src/undo.c

   1 /*
   2  * Claws Mail -- a GTK based, lightweight, and fast e-mail client
   3  * Copyright (C) 1999-2016 Hiroyuki Yamamoto and the Claws Mail team
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 /* code ported from gedit */
  20 /* This is for my patient girlfirend Regina */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #  include "config.h"
  24 #include "claws-features.h"
  25 #endif
  26
  27 #include <glib.h>
  28
  29 #include <string.h> /* for strlen */
  30 #include <stdlib.h> /* for mbstowcs */
  31
  32 #include "undo.h"
  33 #include "utils.h"
  34 #include "prefs_common.h"
  35
  36 typedef struct _UndoInfo UndoInfo;
  37
  38 struct _UndoInfo
  39 {
  40         UndoAction action;
  41         gchar *text;
  42         gint start_pos;
  43         gint end_pos;
  44         gfloat window_position;
  45         gint mergeable;
  46 };
  47
  48 struct _UndoWrap
  49 {
  50         gint lock;
  51         gchar *pre_wrap_content;
  52         gint start_pos;
  53         gint end_pos;
  54         gint len_change;
  55 };
  56
  57 static void undo_free_list      (GList         **list_pointer);
  58 static void undo_check_size     (UndoMain       *undostruct);
  59 static gint undo_merge          (GList          *list,
  60                                  guint           start_pos,
  61                                  guint           end_pos,
  62                                  gint            action,
  63                                  const guchar   *text);
  64 static void undo_add            (const gchar    *text,
  65                                  gint            start_pos,
  66                                  gint            end_pos,
  67                                  UndoAction      action,
  68                                  UndoMain       *undostruct);
  69 static gint undo_get_selection  (GtkTextView    *textview,
  70                                  guint          *start,
  71                                  guint          *end);
  72 static void undo_insert_text_cb (GtkTextBuffer  *textbuf,
  73                                  GtkTextIter    *iter,
  74                                  gchar          *new_text,
  75                                  gint           new_text_length,
  76                                  UndoMain       *undostruct);
  77 static void undo_delete_text_cb (GtkTextBuffer  *textbuf,
  78                                  GtkTextIter    *start,
  79                                  GtkTextIter    *end,
  80                                  UndoMain       *undostruct);
  81
  82 static void undo_paste_clipboard_cb     (GtkTextView    *textview,
  83                                          UndoMain       *undostruct);
  84
  85 void undo_undo                  (UndoMain       *undostruct);
  86 void undo_redo                  (UndoMain       *undostruct);
  87
  88
  89 UndoMain *undo_init(GtkWidget *text)
  90 {
  91         UndoMain *undostruct;
  92         GtkTextView *textview = GTK_TEXT_VIEW(text);
  93         GtkTextBuffer *textbuf = gtk_text_view_get_buffer(textview);
  94
  95         cm_return_val_if_fail(text != NULL, NULL);
  96
  97         undostruct = g_new0(UndoMain, 1);
  98         undostruct->textview = textview;
  99         undostruct->undo = NULL;
 100         undostruct->redo = NULL;
 101         undostruct->paste = 0;
 102         undostruct->undo_state = FALSE;
 103         undostruct->redo_state = FALSE;
 104
 105         g_signal_connect(G_OBJECT(textbuf), "insert-text",
 106                          G_CALLBACK(undo_insert_text_cb), undostruct);
 107         g_signal_connect(G_OBJECT(textbuf), "delete-range",
