src/undo.c

   1 /*
   2  * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
   3  * Copyright (C) 1999-2001 Hiroyuki Yamamoto
   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 2 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, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18  */
  19
  20 /* code ported from gedit */
  21 /* This is for my patient girlfirend Regina */
  22
  23 #ifdef HAVE_CONFIG_H
  24 #  include "config.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 #include "gtkstext.h"
  36
  37 typedef struct _UndoInfo UndoInfo;
  38
  39 struct _UndoInfo
  40 {
  41         UndoAction action;
  42         gchar *text;
  43         gint start_pos;
  44         gint end_pos;
  45         gfloat window_position;
  46         gint mergeable;
  47 };
  48
  49 static void undo_free_list      (GList         **list_pointer);
  50 static void undo_check_size     (UndoMain       *undostruct);
  51 static gint undo_merge          (GList          *list,
  52                                  guint           start_pos,
  53                                  guint           end_pos,
  54                                  gint            action,
  55                                  const guchar   *text);
  56 static void undo_add            (const gchar    *text,
  57                                  gint            start_pos,
  58                                  gint            end_pos,
  59                                  UndoAction      action,
  60                                  UndoMain       *undostruct);
  61 static gint undo_get_selection  (GtkEditable    *text,
  62                                  guint          *start,
  63                                  guint          *end);
  64 static void undo_insert_text_cb (GtkEditable    *editable,
  65                                  gchar          *new_text,
  66                                  gint            new_text_length,
  67                                  gint           *position,
  68                                  UndoMain       *undostruct);
  69 static void undo_delete_text_cb (GtkEditable    *editable,
  70                                  gint            start_pos,
  71                                  gint            end_pos,
  72                                  UndoMain       *undostruct);
  73
  74 static void undo_paste_clipboard_cb     (GtkEditable    *editable,
  75                                          UndoMain       *undostruct);
  76
  77 void undo_undo                  (UndoMain       *undostruct);
  78 void undo_redo                  (UndoMain       *undostruct);
  79
  80
  81 UndoMain *undo_init(GtkWidget *text)
  82 {
  83         UndoMain *undostruct;
  84
  85         g_return_val_if_fail(text != NULL, NULL);
  86
  87         undostruct = g_new(UndoMain, 1);
  88         undostruct->text = text;
  89         undostruct->undo = NULL;
  90         undostruct->redo = NULL;
  91         undostruct->paste = 0;
  92         undostruct->undo_state = FALSE;
  93         undostruct->redo_state = FALSE;
  94
  95         gtk_signal_connect(GTK_OBJECT(text), "insert-text",
  96                            GTK_SIGNAL_FUNC(undo_insert_text_cb), undostruct);
  97         gtk_signal_connect(GTK_OBJECT(text), "delete-text",
  98                            GTK_SIGNAL_FUNC(undo_delete_text_cb), undostruct);
  99         gtk_signal_connect(GTK_OBJECT(text), "paste-clipboard",
 100                            GTK_SIGNAL_FUNC(undo_paste_clipboard_cb), undostruct);
 101
 102         return undostruct;
 103 }
 104
 105 void undo_destroy (UndoMain *undostruct)
 106 {
 107         undo_free_list(&undostruct->undo);
 108         undo_free_list(&undostruct->redo);
 109         g_free(undostruct);
 110 }
 111
 112 static UndoInfo *undo_object_new(gchar *text, gint start_pos, gint end_pos,
 113                                  UndoAction action, gfloat window_position)
 114 {
 115         UndoInfo *undoinfo;
 116         undoinfo = g_new (UndoInfo, 1);
 117         undoinfo->text      = text;
 118         undoinfo->start_pos = start_pos;
 119         undoinfo->end_pos   = end_pos;
 120         undoinfo->action    = action;
 121         undoinfo->window_position = window_position;
 122         return undoinfo;
 123 }
 124
 125 static void undo_object_free(UndoInfo *undo)
 126 {
 127         g_free (undo->text);
 128         g_free (undo);
 129 }
 130
 131 /**
 132  * undo_free_list:
 133  * @list_pointer: list to be freed
 134  *
 135  * frees and undo structure list
 136  **/
 137 static void undo_free_list(GList **list_pointer)
 138 {
 139         UndoInfo *undo;
 140         GList *cur, *list = *list_pointer;
 141
 142         if (list == NULL) return;
 143
 144         for (cur = list; cur != NULL; cur = cur->next) {
 145                 undo = (UndoInfo *)cur->data;
 146                 undo_object_free(undo);
 147         }
 148
 149         g_list_free(list);
 150         *list_pointer = NULL;
 151 }
 152
 153 void undo_set_change_state_func(UndoMain *undostruct, UndoChangeStateFunc func,
 154                                 gpointer data)
 155 {
 156         g_return_if_fail(undostruct != NULL);
 157
 158         undostruct->change_state_func = func;
 159         undostruct->change_state_data = data;
 160 }
 161
 162 /**
 163  * undo_check_size:
 164  * @compose: document to check
 165  *
 166  * Checks that the size of compose->undo does not excede settings->undo_levels and
 167  * frees any undo level above sett->undo_level.
