Gtk.TextBuffer.prototype.get_selection_bound

function get_selection_bound():Gtk.TextMark {
    // Gjs wrapper for gtk_text_buffer_get_selection_bound()
}

Returns the mark that represents the selection bound. Equivalent to calling Gtk.TextBuffer.prototype.get_mark to get the mark named "selection_bound", but very slightly more efficient, and involves less typing.

The currently-selected text in buffer is the region between the "selection_bound" and "insert" marks. If "selection_bound" and "insert" are in the same place, then there is no current selection. Gtk.get_selection_bounds is another convenient function for handling the selection, if you just want to know whether there's a selection and what its bounds are.