 108                          G_CALLBACK(undo_delete_text_cb), undostruct);
 109         g_signal_connect(G_OBJECT(textview), "paste-clipboard",
 110                          G_CALLBACK(undo_paste_clipboard_cb), undostruct);
 111
 112         return undostruct;
 113 }
 114
 115 void undo_destroy (UndoMain *undostruct)
 116 {
 117         undo_free_list(&undostruct->undo);
 118         undo_free_list(&undostruct->redo);
 119         g_free(undostruct);
 120 }
 121
 122 static UndoInfo *undo_object_new(gchar *text, gint start_pos, gint end_pos,
 123                                  UndoAction action, gfloat window_position)
 124 {
 125         UndoInfo *undoinfo;
 126         undoinfo = g_new (UndoInfo, 1);
 127         undoinfo->text      = text;
 128         undoinfo->start_pos = start_pos;
 129         undoinfo->end_pos   = end_pos;
 130         undoinfo->action    = action;
 131         undoinfo->window_position = window_position;
 132         return undoinfo;
 133 }
 134
 135 static void undo_object_free(UndoInfo *undo)
 136 {
 137         g_free (undo->text);
 138         g_free (undo);
 139 }
 140
 141 /**
 142  * undo_free_list:
 143  * @list_pointer: list to be freed
 144  *
 145  * frees and undo structure list
 146  **/
 147 static void undo_free_list(GList **list_pointer)
 148 {
 149         UndoInfo *undo;
 150         GList *cur, *list = *list_pointer;
 151
 152         if (list == NULL) return;
 153
 154         for (cur = list; cur != NULL; cur = cur->next) {
 155                 undo = (UndoInfo *)cur->data;
 156                 undo_object_free(undo);
 157         }
 158
 159         g_list_free(list);
 160         *list_pointer = NULL;
 161 }
 162
 163 void undo_set_change_state_func(UndoMain *undostruct, UndoChangeStateFunc func,
 164                                 gpointer data)
 165 {
 166         cm_return_if_fail(undostruct != NULL);
 167
 168         undostruct->change_state_func = func;
 169         undostruct->change_state_data = data;
 170 }
 171
 172 /**
 173  * undo_check_size:
 174  * @compose: document to check
 175  *
 176  * Checks that the size of compose->undo does not excede settings->undo_levels and
 177  * frees any undo level above sett->undo_level.
 178  *
 179  **/
 180 static void undo_check_size(UndoMain *undostruct)
 181 {
 182         UndoInfo *last_undo;
 183         guint length;
 184
 185         if (prefs_common.undolevels < 1) return;
 186
 187         /* No need to check for the redo list size since the undo
 188            list gets freed on any call to compose_undo_add */
 189         length = g_list_length(undostruct->undo);
 190         if (length >= prefs_common.undolevels && prefs_common.undolevels > 0) {
 191                 last_undo = (UndoInfo *)g_list_last(undostruct->undo)->data;
 192                 undostruct->undo = g_list_remove(undostruct->undo, last_undo);
 193                 undo_object_free(last_undo);
 194         }
 195 }
 196
 197 /**
 198  * undo_merge:
 199  * @last_undo:
 200  * @start_pos:
 201  * @end_pos:
 202  * @action:
 203  *
 204  * This function tries to merge the undo object at the top of
 205  * the stack with a new set of data. So when we undo for example
 206  * typing, we can undo the whole word and not each letter by itself
 207  *
 208  * Return Value: TRUE is merge was sucessful, FALSE otherwise
 209  **/
 210 static gint undo_merge(GList *list, guint start_pos, guint end_pos,
 211                        gint action, const guchar *text)
 212 {
 213         guchar *temp_string;
 214         UndoInfo *last_undo;
 215
 216         /* This are the cases in which we will NOT merge :
 217            1. if (last_undo->mergeable == FALSE)
 218            [mergeable = FALSE when the size of the undo data was not 1.
