About the LoadingPanel category

Directory LoadingPanel
1

LoadingPanel is a UI component, that gives you the possibility, to switch between a loading animation and the normal content. The idea is that you can show a loading animation instead of the normal content content, while the data for the normal content is queried in the background (with a own thread). This gives you the possibility to implement some kind of async ajax behavioure.

LoadingPanel uses the great Refresher Add-on (Vaadin Add-on Directory) by Henrik Paul.

The way a LoadingPanel works is simple:

  1. create: LoadingPanel loadingPanel = new LoadingPanel();
  2. set the normal content: loadingPanel.setNormalContent(any UI Component you want);
  3. show the loading animation: loadingPanel.showLoading();
  4. show the normal content: loadingPanel.showContent();

Under the hood the Refresher Add-on is used to poll periodically the server for UI changes. But this is not done all the time. It starts to polling when you call loadingPanel.showLoadingPanel(); and will stop when loadingPanel.showContent(); is called.