163         if (page_cache->page_info) {
 164                 ev_document_info_free (page_cache->page_info);
 165                 page_cache->page_info = NULL;
 166         }
 167
 168         G_OBJECT_CLASS (ev_page_cache_parent_class)->finalize (object);
 169 }
 170
 171 static void
 172 build_height_to_page (EvPageCache *page_cache)
 173 {
 174         gboolean swap;
 175         int i;
 176         double uniform_height, page_height, next_page_height;
 177         double saved_height;
 178
 179         swap = (page_cache->rotation == 90 ||
 180                 page_cache->rotation == 270);
 181
 182         g_free (page_cache->height_to_page);
 183         g_free (page_cache->dual_height_to_page);
 184
 185         page_cache->height_to_page = g_new0(double, page_cache->n_pages + 1);
 186         page_cache->dual_height_to_page = g_new0(double, page_cache->n_pages + 2);
 187
 188         saved_height = 0;
 189         for (i = 0; i <= page_cache->n_pages; i++) {
 190                 if (page_cache->uniform) {
 191                         if (!swap) {
 192                                 uniform_height = page_cache->uniform_height;
 193                         } else {
 194                                 uniform_height = page_cache->uniform_width;
 195                         }
 196                         page_cache->height_to_page [i] = i * uniform_height;
 197                 } else {
 198                         if (i < page_cache->n_pages) {
 199                                 if (!swap) {
 200                                         page_height = page_cache->size_cache [i].height;
 201                                 } else {
 202                                         page_height = page_cache->size_cache [i].width;
 203                                 }
 204                         } else {
 205                                 page_height = 0;
 206                         }
 207                         page_cache->height_to_page [i] = saved_height;
 208                         saved_height += page_height;
 209                 }
 210         }
 211
 212         if (page_cache->dual_even_left && !page_cache->uniform) {
 213                 if (!swap) {
 214                         saved_height = page_cache->size_cache [0].height;
 215                 } else {
 216                         saved_height = page_cache->size_cache [0].width;
 217                 }
 218         } else {
 219                 saved_height = 0;
 220         }
 221         for (i = page_cache->dual_even_left; i < page_cache->n_pages + 2; i += 2) {
 222                 if (page_cache->uniform) {
 223                         if (!swap) {
 224                                 uniform_height = page_cache->uniform_height;
 225                         } else {
 226                                 uniform_height = page_cache->uniform_width;
 227                         }
 228                         page_cache->dual_height_to_page [i] = ((i + page_cache->dual_even_left) / 2) * uniform_height;
 229                         if (i + 1 < page_cache->n_pages + 2)
 230                                 page_cache->dual_height_to_page [i + 1] = ((i + page_cache->dual_even_left) / 2) * uniform_height;
 231                 } else {
 232                         if (i + 1 < page_cache->n_pages) {
 233                                 if (!swap) {
 234                                         next_page_height = page_cache->size_cache [i + 1].height;
 235                                 } else {
 236                                         next_page_height = page_cache->size_cache [i + 1].width;
 237                                 }
 238                         } else {
 239                                 next_page_height = 0;
 240                         }
 241                         if (i < page_cache->n_pages) {
 242                                 if (!swap) {
 243                                         page_height = page_cache->size_cache [i].height;
 244                                 } else {
 245                                         page_height = page_cache->size_cache [i].width;
 246                                 }
 247                         } else {
 248                                 page_height = 0;
 249                         }
 250                         if (i + 1 < page_cache->n_pages + 2) {
 251                                 page_cache->dual_height_to_page [i] = saved_height;
 252                                 page_cache->dual_height_to_page [i + 1] = saved_height;