 219            or if the data was size = 1 but = '\n' or if the undo object
 220            has been "undone" already ]
 221            2. The size of text is not 1
 222            3. If the new merging data is a '\n'
 223            4. If the last char of the undo_last data is a space/tab
 224            and the new char is not a space/tab ( so that we undo
 225            words and not chars )
 226            5. If the type (action) of undo is different from the last one
 227            Chema */
 228
 229         if (list == NULL) return FALSE;
 230
 231         last_undo = list->data;
 232
 233         if (!last_undo->mergeable) return FALSE;
 234
 235         if (end_pos - start_pos != 1 ||
 236             text[0] == '\n' ||
 237             action != last_undo->action ||
 238             action == UNDO_ACTION_REPLACE_INSERT ||
 239             action == UNDO_ACTION_REPLACE_DELETE) {
 240                 last_undo->mergeable = FALSE;
 241                 return FALSE;
 242         }
 243
 244         if (action == UNDO_ACTION_DELETE) {
 245                 if (last_undo->start_pos != end_pos &&
 246                     last_undo->start_pos != start_pos) {
 247                         last_undo->mergeable = FALSE;
 248                         return FALSE;
 249                 } else if (last_undo->start_pos == start_pos) {
 250                         /* Deleted with the delete key */
 251                         temp_string = g_strdup_printf("%s%s", last_undo->text, text);
 252                         last_undo->end_pos++;
 253                         g_free(last_undo->text);
 254                         last_undo->text = temp_string;
 255                 } else {
 256                         /* Deleted with the backspace key */
 257                         temp_string = g_strdup_printf("%s%s", text, last_undo->text);
 258                         last_undo->start_pos = start_pos;
 259                         g_free(last_undo->text);
 260                         last_undo->text = temp_string;
 261                 }
 262         } else if (action == UNDO_ACTION_INSERT) {
 263                 if (last_undo->end_pos != start_pos) {
 264                         last_undo->mergeable = FALSE;
 265                         return FALSE;
 266                 } else {
 267                         temp_string = g_strdup_printf("%s%s", last_undo->text, text);
 268                         g_free(last_undo->text);
 269                         last_undo->end_pos = end_pos;
 270                         last_undo->text = temp_string;
 271                 }
 272         } else
 273                 debug_print("Unknown action [%i] inside undo merge encountered\n", action);
 274
 275         return TRUE;
 276 }
 277
 278 /**
 279  * compose_undo_add:
 280  * @text:
 281  * @start_pos:
 282  * @end_pos:
 283  * @action: either UNDO_ACTION_INSERT or UNDO_ACTION_DELETE
 284  * @compose:
 285  * @view: The view so that we save the scroll bar position.
 286  *
 287  * Adds text to the undo stack. It also performs test to limit the number
 288  * of undo levels and deltes the redo list
 289  **/
 290
 291 static void undo_add(const gchar *text,
 292                      gint start_pos, gint end_pos,
 293                      UndoAction action, UndoMain *undostruct)
 294 {
 295         UndoInfo *undoinfo;
 296         GtkAdjustment *vadj;
 297
 298         cm_return_if_fail(text != NULL);
 299         cm_return_if_fail(end_pos >= start_pos);
 300
 301         undo_free_list(&undostruct->redo);
 302
 303         /* Set the redo sensitivity */
 304         undostruct->change_state_func(undostruct,
 305                                       UNDO_STATE_UNCHANGED, UNDO_STATE_FALSE,
 306                                       undostruct->change_state_data);
 307
 308         if (undostruct->paste != 0) {
 309                 if (action == UNDO_ACTION_INSERT)
 310                         action = UNDO_ACTION_REPLACE_INSERT;
 311                 else
 312                         action = UNDO_ACTION_REPLACE_DELETE;
 313                 undostruct->paste = undostruct->paste + 1;
 314                 if (undostruct->paste == 3)
 315                         undostruct->paste = 0;
 316         }
 317
 318         if (undo_merge(undostruct->undo, start_pos, end_pos, action, text))
 319                 return;
 320
 321         undo_check_size(undostruct);
 322
