Pileus Git - ~andy/gtk/blob - gtk/gtktextdisplay.c

   1 /* gtktextdisplay.c - display layed-out text
   2  *
   3  * Copyright (c) 1992-1994 The Regents of the University of California.
   4  * Copyright (c) 1994-1997 Sun Microsystems, Inc.
   5  * Copyright (c) 2000 Red Hat, Inc.
   6  * Tk->Gtk port by Havoc Pennington
   7  *
   8  * This file can be used under your choice of two licenses, the LGPL
   9  * and the original Tk license.
  10  *
  11  * LGPL:
  12  *
  13  * This library is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU Lesser General Public
  15  * License as published by the Free Software Foundation; either
  16  * version 2 of the License, or (at your option) any later version.
  17  *
  18  * This library is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  21  * Lesser General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU Lesser General Public
  24  * License along with this library; if not, write to the Free
  25  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  26  *
  27  * Original Tk license:
  28  *
  29  * This software is copyrighted by the Regents of the University of
  30  * California, Sun Microsystems, Inc., and other parties.  The
  31  * following terms apply to all files associated with the software
  32  * unless explicitly disclaimed in individual files.
  33  *
  34  * The authors hereby grant permission to use, copy, modify,
  35  * distribute, and license this software and its documentation for any
  36  * purpose, provided that existing copyright notices are retained in
  37  * all copies and that this notice is included verbatim in any
  38  * distributions. No written agreement, license, or royalty fee is
  39  * required for any of the authorized uses.  Modifications to this
  40  * software may be copyrighted by their authors and need not follow
  41  * the licensing terms described here, provided that the new terms are
  42  * clearly indicated on the first page of each file where they apply.
  43  *
  44  * IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY
  45  * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
  46  * DAMAGES ARISING OUT OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION,
  47  * OR ANY DERIVATIVES THEREOF, EVEN IF THE AUTHORS HAVE BEEN ADVISED
  48  * OF THE POSSIBILITY OF SUCH DAMAGE.
  49  *
  50  * THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES,
  51  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  52  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND
  53  * NON-INFRINGEMENT.  THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS,
  54  * AND THE AUTHORS AND DISTRIBUTORS HAVE NO OBLIGATION TO PROVIDE
  55  * MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  56  *
  57  * GOVERNMENT USE: If you are acquiring this software on behalf of the
  58  * U.S. government, the Government shall have only "Restricted Rights"
  59  * in the software and related documentation as defined in the Federal
  60  * Acquisition Regulations (FARs) in Clause 52.227.19 (c) (2).  If you
  61  * are acquiring the software on behalf of the Department of Defense,
  62  * the software shall be classified as "Commercial Computer Software"
  63  * and the Government shall have only "Restricted Rights" as defined
  64  * in Clause 252.227-7013 (c) (1) of DFARs.  Notwithstanding the
  65  * foregoing, the authors grant the U.S. Government and others acting
  66  * in its behalf permission to use and distribute the software in
  67  * accordance with the terms specified in this license.
  68  *
  69  */
  70 /*
  71  * Modified by the GTK+ Team and others 1997-2000.  See the AUTHORS
  72  * file for a list of people on the GTK+ Team.  See the ChangeLog
  73  * files for a list of changes.  These files are distributed with
  74  * GTK+ at ftp://ftp.gtk.org/pub/gtk/.
