dlls/riched20/wrap.c

   1 /*
   2  * RichEdit - Paragraph wrapping. Don't try to understand it. You've been
   3  * warned !
   4  *
   5  * Copyright 2004 by Krzysztof Foltman
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  20  */
  21
  22
  23 #include "editor.h"
  24
  25 WINE_DEFAULT_DEBUG_CHANNEL(richedit);
  26
  27 /*
  28  * Unsolved problems:
  29  *
  30  * - center and right align in WordPad omits all spaces at the start, we don't
  31  * - objects/images are not handled yet
  32  * - no tabs
  33  */
  34
  35 static ME_DisplayItem *ME_MakeRow(int height, int baseline, int width)
  36 {
  37   ME_DisplayItem *item = ME_MakeDI(diStartRow);
  38
  39   item->member.row.nHeight = height;
  40   item->member.row.nBaseline = baseline;
  41   item->member.row.nWidth = width;
  42   return item;
  43 }
  44
  45 static void ME_BeginRow(ME_WrapContext *wc)
  46 {
  47   wc->pRowStart = NULL;
  48   wc->bOverflown = FALSE;
  49   wc->pLastSplittableRun = NULL;
  50   if (wc->context->editor->bWordWrap)
  51     wc->nAvailWidth = wc->context->rcView.right - wc->context->rcView.left -
  52         (wc->nRow ? wc->nLeftMargin : wc->nFirstMargin) - wc->nRightMargin;
  53   else
  54     wc->nAvailWidth = ~0u >> 1;
  55   wc->pt.x = 0;
  56 }
  57
  58 static void ME_InsertRowStart(ME_WrapContext *wc, const ME_DisplayItem *pEnd)
  59 {
  60   ME_DisplayItem *p, *row, *para;
  61   BOOL bSkippingSpaces = TRUE;
  62   int ascent = 0, descent = 0, width=0, shift = 0, align = 0;
  63   /* wrap text */
  64   para = ME_GetParagraph(wc->pRowStart);
  65
  66   for (p = pEnd->prev; p!=wc->pRowStart->prev; p = p->prev)
  67   {
  68       /* ENDPARA run shouldn't affect row height, except if it's the only run in the paragraph */
  69       if (p->type==diRun && ((p==wc->pRowStart) || !(p->member.run.nFlags & MERF_ENDPARA))) { /* FIXME add more run types */
  70         if (p->member.run.nAscent>ascent)
  71           ascent = p->member.run.nAscent;
  72         if (p->member.run.nDescent>descent)
  73           descent = p->member.run.nDescent;
  74         if (bSkippingSpaces)
  75         {
  76           /* Exclude space characters from run width.
  77            * Other whitespace or delimiters are not treated this way. */
  78           SIZE sz;
  79           int len = p->member.run.strText->nLen;
  80           WCHAR *text = p->member.run.strText->szData + len - 1;
  81
  82           assert (len);
  83           while (len && *(text--) == ' ')
  84               len--;
  85           if (len)
  86           {
  87               if (len == p->member.run.strText->nLen)
  88               {
  89                   width += p->member.run.nWidth;
  90               } else {
  91                   sz = ME_GetRunSize(wc->context, &para->member.para,
  92                                      &p->member.run, len, p->member.run.pt.x);
  93                   width += sz.cx;
  94               }
  95           }
  96           bSkippingSpaces = !len;
  97         } else if (!(p->member.run.nFlags & MERF_ENDPARA))
  98           width += p->member.run.nWidth;
  99       }
 100   }
 101
 102   row = ME_MakeRow(ascent+descent, ascent, width);
 103   row->member.row.nYPos = wc->pt.y;
 104   row->member.row.nLMargin = (!wc->nRow ? wc->nFirstMargin : wc->nLeftMargin);
 105   row->member.row.nRMargin = wc->nRightMargin;
