@Override
public void containerItemSetChange(com.vaadin.data.Container.ItemSetChangeEvent event) {
super.containerItemSetChange(event);
if (getContainerDataSource() instanceof Filterable) {
boolean hasFilters = !((Filterable) getContainerDataSource()).getContainerFilters().isEmpty();
if (!hasFilters) {
/*
* If Container is not filtered then the itemsetchange is caused
* by either adding or removing items to the container. To
* prevent a memory leak we should cleanup the expanded list
* from items which was removed.
*
* However, there will still be a leak if the container is
* filtered to show only a subset of the items in the tree and
* later unfiltered items are removed from the container. In
* that case references to the unfiltered item ids will remain
* in the expanded list until the Tree instance is removed and
* the list is destroyed, or the container data source is
* replaced/updated. To force the removal of the removed items
* the application developer needs to a) remove the container
* filters temporarly or b) re-apply the container datasource
* using setContainerDataSource(getContainerDataSource())
*/
cleanupExpandedItems();
}
}
}
/**
* Sets the Container that serves as the data source of the viewer.
*
* @see com.vaadin.data.Container.Viewer#setContainerDataSource(Container)
*/
@Override
public void setContainerDataSource(Container newDataSource) {
if (newDataSource == null) {
newDataSource = new HierarchicalContainer();
}
// Assure that the data source is ordered by making unordered
// containers ordered by wrapping them
if (Container.Hierarchical.class.isAssignableFrom(newDataSource.getClass())) {
super.setContainerDataSource(newDataSource);
} else {
super.setContainerDataSource(new ContainerHierarchicalWrapper(newDataSource));
}
/*
* Ensure previous expanded items are cleaned up if they don't exist in
* the new container
*/
if (expanded != null) {
/*
* We need to check that the expanded-field is not null since
* setContainerDataSource() is called from the parent constructor
* (AbstractSelect()) and at that time the expanded field is not yet
* initialized.
*/
cleanupExpandedItems();
}
}