// Returns the left column in a range of the string.
internal static int CalculateLeftColumn(List <Rune> t, int start, int end, int width, int currentColumn)
{
if (t == null)
{
return(0);
}
(var dSize, _) = TextModel.DisplaySize(t, start, end);
if (dSize < width)
{
return(start);
}
int size = 0;
int tcount = end > t.Count - 1 ? t.Count - 1 : end;
int col = 0;
for (int i = tcount; i > start; i--)
{
var rune = t [i];
var s = Rune.ColumnWidth(rune);
size += s;
if (size >= dSize - width)
{
col = tcount - i + start;
if (start == 0 || col == start || (currentColumn == t.Count && (currentColumn - col > width)))
{
col++;
}
break;
}
}
return(col);
}
internal static int GetColFromX(List <Rune> t, int start, int x)
{
if (x < 0)
{
return(x);
}
int size = start;
var pX = x + start;
for (int i = start; i < t.Count; i++)
{
var r = t [i];
size += Rune.ColumnWidth(r);
if (i == pX || (size > pX))
{
return(i - start);
}
}
return(t.Count - start);
}
void RenderUstr(ConsoleDriver driver, ustring ustr, int col, int line, int width)
{
int byteLen = ustr.Length;
int used = 0;
for (int i = 0; i < byteLen;)
{
(var rune, var size) = Utf8.DecodeRune(ustr, i, i - byteLen);
var count = Rune.ColumnWidth(rune);
if (used + count >= width)
{
break;
}
driver.AddRune(rune);
used += count;
i += size;
}
for (; used < width; used++)
{
driver.AddRune(' ');
}
}
// Returns the size and length in a range of the string.
internal static (int size, int length) DisplaySize(List <Rune> t, int start = -1, int end = -1, bool checkNextRune = true)
{
if (t == null || t.Count == 0)
{
return(0, 0);
}
int size = 0;
int len = 0;
int tcount = end == -1 ? t.Count : end > t.Count ? t.Count : end;
int i = start == -1 ? 0 : start;
for (; i < tcount; i++)
{
var rune = t [i];
size += Rune.ColumnWidth(rune);
len += Rune.RuneLen(rune);
if (checkNextRune && i == tcount - 1 && t.Count > tcount && Rune.ColumnWidth(t [i + 1]) > 1)
{
size += Rune.ColumnWidth(t [i + 1]);
len += Rune.RuneLen(t [i + 1]);
}
}
return(size, len);
}