 106   assert(para->member.para.pFmt->dwMask & PFM_ALIGNMENT);
 107   align = para->member.para.pFmt->wAlignment;
 108   if (align == PFA_CENTER)
 109     shift = (wc->nAvailWidth-width)/2;
 110   if (align == PFA_RIGHT)
 111     shift = wc->nAvailWidth-width;
 112   for (p = wc->pRowStart; p!=pEnd; p = p->next)
 113   {
 114     if (p->type==diRun) { /* FIXME add more run types */
 115       p->member.run.pt.x += row->member.row.nLMargin+shift;
 116     }
 117   }
 118   ME_InsertBefore(wc->pRowStart, row);
 119   wc->nRow++;
 120   wc->pt.y += ascent+descent;
 121   ME_BeginRow(wc);
 122 }
 123
 124 static void ME_WrapEndParagraph(ME_WrapContext *wc, ME_DisplayItem *p)
 125 {
 126   if (wc->pRowStart)
 127     ME_InsertRowStart(wc, p);
 128
 129   /*
 130   p = p->member.para.prev_para->next;
 131   while(p) {
 132     if (p->type == diParagraph || p->type == diTextEnd)
 133       return;
 134     if (p->type == diRun)
 135     {
 136       ME_Run *run = &p->member.run;
 137       TRACE("%s - (%d, %d)\n", debugstr_w(run->strText->szData), run->pt.x, run->pt.y);
 138     }
 139     p = p->next;
 140   }
 141   */
 142 }
 143
 144 static void ME_WrapSizeRun(ME_WrapContext *wc, ME_DisplayItem *p)
 145 {
 146   /* FIXME compose style (out of character and paragraph styles) here */
 147
 148   ME_UpdateRunFlags(wc->context->editor, &p->member.run);
 149
 150   ME_CalcRunExtent(wc->context, &ME_GetParagraph(p)->member.para,
 151                    wc->nRow ? wc->nLeftMargin : wc->nFirstMargin, &p->member.run);
 152 }
 153
 154 static ME_DisplayItem *ME_MaximizeSplit(ME_WrapContext *wc, ME_DisplayItem *p, int i)
 155 {
 156   ME_DisplayItem *pp, *piter = p;
 157   int j;
 158   if (!i)
 159     return NULL;
 160   j = ME_ReverseFindNonWhitespaceV(p->member.run.strText, i);
 161   if (j>0) {
 162     pp = ME_SplitRun(wc, piter, j);
 163     wc->pt.x += piter->member.run.nWidth;
 164     return pp;
 165   }
 166   else
 167   {
 168     pp = piter;
 169     /* omit all spaces before split point */
 170     while(piter != wc->pRowStart)
 171     {
 172       piter = ME_FindItemBack(piter, diRun);
 173       if (piter->member.run.nFlags & MERF_WHITESPACE)
 174       {
 175         pp = piter;
 176         continue;
 177       }
 178       if (piter->member.run.nFlags & MERF_ENDWHITE)
 179       {
 180         j = ME_ReverseFindNonWhitespaceV(piter->member.run.strText, i);
 181         pp = ME_SplitRun(wc, piter, i);
 182         wc->pt = pp->member.run.pt;
 183         return pp;
 184       }
 185       /* this run is the end of spaces, so the run edge is a good point to split */
 186       wc->pt = pp->member.run.pt;
 187       wc->bOverflown = TRUE;
 188       TRACE("Split point is: %s|%s\n", debugstr_w(piter->member.run.strText->szData), debugstr_w(pp->member.run.strText->szData));
 189       return pp;
 190     }
 191     wc->pt = piter->member.run.pt;
 192     return piter;
 193   }
 194 }
 195
 196 static ME_DisplayItem *ME_SplitByBacktracking(ME_WrapContext *wc, ME_DisplayItem *p, int loc)
 197 {
 198   ME_DisplayItem *piter = p, *pp;
 199   int i, idesp, len;
 200   ME_Run *run = &p->member.run;
 201
 202   idesp = i = ME_CharFromPoint(wc->context, loc, run);
 203   len = ME_StrVLen(run->strText);
 204   assert(len>0);
 205   assert(i<len);
 206   if (i) {
 207     /* don't split words */
