Using the JavaFX UI Controls - JavaFX 8: A Definitive Guide to Building Desktop, Mobile, and Embedded Java Clients - page 252

In addition, we want the first TitledPane in our example initially to be expanded, so the setExpandedPane()
method of the Accordion is used to accomplish this.
Now that you know how to create Accordion and TitledPane controls, we move on to the next tab,
SplitPane/TreeView/ListView.
Creating a TreeView
As you experienced in Steps 10 and 11 of the exercise, the TreeView shown in Figure 6-5 contains a hierarchical
structure of tree items, each of which may be expanded and collapsed. The code that defines and populates the
TreeView in the StarterApp program is shown in Listing 6-9.
Listing 6-9. The createSplitTreeListDemoNode() Method Located in StarterAppMain.java
Node createSplitTreeListDemoNode() {
TreeItem animalTree = new TreeItem("Animal");
animalTree.getChildren().addAll(new TreeItem("Lion"), new TreeItem("Tiger"), new
TreeItem("Bear"));
TreeItem mineralTree = new TreeItem("Mineral");
mineralTree.getChildren().addAll(new TreeItem("Copper"), new TreeItem("Diamond"), new
TreeItem("Quartz"));
TreeItem vegetableTree = new TreeItem("Vegetable");
vegetableTree.getChildren().addAll(new TreeItem("Arugula"), new TreeItem("Broccoli"),
new TreeItem("Cabbage"));
TreeItem root = new TreeItem("Root");
root.getChildren().addAll(animalTree, mineralTree, vegetableTree);
TreeView treeView = new TreeView(root);
treeView.setMinWidth(150);
treeView.setShowRoot(false);
treeView.setEditable(false);
ListView listView = new ListView(model.listViewItems);
SplitPane splitPane = new SplitPane();
splitPane.getItems().addAll(treeView, listView);
treeView.getSelectionModel().setSelectionMode(SelectionMode.SINGLE);
treeView.getSelectionModel().selectedItemProperty()
.addListener((ObservableValue observable, Object oldValue, Object newValue) -> {
TreeItem treeItem = (TreeItem) newValue;
if (newValue != null && treeItem.isLeaf()) {
model.listViewItems.clear();
for (int i = 1; i <= 10000; i++) {
model.listViewItems.add(treeItem.getValue() + " " + i);
}
}
});
return splitPane;
}