 323         vadj = GTK_ADJUSTMENT(gtk_scrollable_get_vadjustment(
 324                                 GTK_SCROLLABLE(undostruct->textview)));
 325         undoinfo = undo_object_new(g_strdup(text), start_pos, end_pos, action,
 326                                    gtk_adjustment_get_value(vadj));
 327
 328         if (end_pos - start_pos != 1 || text[0] == '\n')
 329                 undoinfo->mergeable = FALSE;
 330         else
 331                 undoinfo->mergeable = TRUE;
 332
 333         undostruct->undo = g_list_prepend(undostruct->undo, undoinfo);
 334
 335         undostruct->change_state_func(undostruct,
 336                                       UNDO_STATE_TRUE, UNDO_STATE_UNCHANGED,
 337                                       undostruct->change_state_data);
 338 }
 339
 340 /**
 341  * undo_undo:
 342  * @w: not used
 343  * @data: not used
 344  *
 345  * Executes an undo request on the current document
 346  **/
 347 void undo_undo(UndoMain *undostruct)
 348 {
 349         UndoInfo *undoinfo;
 350         GtkTextView *textview;
 351         GtkTextBuffer *buffer;
 352         GtkTextIter iter, start_iter, end_iter;
 353         GtkTextMark *mark;
 354
 355         cm_return_if_fail(undostruct != NULL);
 356
 357         if (undostruct->undo == NULL) return;
 358
 359         /* The undo data we need is always at the top op the
 360            stack. So, therefore, the first one */
 361         undoinfo = (UndoInfo *)undostruct->undo->data;
 362         cm_return_if_fail(undoinfo != NULL);
 363         undoinfo->mergeable = FALSE;
 364         undostruct->redo = g_list_prepend(undostruct->redo, undoinfo);
 365         undostruct->undo = g_list_remove(undostruct->undo, undoinfo);
 366
 367         textview = undostruct->textview;
 368         buffer = gtk_text_view_get_buffer(textview);
 369
 370         undo_block(undostruct);
 371
 372         /* Check if there is a selection active */
 373         mark = gtk_text_buffer_get_insert(buffer);
 374         gtk_text_buffer_get_iter_at_mark(buffer, &iter, mark);
 375         gtk_text_buffer_place_cursor(buffer, &iter);
 376
 377         /* Move the view (scrollbars) to the correct position */
 378         gtk_adjustment_set_value
 379                 (GTK_ADJUSTMENT(gtk_scrollable_get_vadjustment(GTK_SCROLLABLE(textview))),
 380                  undoinfo->window_position);
 381
 382         switch (undoinfo->action) {
 383         case UNDO_ACTION_DELETE:
 384                 gtk_text_buffer_get_iter_at_offset(buffer, &iter, undoinfo->start_pos);
 385                 gtk_text_buffer_insert(buffer, &iter, undoinfo->text, -1);
 386                 break;
 387         case UNDO_ACTION_INSERT:
 388                 gtk_text_buffer_get_iter_at_offset(buffer, &start_iter, undoinfo->start_pos);
 389                 gtk_text_buffer_get_iter_at_offset(buffer, &end_iter, undoinfo->end_pos);
 390                 gtk_text_buffer_delete(buffer, &start_iter, &end_iter);
 391                 break;
 392         case UNDO_ACTION_REPLACE_INSERT:
 393                 gtk_text_buffer_get_iter_at_offset(buffer, &start_iter, undoinfo->start_pos);
 394                 gtk_text_buffer_get_iter_at_offset(buffer, &end_iter, undoinfo->end_pos);
 395                 gtk_text_buffer_delete(buffer, &start_iter, &end_iter);
 396                 /* "pull" previous matching DELETE data structure from the list */
 397                 if (undostruct->undo){
 398                         undoinfo = (UndoInfo *)undostruct->undo->data;
 399                         undostruct->redo = g_list_prepend(undostruct->redo, undoinfo);
 400                         undostruct->undo = g_list_remove(undostruct->undo, undoinfo);
 401                         cm_return_if_fail(undoinfo != NULL);
 402                         cm_return_if_fail(undoinfo->action == UNDO_ACTION_REPLACE_DELETE);
 403                         gtk_text_buffer_insert(buffer, &start_iter, undoinfo->text, -1);
 404                 }
 405                 break;
 406         case UNDO_ACTION_REPLACE_DELETE:
 407                 gtk_text_buffer_get_iter_at_offset(buffer, &start_iter, undoinfo->start_pos);
 408                 gtk_text_buffer_insert(buffer, &start_iter, undoinfo->text, -1);
 409                 /* "pull" previous matching INSERT data structure from the list */
 410                 if (undostruct->undo){
