JavaFX Tree Scenario

Question

At present I am experimenting with trees in JavaFX and would like to know if the following scenario is possible? At present I have a tree structure that displays a checkbox for every tree node except the root node where I use a graphics icon. Now what I would like to combine with the above is for a textbox to appear when a node is selected, so that the user can edit the treeitems value/label. Can this be achieved in conjunction with what I have at present, cause I have the nasty feeling it probably is not possible in combination? If I use the TableView tutorial on the JavaFX website as an example. I'm curious to see what other peoples responses are in relation to this?

Answer 1

Yeah it's possible, I tried hacking up some really ugly buggy code which I won't paste here to verify an approach for this.
Approach was:
1. Create a TreeView as here => http://download.oracle.com/javafx/2.0/api/javafx/scene/control/TreeView.html
2. Type the TreeView as a new CheckedString utility class containing both a boolean value for the check and a string value for the check label.
3. On the root of the treeview set a graphic.
4. Create an editable TreeView cell factory as detailed in 13-9 and 13-10 here => http://download.oracle.com/javafx/2.0/ui_controls/table-view.htm
5. In this case you don't want to use the setContentDisplay method as is done in 13-9
6. In the editing tree cell, instead of setting the content display of the node, store two views on the field, one an editable view and another one readonly.
7. Editable view consists of a checkbox + textfield in a hbox.
8. Readonly view consists of just a labeled checkbox.
9. When the startEdit method is called, reject the call if the call is for the tree root (that way the root graphic is not editable).
10. In startEdit switch the state of the TreeCells current view to the editable view by setting the cells graphic to the edit view.
11. In the cancelEdit switch the state of the TreeCells current view to the readonly view by setting the cells graphic to the read only view.
12. In the updateItem, if it is the root item, just show the root graphic, otherwise query the current state of the TreeCell and refresh and show either the edit or read only view as appropriate (by switching the cells graphic).
Seems complicated, but you are also trying to design a reasonably complicated UI node. You will have to tweak the thing a bit to make it nice and usable. If at all possible, I'd advise a reconsidering the UI design and trying for something simpler.