Lazy TreeDataGrid Items

The project contains an example of implementing lazy data loading for TreeDataGrid.

• Task - hierarchy entity
• LazyTreeDataGrid - replaces standard TreeDataGrid and creates specific vaadin DataProvider instance in case LazyTreeDataGridItems is passed. It registered in LazyTreeComponentApplication using ComponentRegistration.
• LazyHierarchicalDataGridDataProvider - vaadin DataProvider implementation that works with LazyTreeDataGridItems.
• TaskBrowse.TaskLazyTreeDataGridItems - sample implementation of LazyTreeDataGridItems. It uses DataManager to fetch data every time TreeDataGrid requested it. Query parameters are obtained from vaadin HierarchicalQuery object.