TreeView in FXML

Question

How can I create a TreeView in FXML including all the branches and components in it? I can't find documentation about it. There is just code about how to populate it but I want to do it in FXML so y can have the design apart of the logic.

Answer 1

There's no specific documentation for FXML (beyond the Introduction to FXML document): but there is no need for any. An element beginning with an uppercase character is an instruction to instantiate the class of that name, so

<TreeView></TreeView>

will instantiate a TreeView. Attributes correspond to properties, so if you needed you could do

<TreeView editable="true"></TreeView>

Nested elements beginning with lower case also correspond to properties, and will be set to the enclosed FXML structure. So you can create a tree view with code like

<TreeView fx:id = "treeView">
    <root>
        <TreeItem fx:id="rootItem" value="Root" expanded="true">
            <children>
                <TreeItem fx:id="child1" value="Child 1" expanded="true">
                    <children>
                        <TreeItem fx:id="child11" value="Child 1.1"></TreeItem>
                        <TreeItem fx:id="child12" value="Child 1.2"></TreeItem>
                    </children>
                </TreeItem>
                <TreeItem fx:id="child2" value="Child 2">
                    <children>
                        <TreeItem fx:id="child21" value="Child 2.1"></TreeItem>
                        <TreeItem fx:id="child22" value="Child 2.2"></TreeItem>
                    </children>
                </TreeItem>
            </children>
        </TreeItem>
    </root>
</TreeView>

You can, of course, see all the properties in the API documentation.