Adding nodes to a TreeItem in JavaFX - javafx

Question

I have a TreeItem<String> object.
I would like to put a button in it.
Button button = new Button("Hello!");
root.setGraphic(button); // root is the TreeItem object
Not bad, but I would like to freely position this button. I would like to the right of "Root".
Changing the button's layout X doesn't seem to do anything. How can I do this then?

Answer 1

You can create custom class extending HBox class and containing constructor declarations with Label and Button initialization. Next, you can use this class to specify TreeView<T> and TreeItem<T> generic types. Sample of such simple HBox custom class can look like this:
import javafx.geometry.Pos;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.layout.HBox;
public class CustomItem extends HBox {
private Label boxText;
private Button boxButton;
CustomItem(Label txt) {
super();
this.boxText = txt;
this.getChildren().add(boxText);
this.setAlignment(Pos.CENTER_LEFT);
}
CustomItem(Label txt, Button bt) {
super(5);
this.boxText = txt;
this.boxButton = bt;
this.getChildren().addAll(boxText, boxButton);
this.setAlignment(Pos.CENTER_LEFT);
}
}
And the use of it in practice can look like shown below:
import javafx.application.Application;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeView;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
public class TreeViewDemo extends Application {
public Parent createContent() {
/* layout */
BorderPane layout = new BorderPane();
/* layout -> center */
/* initialize TreeView<CustomItem> object */
TreeView<CustomItem> tree = new TreeView<CustomItem>();
/* initialize tree root item */
TreeItem<CustomItem> root = new TreeItem<CustomItem>(new CustomItem(new Label("Root")));
/* initialize TreeItem<CustomItem> as container for CustomItem object */
TreeItem<CustomItem> node = new TreeItem<CustomItem>(new CustomItem(new Label("Node 1"), new Button("Button 1")));
/* add node to root */
root.getChildren().add(node);
/* set tree root */
tree.setRoot(root);
/* add items to the layout */
layout.setCenter(tree);
return layout;
}
#Override
public void start(Stage stage) throws Exception {
stage.setScene(new Scene(createContent()));
stage.setWidth(200);
stage.setHeight(200);
stage.show();
}
public static void main(String args[]) {
launch(args);
}
}
Effect will look like this:

Answer 2

The quick way will be not to set the valueProperty of tree item and add the desired value as text (or label) to the graphicProperty.
root.setValue("");
Text text = new Text("Root");
Button button = new Button("Hello!");
HBox hbox = new HBox(5);
hbox.getChildren().addAll(text, button);
root.setGraphic(vbox);
The other long way, will be looking up the sub node of tree item and change its properties accordingly.
Edit note: Well it would more appropriate to use HBox instead of VBox. I was in hurry :)