 411                         undoinfo = (UndoInfo *)undostruct->undo->data;
 412                         undostruct->redo = g_list_prepend(undostruct->redo, undoinfo);
 413                         undostruct->undo = g_list_remove(undostruct->undo, undoinfo);
 414                         cm_return_if_fail(undoinfo != NULL);
 415                         cm_return_if_fail(undoinfo->action == UNDO_ACTION_REPLACE_INSERT);
 416                         gtk_text_buffer_get_iter_at_offset(buffer, &start_iter, undoinfo->start_pos);
 417                         gtk_text_buffer_get_iter_at_offset(buffer, &end_iter, undoinfo->end_pos);
 418                         gtk_text_buffer_delete(buffer, &start_iter, &end_iter);
 419                 }
 420                 break;
 421         default:
 422                 g_assert_not_reached();
 423                 break;
 424         }
 425
 426         undostruct->change_state_func(undostruct,
 427                                       UNDO_STATE_UNCHANGED, UNDO_STATE_TRUE,
 428                                       undostruct->change_state_data);
 429
 430         if (undostruct->undo == NULL)
 431                 undostruct->change_state_func(undostruct,
 432                                               UNDO_STATE_FALSE,
 433                                               UNDO_STATE_UNCHANGED,
 434                                               undostruct->change_state_data);
 435
 436         undo_unblock(undostruct);
 437 }
 438
 439 /**
 440  * undo_redo:
 441  * @w: not used
 442  * @data: not used
 443  *
 444  * executes a redo request on the current document
 445  **/
 446 void undo_redo(UndoMain *undostruct)
 447 {
 448         UndoInfo *redoinfo;
 449         GtkTextView *textview;
 450         GtkTextBuffer *buffer;
 451         GtkTextIter iter, start_iter, end_iter;
 452         GtkTextMark *mark;
 453
 454         cm_return_if_fail(undostruct != NULL);
 455
 456         if (undostruct->redo == NULL) return;
 457
 458         redoinfo = (UndoInfo *)undostruct->redo->data;
 459         cm_return_if_fail (redoinfo != NULL);
 460         undostruct->undo = g_list_prepend(undostruct->undo, redoinfo);
 461         undostruct->redo = g_list_remove(undostruct->redo, redoinfo);
 462
 463         textview = undostruct->textview;
 464         buffer = gtk_text_view_get_buffer(textview);
 465
 466         undo_block(undostruct);
 467
 468         /* Check if there is a selection active */
 469         mark = gtk_text_buffer_get_insert(buffer);
 470         gtk_text_buffer_get_iter_at_mark(buffer, &iter, mark);
 471         gtk_text_buffer_place_cursor(buffer, &iter);
 472
 473         /* Move the view to the right position. */
 474         gtk_adjustment_set_value(gtk_scrollable_get_vadjustment(GTK_SCROLLABLE(textview)),
 475                                  redoinfo->window_position);
 476
 477         switch (redoinfo->action) {
 478         case UNDO_ACTION_INSERT:
 479                 gtk_text_buffer_get_iter_at_offset(buffer, &iter, redoinfo->start_pos);
 480                 gtk_text_buffer_insert(buffer, &iter, redoinfo->text, -1);
 481                 break;
 482         case UNDO_ACTION_DELETE:
 483                 gtk_text_buffer_get_iter_at_offset(buffer, &start_iter, redoinfo->start_pos);
 484                 gtk_text_buffer_get_iter_at_offset(buffer, &end_iter, redoinfo->end_pos);
 485                 gtk_text_buffer_delete(buffer, &start_iter, &end_iter);
 486                 break;
 487         case UNDO_ACTION_REPLACE_DELETE:
 488                 gtk_text_buffer_get_iter_at_offset(buffer, &start_iter, redoinfo->start_pos);
 489                 gtk_text_buffer_get_iter_at_offset(buffer, &end_iter, redoinfo->end_pos);
 490                 gtk_text_buffer_delete(buffer, &start_iter, &end_iter);
 491                 debug_print("UNDO_ACTION_REPLACE %s\n", redoinfo->text);
 492                 /* "pull" previous matching INSERT data structure from the list */
 493                 redoinfo = (UndoInfo *)undostruct->redo->data;
 494                 cm_return_if_fail(redoinfo != NULL);
 495                 undostruct->undo = g_list_prepend(undostruct->undo, redoinfo);
 496                 undostruct->redo = g_list_remove(undostruct->redo, redoinfo);
 497                 cm_return_if_fail(redoinfo->action == UNDO_ACTION_REPLACE_INSERT);
 498                 gtk_text_buffer_insert(buffer, &start_iter, redoinfo->text, -1);