 208     i = ME_ReverseFindWhitespaceV(run->strText, i);
 209     pp = ME_MaximizeSplit(wc, p, i);
 210     if (pp)
 211       return pp;
 212   }
 213   TRACE("Must backtrack to split at: %s\n", debugstr_w(p->member.run.strText->szData));
 214   if (wc->pLastSplittableRun)
 215   {
 216     if (wc->pLastSplittableRun->member.run.nFlags & (MERF_GRAPHICS|MERF_TAB))
 217     {
 218       wc->pt = wc->ptLastSplittableRun;
 219       return wc->pLastSplittableRun;
 220     }
 221     else if (wc->pLastSplittableRun->member.run.nFlags & MERF_SPLITTABLE)
 222     {
 223       /* the following two lines are just to check if we forgot to call UpdateRunFlags earlier,
 224          they serve no other purpose */
 225       ME_UpdateRunFlags(wc->context->editor, run);
 226       assert((wc->pLastSplittableRun->member.run.nFlags & MERF_SPLITTABLE));
 227
 228       piter = wc->pLastSplittableRun;
 229       run = &piter->member.run;
 230       len = ME_StrVLen(run->strText);
 231       /* don't split words */
 232       i = ME_ReverseFindWhitespaceV(run->strText, len);
 233       if (i == len)
 234         i = ME_ReverseFindNonWhitespaceV(run->strText, len);
 235       if (i) {
 236         ME_DisplayItem *piter2 = ME_SplitRun(wc, piter, i);
 237         wc->pt = piter2->member.run.pt;
 238         return piter2;
 239       }
 240       /* splittable = must have whitespaces */
 241       assert(0 == "Splittable, but no whitespaces");
 242     }
 243     else
 244     {
 245       /* restart from the first run beginning with spaces */
 246       wc->pt = wc->ptLastSplittableRun;
 247       return wc->pLastSplittableRun;
 248     }
 249   }
 250   TRACE("Backtracking failed, trying desperate: %s\n", debugstr_w(p->member.run.strText->szData));
 251   /* OK, no better idea, so assume we MAY split words if we can split at all*/
 252   if (idesp)
 253     return ME_SplitRun(wc, piter, idesp);
 254   else
 255   if (wc->pRowStart && piter != wc->pRowStart)
 256   {
 257     /* don't need to break current run, because it's possible to split
 258        before this run */
 259     wc->bOverflown = TRUE;
 260     return piter;
 261   }
 262   else
 263   {
 264     /* split point inside first character - no choice but split after that char */
 265     int chars = 1;
 266     int pos2 = ME_StrRelPos(run->strText, 0, &chars);
 267     if (pos2 != len) {
 268       /* the run is more than 1 char, so we may split */
 269       return ME_SplitRun(wc, piter, pos2);
 270     }
 271     /* the run is one char, can't split it */
 272     return piter;
 273   }
 274 }
 275
 276 static ME_DisplayItem *ME_WrapHandleRun(ME_WrapContext *wc, ME_DisplayItem *p)
 277 {
 278   ME_DisplayItem *pp;
 279   ME_Run *run;
 280   int len;
 281
 282   assert(p->type == diRun);
 283   if (!wc->pRowStart)
 284     wc->pRowStart = p;
 285   run = &p->member.run;
 286   run->pt.x = wc->pt.x;
 287   run->pt.y = wc->pt.y;
 288   ME_WrapSizeRun(wc, p);
 289   len = ME_StrVLen(run->strText);
 290
 291   if (wc->bOverflown) /* just skipping final whitespaces */
 292   {
 293     if (run->nFlags & (MERF_WHITESPACE|MERF_TAB)) {
 294       p->member.run.nFlags |= MERF_SKIPPED;
 295       /* wc->pt.x += run->nWidth; */
 296       /* skip runs consisting of only whitespaces */
 297       return p->next;
 298     }
 299
 300     if (run->nFlags & MERF_STARTWHITE) {
