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。

  assert(run->type == diParagraph);
  assert(run->member.para.bTable);
  assert(run->member.para.pCells);
  p->member.run.pCell = run->member.para.pCells;
}


void ME_InsertTextFromCursor(ME_TextEditor *editor, int nCursor, 
  const WCHAR *str, int len, ME_Style *style)
{
  const WCHAR *pos;
  ME_Cursor *p = NULL;
  int freeSpace;

  /* FIXME really HERE ? */
  if (ME_IsSelection(editor))
    ME_DeleteSelection(editor);

  /* FIXME: is this too slow? */
  /* Didn't affect performance for WM_SETTEXT (around 50sec/30K) */
  freeSpace = editor->nTextLimit - ME_GetTextLength(editor);

  /* text operations set modified state */
  editor->nModifyStep = 1;

  assert(style);

  assert(nCursor>=0 && nCursor<editor->nCursors);
  if (len == -1)
    len = lstrlenW(str);
  len = min(len, freeSpace);
  while (len)
  {
    pos = str;
    /* FIXME this sucks - no respect for unicode (what else can be a line separator in unicode?) */
    while(pos-str < len && *pos != '\r' && *pos != '\n' && *pos != '\t')
      pos++;
    if (pos-str < len && *pos == '\t') { /* handle tabs */
      WCHAR tab = '\t';

      if (pos!=str)
        ME_InternalInsertTextFromCursor(editor, nCursor, str, pos-str, style, 0);
    
      ME_InternalInsertTextFromCursor(editor, nCursor, &tab, 1, style, MERF_TAB);
 
      pos++;
      if(pos-str <= len) {
        len -= pos - str;
        str = pos;
        continue;
      }
    }
    if (pos-str < len) {   /* handle EOLs */
      ME_DisplayItem *tp, *end_run;
      ME_Style *tmp_style;
      if (pos!=str)
        ME_InternalInsertTextFromCursor(editor, nCursor, str, pos-str, style, 0);
      p = &editor->pCursors[nCursor];
      if (p->nOffset) {
        ME_SplitRunSimple(editor, p->pRun, p->nOffset);
        p = &editor->pCursors[nCursor];
      }
      tmp_style = ME_GetInsertStyle(editor, nCursor);
      /* ME_SplitParagraph increases style refcount */
      tp = ME_SplitParagraph(editor, p->pRun, p->pRun->member.run.style);
      p->pRun = ME_FindItemFwd(tp, diRun);
      end_run = ME_FindItemBack(tp, diRun);
      ME_ReleaseStyle(end_run->member.run.style);
      end_run->member.run.style = tmp_style;
      p->nOffset = 0;
      if(pos-str < len && *pos =='\r')
        pos++;
      if(pos-str < len && *pos =='\n')
        pos++;
      if(pos-str <= len) {
        len -= pos - str;
        str = pos;
        continue;
      }
    }
    ME_InternalInsertTextFromCursor(editor, nCursor, str, len, style, 0);
    len = 0;
  }
}


static BOOL
ME_MoveCursorChars(ME_TextEditor *editor, ME_Cursor *pCursor, int nRelOfs)
{
  ME_DisplayItem *pRun = pCursor->pRun;
  
  if (nRelOfs == -1)
  {
    if (!pCursor->nOffset)
    {
      do {
        pRun = ME_FindItemBack(pRun, diRunOrParagraph);
        assert(pRun);
        switch (pRun->type)
        {
          case diRun:
            break;
          case diParagraph:
            if (pRun->member.para.prev_para->type == diTextStart)
              return FALSE;
            pRun = ME_FindItemBack(pRun, diRunOrParagraph);
            /* every paragraph ought to have at least one run */
            assert(pRun && pRun->type == diRun);
            assert(pRun->member.run.nFlags & MERF_ENDPARA);
            break;
          default:
            assert(pRun->type != diRun && pRun->type != diParagraph);
            return FALSE;
        }
      } while (RUN_IS_HIDDEN(&pRun->member.run));
      pCursor->pRun = pRun;
      if (pRun->member.run.nFlags & MERF_ENDPARA)
        pCursor->nOffset = 0;
      else
        pCursor->nOffset = pRun->member.run.strText->nLen;
    }
    
    if (pCursor->nOffset)
      pCursor->nOffset = ME_StrRelPos2(pCursor->pRun->member.run.strText, pCursor->nOffset, nRelOfs);
    return TRUE;
  }
  else
  {
    if (!(pRun->member.run.nFlags & MERF_ENDPARA))
    {
      int new_ofs = ME_StrRelPos2(pRun->member.run.strText, pCursor->nOffset, nRelOfs);
    
