Query about list_dialog()

[Tony Balinski]

Quoting YT Lim <ytlim23 at yahoo.com.au>:

> Not sure if this has been asked before. Is there a way
> to move the highlight bar to a specific line in the
> list_dialog box when it pops up?
>
> Send instant messages to your online friends http://au.messenger.yahoo.com

No there is not. For that sort of thing I add a prefix to the line I
would like to have highlighted (usually ">> ") and another ("   ") to
all the other lines. If the list dialog returns an empty string (when
no line was selected), I look in the list string for a line with my
"pre-selected" prefix. Something like:

  list = "a\nb\nc" # three line list string
  # "pre-select" b
  selline = "b"
  # add prefix to all lines
  list_for_dlg = "\n" replace_in_string(list, "^", "   ", "regex") "\n"
  list_for_dlg = replace_in_string(list_for_dlg, "\n" selline "\n", \
                                                 "\n>> " selline "\n", \
                                                 "regex")
  # call
  sel = list_dialog("select a line", list_for_dlg, "OK", "Cancel")
  if ($list_dialog_button != 1)
    return
  if (sel == "") {
    # remove lines with non-selected prefix
    sel = replace_in_string(list_for_dlg, "^   .*\n", "", "regex")
    # remove "pre-selected" prefix
    sel = replace_in_string(sel, "^\\>\\> ", "", "regex")
    # remove newlines
    sel = replace_in_string(sel, "\n", "")
  } else {
    # remove any prefix on selected line returned by list_dialog()
    sel = replace_in_string(sel, "^.. ", "", "regex")
  }

It's a bit clumsy and visually rather unappealing, but it works well enough.

In future, extending list_dialog() could allow for preselecting a line (I did
some work on handling "keyword parameters" to functions, for calls like

  sel = list_dialog("choose a line", \
                    .select="multiple", \
                    .preselect=b, \
                    list, \
                    .buttons = {"OK", "Cancel"})


Tony