 301       /* try to split the run at the first non-white char */
 302       int black;
 303       black = ME_FindNonWhitespaceV(run->strText, 0);
 304       if (black) {
 305         wc->bOverflown = FALSE;
 306         pp = ME_SplitRun(wc, p, black);
 307         p->member.run.nFlags |= MERF_SKIPPED;
 308         ME_InsertRowStart(wc, pp);
 309         return pp;
 310       }
 311     }
 312     /* black run: the row goes from pRowStart to the previous run */
 313     ME_InsertRowStart(wc, p);
 314     return p;
 315   }
 316   /* simply end the current row and move on to next one */
 317   if (run->nFlags & MERF_ENDROW)
 318   {
 319     p = p->next;
 320     ME_InsertRowStart(wc, p);
 321     return p;
 322   }
 323
 324   /* will current run fit? */
 325   if (wc->pt.x + run->nWidth > wc->nAvailWidth)
 326   {
 327     int loc = wc->nAvailWidth - wc->pt.x;
 328     /* total white run ? */
 329     if (run->nFlags & MERF_WHITESPACE) {
 330       /* let the overflow logic handle it */
 331       wc->bOverflown = TRUE;
 332       return p;
 333     }
 334     /* TAB: we can split before */
 335     if (run->nFlags & MERF_TAB) {
 336       wc->bOverflown = TRUE;
 337       return p;
 338     }
 339     /* graphics: we can split before, if run's width is smaller than row's width */
 340     if ((run->nFlags & MERF_GRAPHICS) && run->nWidth <= wc->nAvailWidth) {
 341       wc->bOverflown = TRUE;
 342       return p;
 343     }
 344     /* can we separate out the last spaces ? (to use overflow logic later) */
 345     if (run->nFlags & MERF_ENDWHITE)
 346     {
 347       /* we aren't sure if it's *really* necessary, it's a good start however */
 348       int black = ME_ReverseFindNonWhitespaceV(run->strText, len);
 349       ME_SplitRun(wc, p, black);
 350       /* handle both parts again */
 351       return p;
 352     }
 353     /* determine the split point by backtracking */
 354     pp = ME_SplitByBacktracking(wc, p, loc);
 355     if (pp == wc->pRowStart)
 356     {
 357       /* we had only spaces so far, entire content can be omitted */
 358       wc->pt.x = 0;
 359       return p->next;
 360     }
 361     if (p != pp) /* found a suitable split point */
 362     {
 363       wc->bOverflown = TRUE;
 364       return pp;
 365     }
 366     /* we detected that it's best to split on start of this run */
 367     if (wc->bOverflown)
 368       return pp;
 369     ERR("failure!\n");
 370     /* not found anything - writing over margins is the only option left */
 371   }
 372   if ((run->nFlags & (MERF_SPLITTABLE | MERF_STARTWHITE))
 373     || ((run->nFlags & (MERF_GRAPHICS|MERF_TAB)) && (p != wc->pRowStart)))
 374   {
 375     wc->pLastSplittableRun = p;
 376     wc->ptLastSplittableRun = wc->pt;
 377   }
 378   wc->pt.x += run->nWidth;
 379   return p->next;
 380 }
 381
 382 static void ME_PrepareParagraphForWrapping(ME_Context *c, ME_DisplayItem *tp);
 383
 384 static void ME_WrapTextParagraph(ME_Context *c, ME_DisplayItem *tp, DWORD beginofs) {
 385   ME_DisplayItem *p;
 386   ME_WrapContext wc;
 387   int border = 0;
 388   int linespace = 0;
 389
 390   assert(tp->type == diParagraph);
 391   if (!(tp->member.para.nFlags & MEPF_REWRAP)) {
 392     return;
 393   }
 394   ME_PrepareParagraphForWrapping(c, tp);
 395
 396   wc.context = c;
 397 /*   wc.para_style = tp->member.para.style; */
 398   wc.style = NULL;
