internal override int Length(string str, int offset)
{
if (string.IsNullOrEmpty(str))
{
return(0);
}
if (offset < 0 || offset >= str.Length)
{
throw PSTraceSource.NewArgumentException(nameof(offset));
}
try
{
var valueStrDec = new ValueStringDecorated(str);
if (valueStrDec.IsDecorated)
{
str = valueStrDec.ToString(OutputRendering.PlainText);
}
int length = 0;
for (; offset < str.Length; offset++)
{
length += _rawUserInterface.LengthInBufferCells(str[offset]);
}
return(length);
}
catch
{
// thrown when external host rawui is not implemented, in which case
// we will fallback to the default value.
return(base.Length(str, offset));
}
}
/// <summary>
/// Truncate from the tail of the string.
/// </summary>
/// <param name="str">String that may contain VT escape sequences.</param>
/// <param name="offset">
/// When the string doesn't contain VT sequences, it's the starting index.
/// When the string contains VT sequences, it means starting from the 'n-th' char that doesn't belong to a escape sequence.</param>
/// <param name="displayCells">Number of buffer cells to fit in.</param>
/// <returns>Number of non-escape-sequence characters from head of the string that can fit in the space.</returns>
internal int TruncateTail(string str, int offset, int displayCells)
{
var valueStrDec = new ValueStringDecorated(str);
if (valueStrDec.IsDecorated)
{
str = valueStrDec.ToString(OutputRendering.PlainText);
}
return(GetFitLength(str, offset, displayCells, startFromHead: true));
}
/// <summary>
/// Truncate from the head of the string.
/// </summary>
/// <param name="str">String that may contain VT escape sequences.</param>
/// <param name="displayCells">Number of buffer cells to fit in.</param>
/// <returns>Number of non-escape-sequence characters from head of the string that should be skipped.</returns>
internal int TruncateHead(string str, int displayCells)
{
var valueStrDec = new ValueStringDecorated(str);
if (valueStrDec.IsDecorated)
{
str = valueStrDec.ToString(OutputRendering.PlainText);
}
int tailCount = GetFitLength(str, offset: 0, displayCells, startFromHead: false);
return(str.Length - tailCount);
}
/// <summary>
/// Calculate the buffer cell length of the given string.
/// </summary>
/// <param name="str">String that may contain VT escape sequences.</param>
/// <param name="offset">
/// When the string doesn't contain VT sequences, it's the starting index.
/// When the string contains VT sequences, it means starting from the 'n-th' char that doesn't belong to a escape sequence.</param>
/// <returns>Number of buffer cells the string needs to take.</returns>
internal virtual int Length(string str, int offset)
{
if (string.IsNullOrEmpty(str))
{
return(0);
}
var valueStrDec = new ValueStringDecorated(str);
if (valueStrDec.IsDecorated)
{
str = valueStrDec.ToString(OutputRendering.PlainText);
}
int length = 0;
for (; offset < str.Length; offset++)
{
length += CharLengthInBufferCells(str[offset]);
}
return(length);
}
