GWT in Action, Second Edition

10.5. Walking through a CellTree

A CellTree provides a tree-like structure to data representation, as in figure 10.16. Be careful, though, not to confuse it with the more basic Tree widget (if possible, you should use CellTree over Tree). In our CellTree example we’ll be able to navigate a list of photos, dropping down the hierarchy of year, month, and date, in that order.

Figure 10.16. Example of the CellTree widget in action.

Creating a CellTree is done this way:

CellTree photoList = new CellTree(treeViewModel, open_node);

Typically the node to show (second parameter) is set to null, and that will reveal the tree’s root nodes (that’s how ...