 399   wc.nFirstMargin = ME_twips2pointsX(c, tp->member.para.pFmt->dxStartIndent) + beginofs;
 400   wc.nLeftMargin = wc.nFirstMargin + ME_twips2pointsX(c, tp->member.para.pFmt->dxOffset);
 401   wc.nRightMargin = ME_twips2pointsX(c, tp->member.para.pFmt->dxRightIndent);
 402   wc.nRow = 0;
 403   wc.pt.x = 0;
 404   wc.pt.y = 0;
 405   if (tp->member.para.pFmt->dwMask & PFM_SPACEBEFORE)
 406     wc.pt.y += ME_twips2pointsY(c, tp->member.para.pFmt->dySpaceBefore);
 407   if (tp->member.para.pFmt->dwMask & PFM_BORDER)
 408   {
 409     border = ME_GetParaBorderWidth(c->editor, tp->member.para.pFmt->wBorders);
 410     if (tp->member.para.pFmt->wBorders & 1) {
 411       wc.nFirstMargin += border;
 412       wc.nLeftMargin += border;
 413     }
 414     if (tp->member.para.pFmt->wBorders & 2)
 415       wc.nRightMargin -= border;
 416     if (tp->member.para.pFmt->wBorders & 4)
 417       wc.pt.y += border;
 418   }
 419
 420   linespace = ME_GetParaLineSpace(c, &tp->member.para);
 421
 422   ME_BeginRow(&wc);
 423   for (p = tp->next; p!=tp->member.para.next_para; ) {
 424     assert(p->type != diStartRow);
 425     if (p->type == diRun) {
 426       p = ME_WrapHandleRun(&wc, p);
 427     }
 428     else p = p->next;
 429     if (wc.nRow && p == wc.pRowStart)
 430       wc.pt.y += linespace;
 431   }
 432   ME_WrapEndParagraph(&wc, p);
 433   if ((tp->member.para.pFmt->dwMask & PFM_BORDER) && (tp->member.para.pFmt->wBorders & 8))
 434     wc.pt.y += border;
 435   if (tp->member.para.pFmt->dwMask & PFM_SPACEAFTER)
 436     wc.pt.y += ME_twips2pointsY(c, tp->member.para.pFmt->dySpaceAfter);
 437
 438   tp->member.para.nFlags &= ~MEPF_REWRAP;
 439   tp->member.para.nHeight = wc.pt.y;
 440   tp->member.para.nRows = wc.nRow;
 441 }
 442
 443
 444 static void ME_PrepareParagraphForWrapping(ME_Context *c, ME_DisplayItem *tp) {
 445   ME_DisplayItem *p, *pRow;
 446
 447   /* remove all items that will be reinserted by paragraph wrapper anyway */
 448   tp->member.para.nRows = 0;
 449   for (p = tp->next; p!=tp->member.para.next_para; p = p->next) {
 450     switch(p->type) {
 451       case diStartRow:
 452         pRow = p;
 453         p = p->prev;
 454         ME_Remove(pRow);
 455         ME_DestroyDisplayItem(pRow);
 456         break;
 457       default:
 458         break;
 459     }
 460   }
 461   /* join runs that can be joined, set up flags */
 462   for (p = tp->next; p!=tp->member.para.next_para; p = p->next) {
 463     int changed = 0;
 464     switch(p->type) {
 465       case diStartRow: assert(0); break; /* should have deleted it */
 466       case diRun:
 467         while (p->next->type == diRun) { /* FIXME */
 468           if (ME_CanJoinRuns(&p->member.run, &p->next->member.run)) {
 469             ME_JoinRuns(c->editor, p);
 470             changed = 1;
 471           }
 472           else
 473             break;
 474         }
 475         p->member.run.nFlags &= ~MERF_CALCBYWRAP;
 476         break;
 477       default:
 478         break;
 479     }
 480   }
 481 }
 482
 483 BOOL ME_WrapMarkedParagraphs(ME_TextEditor *editor) {
 484   ME_DisplayItem *item;
 485   ME_Context c;
 486   BOOL bModified = FALSE;
 487   int yStart = -1;
 488   int yLastPos = 0;
 489
 490   ME_InitContext(&c, editor, GetDC(editor->hWnd));
 491   editor->nHeight = 0;
 492   item = editor->pBuffer->pFirst->next;