 499                 break;
 500         case UNDO_ACTION_REPLACE_INSERT:
 501                 gtk_text_buffer_get_iter_at_offset(buffer, &iter, redoinfo->start_pos);
 502                 gtk_text_buffer_insert(buffer, &iter, redoinfo->text, -1);
 503                 /* "pull" previous matching DELETE structure from the list */
 504                 redoinfo = (UndoInfo *)undostruct->redo->data;
 505                 /* Do nothing if we redo from a middle-click button
 506                  * and next action is not UNDO_ACTION_REPLACE_DELETE */
 507                 if (redoinfo && redoinfo->action == UNDO_ACTION_REPLACE_DELETE) {
 508                         undostruct->undo = g_list_prepend(undostruct->undo, redoinfo);
 509                         undostruct->redo = g_list_remove(undostruct->redo, redoinfo);
 510                         gtk_text_buffer_get_iter_at_offset(buffer, &start_iter, redoinfo->start_pos);
 511                         gtk_text_buffer_get_iter_at_offset(buffer, &end_iter, redoinfo->end_pos);
 512                         gtk_text_buffer_delete(buffer, &start_iter, &end_iter);
 513                 }
 514                 break;
 515         default:
 516                 g_assert_not_reached();
 517                 break;
 518         }
 519
 520         undostruct->change_state_func(undostruct,
 521                                       UNDO_STATE_TRUE, UNDO_STATE_UNCHANGED,
 522                                       undostruct->change_state_data);
 523
 524         if (undostruct->redo == NULL)
 525                 undostruct->change_state_func(undostruct,
 526                                               UNDO_STATE_UNCHANGED,
 527                                               UNDO_STATE_FALSE,
 528                                               undostruct->change_state_data);
 529
 530         undo_unblock(undostruct);
 531 }
 532
 533 void undo_block(UndoMain *undostruct)
 534 {
 535         GtkTextBuffer *buffer;
 536
 537         cm_return_if_fail(GTK_IS_TEXT_VIEW(undostruct->textview));
 538
 539         buffer = gtk_text_view_get_buffer(undostruct->textview);
 540         g_signal_handlers_block_by_func(buffer, undo_insert_text_cb, undostruct);
 541         g_signal_handlers_block_by_func(buffer, undo_delete_text_cb, undostruct);
 542         g_signal_handlers_block_by_func(buffer, undo_paste_clipboard_cb,
 543                                           undostruct);
 544 }
 545
 546 void undo_unblock(UndoMain *undostruct)
 547 {
 548         GtkTextBuffer *buffer;
 549
 550         cm_return_if_fail(GTK_IS_TEXT_VIEW(undostruct->textview));
 551
 552         buffer = gtk_text_view_get_buffer(undostruct->textview);
 553         g_signal_handlers_unblock_by_func(buffer, undo_insert_text_cb, undostruct);
 554         g_signal_handlers_unblock_by_func(buffer, undo_delete_text_cb, undostruct);
 555         g_signal_handlers_unblock_by_func(buffer, undo_paste_clipboard_cb,
 556                                           undostruct);
 557 }
 558
 559 /* Init the WrapInfo structure */
 560 static void init_wrap_undo(UndoMain *undostruct)
 561 {
 562         GtkTextBuffer *buffer;
 563         GtkTextIter start, end;
 564
 565         cm_return_if_fail(undostruct != NULL);
 566         cm_return_if_fail(undostruct->wrap_info == NULL);
 567
 568         undostruct->wrap_info = g_new0(UndoWrap, 1);
 569
 570         /* Save the whole buffer as original contents. We'll retain the
 571          * changed region when exiting wrap mode.
 572          */
 573         buffer = gtk_text_view_get_buffer(undostruct->textview);
 574         gtk_text_buffer_get_start_iter(buffer, &start);
 575         gtk_text_buffer_get_end_iter(buffer, &end);
 576         undostruct->wrap_info->pre_wrap_content
 577                 = gtk_text_buffer_get_text(buffer, &start, &end, FALSE);
 578
 579         undostruct->wrap_info->lock = 0;
 580
 581         /* start_pos == -1 means nothing changed yet. */
 582         undostruct->wrap_info->start_pos = -1;
 583         undostruct->wrap_info->end_pos = -1;
 584         undostruct->wrap_info->len_change = 0;
 585 }
 586
 587 static void end_wrap_undo(UndoMain *undostruct)
 588 {
 589         GtkTextBuffer *buffer;
 590         GtkTextIter start, end;
 591         gchar *old_contents = NULL;
 592         gchar *cur_contents = NULL;
 593         gchar *new_contents = NULL;
 594