  75  */
  76
  77 #include "gtktextdisplay.h"
  78 #include "gtktextiterprivate.h"
  79
  80 #include <pango/pango.h>
  81
  82 typedef struct _GtkTextRenderState GtkTextRenderState;
  83
  84 struct _GtkTextRenderState
  85 {
  86   GtkWidget *widget;
  87
  88   GtkTextAppearance *last_appearance;
  89   GtkTextAppearance *last_bg_appearance;
  90   GdkGC *fg_gc;
  91   GdkGC *bg_gc;
  92   GdkRectangle clip_rect;
  93 };
  94
  95 static void       get_item_properties (PangoItem           *item,
  96                                        GtkTextAppearance  **appearance);
  97 static GdkRegion *get_selected_clip   (GtkTextRenderState  *render_state,
  98                                        PangoLayout         *layout,
  99                                        PangoLayoutLine     *line,
 100                                        int                  x,
 101                                        int                  y,
 102                                        int                  height,
 103                                        int                  start_index,
 104                                        int                  end_index);
 105
 106 static GtkTextRenderState *
 107 gtk_text_render_state_new (GtkWidget    *widget,
 108                            GdkDrawable  *drawable,
 109                            GdkRectangle *clip_rect)
 110 {
 111   GtkTextRenderState *state = g_new0 (GtkTextRenderState, 1);
 112
 113   state->widget = widget;
 114   state->fg_gc = gdk_gc_new (drawable);
 115   state->bg_gc = gdk_gc_new (drawable);
 116   state->clip_rect = *clip_rect;
 117
 118   return state;
 119 }
 120
 121 static void
 122 gtk_text_render_state_destroy (GtkTextRenderState *state)
 123 {
 124   gdk_gc_unref (state->fg_gc);
 125   gdk_gc_unref (state->bg_gc);
 126
 127   g_free (state);
 128 }
 129
 130 static void
 131 gtk_text_render_state_set_color (GtkTextRenderState *state,
 132                                  GdkGC              *gc,
 133                                  GdkColor           *color)
 134 {
 135   gdk_colormap_alloc_color (gtk_widget_get_colormap (state->widget), color, FALSE, TRUE);
 136   gdk_gc_set_foreground (gc, color);
 137 }
 138
 139 static void
 140 gtk_text_render_state_update (GtkTextRenderState *state,
 141                               GtkTextAppearance  *new_appearance)
 142 {
 143   if (!state->last_appearance ||
 144       !gdk_color_equal (&new_appearance->fg_color, &state->last_appearance->fg_color))
 145     gtk_text_render_state_set_color (state, state->fg_gc, &new_appearance->fg_color);
 146
 147   if (!state->last_appearance ||
 148       new_appearance->fg_stipple != state->last_appearance->fg_stipple)
 149     {
 150       if (new_appearance->fg_stipple)
 151         {
 152           gdk_gc_set_fill (state->fg_gc, GDK_STIPPLED);
 153           gdk_gc_set_stipple (state->fg_gc, new_appearance->fg_stipple);
 154         }
 155       else
 156         {
 157           gdk_gc_set_fill (state->fg_gc, GDK_SOLID);
 158         }
 159     }
 160
 161   if (new_appearance->draw_bg)
 162     {
 163       if (!state->last_bg_appearance ||
 164           !gdk_color_equal (&new_appearance->bg_color, &state->last_bg_appearance->bg_color))
 165         gtk_text_render_state_set_color (state, state->bg_gc, &new_appearance->bg_color);
 166
 167       if (!state->last_bg_appearance ||
 168           new_appearance->bg_stipple != state->last_bg_appearance->bg_stipple)
 169         {
 170           if (new_appearance->bg_stipple)
 171             {
 172               gdk_gc_set_fill (state->bg_gc, GDK_STIPPLED);
 173               gdk_gc_set_stipple (state->bg_gc, new_appearance->bg_stipple);
 174             }
 175           else
 176             {
 177               gdk_gc_set_fill (state->bg_gc, GDK_SOLID);
 178             }
 179         }
 180
 181       state->last_bg_appearance = new_appearance;
 182     }
 183
 184   state->last_appearance = new_appearance;
 185 }
 186
 187 static void
 188 get_shape_extents (PangoLayoutRun *run,
 189                    PangoRectangle *ink_rect,
 190                    PangoRectangle *logical_rect)
 191 {
