Treeitem contains a row of data (
treerow), and an optional treechildren.
If the component doesn't contain a
treechildren, it is a leaf node that doesn't accept any child items.
If it contains a
treechildren, it is a branch node that might contain other items.
For a branch node, an +/- button will appear at the beginning of the row, such that user could open and close the item by clicking on the +/- button.
<window title="tree demo" border="normal" width="400px"> <tree id="tree" width="90%"> <treecols sizable="true"> <treecol label="Name" /> <treecol label="Description" /> </treecols> <treechildren> <treeitem> <treerow> <treecell> <image src="/img/folder.gif" /> Item 1 </treecell> <treecell> <textbox value="Item 1 description" /> </treecell> </treerow> </treeitem> <treeitem> <treerow> <treecell label="Item 2" /> <treecell label="Item 2 description" /> </treerow> <treechildren> <treeitem open="false"> <treerow> <treecell label="Item 2.1"> <image src="/img/folder.gif" /> </treecell> </treerow> <treechildren> <treeitem> <treerow> <treecell label="Item 2.1.1" /> </treerow> </treeitem> </treechildren> </treeitem> </treechildren> </treeitem> <treeitem label="Item 3" /> </treechildren> </tree> </window>
More examples please refer to Tree
Label and Image
Treeitem provides Treeitem.setImage(String) and Treeitem.setLabel(String) to simplify the assignment of image and label to a treeitem. However, they are actually placed in the first treecell (of the child treerow). Furthermore, if the treecell or treerow are not created, they will be created automatically. For example,
is equivalent to
<treeitem> <treerow> <treecell label="hello"/> </treerow>
It also means you cannot attach a treerow child to the treeitem, after setImage or setLabel was invoked. It means, though a bit subtle, the following will cause an exception:
<treeitem label="hello"> <!-- treerow is created automatically because of setLabel --> <treerow/> <!-- exception since only one treerow is allowed per treeitem --> </treeitem>
Denotes user has opened or closed a component. It is useful to implement load-on-demand by listening to the onOpen event, and creating components when the first time the component is opened.
- Inherited Supported Events: XulElement