GWT popup is not centered when built within onClickHandler

Question

My aim is to use GWT.runSync to load the popup contents only when required.

If I construct my widget as:

public class CreateButton extends Button {

public CreateButton() {
    super("Create");
    buildUI();
}

private void buildUI() {

    final CreateWidget createWidget = new CreateWidget();

    final PopupPanel popupPanel = new PopupPanel(false);
    popupPanel.setWidget(createWidget);
    popupPanel.setGlassEnabled(true);
    popupPanel.setAnimationEnabled(true);
    addClickHandler(new ClickHandler() {

        @Override
        public void onClick(ClickEvent event) {
            popupPanel.center();

        }
    });
}
}

Then the popup will be centered correctly.

If I build the popup within the clickHandler:

public class CreateButton extends Button {

public CreateButton() {
    super("Create");
    buildUI();
}

private void buildUI() {

        @Override
        public void onClick(ClickEvent event) {
            final CreateWidget createWidget = new CreateWidget();

            final PopupPanel popupPanel = new PopupPanel(false);
            popupPanel.setWidget(createWidget);
            popupPanel.setGlassEnabled(true);
            popupPanel.setAnimationEnabled(true);
            addClickHandler(new ClickHandler() {

            popupPanel.center();

        }
    });

}
}

The popup will not center correctly. I have tried using setPositionAndShow, however the supplied offsets are 12, even though the CreateWidget is actually about 200px for both width and height.

I want to use the second method so I can eventually use GWT.runAsync within the onClick as CreateWidget is very complex.

I am using GWT-2.1.1

Answer 1

Seems to work by delaying the call to center. Perhaps a once off Timer would work as well. Delaying the call also works when wrapping buildUI within GWT.runAsync

public class CreateButton extends Button {

    public CreateButton() {
        super("Create");
        buildUI();
    }

    private void buildUI() {

        @Override
        public void onClick(ClickEvent event) {
            final CreateWidget createWidget = new CreateWidget();

            final PopupPanel popupPanel = new PopupPanel(false);
            popupPanel.setWidget(createWidget);
            popupPanel.setGlassEnabled(true);
            popupPanel.setAnimationEnabled(true);
            addClickHandler(new ClickHandler() {

                Scheduler.get().scheduleFixedDelay(new RepeatingCommand() {

                    @Override
                    public boolean execute() {

                        popupPanel.center();
                        return false;

                    }
                }, 50); //a value greater than 50 maybe needed here.
            });    
        }
    }

}
}