JavaFX Tutorial - JavaFX TreeView

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The TreeView UI control provides us a way to present tree structures. A tree has a root node which contains all the hierarchical values.

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeView;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
/*w  w  w . j a v  a 2s . c o  m*/
public class Main extends Application {
  public static void main(String[] args) {
    launch(args);
  }

  @Override
  public void start(Stage primaryStage) {
     TreeItem<String> rootItem = new TreeItem<>("Root");
    rootItem.setExpanded(true);

    TreeItem<String> item = new TreeItem<>("A");
    rootItem.getChildren().add(item);
    
    item = new TreeItem<>("B");
    rootItem.getChildren().add(item);

    TreeView<String> tree = new TreeView<>(rootItem);
    StackPane root = new StackPane();
    root.getChildren().add(tree);
    primaryStage.setScene(new Scene(root, 300, 250));
    primaryStage.show();
  }
}

The code above generates the following result.

Creating Tree Views

When creating a tree view we usually start with building TreeItem objects for the root. Then we add the root to the tree view and create other tree item objects and add them to the root.

We can a graphical icon to tree item by the setGraphic method or using its constructor. The recommended size for icons is 16x16.

The setExpanded method called on the root item defines the initial appearance of the tree view item.

The following code create a dynamic tree from the local file system.

import java.io.File;
//from ww w . jav  a 2s. c om
import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeView;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class Main extends Application {
  public static void main(String[] args) {
    launch(args);
  }

  private TreeItem<File> createNode(final File f) {
    return new TreeItem<File>(f) {
      private boolean isLeaf;
      private boolean isFirstTimeChildren = true;
      private boolean isFirstTimeLeaf = true;

      @Override
      public ObservableList<TreeItem<File>> getChildren() {
        if (isFirstTimeChildren) {
          isFirstTimeChildren = false;
          super.getChildren().setAll(buildChildren(this));
        }
        return super.getChildren();
      }

      @Override
      public boolean isLeaf() {
        if (isFirstTimeLeaf) {
          isFirstTimeLeaf = false;
          File f = (File) getValue();
          isLeaf = f.isFile();
        }
        return isLeaf;
      }

      private ObservableList<TreeItem<File>> buildChildren(
          TreeItem<File> TreeItem) {
        File f = TreeItem.getValue();
        if (f == null) {
          return FXCollections.emptyObservableList();
        }
        if (f.isFile()) {
          return FXCollections.emptyObservableList();
        }
        File[] files = f.listFiles();
        if (files != null) {
          ObservableList<TreeItem<File>> children = FXCollections
              .observableArrayList();
          for (File childFile : files) {
            children.add(createNode(childFile));
          }
          return children;
        }
        return FXCollections.emptyObservableList();
      }
    };
  }

  @Override
  public void start(Stage stage) {
    Scene scene = new Scene(new Group(), 300, 300);
    VBox vbox = new VBox();

    TreeItem<File> root = createNode(new File("c:/"));
    TreeView treeView = new TreeView<File>(root);

    vbox.getChildren().add(treeView);
    ((Group) scene.getRoot()).getChildren().add(vbox);

    stage.setScene(scene);
    stage.show();
  }
}

The code above generates the following result.

User Domain Model

The following code shows how to use user domain model data with the TreeView.

An Employee class is created to capture the user domain model, and the code uses a loop to add all employee to the tree view.

/*// ww  w  . ja v  a2s  .  c  o  m
 * Copyright (c) 2008, 2014, Oracle and/or its affiliates.
 * All rights reserved. Use is subject to license terms.
 *
 * This file is available and licensed under the following license:
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  - Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  - Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the distribution.
 *  - Neither the name of Oracle nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
import java.util.Arrays;
import java.util.List;

import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeView;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

public class Main extends Application {
    List<Employee> employees = Arrays.<Employee>asList(
            new Employee("a1", "A"),
            new Employee("a2", "A"),
            new Employee("e1", "E"));
    private final Node rootIcon =  new ImageView(new Image(getClass().getResourceAsStream("root.png")));
    TreeItem<String> rootNode = new TreeItem<String>("Root",rootIcon);

    public static void main(String[] args) {
        Application.launch(args);
    }

    @Override
    public void start(Stage stage) {
        rootNode.setExpanded(true);
        for (Employee employee : employees) {
            TreeItem<String> empLeaf = new TreeItem<String>(employee.getName());
            boolean found = false;
            for (TreeItem<String> depNode : rootNode.getChildren()) {
                if (depNode.getValue().contentEquals(employee.getDepartment())){
                    depNode.getChildren().add(empLeaf);
                    found = true;
                    break;
                }
            }
            if (!found) {
                TreeItem depNode = new TreeItem(employee.getDepartment());
                rootNode.getChildren().add(depNode);
                depNode.getChildren().add(empLeaf);
            }
        }
        stage.setTitle("Tree View Sample");
        VBox box = new VBox();
        final Scene scene = new Scene(box, 400, 300);
        scene.setFill(Color.LIGHTGRAY);