      if (new_ofs < pRun->member.run.strText->nLen)
      {
        pCursor->nOffset = new_ofs;
        return TRUE;
      }
    }
    do {
      pRun = ME_FindItemFwd(pRun, diRun);
    } while (pRun && RUN_IS_HIDDEN(&pRun->member.run));
    if (pRun)
    {
      pCursor->pRun = pRun;
      pCursor->nOffset = 0;
      return TRUE;
    }
  }
  return FALSE;
}


static BOOL
ME_MoveCursorWords(ME_TextEditor *editor, ME_Cursor *cursor, int nRelOfs)
{
  ME_DisplayItem *pRun = cursor->pRun, *pOtherRun;
  int nOffset = cursor->nOffset;
  
  if (nRelOfs == -1)
  {
    /* Backward movement */
    while (TRUE)
    {
      nOffset = ME_CallWordBreakProc(editor, pRun->member.run.strText,
                                     nOffset, WB_MOVEWORDLEFT);
       if (nOffset)
        break;
      pOtherRun = ME_FindItemBack(pRun, diRunOrParagraph);
      if (pOtherRun->type == diRun)
      {
        if (ME_CallWordBreakProc(editor, pOtherRun->member.run.strText,
                                 pOtherRun->member.run.strText->nLen - 1,
                                 WB_ISDELIMITER)
            && !(pRun->member.run.nFlags & MERF_ENDPARA)
            && !(cursor->pRun == pRun && cursor->nOffset == 0)
            && !ME_CallWordBreakProc(editor, pRun->member.run.strText, 0,
                                     WB_ISDELIMITER))
          break;
        pRun = pOtherRun;
        nOffset = pOtherRun->member.run.strText->nLen;
      }
      else if (pOtherRun->type == diParagraph)
      {
        if (cursor->pRun == pRun && cursor->nOffset == 0)
        {
          /* Paragraph breaks are treated as separate words */
          if (pOtherRun->member.para.prev_para->type == diTextStart)
            return FALSE;
          pRun = ME_FindItemBack(pOtherRun, diRunOrParagraph);
        }
        break;
      }
    }
  }
  else
  {
    /* Forward movement */
    BOOL last_delim = FALSE;
    
    while (TRUE)
    {
      if (last_delim && !ME_CallWordBreakProc(editor, pRun->member.run.strText,
                                              nOffset, WB_ISDELIMITER))
        break;
      nOffset = ME_CallWordBreakProc(editor, pRun->member.run.strText,
                                     nOffset, WB_MOVEWORDRIGHT);
      if (nOffset < pRun->member.run.strText->nLen)
        break;
      pOtherRun = ME_FindItemFwd(pRun, diRunOrParagraphOrEnd);
      if (pOtherRun->type == diRun)
      {
        last_delim = ME_CallWordBreakProc(editor, pRun->member.run.strText,
                                          nOffset - 1, WB_ISDELIMITER);
        pRun = pOtherRun;
        nOffset = 0;
      }
      else if (pOtherRun->type == diParagraph)
      {
        if (cursor->pRun == pRun)
          pRun = ME_FindItemFwd(pOtherRun, diRun);
        nOffset = 0;
        break;
      }
      else /* diTextEnd */
      {
        if (cursor->pRun == pRun)
          return FALSE;
        nOffset = 0;
        break;
      }
    }
  }
  cursor->pRun = pRun;
  cursor->nOffset = nOffset;
  return TRUE;
}


void
ME_SelectWord(ME_TextEditor *editor)
{
  if (!(editor->pCursors[0].pRun->member.run.nFlags & MERF_ENDPARA))
    ME_MoveCursorWords(editor, &editor->pCursors[0], -1);
  ME_MoveCursorWords(editor, &editor->pCursors[1], +1);
  ME_InvalidateSelection(editor);
  ME_SendSelChange(editor);
}


int ME_GetCursorOfs(ME_TextEditor *editor, int nCursor)
{
  ME_Cursor *pCursor = &editor->pCursors[nCursor];
  
  return ME_GetParagraph(pCursor->pRun)->member.para.nCharOfs
    + pCursor->pRun->member.run.nCharOfs + pCursor->nOffset;
}

int ME_FindPixelPos(ME_TextEditor *editor, int x, int y, ME_Cursor *result, BOOL *is_eol)
{
  ME_DisplayItem *p = editor->pBuffer->pFirst->member.para.next_para;
  int rx = 0;
  
  if (is_eol)
    *is_eol = 0;