 192   GSList *tmp_list = run->item->extra_attrs;
 193
 194   while (tmp_list)
 195     {
 196       PangoAttribute *attr = tmp_list->data;
 197
 198       if (attr->klass->type == PANGO_ATTR_SHAPE)
 199         {
 200           if (logical_rect)
 201             *logical_rect = ((PangoAttrShape *)attr)->logical_rect;
 202
 203           if (ink_rect)
 204             *ink_rect = ((PangoAttrShape *)attr)->ink_rect;
 205
 206           return;
 207         }
 208
 209       tmp_list = tmp_list->next;
 210     }
 211
 212   g_assert_not_reached ();
 213 }
 214
 215 static void
 216 render_layout_line (GdkDrawable        *drawable,
 217                     GtkTextRenderState *render_state,
 218                     PangoLayoutLine    *line,
 219                     GSList            **shaped_pointer,
 220                     int                 x,
 221                     int                 y,
 222                     gboolean            selected)
 223 {
 224   GSList *tmp_list = line->runs;
 225   PangoRectangle overall_rect;
 226   PangoRectangle logical_rect;
 227   PangoRectangle ink_rect;
 228   gint x_off = 0;
 229   GdkGC *fg_gc;
 230
 231   pango_layout_line_get_extents (line, NULL, &overall_rect);
 232
 233   while (tmp_list)
 234     {
 235       PangoLayoutRun *run = tmp_list->data;
 236       GtkTextAppearance *appearance;
 237       gint risen_y;
 238       gint shaped_width_pixels = 0;
 239       gboolean need_ink = FALSE;
 240
 241       tmp_list = tmp_list->next;
 242
 243       get_item_properties (run->item, &appearance);
 244
 245       g_assert (appearance != NULL);
 246
 247       risen_y = y - PANGO_PIXELS (appearance->rise);
 248
 249       if (selected)
 250         {
 251           fg_gc = render_state->widget->style->fg_gc[GTK_STATE_SELECTED];
 252         }
 253       else
 254         {
 255           gtk_text_render_state_update (render_state, appearance);
 256
 257           fg_gc = render_state->fg_gc;
 258         }
 259
 260       if (appearance->underline != PANGO_UNDERLINE_NONE ||
 261           appearance->strikethrough)
 262         need_ink = TRUE;
 263
 264       if (appearance->is_text)
 265         {
 266           if (need_ink)
 267             pango_glyph_string_extents (run->glyphs, run->item->analysis.font,
 268                                         &ink_rect, &logical_rect);
 269           else
 270             pango_glyph_string_extents (run->glyphs, run->item->analysis.font,
 271                                         NULL, &logical_rect);
 272         }
 273       else
 274         {
 275           if (need_ink)
 276             get_shape_extents (run, &ink_rect, &logical_rect);
 277           else
 278             get_shape_extents (run, NULL, &logical_rect);
 279         }
 280
 281       if (appearance->draw_bg && !selected)
 282         gdk_draw_rectangle (drawable, render_state->bg_gc, TRUE,
 283                             x + PANGO_PIXELS (x_off) + PANGO_PIXELS (logical_rect.x),
 284                             risen_y + PANGO_PIXELS (logical_rect.y),
 285                             PANGO_PIXELS (logical_rect.width),
 286                             PANGO_PIXELS (logical_rect.height));
 287
 288       if (appearance->is_text)
 289         gdk_draw_glyphs (drawable, fg_gc,
 290                          run->item->analysis.font,
 291                          x + PANGO_PIXELS (x_off),
 292                          risen_y, run->glyphs);
 293       else
 294         {
 295           GObject *shaped = (*shaped_pointer)->data;
 296
 297           *shaped_pointer = (*shaped_pointer)->next;
 298
 299           if (GDK_IS_PIXBUF (shaped))
 300             {
 301               gint width, height;
 302               GdkRectangle pixbuf_rect, draw_rect;
 303               GdkPixbuf *pixbuf;
 304
 305               pixbuf = GDK_PIXBUF (shaped);
 306
 307               width = gdk_pixbuf_get_width (pixbuf);
 308               height = gdk_pixbuf_get_height (pixbuf);
 309
 310               pixbuf_rect.x = x + x_off / PANGO_SCALE;
 311               pixbuf_rect.y = risen_y - height;
 312               pixbuf_rect.width = width;