 253                                 saved_height += MAX(page_height, next_page_height);
 254                         } else {
 255                                 page_cache->dual_height_to_page [i] = saved_height;
 256                         }
 257                 }
 258         }
 259 }
 260
 261 EvPageCache *
 262 ev_page_cache_new (EvDocument *document)
 263 {
 264         EvPageCache *page_cache;
 265         EvPageCacheInfo *info;
 266         EvPageThumbsInfo *thumb_info;
 267         EvRenderContext *rc = NULL;
 268         gboolean has_thumbs;
 269         gint i;
 270
 271         page_cache = (EvPageCache *) g_object_new (EV_TYPE_PAGE_CACHE, NULL);
 272
 273         ev_document_doc_mutex_lock ();
 274
 275         /* We read page information out of the document */
 276
 277         /* Assume all pages are the same size until proven otherwise */
 278         page_cache->uniform = TRUE;
 279         page_cache->has_labels = FALSE;
 280         page_cache->n_pages = ev_document_get_n_pages (document);
 281         page_cache->dual_even_left = (page_cache->n_pages > 2);
 282         page_cache->page_labels = g_new0 (char *, page_cache->n_pages);
 283         page_cache->max_width = 0;
 284         page_cache->max_height = 0;
 285         page_cache->page_info = ev_document_get_info (document);
 286         page_cache->thumbs_uniform = TRUE;
 287
 288         if (page_cache->page_info->fields_mask & EV_DOCUMENT_INFO_TITLE) {
 289                 page_cache->title = g_strdup (page_cache->page_info->title);
 290         } else {
 291                 page_cache->title = NULL;
 292         }
 293
 294         has_thumbs = EV_IS_DOCUMENT_THUMBNAILS (document);
 295
 296         for (i = 0; i < page_cache->n_pages; i++) {
 297                 EvPage *page;
 298                 double  page_width = 0;
 299                 double  page_height = 0;
 300                 gint    thumb_width = 0;
 301                 gint    thumb_height = 0;
 302
 303                 page = ev_document_get_page (document, i);
 304
 305                 ev_document_get_page_size (document, page, &page_width, &page_height);
 306
 307                 page_cache->page_labels[i] = ev_document_get_page_label (document, page);
 308
 309                 if (page_cache->page_labels[i] != NULL) {
 310
 311                         page_cache->max_label_chars = MAX (page_cache->max_label_chars,
 312                                                            g_utf8_strlen (page_cache->page_labels[i], 256));
 313                         if (!page_cache->has_labels) {
 314                                 gchar *expected_label;
 315
 316                                 expected_label = g_strdup_printf ("%d", i + 1);
 317                                 if (strcmp (expected_label, page_cache->page_labels[i]))
 318                                         page_cache->has_labels = TRUE;
 319                                 g_free (expected_label);
 320                         }
 321                 }
 322
 323                 if (page_width > page_cache->max_width) {
 324                         page_cache->max_width = page_width;
 325                 }
 326
 327                 if (page_height > page_cache->max_height) {
 328                         page_cache->max_height = page_height;
 329                 }
 330
 331                 if (i == 0) {
 332                         page_cache->uniform_width = page_width;
 333                         page_cache->uniform_height = page_height;
 334                 } else if (page_cache->uniform &&
 335                            (page_cache->uniform_width != page_width ||
 336                             page_cache->uniform_height != page_height)) {
 337                         /* It's a different page size.  Backfill the array. */
 338                         int j;
 339
 340                         page_cache->size_cache = g_new0 (EvPageCacheInfo, page_cache->n_pages);
 341
 342                         for (j = 0; j < i; j++) {
 343                                 info = &(page_cache->size_cache [j]);
 344                                 info->width = page_cache->uniform_width;
 345                                 info->height = page_cache->uniform_height;
 346                         }
 347                         page_cache->uniform = FALSE;
 348
 349                 }
 350
 351                 if (! page_cache->uniform) {
 352                         info = &(page_cache->size_cache [i]);
