Gtk.TextView.prototype.get_line_at_y

function get_line_at_y(y:Number):void {
    // Gjs wrapper for gtk_text_view_get_line_at_y()
}

Gets the Gtk.TextIter at the start of the line containing the coordinate y. y is in buffer coordinates, convert from window coordinates with Gtk.window_to_buffer_coords. If non-null, line_top will be filled with the coordinate of the top edge of the line.