1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584
|
/*******************************************************************************
* *
* textDrag.c - Text Dragging routines for NEdit text widget *
* *
* Copyright (C) 1999 Mark Edel *
* *
* This is free software; you can redistribute it and/or modify it under the *
* terms of the GNU General Public License as published by the Free Software *
* Foundation; either version 2 of the License, or (at your option) any later *
* version. In addition, you may distribute version of this program linked to *
* Motif or Open Motif. See README for details. *
* *
* This software is distributed in the hope that it will be useful, but WITHOUT *
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or *
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
* for more details. *
* *
* You should have received a copy of the GNU General Public License along with *
* software; if not, write to the Free Software Foundation, Inc., 59 Temple *
* Place, Suite 330, Boston, MA 02111-1307 USA *
* *
* Nirvana Text Editor *
* Dec. 15, 1995 *
* *
* Written by Mark Edel *
* *
*******************************************************************************/
#ifdef HAVE_CONFIG_H
#include "../config.h"
#endif
#include "textDrag.h"
#include "textBuf.h"
#include "textDisp.h"
#include "textP.h"
#include "../util/nedit_malloc.h"
#include <limits.h>
#include <X11/Intrinsic.h>
#include <X11/IntrinsicP.h>
#include <Xm/Xm.h>
#include <Xm/XmP.h>
#if XmVersion >= 1002
#include <Xm/PrimitiveP.h>
#endif
#ifdef HAVE_DEBUG_H
#include "../debug.h"
#endif
static void trackModifyRange(int *rangeStart, int *modRangeEnd,
int *unmodRangeEnd, int modPos, int nInserted, int nDeleted);
static void findTextMargins(textBuffer *buf, int start, int end, int *leftMargin,
int *rightMargin);
static int findRelativeLineStart(textBuffer *buf, int referencePos,
int referenceLineNum, int newLineNum);
static int min3(int i1, int i2, int i3);
static int max3(int i1, int i2, int i3);
static int max(int i1, int i2);
/*
** Start the process of dragging the current primary-selected text across
** the window (move by dragging, as opposed to dragging to create the
** selection)
*/
void BeginBlockDrag(TextWidget tw)
{
textDisp *textD = tw->text.textD;
textBuffer *buf = textD->buffer;
int fontHeight = textD->fontStruct->ascent + textD->fontStruct->descent;
int fontWidth = textD->fontStruct->max_bounds.width;
selection *sel = &buf->primary;
int nLines, mousePos, lineStart;
int x, y, lineEnd;
char *text;
/* Save a copy of the whole text buffer as a backup, and for
deriving changes */
tw->text.dragOrigBuf = BufCreate();
BufSetTabDistance(tw->text.dragOrigBuf, buf->tabDist);
tw->text.dragOrigBuf->useTabs = buf->useTabs;
text = BufGetAll(buf);
BufSetAll(tw->text.dragOrigBuf, text);
NEditFree(text);
if (sel->rectangular)
BufRectSelect(tw->text.dragOrigBuf, sel->start, sel->end, sel->rectStart,
sel->rectEnd);
else
BufSelect(tw->text.dragOrigBuf, sel->start, sel->end);
/* Record the mouse pointer offsets from the top left corner of the
selection (the position where text will actually be inserted In dragging
non-rectangular selections) */
if (sel->rectangular) {
tw->text.dragXOffset = tw->text.btnDownX + textD->horizOffset -
textD->left - sel->rectStart * fontWidth;
} else {
if (!TextDPositionToXY(textD, sel->start, &x, &y))
x = BufCountDispChars(buf, TextDStartOfLine(textD, sel->start),
sel->start) * fontWidth + textD->left -
textD->horizOffset;
tw->text.dragXOffset = tw->text.btnDownX - x;
}
mousePos = TextDXYToPosition(textD, tw->text.btnDownX, tw->text.btnDownY);
nLines = BufCountLines(buf, sel->start, mousePos);
tw->text.dragYOffset = nLines * fontHeight + (((tw->text.btnDownY -
