/// <summary>
///
/// </summary>
/// <param name="start"></param>
/// <param name="length"></param>
/// <param name="text"></param>
public void Substitute(int start, int length, string text)
{
if (MessageBlocks.Count == 0 || start < 0 || length < 0)
{
return;
}
int count = 0;
int startBlock = -1;
int endBlock = -1;
var blocks = new List <TextMessageBlock>();
for (int i = 0; i < MessageBlocks.Count; ++i)
{
if (start < count + MessageBlocks[i].Text.Length)
{
startBlock = i;
break;
}
count += MessageBlocks[i].Text.Length;
}
if (startBlock == -1)
{
return;
}
var indexInStartBlock = start - count;
for (int i = startBlock; i < MessageBlocks.Count; ++i)
{
if (start + length <= count + MessageBlocks[i].Text.Length)
{
endBlock = i;
break;
}
count += MessageBlocks[i].Text.Length;
}
if (endBlock == -1)
{
return;
}
var indexInEndBlock = start + length - count;
if (indexInStartBlock > 0)
{
blocks.Add(new TextMessageBlock(MessageBlocks[startBlock].Text.Substring(0, indexInStartBlock), MessageBlocks[startBlock].Foreground, MessageBlocks[startBlock].Background));
}
blocks.Add(new TextMessageBlock(text, MessageBlocks[startBlock].Foreground, MessageBlocks[startBlock].Background));
if (indexInEndBlock < MessageBlocks[endBlock].Text.Length)
{
blocks.Add(new TextMessageBlock(MessageBlocks[endBlock].Text.Substring(indexInEndBlock), MessageBlocks[endBlock].Foreground, MessageBlocks[endBlock].Background));
}
MessageBlocks.RemoveRange(startBlock, endBlock + 1 - startBlock);
MessageBlocks.InsertRange(startBlock, blocks);
UpdateInnerText();
}