 313               pixbuf_rect.height = height;
 314
 315               if (gdk_rectangle_intersect (&pixbuf_rect, &render_state->clip_rect,
 316                                            &draw_rect))
 317                 {
 318                   GdkBitmap *mask = NULL;
 319
 320                   if (gdk_pixbuf_get_has_alpha (pixbuf))
 321                     {
 322                       mask = gdk_pixmap_new (drawable,
 323                                              gdk_pixbuf_get_width (pixbuf),
 324                                              gdk_pixbuf_get_height (pixbuf),
 325                                              1);
 326
 327                       gdk_pixbuf_render_threshold_alpha (pixbuf, mask,
 328                                                          0, 0, 0, 0,
 329                                                          gdk_pixbuf_get_width (pixbuf),
 330                                                          gdk_pixbuf_get_height (pixbuf),
 331                                                          128);
 332
 333                     }
 334
 335                   if (mask)
 336                     {
 337                       gdk_gc_set_clip_mask (render_state->fg_gc, mask);
 338                       gdk_gc_set_clip_origin (render_state->fg_gc,
 339                                               pixbuf_rect.x, pixbuf_rect.y);
 340                     }
 341
 342                   gdk_pixbuf_render_to_drawable (pixbuf,
 343                                                  drawable,
 344                                                  render_state->fg_gc,
 345                                                  draw_rect.x - pixbuf_rect.x,
 346                                                  draw_rect.y - pixbuf_rect.y,
 347                                                  draw_rect.x, draw_rect.y,
 348                                                  draw_rect.width,
 349                                                  draw_rect.height,
 350                                                  GDK_RGB_DITHER_NORMAL,
 351                                                  0, 0);
 352
 353                   if (mask)
 354                     {
 355                       gdk_gc_set_clip_rectangle (render_state->fg_gc,
 356                                                  &render_state->clip_rect);
 357                       g_object_unref (G_OBJECT (mask));
 358                     }
 359                 }
 360
 361               shaped_width_pixels = width;
 362             }
 363           else if (GTK_IS_WIDGET (shaped))
 364             {
 365               gint width, height;
 366               GdkRectangle draw_rect;
 367               GtkWidget *widget;
 368
 369               widget = GTK_WIDGET (shaped);
 370
 371               width = widget->allocation.width;
 372               height = widget->allocation.height;
 373
 374               printf ("widget allocation at %d,%d %d x %d\n",
 375                       widget->allocation.x,
 376                       widget->allocation.y,
 377                       widget->allocation.width,
 378                       widget->allocation.height);
 379
 380               if (GTK_WIDGET_DRAWABLE (widget) &&
 381                   gdk_rectangle_intersect (&widget->allocation,
 382                                            &render_state->clip_rect,
 383                                            &draw_rect))
 384
 385                 {
 386                   printf ("drawing widget area %d,%d %d x %d\n",
 387                           draw_rect.x,
 388                           draw_rect.y,
 389                           draw_rect.width,
 390                           draw_rect.height);
 391
 392                   gtk_widget_draw (widget, &draw_rect);
 393                 }
 394
 395               shaped_width_pixels = width;
 396             }
 397           else
 398             g_assert_not_reached (); /* not a pixbuf or widget */
 399         }
 400
 401       switch (appearance->underline)
 402         {
 403         case PANGO_UNDERLINE_NONE:
 404           break;
 405         case PANGO_UNDERLINE_DOUBLE:
 406           g_assert (need_ink);