tw->text.marginHeight) % fontHeight) - fontHeight/2);
tw->text.dragNLines = BufCountLines(buf, sel->start, sel->end);
/* Record the current drag insert position and the information for
undoing the fictional insert of the selection in its new position */
tw->text.dragInsertPos = sel->start;
tw->text.dragInserted = sel->end - sel->start;
if (sel->rectangular) {
textBuffer *testBuf = BufCreate();
char *testText = BufGetRange(buf, sel->start, sel->end);
BufSetTabDistance(testBuf, buf->tabDist);
testBuf->useTabs = buf->useTabs;
BufSetAll(testBuf, testText);
NEditFree(testText);
BufRemoveRect(testBuf, 0, sel->end - sel->start, sel->rectStart,
sel->rectEnd);
tw->text.dragDeleted = testBuf->length;
BufFree(testBuf);
tw->text.dragRectStart = sel->rectStart;
} else {
tw->text.dragDeleted = 0;
tw->text.dragRectStart = 0;
}
tw->text.dragType = DRAG_MOVE;
tw->text.dragSourceDeletePos = sel->start;
tw->text.dragSourceInserted = tw->text.dragDeleted;
tw->text.dragSourceDeleted = tw->text.dragInserted;
/* For non-rectangular selections, fill in the rectangular information in
the selection for overlay mode drags which are done rectangularly */
if (!sel->rectangular) {
lineStart = BufStartOfLine(buf, sel->start);
if (tw->text.dragNLines == 0) {
tw->text.dragOrigBuf->primary.rectStart =
BufCountDispChars(buf, lineStart, sel->start);
tw->text.dragOrigBuf->primary.rectEnd =
BufCountDispChars(buf, lineStart, sel->end);
} else {
lineEnd = BufGetCharacter(buf, sel->end - 1) == '\n' ?
sel->end - 1 : sel->end;
findTextMargins(buf, lineStart, lineEnd,
&tw->text.dragOrigBuf->primary.rectStart,
&tw->text.dragOrigBuf->primary.rectEnd);
}
}
/* Set the drag state to announce an ongoing block-drag */
tw->text.dragState = PRIMARY_BLOCK_DRAG;
/* Call the callback announcing the start of a block drag */
XtCallCallbacks((Widget)tw, textNdragStartCallback, (XtPointer)NULL);
}
/*
** Reposition the primary-selected text that is being dragged as a block
** for a new mouse position of (x, y)
*/
void BlockDragSelection(TextWidget tw, int x, int y, int dragType)
{
textDisp *textD = tw->text.textD;
textBuffer *buf = textD->buffer;
int fontHeight = textD->fontStruct->ascent + textD->fontStruct->descent;
int fontWidth = textD->fontStruct->max_bounds.width;
textBuffer *origBuf = tw->text.dragOrigBuf;
int dragXOffset = tw->text.dragXOffset;
textBuffer *tempBuf;
selection *origSel = &origBuf->primary;
int rectangular = origSel->rectangular;
int overlay, oldDragType = tw->text.dragType;
int nLines = tw->text.dragNLines;
int insLineNum, insLineStart, insRectStart, insRectEnd, insStart;
char *repText, *text, *insText;
int modRangeStart = -1, tempModRangeEnd = -1, bufModRangeEnd = -1;
int referenceLine, referencePos, tempStart, tempEnd, origSelLen;
int insertInserted, insertDeleted, row, column;
int origSelLineStart, origSelLineEnd;
int sourceInserted, sourceDeleted, sourceDeletePos;
if (tw->text.dragState != PRIMARY_BLOCK_DRAG)
return;
/* The operation of block dragging is simple in theory, but not so simple
in practice. There is a backup buffer (tw->text.dragOrigBuf) which
holds a copy of the buffer as it existed before the drag. When the
user drags the mouse to a new location, this routine is called, and
a temporary buffer is created and loaded with the local part of the
buffer (from the backup) which might be changed by the drag. The
changes are all made to this temporary buffer, and the parts of this
buffer which then differ from the real (displayed) buffer are used to
replace those parts, thus one replace operation serves as both undo
and modify. This double-buffering of the operation prevents excessive
redrawing (though there is still plenty of needless redrawing due to
re-selection and rectangular operations).