 353
 354                         info->width = page_width;
 355                         info->height = page_height;
 356                 }
 357
 358                 if (!has_thumbs) {
 359                         g_object_unref (page);
 360                         continue;
 361                 }
 362
 363                 if (!rc) {
 364                         rc = ev_render_context_new (page, 0, (gdouble)THUMBNAIL_WIDTH / page_width);
 365                 } else {
 366                         ev_render_context_set_page (rc, page);
 367                         ev_render_context_set_scale (rc, (gdouble)THUMBNAIL_WIDTH / page_width);
 368                 }
 369
 370                 ev_document_thumbnails_get_dimensions (EV_DOCUMENT_THUMBNAILS (document),
 371                                                        rc, &thumb_width, &thumb_height);
 372
 373                 if (thumb_width > page_cache->thumbs_max_width) {
 374                         page_cache->thumbs_max_width = thumb_width;
 375                 }
 376
 377                 if (thumb_height > page_cache->thumbs_max_height) {
 378                         page_cache->thumbs_max_height = thumb_height;
 379                 }
 380
 381                 if (i == 0) {
 382                         page_cache->thumbs_uniform_width = thumb_width;
 383                         page_cache->thumbs_uniform_height = thumb_height;
 384                 } else if (page_cache->thumbs_uniform &&
 385                            (page_cache->thumbs_uniform_width != thumb_width ||
 386                             page_cache->thumbs_uniform_height != thumb_height)) {
 387                         /* It's a different thumbnail size.  Backfill the array. */
 388                         int j;
 389
 390                         page_cache->thumbs_size_cache = g_new0 (EvPageThumbsInfo, page_cache->n_pages);
 391
 392                         for (j = 0; j < i; j++) {
 393                                 thumb_info = &(page_cache->thumbs_size_cache [j]);
 394                                 thumb_info->width = page_cache->thumbs_uniform_width;
 395                                 thumb_info->height = page_cache->thumbs_uniform_height;
 396                         }
 397                         page_cache->thumbs_uniform = FALSE;
 398                 }
 399
 400                 if (! page_cache->thumbs_uniform) {
 401                         thumb_info = &(page_cache->thumbs_size_cache [i]);
 402
 403                         thumb_info->width = thumb_width;
 404                         thumb_info->height = thumb_height;
 405                 }
 406
 407                 g_object_unref (page);
 408         }
 409
 410         if (rc) {
 411                 g_object_unref (rc);
 412         }
 413
 414         build_height_to_page (page_cache);
 415
 416         /* make some sanity check assertions */
 417         if (! page_cache->uniform)
 418                 g_assert (page_cache->size_cache != NULL);
 419         if (page_cache->uniform && page_cache->n_pages > 0)
 420                 g_assert (page_cache->uniform_width > 0 && page_cache->uniform_height > 0);
 421
 422         ev_document_doc_mutex_unlock ();
 423
 424         if (page_cache->n_pages > 0)
 425                 ev_page_cache_set_current_page (page_cache, 0);
 426
 427         return page_cache;
 428 }
 429
 430 gint
 431 ev_page_cache_get_n_pages (EvPageCache *page_cache)
 432 {
 433         g_return_val_if_fail (EV_IS_PAGE_CACHE (page_cache), 0);
 434
 435         return page_cache->n_pages;
 436 }
 437
 438 gint
 439 ev_page_cache_get_current_page (EvPageCache *page_cache)
 440 {
 441         g_return_val_if_fail (EV_IS_PAGE_CACHE (page_cache), 0);
 442
 443         return page_cache->current_page;
 444 }
 445
 446 void
 447 ev_page_cache_set_current_page (EvPageCache *page_cache,
 448                                 int          page)
 449 {
 450         g_return_if_fail (EV_IS_PAGE_CACHE (page_cache));
 451         g_return_if_fail (page >= 0 || page < page_cache->n_pages);
 452
 453         if (page == page_cache->current_page)
 454                 return;
 455
 456         page_cache->current_page = page;
 457         g_signal_emit (page_cache, signals[PAGE_CHANGED], 0, page);
 458 }
 459
 460 void
 461 ev_page_cache_set_current_page_history (EvPageCache *page_cache,
 462                                         int          page)
 463 {
 464         if (abs (page - page_cache->current_page) > 1)
