Wt

Hi.

It seems setting row height on a treeview to a adjusting value (like em) confuses the treeview

and the "Loading" image is not correctly replaced when scrolling.

In the example provided below simple scroll to the bottom and you'll see that the values are not displayed.

Wt 4.4.0 / Windows10 / FireFox

class App : public Wt::WApplication {
public:
    App(const Wt::WEnvironment& env) : Wt::WApplication(env)
    {

    }

    void initialize() override
    {
        Wt::WApplication::initialize();

        auto tree = root()->addWidget(std::make_unique<Wt::WTreeView>());
        tree->resize(400, 600);

        std::shared_ptr<Wt::WStringListModel> _model(new Wt::WStringListModel);
        tree->setModel(_model);

        std::vector<Wt::WString> data;

        for(int index = 0; index < 1000; ++index)
        {
            Wt::WString d("1");
            data.push_back(d);
        }

        _model->setStringList(data);

        const Wt::WLength lineHeight(1.5, Wt::LengthUnit::FontEm);
        tree->setRowHeight(lineHeight);
    }
};