The hard part is keeping track of the changes such that a single replace
operation will do everyting. This is done using a routine called
trackModifyRange which tracks expanding ranges of changes in the two
buffers in modRangeStart, tempModRangeEnd, and bufModRangeEnd. */
/* Create a temporary buffer for accumulating changes which will
eventually be replaced in the real buffer. Load the buffer with the
range of characters which might be modified in this drag step
(this could be tighter, but hopefully it's not too slow) */
tempBuf = BufCreate();
tempBuf->tabDist = buf->tabDist;
tempBuf->useTabs = buf->useTabs;
tempStart = min3(tw->text.dragInsertPos, origSel->start,
BufCountBackwardNLines(buf, textD->firstChar, nLines+2));
tempEnd = BufCountForwardNLines(buf, max3(tw->text.dragInsertPos,
origSel->start, textD->lastChar), nLines+2) +
origSel->end - origSel->start;
text = BufGetRange(origBuf, tempStart, tempEnd);
BufSetAll(tempBuf, text);
NEditFree(text);
/* If the drag type is USE_LAST, use the last dragType applied */
if (dragType == USE_LAST)
dragType = tw->text.dragType;
overlay = dragType == DRAG_OVERLAY_MOVE || dragType == DRAG_OVERLAY_COPY;
/* Overlay mode uses rectangular selections whether or not the original
was rectangular. To use a plain selection as if it were rectangular,
the start and end positions need to be moved to the line boundaries
and trailing newlines must be excluded */
origSelLineStart = BufStartOfLine(origBuf, origSel->start);
if (!rectangular && BufGetCharacter(origBuf, origSel->end - 1) == '\n')
origSelLineEnd = origSel->end - 1;
else
origSelLineEnd = BufEndOfLine(origBuf, origSel->end);
if (!rectangular && overlay && nLines != 0)
dragXOffset -= fontWidth * (origSel->rectStart -
(origSel->start - origSelLineStart));
/* If the drag operation is of a different type than the last one, and the
operation is a move, expand the modified-range to include undoing the
text-removal at the site from which the text was dragged. */
if (dragType != oldDragType && tw->text.dragSourceDeleted != 0)
trackModifyRange(&modRangeStart, &bufModRangeEnd, &tempModRangeEnd,
tw->text.dragSourceDeletePos, tw->text.dragSourceInserted,
tw->text.dragSourceDeleted);
/* Do, or re-do the original text removal at the site where a move began.