 168  *
 169  **/
 170 static void undo_check_size(UndoMain *undostruct)
 171 {
 172         UndoInfo *last_undo;
 173         guint length;
 174
 175         if (prefs_common.undolevels < 1) return;
 176
 177         /* No need to check for the redo list size since the undo
 178            list gets freed on any call to compose_undo_add */
 179         length = g_list_length(undostruct->undo);
 180         if (length >= prefs_common.undolevels && prefs_common.undolevels > 0) {
 181                 last_undo = (UndoInfo *)g_list_last(undostruct->undo)->data;
 182                 undostruct->undo = g_list_remove(undostruct->undo, last_undo);
 183                 undo_object_free(last_undo);
 184         }
 185         debug_print("g_list_length(undostruct->undo): %d\n", length);
 186 }
 187
 188 /**
 189  * undo_merge:
 190  * @last_undo:
 191  * @start_pos:
 192  * @end_pos:
 193  * @action:
 194  *
 195  * This function tries to merge the undo object at the top of
 196  * the stack with a new set of data. So when we undo for example
 197  * typing, we can undo the whole word and not each letter by itself
 198  *
 199  * Return Value: TRUE is merge was sucessful, FALSE otherwise
 200  **/
 201 static gint undo_merge(GList *list, guint start_pos, guint end_pos,
 202                        gint action, const guchar *text)
 203 {
 204         guchar *temp_string;
 205         UndoInfo *last_undo;
 206
 207         /* This are the cases in which we will NOT merge :
 208            1. if (last_undo->mergeable == FALSE)
 209            [mergeable = FALSE when the size of the undo data was not 1.
 210            or if the data was size = 1 but = '\n' or if the undo object
 211            has been "undone" already ]
 212            2. The size of text is not 1
 213            3. If the new merging data is a '\n'
 214            4. If the last char of the undo_last data is a space/tab
 215            and the new char is not a space/tab ( so that we undo
 216            words and not chars )
 217            5. If the type (action) of undo is different from the last one
 218            Chema */
 219
 220         if (list == NULL) return FALSE;
 221
 222         last_undo = list->data;
 223
 224         if (!last_undo->mergeable) return FALSE;
 225
 226         if (end_pos - start_pos != 1 ||
 227             text[0] == '\n' ||
 228             action != last_undo->action ||
 229             action == UNDO_ACTION_REPLACE_INSERT ||
 230             action == UNDO_ACTION_REPLACE_DELETE) {
 231                 last_undo->mergeable = FALSE;
 232                 return FALSE;
 233         }
 234
 235         if (action == UNDO_ACTION_DELETE) {
 236                 gboolean checkit = TRUE;
 237
 238                 if (last_undo->start_pos != end_pos &&
 239                     last_undo->start_pos != start_pos) {
 240                         last_undo->mergeable = FALSE;
 241                         return FALSE;
 242                 } else if (last_undo->start_pos == start_pos) {
 243                         /* Deleted with the delete key */
 244                         if (text[0] != ' ' && text[0] != '\t' &&
 245                             (last_undo->text[last_undo->end_pos - last_undo->start_pos - 1] == ' ' ||
 246                              last_undo->text[last_undo->end_pos - last_undo->start_pos - 1] == '\t'))
 247                                 checkit = FALSE;
 248
 249                         temp_string = g_strdup_printf("%s%s", last_undo->text, text);
 250                         last_undo->end_pos++;
 251                         g_free(last_undo->text);
 252                         last_undo->text = temp_string;
 253                 } else {
 254                         /* Deleted with the backspace key */
 255                         if (text[0] != ' ' && text[0] != '\t' &&