        TreeView<String> treeView = new TreeView<String>(rootNode);
        treeView.setShowRoot(true);
        treeView.setEditable(true);
        box.getChildren().add(treeView);
        stage.setScene(scene);
        stage.show();
    }
    public static class Employee {

        private final SimpleStringProperty name;
        private final SimpleStringProperty department;

        private Employee(String name, String department) {
            this.name = new SimpleStringProperty(name);
            this.department = new SimpleStringProperty(department);
        }

        public String getName() {
            return name.get();
        }

        public void setName(String fName) {
            name.set(fName);
        }

        public String getDepartment() {
            return department.get();
        }

        public void setDepartment(String fName) {
            department.set(fName);
        }
    }
}

New Tree Items on Demand

/*/*w  ww. j  a v  a  2 s .c o m*/
 * Copyright (c) 2008, 2014, Oracle and/or its affiliates.
 * All rights reserved. Use is subject to license terms.
 *
 * This file is available and licensed under the following license:
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  - Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  - Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the distribution.
 *  - Neither the name of Oracle nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

import java.util.Arrays;
import java.util.List;

import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.event.ActionEvent;
import javafx.scene.Scene;
import javafx.scene.control.ContextMenu;
import javafx.scene.control.MenuItem;
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.VBox;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
 
public class Main extends Application {
    List<Employee> employees = Arrays.<Employee>asList(
            new Employee("Jacob Smith", "Accounts Department"),
            new Employee("Judy Mayer", "IT Support"),
            new Employee("Gregory Smith", "IT Support"));
    TreeItem<String> rootNode = 
        new TreeItem<>("MyCompany Human Resources");
 
    public static void main(String[] args) {
        Application.launch(args);
    }
 
    @Override
    public void start(Stage stage) {
        rootNode.setExpanded(true);
        for (Employee employee : employees) {
            TreeItem<String> empLeaf = new TreeItem<>(employee.getName());
            boolean found = false;
            for (TreeItem<String> depNode : rootNode.getChildren()) {
                if (depNode.getValue().contentEquals(employee.getDepartment())){
                    depNode.getChildren().add(empLeaf);
                    found = true;
                    break;
                }
            }
            if (!found) {
                TreeItem depNode = new TreeItem(employee.getDepartment());
                rootNode.getChildren().add(depNode);
                depNode.getChildren().add(empLeaf);
            }
        }
 
        stage.setTitle("Tree View Sample");
        VBox box = new VBox();
        final Scene scene = new Scene(box, 400, 300);
        scene.setFill(Color.LIGHTGRAY);
 
        TreeView<String> treeView = new TreeView<>(rootNode);
        treeView.setEditable(true);
        treeView.setCellFactory((TreeView<String> p) -> 
            new TextFieldTreeCellImpl());
 
        box.getChildren().add(treeView);
        stage.setScene(scene);
        stage.show();
    }
 
    private final class TextFieldTreeCellImpl extends TreeCell<String> {
 
        private TextField textField;
        private final ContextMenu addMenu = new ContextMenu();
 
        public TextFieldTreeCellImpl() {
            MenuItem addMenuItem = new MenuItem("Add Employee");
            addMenu.getItems().add(addMenuItem);
            addMenuItem.setOnAction((ActionEvent t) -> {
                TreeItem newEmployee = 
                    new TreeItem<>("New Employee");
                getTreeItem().getChildren().add(newEmployee);
            });
        }
 
        @Override
        public void startEdit() {
            super.startEdit();
 
            if (textField == null) {
                createTextField();
            }
            setText(null);
            setGraphic(textField);
            textField.selectAll();
        }
 
        @Override
        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());
                    if (
                        !getTreeItem().isLeaf()&&getTreeItem().getParent()!= null
                    ){
                        setContextMenu(addMenu);
                    }
                }
            }
        }
        
        private void createTextField() {
            textField = new TextField(getString());
            textField.setOnKeyReleased((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();
        }
    }
 
    public static class Employee {
 
        private final SimpleStringProperty name;
        private final SimpleStringProperty department;
 
        private Employee(String name, String department) {
            this.name = new SimpleStringProperty(name);
            this.department = new SimpleStringProperty(department);
        }
 
        public String getName() {
            return name.get();
        }
 
        public void setName(String fName) {
            name.set(fName);
        }
 
        public String getDepartment() {
            return department.get();
        }
 
        public void setDepartment(String fName) {
            department.set(fName);
        }
    }
}

The code above generates the following result.

