caret.c

ReactOS是一些高手根据Windows XP的内核编写出的类XP。内核实现机理和API函数调用几乎相同。甚至可以兼容XP的程序。喜欢研究系统内核的人可以看一看。

/*
 * RichEdit - Caret and selection functions.
 *
 * Copyright 2004 by Krzysztof Foltman
 * Copyright 2005 by Phil Krylov
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */


#include "editor.h"

WINE_DEFAULT_DEBUG_CHANNEL(richedit);

static BOOL
ME_MoveCursorChars(ME_TextEditor *editor, ME_Cursor *pCursor, int nRelOfs);


void ME_GetSelection(ME_TextEditor *editor, int *from, int *to)
{
  *from = ME_GetCursorOfs(editor, 0);
  *to =   ME_GetCursorOfs(editor, 1);
  
  if (*from > *to)
  {
    int tmp = *from;
    *from = *to;
    *to = tmp;    
  }
}

int ME_GetTextLength(ME_TextEditor *editor)
{
  return ME_CharOfsFromRunOfs(editor, ME_FindItemBack(editor->pBuffer->pLast, diRun), 0);   
}


int ME_GetTextLengthEx(ME_TextEditor *editor, GETTEXTLENGTHEX *how)
{
  int length;
  
  if (how->flags & GTL_PRECISE && how->flags & GTL_CLOSE)
    return E_INVALIDARG;
  if (how->flags & GTL_NUMCHARS && how->flags & GTL_NUMBYTES)
    return E_INVALIDARG;
  
  length = ME_GetTextLength(editor);
  
  if (how->flags & GTL_USECRLF)
    length += editor->nParagraphs;
  
  if (how->flags & GTL_NUMBYTES)
  {
    CPINFO cpinfo;
    
    if (how->codepage == 1200)
      return length * 2;
    if (how->flags & GTL_PRECISE)
      FIXME("GTL_PRECISE flag unsupported. Using GTL_CLOSE\n");
    if (GetCPInfo(how->codepage, &cpinfo))
      return length * cpinfo.MaxCharSize;
    ERR("Invalid codepage %u\n", how->codepage);
    return E_INVALIDARG;
  }
  return length; 
}


int ME_SetSelection(ME_TextEditor *editor, int from, int to)
{
  int selectionEnd = 0;
  const int len = ME_GetTextLength(editor);

  /* all negative values are effectively the same */
  if (from < 0)
    from = -1;
  if (to < 0)
    to = -1;

  /* select all */
  if (from == 0 && to == -1)
  {
    editor->pCursors[1].pRun = ME_FindItemFwd(editor->pBuffer->pFirst, diRun);
    editor->pCursors[1].nOffset = 0; 
    editor->pCursors[0].pRun = ME_FindItemBack(editor->pBuffer->pLast, diRun); 
    editor->pCursors[0].nOffset = 0;
    ME_InvalidateSelection(editor);
    ME_ClearTempStyle(editor);
    return len + 1;
  }

  /* if both values are equal and also out of bound, that means to */
  /* put the selection at the end of the text */
  if ((from == to) && (to < 0 || to > len))
  {
    selectionEnd = 1;
  }
  else
  {
    /* if from is negative and to is positive then selection is */
    /* deselected and caret moved to end of the current selection */
    if (from < 0)
    {
      int start, end;
      ME_GetSelection(editor, &start, &end);
      editor->pCursors[1] = editor->pCursors[0];
      ME_Repaint(editor);
      ME_ClearTempStyle(editor);
      return end;
    }

    /* adjust to if it's a negative value */
    if (to < 0)
      to = len + 1;

    /* flip from and to if they are reversed */
    if (from>to)
    {
      int tmp = from;
      from = to;
      to = tmp;
    }

    /* after fiddling with the values, we find from > len && to > len */
    if (from > len)
      selectionEnd = 1;
    /* special case with to too big */
    else if (to > len)
      to = len + 1;
  }

  if (selectionEnd)
  {
    editor->pCursors[1].pRun = editor->pCursors[0].pRun = ME_FindItemBack(editor->pBuffer->pLast, diRun);
    editor->pCursors[1].nOffset = editor->pCursors[0].nOffset = 0;
    ME_InvalidateSelection(editor);
    ME_ClearTempStyle(editor);
    return len;
  }