 256                             (last_undo->text[0] == ' ' ||
 257                              last_undo->text[0] == '\t'))
 258                                 checkit = FALSE;
 259
 260                         temp_string = g_strdup_printf("%s%s", text, last_undo->text);
 261                         last_undo->start_pos = start_pos;
 262                         g_free(last_undo->text);
 263                         last_undo->text = temp_string;
 264                 }
 265
 266                 if (!checkit) {
 267                         last_undo->mergeable = FALSE;
 268                         return FALSE;
 269                 }
 270         } else if (action == UNDO_ACTION_INSERT) {
 271                 if (last_undo->end_pos != start_pos) {
 272                         last_undo->mergeable = FALSE;
 273                         return FALSE;
 274                 } else {
 275                         temp_string = g_strdup_printf("%s%s", last_undo->text, text);
 276                         g_free(last_undo->text);
 277                         last_undo->end_pos = end_pos;
 278                         last_undo->text = temp_string;
 279                 }
 280         } else
 281                 debug_print("Unknown action [%i] inside undo merge encountered", action);
 282
 283         debug_print("Merged: %s\n", text);
 284         return TRUE;
 285 }
 286
 287 /**
 288  * compose_undo_add:
 289  * @text:
 290  * @start_pos:
 291  * @end_pos:
 292  * @action: either UNDO_ACTION_INSERT or UNDO_ACTION_DELETE
 293  * @compose:
 294  * @view: The view so that we save the scroll bar position.
 295  *
 296  * Adds text to the undo stack. It also performs test to limit the number
 297  * of undo levels and deltes the redo list
 298  **/
 299
 300 static void undo_add(const gchar *text,
 301                      gint start_pos, gint end_pos,
 302                      UndoAction action, UndoMain *undostruct)
 303 {
 304         UndoInfo *undoinfo;
 305
 306         debug_print("undo_add(%i)*%s*\n", strlen (text), text);
 307
 308         g_return_if_fail(text != NULL);
 309         g_return_if_fail(end_pos >= start_pos);
 310
 311         undo_free_list(&undostruct->redo);
 312
 313         /* Set the redo sensitivity */
 314         undostruct->change_state_func(undostruct,
 315                                       UNDO_STATE_UNCHANGED, UNDO_STATE_FALSE,
 316                                       undostruct->change_state_data);
 317
 318         if (undostruct->paste != 0) {
 319                 if (action == UNDO_ACTION_INSERT)
 320                         action = UNDO_ACTION_REPLACE_INSERT;
 321                 else
 322                         action = UNDO_ACTION_REPLACE_DELETE;
 323                 undostruct->paste = undostruct->paste + 1;
 324                 if (undostruct->paste == 3)
 325                         undostruct->paste = 0;
 326         }
 327
 328         if (undo_merge(undostruct->undo, start_pos, end_pos, action, text))
 329                 return;
 330
 331         undo_check_size(undostruct);
 332
 333         debug_print("New: %s Action: %d Paste: %d\n", text, action, undostruct->paste);
 334
 335         undoinfo = undo_object_new(g_strdup(text), start_pos, end_pos, action,
 336                                    GTK_ADJUSTMENT(GTK_STEXT(undostruct->text)->vadj)->value);
 337
 338         if (end_pos - start_pos != 1 || text[0] == '\n')
 339                 undoinfo->mergeable = FALSE;
 340         else
 341                 undoinfo->mergeable = TRUE;
 342
 343         undostruct->undo = g_list_prepend(undostruct->undo, undoinfo);
 344
 345         undostruct->change_state_func(undostruct,
 346                                       UNDO_STATE_TRUE, UNDO_STATE_UNCHANGED,
 347                                       undostruct->change_state_data);