Cell Factories

The cell factory can add TreeCell with special functions to a single TreeItem in the TreeView.

/*//ww w. j av  a2  s .  co m
 * Copyright (c) 2008, 2014, Oracle and/or its affiliates.
 * All rights reserved. Use is subject to license terms.
 *
 * This file is available and licensed under the following license:
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  - Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  - Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the distribution.
 *  - Neither the name of Oracle nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
 import java.util.Arrays;
import java.util.List;

import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.scene.Scene;
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.VBox;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

public class Main extends Application {
  List<Employee> employees = Arrays.<Employee> asList(new Employee(
      "Jacob Smith", "Accounts Department"), new Employee("Isabella Johnson",
      "Accounts Department"), new Employee("Mike Graham", "IT Support"),
      new Employee("Judy Mayer", "IT Support"), new Employee("Gregory Smith",
          "IT Support"));
  TreeItem<String> rootNode;

  public static void main(String[] args) {
    Application.launch(args);
  }

  public Main() {
    this.rootNode = new TreeItem<>("MyCompany Human Resources");
  }

  @Override
  public void start(Stage stage) {
    rootNode.setExpanded(true);
    for (Employee employee : employees) {
      TreeItem<String> empLeaf = new TreeItem<>(employee.getName());
      boolean found = false;
      for (TreeItem<String> depNode : rootNode.getChildren()) {
        if (depNode.getValue().contentEquals(employee.getDepartment())) {
          depNode.getChildren().add(empLeaf);
          found = true;
          break;
        }
      }
      if (!found) {
        TreeItem<String> depNode = new TreeItem<>(employee.getDepartment());
        rootNode.getChildren().add(depNode);
        depNode.getChildren().add(empLeaf);
      }
    }

    stage.setTitle("Tree View Sample");
    VBox box = new VBox();
    final Scene scene = new Scene(box, 400, 300);
    scene.setFill(Color.LIGHTGRAY);

    TreeView<String> treeView = new TreeView<>(rootNode);
    treeView.setEditable(true);
    treeView
        .setCellFactory((TreeView<String> p) -> new TextFieldTreeCellImpl());

    box.getChildren().add(treeView);
    stage.setScene(scene);
    stage.show();
  }

  private final 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();
    }

    @Override
    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((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();
    }
  }

  public static class Employee {

    private final SimpleStringProperty name;
    private final SimpleStringProperty department;

    private Employee(String name, String department) {
      this.name = new SimpleStringProperty(name);
      this.department = new SimpleStringProperty(department);
    }

    public String getName() {
      return name.get();
    }

    public void setName(String fName) {
      name.set(fName);
    }

    public String getDepartment() {
      return department.get();
    }

    public void setDepartment(String fName) {
      department.set(fName);
    }
  }
}

The code above generates the following result.

Tree Cell Editors

We can use the following tree cell editors available.

• CheckBoxTreeCell
• ChoiceBoxTreeCell
• ComboBoxTreeCell
• TextFieldTreeCell

There classes extend the TreeCell implementation to render a particular control inside the cell.

The following code creates a tree view with check box tree item.

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.CheckBoxTreeItem;
import javafx.scene.control.TreeView;
import javafx.scene.control.cell.CheckBoxTreeCell;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
/*from  www .  j a  v  a2 s.co m*/
public class Main extends Application {
  public static void main(String[] args) {
    launch(args);
  }
  @Override
  public void start(Stage primaryStage) {
    CheckBoxTreeItem<String> rootItem = new CheckBoxTreeItem<>("A");
    rootItem.setExpanded(true);

    TreeView tree = new TreeView(rootItem);
    tree.setEditable(true);

    tree.setCellFactory(CheckBoxTreeCell.forTreeView());

    CheckBoxTreeItem<String> checkBoxTreeItem = new CheckBoxTreeItem<>("a");
    rootItem.getChildren().add(checkBoxTreeItem);

    checkBoxTreeItem = new CheckBoxTreeItem<>("b");
    rootItem.getChildren().add(checkBoxTreeItem);
    
    tree.setRoot(rootItem);

    StackPane root = new StackPane();
    root.getChildren().add(tree);
    primaryStage.setScene(new Scene(root, 300, 250));
    primaryStage.show();
  }
}

The code above generates the following result.

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