  ME_RunOfsFromCharOfs(editor, from, &editor->pCursors[1].pRun, &editor->pCursors[1].nOffset);
  ME_RunOfsFromCharOfs(editor, to, &editor->pCursors[0].pRun, &editor->pCursors[0].nOffset);
  return to;
}


void
ME_GetCursorCoordinates(ME_TextEditor *editor, ME_Cursor *pCursor,
                        int *x, int *y, int *height)
{
  ME_DisplayItem *pCursorRun = pCursor->pRun;
  ME_DisplayItem *pSizeRun = pCursor->pRun;

  assert(!pCursor->nOffset || !editor->bCaretAtEnd);
  assert(height && x && y);
  assert(!(ME_GetParagraph(pCursorRun)->member.para.nFlags & MEPF_REWRAP));
  assert(pCursor->pRun);
  assert(pCursor->pRun->type == diRun);
  
  if (pCursorRun->type == diRun) {
    ME_DisplayItem *row = ME_FindItemBack(pCursorRun, diStartRowOrParagraph);

    if (row) {
      HDC hDC = GetDC(editor->hWnd);
      ME_Context c;
      ME_DisplayItem *run = pCursorRun;
      ME_DisplayItem *para = NULL;
      SIZE sz = {0, 0};
    
      ME_InitContext(&c, editor, hDC);
      
      if (!pCursor->nOffset && !editor->bCaretAtEnd)
      {
        ME_DisplayItem *prev = ME_FindItemBack(pCursorRun, diRunOrStartRow);
        assert(prev);
        if (prev->type == diRun)
          pSizeRun = prev;
      }
      assert(row->type == diStartRow); /* paragraph -> run without start row ?*/
      para = ME_FindItemBack(row, diParagraph);
      assert(para);
      assert(para->type == diParagraph);
      if (editor->bCaretAtEnd && !pCursor->nOffset && 
          run == ME_FindItemFwd(row, diRun))
      {
        ME_DisplayItem *tmp = ME_FindItemBack(row, diRunOrParagraph);
        assert(tmp);
        if (tmp->type == diRun)
        {
          row = ME_FindItemBack(tmp, diStartRow);
          pSizeRun = run = tmp;
          assert(run);
          assert(run->type == diRun);
          sz = ME_GetRunSize(&c, &para->member.para, &run->member.run, ME_StrLen(run->member.run.strText));
        }
      }
      if (pCursor->nOffset && !(run->member.run.nFlags & MERF_SKIPPED)) {
        sz = ME_GetRunSize(&c, &para->member.para, &run->member.run, pCursor->nOffset);
      }

      *height = pSizeRun->member.run.nAscent + pSizeRun->member.run.nDescent;
      *x = run->member.run.pt.x + sz.cx;
      *y = para->member.para.nYPos + row->member.row.nBaseline + pSizeRun->member.run.pt.y - pSizeRun->member.run.nAscent - ME_GetYScrollPos(editor);
      
      ME_DestroyContext(&c);
      ReleaseDC(editor->hWnd, hDC);
      return;
    }
  }
  *height = 10; /* FIXME use global font */
  *x = 0;
  *y = 0;
}


void
ME_MoveCaret(ME_TextEditor *editor)
{
  int x, y, height;

  ME_WrapMarkedParagraphs(editor);
  ME_GetCursorCoordinates(editor, &editor->pCursors[0], &x, &y, &height);
  if(editor->bHaveFocus)
  {
    CreateCaret(editor->hWnd, NULL, 0, height);
    SetCaretPos(x, y);
  }
}


void ME_ShowCaret(ME_TextEditor *ed)
{
  ME_MoveCaret(ed);
  if(ed->bHaveFocus)
    ShowCaret(ed->hWnd);
}

void ME_HideCaret(ME_TextEditor *ed)
{
  if(ed->bHaveFocus)
  {
    HideCaret(ed->hWnd);
    DestroyCaret();
  }
}

void ME_InternalDeleteText(ME_TextEditor *editor, int nOfs, 
  int nChars)
{
  ME_Cursor c;
  int shift = 0;
  
  while(nChars > 0)
  {
    ME_Run *run;
    ME_CursorFromCharOfs(editor, nOfs, &c);
    run = &c.pRun->member.run;
    if (run->nFlags & MERF_ENDPARA) {
      if (!ME_FindItemFwd(c.pRun, diParagraph))
      {
        return;
      }
      ME_JoinParagraphs(editor, ME_GetParagraph(c.pRun));
      /* ME_SkipAndPropagateCharOffset(p->pRun, shift); */
      ME_CheckCharOffsets(editor);
      nChars--;
      if (editor->bEmulateVersion10 && nChars)
        nChars--;
      continue;
    }
    else
    {
      ME_Cursor cursor;
      int nIntendedChars = nChars;
      int nCharsToDelete = nChars;
      int i;
      int loc = c.nOffset;
      