 348 }
 349
 350 /**
 351  * undo_undo:
 352  * @w: not used
 353  * @data: not used
 354  *
 355  * Executes an undo request on the current document
 356  **/
 357 void undo_undo(UndoMain *undostruct)
 358 {
 359         UndoInfo *undoinfo;
 360         guint start_pos, end_pos;
 361
 362         g_return_if_fail(undostruct != NULL);
 363
 364         if (undostruct->undo == NULL) return;
 365
 366         /* The undo data we need is always at the top op the
 367            stack. So, therefore, the first one */
 368         undoinfo = (UndoInfo *)undostruct->undo->data;
 369         g_return_if_fail(undoinfo != NULL);
 370         undoinfo->mergeable = FALSE;
 371         undostruct->redo = g_list_prepend(undostruct->redo, undoinfo);
 372         undostruct->undo = g_list_remove(undostruct->undo, undoinfo);
 373
 374         /* Check if there is a selection active */
 375         start_pos = GTK_EDITABLE(undostruct->text)->selection_start_pos;
 376         end_pos   = GTK_EDITABLE(undostruct->text)->selection_end_pos;
 377         if ((start_pos > 0 || end_pos > 0) && (start_pos != end_pos))
 378                 gtk_editable_select_region(GTK_EDITABLE(undostruct->text),
 379                                            0, 0);
 380
 381         /* Move the view (scrollbars) to the correct position */
 382         gtk_adjustment_set_value
 383                 (GTK_ADJUSTMENT(GTK_STEXT(undostruct->text)->vadj),
 384                  undoinfo->window_position);
 385
 386         switch (undoinfo->action) {
 387         case UNDO_ACTION_DELETE:
 388                 gtk_stext_set_point(GTK_STEXT(undostruct->text), undoinfo->start_pos);
 389                 gtk_stext_insert(GTK_STEXT(undostruct->text), NULL, NULL, NULL, undoinfo->text, -1);
 390                 debug_print("UNDO_ACTION_DELETE %s\n", undoinfo->text);
 391                 break;
 392         case UNDO_ACTION_INSERT:
 393                 gtk_stext_set_point(GTK_STEXT(undostruct->text), undoinfo->end_pos);
 394                 gtk_stext_backward_delete(GTK_STEXT(undostruct->text), undoinfo->end_pos-undoinfo->start_pos);
 395                 debug_print("UNDO_ACTION_INSERT %d\n", undoinfo->end_pos-undoinfo->start_pos);
 396                 break;
 397         case UNDO_ACTION_REPLACE_INSERT:
 398                 gtk_stext_set_point(GTK_STEXT(undostruct->text), undoinfo->end_pos);
 399                 gtk_stext_backward_delete(GTK_STEXT(undostruct->text), undoinfo->end_pos-undoinfo->start_pos);
 400                 debug_print("UNDO_ACTION_REPLACE %s\n", undoinfo->text);
 401                 /* "pull" another data structure from the list */
 402                 undoinfo = (UndoInfo *)undostruct->undo->data;
 403                 g_return_if_fail(undoinfo != NULL);
 404                 undostruct->redo = g_list_prepend(undostruct->redo, undoinfo);
 405                 undostruct->undo = g_list_remove(undostruct->undo, undoinfo);
 406                 g_return_if_fail(undoinfo->action == UNDO_ACTION_REPLACE_DELETE);
 407                 gtk_stext_set_point(GTK_STEXT(undostruct->text), undoinfo->start_pos);
 408                 gtk_stext_insert(GTK_STEXT(undostruct->text), NULL, NULL, NULL, undoinfo->text, -1);
 409                 debug_print("UNDO_ACTION_REPLACE %s\n", undoinfo->text);
 410                 break;
 411         case UNDO_ACTION_REPLACE_DELETE:
 412                 g_warning("This should not happen. UNDO_REPLACE_DELETE");
 413                 break;
 414         default:
 415                 g_assert_not_reached();
 416                 break;
 417         }
 418
 419         undostruct->change_state_func(undostruct,
 420                                       UNDO_STATE_UNCHANGED, UNDO_STATE_TRUE,
 421                                       undostruct->change_state_data);
 422