  while(p != editor->pBuffer->pLast)
  {
    if (p->type == diParagraph)
    {
      int ry = y - p->member.para.nYPos;
      if (ry < 0)
      {
        result->pRun = ME_FindItemFwd(p, diRun);
        result->nOffset = 0;
        return 0;
      }
      if (ry >= p->member.para.nHeight)
      {
        p = p->member.para.next_para;
        continue;
      }
      p = ME_FindItemFwd(p, diStartRow);
      y = ry;
      continue;
    }
    if (p->type == diStartRow)
    {
      int ry = y - p->member.row.nYPos;
      if (ry < 0)
        return 0;
      if (ry >= p->member.row.nHeight)
      {
        p = ME_FindItemFwd(p, diStartRowOrParagraphOrEnd);
        if (p->type != diStartRow)
          return 0;
        continue;
      }
      p = ME_FindItemFwd(p, diRun);
      continue;
    }
    if (p->type == diRun)
    {
      ME_DisplayItem *pp;
      rx = x - p->member.run.pt.x;
      if (rx < 0)
        rx = 0;
      if (rx >= p->member.run.nWidth) /* not this run yet... find next item */
      {
        pp = p;
        do {
          p = p->next;
          if (p->type == diRun)
          {
            rx = x - p->member.run.pt.x;
            goto continue_search;
          }
          if (p->type == diStartRow)
          {
            p = ME_FindItemFwd(p, diRun);
            if (is_eol)
              *is_eol = 1;
            rx = 0; /* FIXME not sure */
            goto found_here;
          }
          if (p->type == diParagraph || p->type == diTextEnd)
          {
            rx = 0; /* FIXME not sure */
            p = pp;
            goto found_here;
          }
        } while(1);
        continue;
      }
    found_here:
      if (p->member.run.nFlags & MERF_ENDPARA)
        rx = 0;
      result->pRun = p;
      result->nOffset = ME_CharFromPointCursor(editor, rx, &p->member.run);
      if (editor->pCursors[0].nOffset == p->member.run.strText->nLen && rx)
      {
        result->pRun = ME_FindItemFwd(editor->pCursors[0].pRun, diRun);
        result->nOffset = 0;
      }
      return 1;
    }
    assert(0);
  continue_search:
    ;
  }
  result->pRun = ME_FindItemBack(p, diRun);
  result->nOffset = 0;
  assert(result->pRun->member.run.nFlags & MERF_ENDPARA);
  return 0;
}


int
ME_CharFromPos(ME_TextEditor *editor, int x, int y)
{
  ME_Cursor cursor;
  RECT rc;

  GetClientRect(editor->hWnd, &rc);
  if (x < 0 || y < 0 || x >= rc.right || y >= rc.bottom)
    return -1;
  y += ME_GetYScrollPos(editor);
  ME_FindPixelPos(editor, x, y, &cursor, NULL);
  return (ME_GetParagraph(cursor.pRun)->member.para.nCharOfs
          + cursor.pRun->member.run.nCharOfs + cursor.nOffset);
}


void ME_LButtonDown(ME_TextEditor *editor, int x, int y)
{
  ME_Cursor tmp_cursor;
  int is_selection = 0;
  
  editor->nUDArrowX = -1;
  
  y += ME_GetYScrollPos(editor);

  tmp_cursor = editor->pCursors[0];
  is_selection = ME_IsSelection(editor);

  ME_FindPixelPos(editor, x, y, &editor->pCursors[0], &editor->bCaretAtEnd);
  
  if (GetKeyState(VK_SHIFT)>=0)
  {
    editor->pCursors[1] = editor->pCursors[0];
  }
  else
  {
    if (!is_selection) {
      editor->pCursors[1] = tmp_cursor;
      is_selection = 1;
    }
  }
  ME_InvalidateSelection(editor);
  HideCaret(editor->hWnd);
  ME_MoveCaret(editor);
  ShowCaret(editor->hWnd);
  ME_ClearTempStyle(editor);
  ME_SendSelChange(editor);
}

void ME_MouseMove(ME_TextEditor *editor, int x, int y)
{
  ME_Cursor tmp_cursor;
  
  y += ME_GetYScrollPos(editor);

  tmp_cursor = editor->pCursors[0];
  /* FIXME: do something with the return value of ME_FindPixelPos */
  ME_FindPixelPos(editor, x, y, &tmp_cursor, &editor->bCaretAtEnd);
  
  if (tmp_cursor.pRun == editor->pCursors[0].pRun && 
      tmp_cursor.nOffset == editor->pCursors[0].nOffset)
    return;
  
  ME_InvalidateSelection(editor);
  editor->pCursors[0] = tmp_cursor;
  HideCaret(editor->hWnd);
  ME_MoveCaret(editor);
  ME_InvalidateSelection(editor);
  ShowCaret(editor->hWnd);
  ME_SendSelChange(editor);
}

static ME_DisplayItem *ME_FindRunInRow(ME_TextEditor *editor, ME_DisplayItem *pRow, 
                                int x, int *pOffset, int *pbCaretAtEnd)