 595         cm_return_if_fail(undostruct != NULL);
 596         cm_return_if_fail(undostruct->wrap_info != NULL);
 597
 598         /* If start_pos is still == -1, it means nothing changed. */
 599         if (undostruct->wrap_info->start_pos == -1)
 600                 goto cleanup;
 601
 602         cm_return_if_fail(undostruct->wrap_info->end_pos > undostruct->wrap_info->start_pos);
 603         cm_return_if_fail(undostruct->wrap_info->end_pos - undostruct->wrap_info->len_change > undostruct->wrap_info->start_pos);
 604
 605         /* get the whole new (wrapped) contents */
 606         buffer = gtk_text_view_get_buffer(undostruct->textview);
 607         gtk_text_buffer_get_start_iter(buffer, &start);
 608         gtk_text_buffer_get_end_iter(buffer, &end);
 609         cur_contents = gtk_text_buffer_get_text(buffer, &start, &end, FALSE);
 610
 611         debug_print("wrapping done from %d to %d, len change: %d\n",
 612                 undostruct->wrap_info->start_pos,
 613                 undostruct->wrap_info->end_pos,
 614                 undostruct->wrap_info->len_change);
 615
 616         /* keep the relevant old unwrapped part, which is what
 617          * was between start_pos & end_pos - len_change
 618          */
 619         old_contents = g_utf8_substring(
 620                         undostruct->wrap_info->pre_wrap_content,
 621                         undostruct->wrap_info->start_pos,
 622                         undostruct->wrap_info->end_pos
 623                         - undostruct->wrap_info->len_change);
 624
 625         /* and get the changed contents, from start_pos to end_pos. */
 626         new_contents = g_utf8_substring(
 627                         cur_contents,
 628                         undostruct->wrap_info->start_pos,
 629                         undostruct->wrap_info->end_pos);
 630
 631         /* add the deleted (unwrapped) text to the undo pile */
 632         undo_add(old_contents,
 633                  undostruct->wrap_info->start_pos,
 634                  undostruct->wrap_info->end_pos
 635                   - undostruct->wrap_info->len_change,
 636                  UNDO_ACTION_REPLACE_DELETE,
 637                  undostruct);
 638
 639         /* add the inserted (wrapped) text to the undo pile */
 640         undo_add(new_contents,
 641                  undostruct->wrap_info->start_pos,
 642                  undostruct->wrap_info->end_pos,
 643                  UNDO_ACTION_REPLACE_INSERT,
 644                  undostruct);
 645
 646         g_free(old_contents);
 647         g_free(cur_contents);
 648         g_free(new_contents);
 649 cleanup:
 650         g_free(undostruct->wrap_info->pre_wrap_content);
 651         g_free(undostruct->wrap_info);
 652         undostruct->wrap_info = NULL;
 653 }
 654
 655 static void update_wrap_undo(UndoMain *undostruct, const gchar *text, int start,
 656                              int end, UndoAction action)
 657 {
 658         gint len = end - start;
 659
 660         /* If we don't yet have a start position, or farther than
 661          * current, store it.
 662          */
 663         if (undostruct->wrap_info->start_pos == -1
 664          || start < undostruct->wrap_info->start_pos) {
 665                 undostruct->wrap_info->start_pos = start;
 666         }
 667
 668         if (action == UNDO_ACTION_INSERT) {
 669                 /* If inserting, the end of the region is at the end of the
 670                  * change, and the total length of the changed region
 671                  * increases.
 672                  */
 673                 if (end > undostruct->wrap_info->end_pos) {
 674                         undostruct->wrap_info->end_pos = end;
 675                 }
 676                 undostruct->wrap_info->len_change += len;
 677         } else if (action == UNDO_ACTION_DELETE) {
 678                 /* If deleting, the end of the region is at the start of the
 679                  * change, and the total length of the changed region
 680                  * decreases.
 681                  */
 682                 if (start > undostruct->wrap_info->end_pos) {
 683                         undostruct->wrap_info->end_pos = start;
 684                 }
 685                 undostruct->wrap_info->len_change -= len;
 686         }
 687 }
 688
 689 /* Set wrapping mode, in which changes are agglomerated until
 690  * the end of wrapping mode.
