Wt

I want to create a popup widget which appears after a button click.

Here's my code:

#include <Wt/WPopupWidget>
#include <Wt/WText>
#include <Wt/WPushButton>

Wt::WApplication* createApplication(const Wt::WEnvironment& env)
{
    Wt::WApplication *app = new Wt::WApplication(env);

    Wt::WPushButton *btn = new Wt::WPushButton("click", app->root());

    Wt::WPopupWidget *popup = new Wt::WPopupWidget(new Wt::WText("popup"), app);
    popup->setTransient(true);
    popup->setAnchorWidget(btn);

    btn->clicked().connect(popup, &Wt::WPopupWidget::show);

    return app;
}

The problem is that the popup does not appear on the first button click when the transient option set to true: popup->setTransient(true). All further clicks are processed fine.

Also I've noticed that the popup html element gets proper absolute position after the first click, but that click does not change its 'display: none' css rule.