paint_expander

function paint_expander(style:Gtk.Style, cr:cairo.Context, state_type:Gtk.StateType, widget:Gtk.Widget, detail:String, x:Number, y:Number, expander_style:Gtk.ExpanderStyle):void {
    // Gjs wrapper for gtk_paint_expander()
}

Draws an expander as used in Gtk.TreeView. x and y specify the center the expander. The size of the expander is determined by the "expander-size" style property of widget. (If widget is not specified or doesn't have an "expander-size" property, an unspecified default size will be used, since the caller doesn't have sufficient information to position the expander, this is likely not useful.) The expander is expander_size pixels tall in the collapsed position and expander_size pixels wide in the expanded position.