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