internal void SetLineLength(DocumentLine line, Int32 lineLength)
{
line._exactLength = lineLength;
_lineTree.UpdateNodeData(line._node);
}
internal void Remove(Int32 offset, Int32 length, DocumentUpdate update)
{
if (offset == 0 && length == _doc.Length)
{
// 清除后会有空行
update.LineNumberNeedUpdate = 1;
if (_lineTree.LineCount > 1)
{
update.RemovedStartLineNumber = 2;
update.RemovedLineCount = _lineTree.LineCount - 1;
}
// 全删，直接重置
_lineTree.Clear();
return;
}
DocumentLine line = _lineTree.GetLineByOffset(offset);
// 不允许在\r和\n之间删除文本
Int32 lineOffset = line.StartOffset;
Int32 lengthAfterDeletion = lineOffset + line._exactLength - offset;
if ((line._delimiterLength > 0 && length < lengthAfterDeletion) || (line._delimiterLength == 0 && length <= lengthAfterDeletion))
{
update.LineNumberNeedUpdate = line.LineNumber;
// 不需要删除行
SetLineLength(line, line._exactLength - length);
return;
}
Int32 removedLineNum = -1, removedLineCnt = 0;
DocumentLine firstLine = line;
Int32 lengthBeforeDeletion = offset - lineOffset;
DocumentLine nextLine = line.NextLine;
removedLineNum = line.LineNumber;
update.LineNumberNeedUpdate = removedLineNum;
if (lengthBeforeDeletion == 0)
{
++removedLineCnt;
// 当前行需要删除
_lineTree.RemoveLine(line);
firstLine = null;
}
else
{
++removedLineNum;
SetLineLength(line, line._exactLength - lengthAfterDeletion);
line._delimiterLength = 0;
}
line = nextLine;
length -= lengthAfterDeletion;
// 删除中间行
while (length > 0)
{
if (length < line._exactLength)
{
break;
}
nextLine = line.NextLine;
_lineTree.RemoveLine(line);
++removedLineCnt;
length -= line._exactLength;
line = nextLine;
}
if (line != null)
{
if (firstLine != null)
{
// 前置行没有删除，则合并这两行
SetLineLength(firstLine, firstLine._exactLength + (line._exactLength - length));
firstLine._delimiterLength = line._delimiterLength;
_lineTree.RemoveLine(line);
++removedLineCnt;
}
else
{
update.LineNumberNeedUpdate += removedLineCnt;
// 没有前置行了，保留该行
SetLineLength(line, line._exactLength - length);
}
}
else
{
update.LineNumberNeedUpdate = -1;
}
if (removedLineCnt > 0)
{
update.RemovedStartLineNumber = removedLineNum;
update.RemovedLineCount = removedLineCnt;
}
}