 423         if (undostruct->undo == NULL)
 424                 undostruct->change_state_func(undostruct,
 425                                               UNDO_STATE_FALSE,
 426                                               UNDO_STATE_UNCHANGED,
 427                                               undostruct->change_state_data);
 428 }
 429
 430 /**
 431  * undo_redo:
 432  * @w: not used
 433  * @data: not used
 434  *
 435  * executes a redo request on the current document
 436  **/
 437 void undo_redo(UndoMain *undostruct)
 438 {
 439         UndoInfo *redoinfo;
 440         guint start_pos, end_pos;
 441
 442         g_return_if_fail(undostruct != NULL);
 443
 444         if (undostruct->redo == NULL) return;
 445
 446         redoinfo = (UndoInfo *)undostruct->redo->data;
 447         g_return_if_fail (redoinfo != NULL);
 448         undostruct->undo = g_list_prepend(undostruct->undo, redoinfo);
 449         undostruct->redo = g_list_remove(undostruct->redo, redoinfo);
 450
 451         /* Check if there is a selection active */
 452         start_pos = GTK_EDITABLE(undostruct->text)->selection_start_pos;
 453         end_pos   = GTK_EDITABLE(undostruct->text)->selection_end_pos;
 454         if ((start_pos > 0 || end_pos > 0) && (start_pos != end_pos))
 455                 gtk_editable_select_region(GTK_EDITABLE(undostruct->text), 0, 0);
 456
 457         /* Move the view to the right position. */
 458         gtk_adjustment_set_value(GTK_ADJUSTMENT(GTK_STEXT(undostruct->text)->vadj),
 459                                  redoinfo->window_position);
 460
 461         switch (redoinfo->action) {
 462         case UNDO_ACTION_INSERT:
 463                 gtk_stext_set_point(GTK_STEXT(undostruct->text),
 464                                    redoinfo->start_pos);
 465                 gtk_stext_insert(GTK_STEXT(undostruct->text), NULL, NULL,
 466                                 NULL, redoinfo->text, -1);
 467                 debug_print("UNDO_ACTION_DELETE %s\n",redoinfo->text);
 468                 break;
 469         case UNDO_ACTION_DELETE:
 470                 gtk_stext_set_point(GTK_STEXT(undostruct->text),
 471                                    redoinfo->end_pos);
 472                 gtk_stext_backward_delete
 473                         (GTK_STEXT(undostruct->text),
 474                          redoinfo->end_pos - redoinfo->start_pos);
 475                 debug_print("UNDO_ACTION_INSERT %d\n",
 476                             redoinfo->end_pos-redoinfo->start_pos);
 477                 break;
 478         case UNDO_ACTION_REPLACE_DELETE:
 479                 gtk_stext_set_point(GTK_STEXT(undostruct->text),
 480                                    redoinfo->end_pos);
 481                 gtk_stext_backward_delete
 482                         (GTK_STEXT(undostruct->text),
 483                          redoinfo->end_pos - redoinfo->start_pos);
 484                 /* "pull" another data structure from the list */
 485                 redoinfo = (UndoInfo *)undostruct->redo->data;
 486                 g_return_if_fail(redoinfo != NULL);
 487                 undostruct->undo = g_list_prepend(undostruct->undo, redoinfo);
 488                 undostruct->redo = g_list_remove(undostruct->redo, redoinfo);
 489                 g_return_if_fail(redoinfo->action == UNDO_ACTION_REPLACE_INSERT);
 490                 gtk_stext_set_point(GTK_STEXT(undostruct->text),
 491                                    redoinfo->start_pos);
 492                 gtk_stext_insert(GTK_STEXT(undostruct->text), NULL, NULL,
 493                                 NULL, redoinfo->text, -1);
 494                 break;
 495         case UNDO_ACTION_REPLACE_INSERT:
 496                 g_warning("This should not happen. Redo: UNDO_REPLACE_INSERT");
 497                 break;
 498         default:
 499                 g_assert_not_reached();
 500                 break;
 501         }
 502
 503         undostruct->change_state_func(undostruct,
 504                                       UNDO_STATE_TRUE, UNDO_STATE_UNCHANGED,
 505                                       undostruct->change_state_data);
 506
 507         if (undostruct->redo == NULL)
 508                 undostruct->change_state_func(undostruct,
 509                                               UNDO_STATE_UNCHANGED,
 510                                               UNDO_STATE_FALSE,
 511                                               undostruct->change_state_data);
 512 }
 513
 514 void undo_insert_text_cb(GtkEditable *editable, gchar *new_text,
 515                          gint new_text_length, gint *position,
 516                          UndoMain *undostruct)
 517 {
 518         gchar *text_to_insert;
 519         size_t wlen;
 520
 521         if (prefs_common.undolevels <= 0) return;
 522
 523         Xstrndup_a(text_to_insert, new_text, new_text_length, return);
 524         if (MB_CUR_MAX > 1) {
 525                 wchar_t *wstr;
 526
 527                 wstr = g_new(wchar_t, new_text_length + 1);
 528                 wlen = mbstowcs(wstr, text_to_insert, new_text_length + 1);
 529                 g_free(wstr);
 530                 if (wlen < 0) return;
 531         } else
 532                 wlen = new_text_length;
 533
 534         undo_add(text_to_insert, *position, *position + wlen,
 535                  UNDO_ACTION_INSERT, undostruct);
 536 }
 537
 538 void undo_delete_text_cb(GtkEditable *editable, gint start_pos,
 539                          gint end_pos, UndoMain *undostruct)
 540 {
 541         gchar *text_to_delete;
 542
 543         if (prefs_common.undolevels <= 0) return;
 544         if (start_pos == end_pos) return;
 545
 546         text_to_delete = gtk_editable_get_chars(GTK_EDITABLE(editable),
 547                                                 start_pos, end_pos);
 548         undo_add(text_to_delete, start_pos, end_pos, UNDO_ACTION_DELETE,
 549                  undostruct);
 550         g_free(text_to_delete);
 551 }
 552
 553 void undo_paste_clipboard_cb(GtkEditable *editable, UndoMain *undostruct)
 554 {
 555         if (editable->clipboard_text == NULL) return;
 556
 557         debug_print("before Paste: %d\n", undostruct->paste);
 558         if (prefs_common.undolevels > 0)
 559                 if (undo_get_selection(editable, NULL, NULL))
 560                         undostruct->paste = TRUE;
 561         debug_print("after Paste: %d\n", undostruct->paste);
 562 }
 563
 564 /**
 565  * undo_get_selection:
 566  * @text: Text to get the selection from
 567  * @start: return here the start position of the selection
 568  * @end: return here the end position of the selection
 569  *
 570  * Gets the current selection for View
 571  *
 572  * Return Value: TRUE if there is a selection active, FALSE if not
 573  **/
 574 static gint undo_get_selection(GtkEditable *text, guint *start, guint *end)
 575 {
 576         guint start_pos, end_pos;
 577
 578         start_pos = text->selection_start_pos;
 579         end_pos   = text->selection_end_pos;
 580
 581         /* The user can select from end to start too. If so, swap it*/
 582         if (end_pos < start_pos) {
 583                 guint swap_pos;
 584                 swap_pos  = end_pos;
 585                 end_pos   = start_pos;
 586                 start_pos = swap_pos;
 587         }
 588
 589         if (start != NULL)
 590                 *start = start_pos;
 591
 592         if (end != NULL)
 593                 *end = end_pos;
 594
 595         if ((start_pos > 0 || end_pos > 0) && (start_pos != end_pos))
 596                 return TRUE;
 597         else
 598                 return FALSE;
 599 }