GWT popup is not centered when built within onClickHandler - gwt2

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.
});
}
}
}
}