 407           gdk_draw_line (drawable, fg_gc,
 408                          x + (x_off + ink_rect.x) / PANGO_SCALE - 1,
 409                          risen_y + 3,
 410                          x + (x_off + ink_rect.x + ink_rect.width) / PANGO_SCALE,
 411                          risen_y + 3);
 412           /* Fall through */
 413         case PANGO_UNDERLINE_SINGLE:
 414           g_assert (need_ink);
 415           gdk_draw_line (drawable, fg_gc,
 416                          x + (x_off + ink_rect.x) / PANGO_SCALE - 1,
 417                          risen_y + 1,
 418                          x + (x_off + ink_rect.x + ink_rect.width) / PANGO_SCALE,
 419                          risen_y + 1);
 420           break;
 421         case PANGO_UNDERLINE_LOW:
 422           g_assert (need_ink);
 423           gdk_draw_line (drawable, fg_gc,
 424                          x + (x_off + ink_rect.x) / PANGO_SCALE - 1,
 425                          risen_y + (ink_rect.y + ink_rect.height) / PANGO_SCALE + 1,
 426                          x + (x_off + ink_rect.x + ink_rect.width) / PANGO_SCALE,
 427                          risen_y + (ink_rect.y + ink_rect.height) / PANGO_SCALE + 1);
 428           break;
 429         }
 430
 431       if (appearance->strikethrough)
 432         {
 433           gint strikethrough_y = risen_y + (0.3 * logical_rect.y) / PANGO_SCALE;
 434
 435           g_assert (need_ink);
 436
 437           gdk_draw_line (drawable, fg_gc,
 438                          x + (x_off + ink_rect.x) / PANGO_SCALE - 1, strikethrough_y,
 439                          x + (x_off + ink_rect.x + ink_rect.width) / PANGO_SCALE, strikethrough_y);
 440         }
 441
 442       if (appearance->is_text)
 443         x_off += logical_rect.width;
 444       else
 445         x_off += shaped_width_pixels * PANGO_SCALE;
 446     }
 447 }
 448
 449 static void
 450 render_para (GdkDrawable        *drawable,
 451              GtkTextRenderState *render_state,
 452              GtkTextLineDisplay *line_display,
 453              /* Top-left corner of paragraph including all margins */
 454              int                 x,
 455              int                 y,
 456              int                 selection_start_index,
 457              int                 selection_end_index)
 458 {
 459   GSList *shaped_pointer = line_display->shaped_objects;
 460   PangoLayout *layout = line_display->layout;
 461   int byte_offset = 0;
 462   PangoLayoutIter *iter;
 463   PangoRectangle layout_logical;
 464   int screen_width;
 465
 466   gboolean first = TRUE;
 467
 468   iter = pango_layout_get_iter (layout);
 469
 470   pango_layout_iter_get_layout_extents (iter, NULL, &layout_logical);
 471
 472   /* Adjust for margins */
 473
 474   layout_logical.x += line_display->x_offset * PANGO_SCALE;
 475   layout_logical.y += line_display->top_margin * PANGO_SCALE;
 476
 477   screen_width = line_display->total_width;
 478
 479   do
 480     {
 481       PangoLayoutLine *line = pango_layout_iter_get_line (iter);
 482       int selection_y, selection_height;
 483       int first_y, last_y;
 484       PangoRectangle line_rect;
 485       int baseline;
 486
 487       pango_layout_iter_get_line_extents (iter, NULL, &line_rect);
 488       baseline = pango_layout_iter_get_baseline (iter);
 489       pango_layout_iter_get_line_yrange (iter, &first_y, &last_y);
 490
 491       /* Adjust for margins */
 492
 493       line_rect.x += line_display->x_offset * PANGO_SCALE;
 494       line_rect.y += line_display->top_margin * PANGO_SCALE;
 495       baseline += line_display->top_margin * PANGO_SCALE;
 496
 497       /* Selection is the height of the line, plus top/bottom
 498        * margin if we're the first/last line
 499        */
 500       selection_y = y + PANGO_PIXELS (first_y) + line_display->top_margin;
 501       selection_height = PANGO_PIXELS (last_y) - PANGO_PIXELS (first_y);
 502
 503       if (first)
 504         {
 505           selection_y -= line_display->top_margin;
 506           selection_height += line_display->top_margin;
 507         }
 508
 509       if (pango_layout_iter_at_last_line (iter))