If this part has not changed from the last call, do it silently to
bring the temporary buffer in sync with the real (displayed)
buffer. If it's being re-done, track the changes to complete the
redo operation begun above */
if (dragType == DRAG_MOVE || dragType == DRAG_OVERLAY_MOVE) {
if (rectangular || overlay) {
int prevLen = tempBuf->length;
origSelLen = origSelLineEnd - origSelLineStart;
if (overlay)
BufClearRect(tempBuf, origSelLineStart-tempStart,
origSelLineEnd-tempStart, origSel->rectStart,
origSel->rectEnd);
else
BufRemoveRect(tempBuf, origSelLineStart-tempStart,
origSelLineEnd-tempStart, origSel->rectStart,
origSel->rectEnd);
sourceDeletePos = origSelLineStart;
sourceInserted = origSelLen - prevLen + tempBuf->length;
sourceDeleted = origSelLen;
} else {
BufRemove(tempBuf, origSel->start - tempStart,
origSel->end - tempStart);
sourceDeletePos = origSel->start;
sourceInserted = 0;
sourceDeleted = origSel->end - origSel->start;
}
if (dragType != oldDragType)
trackModifyRange(&modRangeStart, &tempModRangeEnd, &bufModRangeEnd,
sourceDeletePos, sourceInserted, sourceDeleted);
} else {
sourceDeletePos = 0;
sourceInserted = 0;
sourceDeleted = 0;
}
/* Expand the modified-range to include undoing the insert from the last
call. */
trackModifyRange(&modRangeStart, &bufModRangeEnd, &tempModRangeEnd,
tw->text.dragInsertPos, tw->text.dragInserted, tw->text.dragDeleted);
/* Find the line number and column of the insert position. Note that in
continuous wrap mode, these must be calculated as if the text were
not wrapped */
TextDXYToUnconstrainedPosition(textD, max(0, x - dragXOffset),
max(0, y - (tw->text.dragYOffset % fontHeight)), &row, &column);
column = TextDOffsetWrappedColumn(textD, row, column);
row = TextDOffsetWrappedRow(textD, row);
insLineNum = row + textD->topLineNum - tw->text.dragYOffset / fontHeight;
/* find a common point of reference between the two buffers, from which
the insert position line number can be translated to a position */
if (textD->firstChar > modRangeStart) {
referenceLine = textD->topLineNum -
BufCountLines(buf, modRangeStart, textD->firstChar);
referencePos = modRangeStart;
} else {
referencePos = textD->firstChar;
referenceLine = textD->topLineNum;
}
/* find the position associated with the start of the new line in the
temporary buffer */
insLineStart = findRelativeLineStart(tempBuf, referencePos - tempStart,
referenceLine, insLineNum) + tempStart;
if (insLineStart - tempStart == tempBuf->length)
insLineStart = BufStartOfLine(tempBuf, insLineStart - tempStart) +
tempStart;
/* Find the actual insert position */
if (rectangular || overlay) {
insStart = insLineStart;
insRectStart = column;
} else { /* note, this will fail with proportional fonts */
insStart = BufCountForwardDispChars(tempBuf, insLineStart - tempStart,
column) + tempStart;
insRectStart = 0;
}
/* If the position is the same as last time, don't bother drawing (it
would be nice if this decision could be made earlier) */
if (insStart == tw->text.dragInsertPos &&
insRectStart == tw->text.dragRectStart && dragType == oldDragType) {
BufFree(tempBuf);
return;
}
/* Do the insert in the temporary buffer */
if (rectangular || overlay) {
insText = BufGetTextInRect(origBuf, origSelLineStart, origSelLineEnd,
origSel->rectStart, origSel->rectEnd);
if (overlay)
BufOverlayRect(tempBuf, insStart - tempStart, insRectStart,
insRectStart + origSel->rectEnd - origSel->rectStart,
insText, &insertInserted, &insertDeleted);
else
BufInsertCol(tempBuf, insRectStart, insStart - tempStart, insText,
&insertInserted, &insertDeleted);
trackModifyRange(&modRangeStart, &tempModRangeEnd, &bufModRangeEnd,
insStart, insertInserted, insertDeleted);
NEditFree(insText);
} else {
insText = BufGetSelectionText(origBuf);
BufInsert(tempBuf, insStart - tempStart, insText);
trackModifyRange(&modRangeStart, &tempModRangeEnd, &bufModRangeEnd,
insStart, origSel->end - origSel->start, 0);
insertInserted = origSel->end - origSel->start;
insertDeleted = 0;
NEditFree(insText);
}
/* Make the changes in the real buffer */
repText = BufGetRange(tempBuf, modRangeStart - tempStart,
tempModRangeEnd - tempStart);
