+/* See tui-winsource.h. */
+
+std::string
+tui_copy_source_line (const char **ptr, int line_no, int first_col,
+ int line_width, int ndigits)
+{
+ const char *lineptr = *ptr;
+
+ /* Init the line with the line number. */
+ std::string result;
+
+ if (line_no > 0)
+ {
+ if (ndigits > 0)
+ result = string_printf ("%*d ", ndigits, line_no);
+ else
+ {
+ result = string_printf ("%-6d", line_no);
+ int len = result.size ();
+ len = len - ((len / tui_tab_width) * tui_tab_width);
+ result.append (len, ' ');
+ }
+ }
+
+ int column = 0;
+ char c;
+ do
+ {
+ int skip_bytes;
+
+ c = *lineptr;
+ if (c == '\033' && skip_ansi_escape (lineptr, &skip_bytes))
+ {
+ /* We always have to preserve escapes. */
+ result.append (lineptr, lineptr + skip_bytes);
+ lineptr += skip_bytes;
+ continue;
+ }
+ if (c == '\0')
+ break;
+
+ ++lineptr;
+ ++column;
+
+ auto process_tab = [&] ()
+ {
+ int max_tab_len = tui_tab_width;
+
+ --column;
+ for (int j = column % max_tab_len;
+ j < max_tab_len && column < first_col + line_width;
+ column++, j++)
+ if (column >= first_col)
+ result.push_back (' ');
+ };
+
+ /* We have to process all the text in order to pick up all the
+ escapes. */
+ if (column <= first_col || column > first_col + line_width)
+ {
+ if (c == '\t')
+ process_tab ();
+ continue;
+ }
+
+ if (c == '\n' || c == '\r' || c == '\0')
+ {
+ /* Nothing. */
+ }
+ else if (c < 040 && c != '\t')
+ {
+ result.push_back ('^');
+ result.push_back (c + 0100);
+ }
+ else if (c == 0177)
+ {
+ result.push_back ('^');
+ result.push_back ('?');
+ }
+ else if (c == '\t')
+ process_tab ();
+ else
+ result.push_back (c);
+ }
+ while (c != '\0' && c != '\n' && c != '\r');
+
+ if (c == '\r' && *lineptr == '\n')
+ ++lineptr;
+ *ptr = lineptr;
+
+ return result;
+}