 493   while(item != editor->pBuffer->pLast) {
 494     BOOL bRedraw = FALSE;
 495
 496     assert(item->type == diParagraph);
 497     editor->nHeight = max(editor->nHeight, item->member.para.nYPos);
 498     if ((item->member.para.nFlags & MEPF_REWRAP)
 499      || (item->member.para.nYPos != c.pt.y))
 500       bRedraw = TRUE;
 501     item->member.para.nYPos = c.pt.y;
 502
 503     ME_WrapTextParagraph(&c, item, editor->selofs);
 504
 505     if (bRedraw)
 506     {
 507       item->member.para.nFlags |= MEPF_REPAINT;
 508       if (yStart == -1)
 509         yStart = c.pt.y;
 510     }
 511
 512     bModified = bModified | bRedraw;
 513
 514     yLastPos = c.pt.y;
 515     c.pt.y += item->member.para.nHeight;
 516     item = item->member.para.next_para;
 517   }
 518   editor->sizeWindow.cx = c.rcView.right-c.rcView.left;
 519   editor->sizeWindow.cy = c.rcView.bottom-c.rcView.top;
 520
 521   editor->nTotalLength = c.pt.y;
 522   editor->pBuffer->pLast->member.para.nYPos = yLastPos;
 523
 524   ME_DestroyContext(&c, editor->hWnd);
 525
 526   /* Each paragraph may contain multiple rows, which should be scrollable, even
 527      if the containing paragraph has nYPos == 0 */
 528   item = editor->pBuffer->pFirst;
 529   while ((item = ME_FindItemFwd(item, diStartRow)) != NULL) {
 530     assert(item->type == diStartRow);
 531     editor->nHeight = max(editor->nHeight, item->member.row.nYPos);
 532   }
 533
 534   if (bModified || editor->nTotalLength < editor->nLastTotalLength)
 535     ME_InvalidateMarkedParagraphs(editor);
 536   return bModified;
 537 }
 538
 539 void ME_InvalidateMarkedParagraphs(ME_TextEditor *editor) {
 540   ME_Context c;
 541
 542   ME_InitContext(&c, editor, GetDC(editor->hWnd));
 543   if (editor->bRedraw)
 544   {
 545     RECT rc = c.rcView;
 546     int ofs = ME_GetYScrollPos(editor);
 547
 548     ME_DisplayItem *item = editor->pBuffer->pFirst;
 549     while(item != editor->pBuffer->pLast) {
 550       if (item->member.para.nFlags & MEPF_REPAINT) {
 551         rc.top = item->member.para.nYPos - ofs;
 552         rc.bottom = item->member.para.nYPos + item->member.para.nHeight - ofs;
 553         InvalidateRect(editor->hWnd, &rc, TRUE);
 554       }
 555       item = item->member.para.next_para;
 556     }
 557     if (editor->nTotalLength < editor->nLastTotalLength)
 558     {
 559       rc.top = editor->nTotalLength - ofs;
 560       rc.bottom = editor->nLastTotalLength - ofs;
 561       InvalidateRect(editor->hWnd, &rc, TRUE);
 562     }
 563   }
 564   ME_DestroyContext(&c, editor->hWnd);
 565 }
 566
 567
 568 void
 569 ME_SendRequestResize(ME_TextEditor *editor, BOOL force)
 570 {
 571   if (editor->nEventMask & ENM_REQUESTRESIZE)
 572   {
 573     RECT rc;
 574
 575     GetClientRect(editor->hWnd, &rc);
 576
 577     if (force || rc.bottom != editor->nTotalLength)
 578     {
 579       REQRESIZE info;
 580
 581       info.nmhdr.hwndFrom = editor->hWnd;
 582       info.nmhdr.idFrom = GetWindowLongW(editor->hWnd, GWLP_ID);
 583       info.nmhdr.code = EN_REQUESTRESIZE;
 584       info.rc = rc;
 585       info.rc.bottom = editor->nTotalLength;
 586
 587       editor->nEventMask &= ~ENM_REQUESTRESIZE;
 588       SendMessageW(GetParent(editor->hWnd), WM_NOTIFY,
 589                    info.nmhdr.idFrom, (LPARAM)&info);
 590       editor->nEventMask |= ENM_REQUESTRESIZE;
 591     }
 592   }
 593 }