 510         selection_height += line_display->bottom_margin;
 511
 512       first = FALSE;
 513
 514       if (selection_start_index < byte_offset &&
 515           selection_end_index > line->length + byte_offset) /* All selected */
 516         {
 517           gdk_draw_rectangle (drawable,
 518                               render_state->widget->style->bg_gc[GTK_STATE_SELECTED],
 519                               TRUE,
 520                               x + line_display->left_margin,
 521                               selection_y,
 522                               screen_width,
 523                               selection_height);
 524
 525           render_layout_line (drawable, render_state, line, &shaped_pointer,
 526                               x + PANGO_PIXELS (line_rect.x),
 527                               y + PANGO_PIXELS (baseline),
 528                               TRUE);
 529         }
 530       else
 531         {
 532           GSList *shaped_pointer_tmp = shaped_pointer;
 533
 534           render_layout_line (drawable, render_state,
 535                               line, &shaped_pointer,
 536                               x + PANGO_PIXELS (line_rect.x),
 537                               y + PANGO_PIXELS (baseline),
 538                               FALSE);
 539
 540           if (selection_start_index < byte_offset + line->length &&
 541               selection_end_index > byte_offset) /* Some selected */
 542             {
 543               GdkRegion *clip_region = get_selected_clip (render_state, layout, line,
 544                                                           x + line_display->x_offset,
 545                                                           selection_y,
 546                                                           selection_height,
 547                                                           selection_start_index, selection_end_index);
 548
 549               gdk_gc_set_clip_region (render_state->widget->style->fg_gc [GTK_STATE_SELECTED], clip_region);
 550               gdk_gc_set_clip_region (render_state->widget->style->bg_gc [GTK_STATE_SELECTED], clip_region);
 551
 552               gdk_draw_rectangle (drawable,
 553                                   render_state->widget->style->bg_gc[GTK_STATE_SELECTED],
 554                                   TRUE,
 555                                   x + PANGO_PIXELS (line_rect.x),
 556                                   selection_y,
 557                                   PANGO_PIXELS (line_rect.width),
 558                                   selection_height);
 559
 560               render_layout_line (drawable, render_state, line, &shaped_pointer_tmp,
 561                                   x + PANGO_PIXELS (line_rect.x),
 562                                   y + PANGO_PIXELS (baseline),
 563                                   TRUE);
 564
 565               gdk_gc_set_clip_region (render_state->widget->style->fg_gc [GTK_STATE_SELECTED], NULL);
 566               gdk_gc_set_clip_region (render_state->widget->style->bg_gc [GTK_STATE_SELECTED], NULL);
 567
 568               gdk_region_destroy (clip_region);
 569
 570               /* Paint in the ends of the line */
 571               if (line_rect.x > line_display->left_margin * PANGO_SCALE &&
 572                   ((line_display->direction == GTK_TEXT_DIR_LTR && selection_start_index < byte_offset) ||
 573                    (line_display->direction == GTK_TEXT_DIR_RTL && selection_end_index > byte_offset + line->length)))
 574                 {
 575                   gdk_draw_rectangle (drawable,
 576                                       render_state->widget->style->bg_gc[GTK_STATE_SELECTED],
 577                                       TRUE,
 578                                       x + line_display->left_margin,
 579                                       selection_y,
 580                                       PANGO_PIXELS (line_rect.x) - line_display->left_margin,
 581                                       selection_height);
 582                 }
 583
 584               if (line_rect.x + line_rect.width <
 585                   (screen_width + line_display->left_margin) * PANGO_SCALE &&
