Tree displays a set of hierarchical data, contains nodes (not only one root node is allowed), and a node could have subnodes. It internally handles scrolling. The following example shows a tree with 2 root nodes ('Node A', and 'Node D'), the first has 2 subnodes (a selected 'Node B' and 'Node C'), the collapsed 'Node D' includes one node.

<tree selection="multiple">
  <node text="Node A" icon="image.gif">
    <node text="Node B" icon="image.gif" selected="true" />
    <node text="Node C" icon="image.gif" />
  <node text="Node D" expanded="false">
    <node text="Node E" icon="image.gif" />

selectionchoicesinglePossible values are: single, interval, and multiple. For the default single value the selection can only contain one path at a time, for interval the selection can only be contiguous (of the currently visible nodes), and for the multiple value the selection can contain any number of nodes that are not necessarily contiguous.
anglebooleanfalseTo specify to draw lines detailing the relationships between nodes.
line, and selection parameters are similar to list
name, enabled, visible, tooltip, property, width, height, colspan, rowspan, weightx, weighty, halign, and valign parameters are similar to component
actionCalls the method whenever the selection changes.
performCalls the method whenever a double-click event occurs.
expandThe listener that's notified when the tree expands a node.
collapseCalled whenever a node in the tree has been collapsed.


Tree node is similar to list item, but maybe contains subnodes, and has collapse control.

selectedbooleanfalseTrue if currently selected.
expandedbooleantrueEnsures that the node is expanded if true, otherwise collapsed.
name, enabled, text, icon, alignment, tooltip, and property parameters are similar to combobox choice
Right arrowExpands current collapsed node, or selects its first subnode
Left arrowCollapses current expanded node, or selects its parent node
Up arrowSelects previous node
Down arrowSelects next node
HomeSelects first node
EndSelects last node
Page UpSelects node one view up
Page DownSelects node one view down
+ShiftExtends selection
+CtrlSet lead node
SpaceSelects lead node
Ctrl-A, Ctrl-SlashSelects all
Ctrl-BackslashDeselects all
Tab, Shift-TabNavigate forward, backward