 465                 g_signal_emit (page_cache, signals [HISTORY_CHANGED], 0, page);
 466
 467         ev_page_cache_set_current_page (page_cache, page);
 468 }
 469
 470 gboolean
 471 ev_page_cache_set_page_label (EvPageCache *page_cache,
 472                               const char  *page_label)
 473 {
 474         gint i, page;
 475         long value;
 476         char *endptr = NULL;
 477
 478         g_return_val_if_fail (EV_IS_PAGE_CACHE (page_cache), FALSE);
 479         g_return_val_if_fail (page_label != NULL, FALSE);
 480
 481         /* First, look for a literal label match */
 482         for (i = 0; i < page_cache->n_pages; i ++) {
 483                 if (page_cache->page_labels[i] != NULL &&
 484                     ! strcmp (page_label, page_cache->page_labels[i])) {
 485                         ev_page_cache_set_current_page (page_cache, i);
 486                         return TRUE;
 487                 }
 488         }
 489
 490         /* Second, look for a match with case insensitively */
 491         for (i = 0; i < page_cache->n_pages; i++) {
 492                 if (page_cache->page_labels[i] != NULL &&
 493                     ! strcasecmp (page_label, page_cache->page_labels[i])) {
 494                         ev_page_cache_set_current_page (page_cache, i);
 495                         return TRUE;
 496                 }
 497         }
 498
 499         /* Next, parse the label, and see if the number fits */
 500         value = strtol (page_label, &endptr, 10);
 501         if (endptr[0] == '\0') {
 502                 /* Page number is an integer */
 503                 page = MIN (G_MAXINT, value);
 504
 505                 /* convert from a page label to a page offset */
 506                 page --;
 507                 if (page >= 0 &&
 508                     page < page_cache->n_pages) {
 509                         ev_page_cache_set_current_page (page_cache, page);
 510                         return TRUE;
 511                 }
 512         }
 513
 514         return FALSE;
 515 }
 516
 517 const char *
 518 ev_page_cache_get_title (EvPageCache *page_cache)
 519 {
 520         g_return_val_if_fail (EV_IS_PAGE_CACHE (page_cache), NULL);
 521
 522         return page_cache->title;
 523 }
 524
 525 void
 526 ev_page_cache_get_size (EvPageCache  *page_cache,
 527                         gint          page,
 528                         gint          rotation,
 529                         gfloat        scale,
 530                         gint         *width,
 531                         gint         *height)
 532 {
 533         double w, h;
 534
 535         g_return_if_fail (EV_IS_PAGE_CACHE (page_cache));
 536         g_return_if_fail (page >= 0 && page < page_cache->n_pages);
 537
 538         if (page_cache->uniform) {
 539                 w = page_cache->uniform_width;
 540                 h = page_cache->uniform_height;
 541         } else {
 542                 EvPageCacheInfo *info;
 543
 544                 info = &(page_cache->size_cache [page]);
 545
 546                 w = info->width;
 547                 h = info->height;
 548         }
 549
 550         w = w * scale + 0.5;
 551         h = h * scale + 0.5;
 552
 553         if (rotation == 0 || rotation == 180) {
 554                 if (width) *width = (int)w;
 555                 if (height) *height = (int)h;
 556         } else {
 557                 if (width) *width = (int)h;
 558                 if (height) *height = (int)w;
 559         }
 560 }
 561
 562 void
 563 ev_page_cache_get_max_width (EvPageCache   *page_cache,
 564                              gint           rotation,
 565                              gfloat         scale,
 566                              gint          *width)
 567 {
 568         g_return_if_fail (EV_IS_PAGE_CACHE (page_cache));
 569
 570         if (width) {
 571                 if (rotation == 0 || rotation == 180) {
 572                         *width = page_cache->max_width * scale;
 573                 } else {
 574                         *width = page_cache->max_height * scale;
 575                 }
 576         }
 577 }
 578
 579 void
 580 ev_page_cache_get_max_height (EvPageCache   *page_cache,
 581                               gint           rotation,
 582                               gfloat         scale,
 583                               gint          *height)
 584 {
 585         g_return_if_fail (EV_IS_PAGE_CACHE (page_cache));
 586
 587         if (height) {
