deinit

pub fn deinit(self: *DropdownWidget) void {
    defer if (dvui.widgetIsAllocated(self)) dvui.widgetFree(self);
    defer self.* = undefined;
    if (self.drop != null) {
        self.drop.?.deinit();
        self.drop = null;
    }
    self.menuItem.deinit();
    self.menu.deinit();
}