单击按钮更改treeitem的文本

Question

Is there a way to change the text of a TreeItem of TreeView, when I click a button? I tried to do something like shown in the oracle example http://docs.oracle.com/javafx/2/ui_controls/tree-view.htm but I don't want to change the TreeItem by click on it, but rather clicking on the button. In a second step, I want to work with context menu to open a window with a Textfield, where I can manually insert the text to change the treeitems naming.

package treeviewexample;    

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.Event;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;
import javafx.scene.control.TreeCell;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeView;
import javafx.scene.input.KeyCode;
import javafx.scene.input.KeyEvent;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import javafx.util.Callback;

public class TreeViewExample extends Application {

    @Override
    public void start(Stage primaryStage) { 

        TreeItem root = new TreeItem ("root");
        TreeItem item1 = new TreeItem ("Level1");
        TreeItem item2 = new TreeItem ("Level1");
        TreeItem item11 = new TreeItem ("Level2");
        TreeView tree = new TreeView ();
        item1.getChildren().add(item11);
        tree.setRoot(root);
        tree.getRoot().getChildren().addAll(item1, item2);
        tree.getRoot().setExpanded(true);
        StackPane rootPane = new StackPane();
        tree.setEditable(true);
        tree.setCellFactory(new Callback<TreeView<String>, TreeCell<String>>(){

            @Override
            public TreeCell<String> call(TreeView<String>  param) {
                return new TextFieldTreeCellImpl();                       
            }
        });            

        rootPane.getChildren().add(tree);

        Button btn = new Button();
        btn.setText("Change Name to 'TEST'");
        btn.setOnAction(new EventHandler<ActionEvent>() {

            @Override
            public void handle(ActionEvent event) {
                //CHANGE TEXT OF SELECTED TreeItem to "TEST"?
            }
        });
        rootPane.getChildren().add(btn);

        Scene scene = new Scene(rootPane);            

        primaryStage.setTitle("Hello World!");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        launch(args);
    }

    public class TextFieldTreeCellImpl extends TreeCell<String> {            

        private TextField textField;

        public TextFieldTreeCellImpl (){
        }    

        @Override
        public void startEdit() {
            super.startEdit();

            if (textField == null) {
                createTextField();
            }
            setText(null);
            setGraphic(textField);
            textField.selectAll();
        }

         public void cancelEdit() {
            super.cancelEdit();
            setText((String) getItem());
            setGraphic(getTreeItem().getGraphic());
        }

        @Override
        public void updateItem(String item, boolean empty){
            super.updateItem(item, empty);

             if (empty) {
                setText(null);
                setGraphic(null);
            } else {
                if (isEditing()) {
                    if (textField != null) {
                        textField.setText(getString());
                    }
                    setText(null);
                    setGraphic(textField);
                } else {
                    setText(getString());
                    setGraphic(getTreeItem().getGraphic());
                }
            }
        };


         private void createTextField() {
            textField = new TextField(getString());

            textField.setOnKeyReleased(new EventHandler<KeyEvent>() {

                @Override
                public void handle(KeyEvent t) {
                    if (t.getCode() == KeyCode.ENTER) {
                        commitEdit(textField.getText());
                    } else if (t.getCode() == KeyCode.ESCAPE) {
                        cancelEdit();
                    }
                } 
            });
        }
         private String getString() {
            return getItem() == null ? "" : getItem().toString();
        }   
    }
}

Answer 1

You can simply use setValue() method to change the text of TreeItem .

    btn.setOnAction(new EventHandler<ActionEvent>() {

        @Override
        public void handle(ActionEvent event) {
              desired_tree_item.setValue("TEST");
        }
    });