The key is to define the radio_button tiles to each have the same fixed width, large enough to accommodate the largest of your labels; for this, I would suggest defining a custom radio_button tile which may then be used through the remainder of the dialog definition, e.g.:
rb : radio_button
{
width = 18;
fixed_width = true;
}
test : dialog
{
spacer;
: boxed_column
{
label = "Test 1";
: radio_row
{
: rb { key = "tpol"; label = "Polyline"; }
: rb { key = "tmtx"; label = "MText"; }
}
spacer;
}
: boxed_column
{
label = "Test 2";
: radio_row
{
: rb { key = "ttep"; label = "Colour"; }
: rb { key = "ttem"; label = "Lineweight"; }
}
spacer;
}
ok_cancel;
}