CellList with cells of CellTree

Question

I used the gwt CellList example to implement a cell-based listbox. It used TextCell cells to represent the data, as it was just text, and worked perfectly.

Now I have to extend this list to include elements of type "tree" (I mean that you can click on some element of the list, and if it's not a leaf, it is opened and displays the information of its children). So I've implemented a CellTree-based widget. (CellTree)

My problem is that I don't know how to insert items of type "tree", which are really CellTrees, into my CellList.

The only approach I could imagine was to create a new type of cell that represents the CellTree, extending "AbstractCell", and use it as the CellList items.

My implementation is:

private class TreeCell extends AbstractCell<CellTreeListBox> {

    public TreeCell() {}

    @Override
    public void render(Context context, CellTreeListBox value,
        SafeHtmlBuilder sb)
    {
      sb.appendEscaped(value.getElement().getInnerHTML());
    }
}

This, once included in a CellList, displays only the root nodes, but when I click on them they don't get opened! so this approach doesn't keep the events neither the functionality of the selectionModel...

So I don't know if it's possible to implement a cell that represents a whole CellTree, and keeps its events and functionalities (if you click, the node is opened and information of its children is displayed, etc...).

I'd really appreciate any information about this!

Answer 1

You should replace your CellList with a CellTree.

Either that or replacing the CellList with some container panel (FlowPanel, VerticalPanel) in which you'd (manually) put widgets (Labels, or possibly CellWidget with a TextCell), and insert your CellTree in between them to show it. You'd then lose the other features of cell widgets though: SelectionModel, paging, etc.

In any case, ditch your CellList. You cannot embed widgets inside cell widgets.