 586                   ((line_display->direction == GTK_TEXT_DIR_LTR && selection_end_index > byte_offset + line->length) ||
 587                    (line_display->direction == GTK_TEXT_DIR_RTL && selection_start_index < byte_offset)))
 588                 {
 589                   int nonlayout_width;
 590
 591                   nonlayout_width =
 592                     line_display->left_margin + screen_width -
 593                     PANGO_PIXELS (line_rect.x) - PANGO_PIXELS (line_rect.width);
 594
 595                   gdk_draw_rectangle (drawable,
 596                                       render_state->widget->style->bg_gc[GTK_STATE_SELECTED],
 597                                       TRUE,
 598                                       x + PANGO_PIXELS (line_rect.x) + PANGO_PIXELS (line_rect.width),
 599                                       selection_y,
 600                                       nonlayout_width,
 601                                       selection_height);
 602                 }
 603             }
 604         }
 605
 606       byte_offset += line->length;
 607     }
 608   while (pango_layout_iter_next_line (iter));
 609
 610   pango_layout_iter_free (iter);
 611 }
 612
 613 static GdkRegion *
 614 get_selected_clip (GtkTextRenderState *render_state,
 615                    PangoLayout        *layout,
 616                    PangoLayoutLine    *line,
 617                    int                 x,
 618                    int                 y,
 619                    int                 height,
 620                    int                 start_index,
 621                    int                 end_index)
 622 {
 623   gint *ranges;
 624   gint n_ranges, i;
 625   GdkRegion *clip_region = gdk_region_new ();
 626   GdkRegion *tmp_region;
 627
 628   pango_layout_line_get_x_ranges (line, start_index, end_index, &ranges, &n_ranges);
 629
 630   for (i=0; i < n_ranges; i++)
 631     {
 632       GdkRectangle rect;
 633
 634       rect.x = x + PANGO_PIXELS (ranges[2*i]);
 635       rect.y = y;
 636       rect.width = PANGO_PIXELS (ranges[2*i + 1]) - PANGO_PIXELS (ranges[2*i]);
 637       rect.height = height;
 638
 639       gdk_region_union_with_rect (clip_region, &rect);
 640     }
 641
 642   tmp_region = gdk_region_rectangle (&render_state->clip_rect);
 643   gdk_region_intersect (clip_region, tmp_region);
 644   gdk_region_destroy (tmp_region);
 645
 646   g_free (ranges);
 647   return clip_region;
 648 }
 649
 650 static void
 651 get_item_properties (PangoItem          *item,
 652                      GtkTextAppearance **appearance)
 653 {
 654   GSList *tmp_list = item->extra_attrs;
 655
 656   *appearance = NULL;
 657
 658   while (tmp_list)
 659     {
 660       PangoAttribute *attr = tmp_list->data;
 661
 662       if (attr->klass->type == gtk_text_attr_appearance_type)
 663         {
 664           *appearance = &((GtkTextAttrAppearance *)attr)->appearance;
 665         }
 666
 667       tmp_list = tmp_list->next;
 668     }
 669 }
 670
 671 void
 672 gtk_text_layout_draw (GtkTextLayout *layout,
 673                       GtkWidget *widget,
 674                       GdkDrawable *drawable,
 675                       /* Location of the drawable
 676                          in layout coordinates */
 677                       gint x_offset,
 678                       gint y_offset,
 679                       /* Region of the layout to
 680                          render */
 681                       gint x,
 682                       gint y,
 683                       gint width,
 684                       gint height)
 685 {
 686   GdkRectangle clip;
 687   gint current_y;
 688   GSList *cursor_list;
 689   GtkTextRenderState *render_state;
 690   GtkTextIter selection_start, selection_end;
 691   gboolean have_selection = FALSE;
 692   GSList *line_list;
 693   GSList *tmp_list;
 694
 695   g_return_if_fail (GTK_IS_TEXT_LAYOUT (layout));
 696   g_return_if_fail (layout->default_style != NULL);
 697   g_return_if_fail (layout->buffer != NULL);
 698   g_return_if_fail (drawable != NULL);
 699   g_return_if_fail (x_offset >= 0);