      ME_FindItemBack(c.pRun, diParagraph)->member.para.nFlags |= MEPF_REWRAP;
      
      cursor = c;
      ME_StrRelPos(run->strText, loc, &nChars);
      /* nChars is the number of characters that should be deleted from the
         FOLLOWING runs (these AFTER cursor.pRun)
         nCharsToDelete is a number of chars to delete from THIS run */
      nCharsToDelete -= nChars;
      shift -= nCharsToDelete;
      TRACE("Deleting %d (intended %d-remaning %d) chars at %d in '%s' (%d)\n", 
        nCharsToDelete, nIntendedChars, nChars, c.nOffset, 
        debugstr_w(run->strText->szData), run->strText->nLen);

      if (!c.nOffset && ME_StrVLen(run->strText) == nCharsToDelete)
      {
        /* undo = reinsert whole run */
        /* nOfs is a character offset (from the start of the document
           to the current (deleted) run */
        ME_UndoItem *pUndo = ME_AddUndoItem(editor, diUndoInsertRun, c.pRun);
        if (pUndo)
          pUndo->di.member.run.nCharOfs = nOfs;
      }
      else
      {
        /* undo = reinsert partial run */
        ME_UndoItem *pUndo = ME_AddUndoItem(editor, diUndoInsertRun, c.pRun);
        if (pUndo) {
          ME_DestroyString(pUndo->di.member.run.strText);
          pUndo->di.member.run.nCharOfs = nOfs;
          pUndo->di.member.run.strText = ME_MakeStringN(run->strText->szData+c.nOffset, nCharsToDelete);
        }
      }
      TRACE("Post deletion string: %s (%d)\n", debugstr_w(run->strText->szData), run->strText->nLen);
      TRACE("Shift value: %d\n", shift);
      ME_StrDeleteV(run->strText, c.nOffset, nCharsToDelete);
      
      /* update cursors (including c) */
      for (i=-1; i<editor->nCursors; i++) {
        ME_Cursor *pThisCur = editor->pCursors + i; 
        if (i == -1) pThisCur = &c;
        if (pThisCur->pRun == cursor.pRun) {
          if (pThisCur->nOffset > cursor.nOffset) {
            if (pThisCur->nOffset-cursor.nOffset < nCharsToDelete)
              pThisCur->nOffset = cursor.nOffset;
            else
              pThisCur->nOffset -= nCharsToDelete;
            assert(pThisCur->nOffset >= 0);
            assert(pThisCur->nOffset <= ME_StrVLen(run->strText));
          }
          if (pThisCur->nOffset == ME_StrVLen(run->strText))
          {
            pThisCur->pRun = ME_FindItemFwd(pThisCur->pRun, diRunOrParagraphOrEnd);
            assert(pThisCur->pRun->type == diRun);
            pThisCur->nOffset = 0;
          }
        }
      }
      
      /* c = updated data now */
      
      if (c.pRun == cursor.pRun)
        ME_SkipAndPropagateCharOffset(c.pRun, shift);
      else
        ME_PropagateCharOffset(c.pRun, shift);

      if (!ME_StrVLen(cursor.pRun->member.run.strText))
      {
        TRACE("Removing useless run\n");
        ME_Remove(cursor.pRun);
        ME_DestroyDisplayItem(cursor.pRun);
      }
      
      shift = 0;
      /*
      ME_CheckCharOffsets(editor);
      */
      continue;
    }
  }
}

void ME_DeleteTextAtCursor(ME_TextEditor *editor, int nCursor, 
  int nChars)
{  
  assert(nCursor>=0 && nCursor<editor->nCursors);
  /* text operations set modified state */
  editor->nModifyStep = 1;
  ME_InternalDeleteText(editor, ME_GetCursorOfs(editor, nCursor), nChars);
}

static ME_DisplayItem *
ME_InternalInsertTextFromCursor(ME_TextEditor *editor, int nCursor,
                                const WCHAR *str, int len, ME_Style *style,
                                int flags)
{
  ME_Cursor *p = &editor->pCursors[nCursor];

  editor->bCaretAtEnd = FALSE;
  
  assert(p->pRun->type == diRun);
  
  return ME_InsertRunAtCursor(editor, p, style, str, len, flags);
}


/* FIXME this is temporary, just to have something to test how bad graphics handler is */
void ME_InsertGraphicsFromCursor(ME_TextEditor *editor, int nCursor)
{
  ME_Style *pStyle = ME_GetInsertStyle(editor, nCursor);
  WCHAR space = ' ';
  
  /* FIXME no no no */
  if (ME_IsSelection(editor))
    ME_DeleteSelection(editor);

  ME_InternalInsertTextFromCursor(editor, nCursor, &space, 1, pStyle,
                                  MERF_GRAPHICS);
  ME_SendSelChange(editor);
}


void
ME_InsertTableCellFromCursor(ME_TextEditor *editor, int nCursor)
{
  WCHAR tab = '\t';
  ME_DisplayItem *p, *run;
  ME_Style *pStyle = ME_GetInsertStyle(editor, nCursor);
  
  p = ME_InternalInsertTextFromCursor(editor, nCursor, &tab, 1, pStyle,
                                      MERF_CELL);
  run = p;
  while ((run = ME_FindItemBack(run, diRunOrParagraph))->type == diRun)
  {
    if (run->member.run.nFlags & MERF_CELL)
    {
      assert(run->member.run.pCell->next);
      p->member.run.pCell = run->member.run.pCell->next;
      return;
    }
  }