 691  */
 692 void undo_wrapping(UndoMain *undostruct, gboolean wrap)
 693 {
 694         if (wrap) {
 695                 /* Start (or go deeper in) wrapping mode */
 696                 if (undostruct->wrap_info == NULL)
 697                         init_wrap_undo(undostruct);
 698                 undostruct->wrap_info->lock++;
 699         } else if (undostruct->wrap_info != NULL) {
 700                 /* exit (& possible stop) one level of wrapping mode */
 701                 undostruct->wrap_info->lock--;
 702                 if (undostruct->wrap_info->lock == 0)
 703                         end_wrap_undo(undostruct);
 704         } else {
 705                 g_warning("undo already out of wrap mode");
 706         }
 707 }
 708
 709 void undo_insert_text_cb(GtkTextBuffer *textbuf, GtkTextIter *iter,
 710                          gchar *new_text, gint new_text_length,
 711                          UndoMain *undostruct)
 712 {
 713         gchar *text_to_insert;
 714         gint pos;
 715         glong utf8_len;
 716
 717         if (prefs_common.undolevels <= 0) return;
 718
 719         pos = gtk_text_iter_get_offset(iter);
 720         Xstrndup_a(text_to_insert, new_text, new_text_length, return);
 721         utf8_len = g_utf8_strlen(text_to_insert, -1);
 722
 723         if (undostruct->wrap_info != NULL) {
 724                 update_wrap_undo(undostruct, text_to_insert,
 725                                  pos, pos + utf8_len, UNDO_ACTION_INSERT);
 726                 return;
 727         }
 728
 729         debug_print("add:undo add %d-%ld\n", pos, utf8_len);
 730         undo_add(text_to_insert, pos, pos + utf8_len,
 731                  UNDO_ACTION_INSERT, undostruct);
 732 }
 733
 734 void undo_delete_text_cb(GtkTextBuffer *textbuf, GtkTextIter *start,
 735                          GtkTextIter *end, UndoMain *undostruct)
 736 {
 737         gchar *text_to_delete;
 738         gint start_pos, end_pos;
 739
 740         if (prefs_common.undolevels <= 0) return;
 741
 742         text_to_delete = gtk_text_buffer_get_text(textbuf, start, end, FALSE);
 743         if (!text_to_delete || !*text_to_delete) return;
 744
 745         start_pos = gtk_text_iter_get_offset(start);
 746         end_pos   = gtk_text_iter_get_offset(end);
 747
 748         if (undostruct->wrap_info != NULL) {
 749                 update_wrap_undo(undostruct, text_to_delete, start_pos, end_pos, UNDO_ACTION_DELETE);
 750                 return;
 751         }
 752         debug_print("del:undo add %d-%d\n", start_pos, end_pos);
 753         undo_add(text_to_delete, start_pos, end_pos, UNDO_ACTION_DELETE,
 754                  undostruct);
 755         g_free(text_to_delete);
 756 }
 757
 758 void undo_paste_clipboard(GtkTextView *textview, UndoMain *undostruct)
 759 {
 760         undo_paste_clipboard_cb(textview, undostruct);
 761 }
 762
 763 static void undo_paste_clipboard_cb(GtkTextView *textview, UndoMain *undostruct)
 764 {
 765         if (prefs_common.undolevels > 0)
 766                 if (undo_get_selection(textview, NULL, NULL))
 767                         undostruct->paste = TRUE;
 768 }
 769
 770 /**
 771  * undo_get_selection:
 772  * @text: Text to get the selection from
 773  * @start: return here the start position of the selection
 774  * @end: return here the end position of the selection
 775  *
 776  * Gets the current selection for View
 777  *
 778  * Return Value: TRUE if there is a selection active, FALSE if not
 779  **/
 780 static gint undo_get_selection(GtkTextView *textview, guint *start, guint *end)
 781 {
 782         GtkTextBuffer *buffer;
 783         GtkTextIter start_iter, end_iter;
 784         guint start_pos, end_pos;
 785
 786         buffer = gtk_text_view_get_buffer(textview);
 787         gtk_text_buffer_get_selection_bounds(buffer, &start_iter, &end_iter);
 788
 789         start_pos = gtk_text_iter_get_offset(&start_iter);
 790         end_pos   = gtk_text_iter_get_offset(&end_iter);
 791
 792         /* The user can select from end to start too. If so, swap it*/
 793         if (end_pos < start_pos) {
 794                 guint swap_pos;
 795                 swap_pos  = end_pos;
 796                 end_pos   = start_pos;
 797                 start_pos = swap_pos;
 798         }
 799
 800         if (start != NULL)
 801                 *start = start_pos;
 802
 803         if (end != NULL)
 804                 *end = end_pos;
 805
 806         if ((start_pos > 0 || end_pos > 0) && (start_pos != end_pos))
 807                 return TRUE;
 808         else
 809                 return FALSE;
 810 }