 588                 if (rotation == 0 || rotation == 180) {
 589                         *height = page_cache->max_height * scale;
 590                 } else {
 591                         *height = page_cache->max_width * scale;
 592                 }
 593         }
 594 }
 595
 596 void
 597 ev_page_cache_get_height_to_page (EvPageCache   *page_cache,
 598                                   gint           page,
 599                                   gint           rotation,
 600                                   gfloat         scale,
 601                                   gint          *height,
 602                                   gint          *dual_height)
 603 {
 604         g_return_if_fail (EV_IS_PAGE_CACHE (page_cache));
 605         g_return_if_fail (page >= 0);
 606         g_return_if_fail (!height || page <= page_cache->n_pages);
 607         g_return_if_fail (!dual_height || page <= page_cache->n_pages + 1);
 608
 609         if (page_cache->rotation != rotation) {
 610                 page_cache->rotation = rotation;
 611                 build_height_to_page (page_cache);
 612         }
 613
 614         if (height)
 615                 *height = page_cache->height_to_page [page] * scale;
 616
 617         if (dual_height)
 618                 *dual_height = page_cache->dual_height_to_page [page] * scale;
 619 }
 620
 621 void
 622 ev_page_cache_get_thumbnail_size (EvPageCache  *page_cache,
 623                                   gint          page,
 624                                   gint          rotation,
 625                                   gint         *width,
 626                                   gint         *height)
 627 {
 628         gint w, h;
 629
 630         g_return_if_fail (EV_IS_PAGE_CACHE (page_cache));
 631         g_return_if_fail (page >= 0 && page < page_cache->n_pages);
 632
 633         if (page_cache->thumbs_uniform) {
 634                 w = page_cache->thumbs_uniform_width;
 635                 h = page_cache->thumbs_uniform_height;
 636         } else {
 637                 EvPageThumbsInfo *info;
 638
 639                 info = &(page_cache->thumbs_size_cache [page]);
 640
 641                 w = info->width;
 642                 h = info->height;
 643         }
 644
 645         if (rotation == 0 || rotation == 180) {
 646                 if (width) *width = w;
 647                 if (height) *height = h;
 648         } else {
 649                 if (width) *width = h;
 650                 if (height) *height = w;
 651         }
 652 }
 653
 654 gint
 655 ev_page_cache_get_max_label_chars (EvPageCache *page_cache)
 656 {
 657         g_return_val_if_fail (EV_IS_PAGE_CACHE (page_cache), 0);
 658
 659         return page_cache->max_label_chars;
 660 }
 661
 662 gboolean
 663 ev_page_cache_get_dual_even_left (EvPageCache *page_cache)
 664 {
 665         g_return_val_if_fail (EV_IS_PAGE_CACHE (page_cache), 0);
 666
 667         return page_cache->dual_even_left;
 668 }
 669
 670 gchar *
 671 ev_page_cache_get_page_label (EvPageCache *page_cache,
 672                               gint         page)
 673 {
 674         g_return_val_if_fail (EV_IS_PAGE_CACHE (page_cache), NULL);
 675         g_return_val_if_fail (page >= 0 && page < page_cache->n_pages, NULL);
 676
 677         if (page_cache->page_labels[page] == NULL)
 678                 return g_strdup_printf ("%d", page + 1);
 679
 680         return g_strdup (page_cache->page_labels[page]);
 681 }
 682
 683 gboolean
 684 ev_page_cache_has_nonnumeric_page_labels (EvPageCache *page_cache)
 685 {
 686         g_return_val_if_fail (EV_IS_PAGE_CACHE (page_cache), FALSE);
 687         return page_cache->has_labels;
 688 }
 689
 690 const EvDocumentInfo *
 691 ev_page_cache_get_info (EvPageCache *page_cache)
 692 {
 693         g_return_val_if_fail (EV_IS_PAGE_CACHE (page_cache), NULL);
 694
 695         return page_cache->page_info;
 696 }
 697
 698 #define PAGE_CACHE_STRING "ev-page-cache"
 699
 700 EvPageCache *
 701 ev_page_cache_get (EvDocument *document)
 702 {
 703         EvPageCache *page_cache;
 704
 705         g_return_val_if_fail (EV_IS_DOCUMENT (document), NULL);
 706
 707         page_cache = g_object_get_data (G_OBJECT (document), PAGE_CACHE_STRING);
 708         if (page_cache == NULL) {
 709                 page_cache = ev_page_cache_new (document);
 710                 g_object_set_data_full (G_OBJECT (document), PAGE_CACHE_STRING, page_cache, g_object_unref);
 711         }
 712
 713         return page_cache;
 714 }