BufFree(tempBuf);
TextDBlankCursor(textD);
BufReplace(buf, modRangeStart, bufModRangeEnd, repText);
NEditFree(repText);
/* Store the necessary information for undoing this step */
tw->text.dragInsertPos = insStart;
tw->text.dragRectStart = insRectStart;
tw->text.dragInserted = insertInserted;
tw->text.dragDeleted = insertDeleted;
tw->text.dragSourceDeletePos = sourceDeletePos;
tw->text.dragSourceInserted = sourceInserted;
tw->text.dragSourceDeleted = sourceDeleted;
tw->text.dragType = dragType;
/* Reset the selection and cursor position */
if (rectangular || overlay) {
insRectEnd = insRectStart + origSel->rectEnd - origSel->rectStart;
BufRectSelect(buf, insStart, insStart + insertInserted, insRectStart,
insRectEnd);
TextDSetInsertPosition(textD, BufCountForwardDispChars(buf,
BufCountForwardNLines(buf, insStart, tw->text.dragNLines),
insRectEnd));
} else {
BufSelect(buf, insStart, insStart + origSel->end - origSel->start);
TextDSetInsertPosition(textD, insStart + origSel->end - origSel->start);
}
TextDUnblankCursor(textD);
XtCallCallbacks((Widget)tw, textNcursorMovementCallback, (XtPointer)NULL);
tw->text.emTabsBeforeCursor = 0;
}
/*
** Complete a block text drag operation
*/
void FinishBlockDrag(TextWidget tw)
{
dragEndCBStruct endStruct;
int modRangeStart = -1, origModRangeEnd, bufModRangeEnd;
char *deletedText;
/* Find the changed region of the buffer, covering both the deletion
of the selected text at the drag start position, and insertion at
the drag destination */
trackModifyRange(&modRangeStart, &bufModRangeEnd, &origModRangeEnd,
tw->text.dragSourceDeletePos, tw->text.dragSourceInserted,
tw->text.dragSourceDeleted);
trackModifyRange(&modRangeStart, &bufModRangeEnd, &origModRangeEnd,
tw->text.dragInsertPos, tw->text.dragInserted,
tw->text.dragDeleted);
/* Get the original (pre-modified) range of text from saved backup buffer */
deletedText = BufGetRange(tw->text.dragOrigBuf, modRangeStart,
origModRangeEnd);
/* Free the backup buffer */
BufFree(tw->text.dragOrigBuf);
/* Return to normal drag state */
tw->text.dragState = NOT_CLICKED;
/* Call finish-drag calback */
endStruct.startPos = modRangeStart;
endStruct.nCharsDeleted = origModRangeEnd - modRangeStart;
endStruct.nCharsInserted = bufModRangeEnd - modRangeStart;
endStruct.deletedText = deletedText;
XtCallCallbacks((Widget)tw, textNdragEndCallback, (XtPointer)&endStruct);
NEditFree(deletedText);
}
/*
** Cancel a block drag operation
*/
void CancelBlockDrag(TextWidget tw)
{
textBuffer *buf = tw->text.textD->buffer;
textBuffer *origBuf = tw->text.dragOrigBuf;
selection *origSel = &origBuf->primary;
int modRangeStart = -1, origModRangeEnd, bufModRangeEnd;
char *repText;
dragEndCBStruct endStruct;
/* If the operation was a move, make the modify range reflect the
removal of the text from the starting position */
if (tw->text.dragSourceDeleted != 0)
trackModifyRange(&modRangeStart, &bufModRangeEnd, &origModRangeEnd,
tw->text.dragSourceDeletePos, tw->text.dragSourceInserted,
tw->text.dragSourceDeleted);
/* Include the insert being undone from the last step in the modified
range. */
trackModifyRange(&modRangeStart, &bufModRangeEnd, &origModRangeEnd,
tw->text.dragInsertPos, tw->text.dragInserted, tw->text.dragDeleted);
/* Make the changes in the buffer */
repText = BufGetRange(origBuf, modRangeStart, origModRangeEnd);
BufReplace(buf, modRangeStart, bufModRangeEnd, repText);
NEditFree(repText);
/* Reset the selection and cursor position */
if (origSel->rectangular)
BufRectSelect(buf, origSel->start, origSel->end, origSel->rectStart,
origSel->rectEnd);
else
BufSelect(buf, origSel->start, origSel->end);
TextDSetInsertPosition(tw->text.textD, buf->cursorPosHint);
XtCallCallbacks((Widget)tw, textNcursorMovementCallback, NULL);
tw->text.emTabsBeforeCursor = 0;
/* Free the backup buffer */
BufFree(origBuf);
/* Indicate end of drag */
tw->text.dragState = DRAG_CANCELED;
/* Call finish-drag calback */
endStruct.startPos = 0;
endStruct.nCharsDeleted = 0;
endStruct.nCharsInserted = 0;
endStruct.deletedText = NULL;
XtCallCallbacks((Widget)tw, textNdragEndCallback, (XtPointer)&endStruct);