 700   g_return_if_fail (y_offset >= 0);
 701   g_return_if_fail (width >= 0);
 702   g_return_if_fail (height >= 0);
 703
 704   if (width == 0 || height == 0)
 705     return;
 706
 707   line_list =  gtk_text_layout_get_lines (layout, y + y_offset, y + y_offset + height, &current_y);
 708   current_y -= y_offset;
 709
 710   if (line_list == NULL)
 711     return; /* nothing on the screen */
 712
 713   clip.x = x;
 714   clip.y = y;
 715   clip.width = width;
 716   clip.height = height;
 717
 718   render_state = gtk_text_render_state_new (widget, drawable, &clip);
 719
 720   gdk_gc_set_clip_rectangle (render_state->fg_gc, &clip);
 721   gdk_gc_set_clip_rectangle (render_state->bg_gc, &clip);
 722
 723   gtk_text_layout_wrap_loop_start (layout);
 724
 725   if (gtk_text_buffer_get_selection_bounds (layout->buffer,
 726                                             &selection_start,
 727                                             &selection_end))
 728     have_selection = TRUE;
 729
 730   tmp_list = line_list;
 731   while (tmp_list != NULL)
 732     {
 733       GtkTextLineDisplay *line_display;
 734       gint selection_start_index = -1;
 735       gint selection_end_index = -1;
 736
 737       GtkTextLine *line = tmp_list->data;
 738
 739       line_display = gtk_text_layout_get_line_display (layout, line, FALSE);
 740
 741       if (have_selection)
 742         {
 743           GtkTextIter line_start, line_end;
 744           gint byte_count = gtk_text_line_byte_count (line);
 745
 746           gtk_text_btree_get_iter_at_line (_gtk_text_buffer_get_btree (layout->buffer),
 747                                            &line_start,
 748                                            line, 0);
 749           gtk_text_btree_get_iter_at_line (_gtk_text_buffer_get_btree (layout->buffer),
 750                                            &line_end,
 751                                            line, byte_count - 1);
 752
 753           if (gtk_text_iter_compare (&selection_start, &line_end) < 0 &&
 754               gtk_text_iter_compare (&selection_end, &line_start) > 0)
 755             {
 756               if (gtk_text_iter_compare (&selection_start, &line_start) >= 0)
 757                 selection_start_index = gtk_text_iter_get_line_index (&selection_start);
 758               else
 759                 selection_start_index = -1;
 760
 761               if (gtk_text_iter_compare (&selection_end, &line_end) <= 0)
 762                 selection_end_index = gtk_text_iter_get_line_index (&selection_end);
 763               else
 764                 selection_end_index = byte_count;
 765             }
 766         }
 767
 768       render_para (drawable, render_state, line_display,
 769                    - x_offset,
 770                    current_y,
 771                    selection_start_index, selection_end_index);
 772
 773
 774       /* We paint the cursors last, because they overlap another chunk
 775          and need to appear on top. */
 776
 777       cursor_list = line_display->cursors;
 778       while (cursor_list)
 779         {
 780           GtkTextCursorDisplay *cursor = cursor_list->data;
 781           GdkGC *gc;
 782
 783           if (cursor->is_strong)
 784             gc = widget->style->bg_gc[GTK_STATE_SELECTED];
 785           else
 786             gc = widget->style->fg_gc[GTK_STATE_NORMAL];
 787
 788           gdk_draw_line (drawable, gc,
 789                          line_display->x_offset + cursor->x - x_offset,
 790                          current_y + line_display->top_margin + cursor->y,
 791                          line_display->x_offset + cursor->x - x_offset,
 792                          current_y + line_display->top_margin + cursor->y + cursor->height - 1);
 793
 794           cursor_list = cursor_list->next;
 795         }
 796
 797       current_y += line_display->height;
 798       gtk_text_layout_free_line_display (layout, line_display);
 799
 800       tmp_list = g_slist_next (tmp_list);
 801     }
 802
 803   gtk_text_layout_wrap_loop_end (layout);
 804   gtk_text_render_state_destroy (render_state);
 805
 806   g_slist_free (line_list);
 807 }