}
/*
** Maintain boundaries of changed region between two buffers which
** start out with identical contents, but diverge through insertion,
** deletion, and replacement, such that the buffers can be reconciled
** by replacing the changed region of either buffer with the changed
** region of the other.
**
** rangeStart is the beginning of the modification region in the shared
** coordinates of both buffers (which are identical up to rangeStart).
** modRangeEnd is the end of the changed region for the buffer being
** modified, unmodRangeEnd is the end of the region for the buffer NOT
** being modified. A value of -1 in rangeStart indicates that there
** have been no modifications so far.
*/
static void trackModifyRange(int *rangeStart, int *modRangeEnd,
int *unmodRangeEnd, int modPos, int nInserted, int nDeleted)
{
if (*rangeStart == -1) {
*rangeStart = modPos;
*modRangeEnd = modPos + nInserted;
*unmodRangeEnd = modPos + nDeleted;
} else {
if (modPos < *rangeStart)
*rangeStart = modPos;
if (modPos + nDeleted > *modRangeEnd) {
*unmodRangeEnd += modPos + nDeleted - *modRangeEnd;
*modRangeEnd = modPos + nInserted;
} else
*modRangeEnd += nInserted - nDeleted;
}
}
/*
** Find the left and right margins of text between "start" and "end" in
** buffer "buf". Note that "start is assumed to be at the start of a line.
*/
static void findTextMargins(textBuffer *buf, int start, int end, int *leftMargin,
int *rightMargin)
{
char c;
int pos, width = 0, maxWidth = 0, minWhite = INT_MAX, inWhite = True;
for (pos=start; pos<end; pos++) {
c = BufGetCharacter(buf, pos);
if (inWhite && c != ' ' && c != '\t') {
inWhite = False;
if (width < minWhite)
minWhite = width;
}
if (c == '\n') {
if (width > maxWidth)
maxWidth = width;
width = 0;
inWhite = True;
} else
width += BufCharWidth(c, width, buf->tabDist, buf->nullSubsChar);
}
if (width > maxWidth)
maxWidth = width;
*leftMargin = minWhite == INT_MAX ? 0 : minWhite;
*rightMargin = maxWidth;
}
/*
** Find a text position in buffer "buf" by counting forward or backward
** from a reference position with known line number
*/
static int findRelativeLineStart(textBuffer *buf, int referencePos,
int referenceLineNum, int newLineNum)
{
if (newLineNum < referenceLineNum)
return BufCountBackwardNLines(buf, referencePos,
referenceLineNum - newLineNum);
else if (newLineNum > referenceLineNum)
return BufCountForwardNLines(buf, referencePos,
newLineNum - referenceLineNum);
return BufStartOfLine(buf, referencePos);
}
static int min3(int i1, int i2, int i3)
{
if (i1 <= i2 && i1 <= i3)
return i1;
return i2 <= i3 ? i2 : i3;
}
static int max3(int i1, int i2, int i3)
{
if (i1 >= i2 && i1 >= i3)
return i1;
return i2 >= i3 ? i2 : i3;
}
static int max(int i1, int i2)
{
return i1 >= i2 ? i1 : i2;
}
|