How to delete a specific TreeItem from the TreeView in javafx?

Question

I've got a TreeView called foodTree to which I've added some TreeItem . The code:

import javafx.application.Application ;
import javafx.scene.Scene ;
import javafx.event.* ;
import javafx.stage.* ;
import javafx.scene.layout.* ;
import javafx.scene.control.* ;
import javafx.geometry.* ;
import javafx.scene.control.cell.PropertyValueFactory ;
import javafx.collections.* ;

public class Tree extends Application
{
    TreeView foodTree ;

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

    @Override
    public void start(Stage window)
    {
        TreeItem<String> root, vegetables, fruits ;

        root = new TreeItem<>() ;
        root.setExpanded(true) ;

        vegetables = makeBranch("Vegies", root) ;
        makeBranch("Cabbage", vegetables) ;
        makeBranch("Beans", vegetables) ;

        fruits = makeBranch("Fruits", root) ;
        makeBranch("Apples", fruits) ;
        makeBranch("Mangoes", fruits) ;

        foodTree = new TreeView<>(root) ;
        foodTree.setShowRoot(false) ;
        foodTree.setPrefWidth(180) ;
        foodTree.setMaxSize(Region.USE_PREF_SIZE, Region.USE_PREF_SIZE) ;

        BorderPane b_pane = new BorderPane() ;
        b_pane.setLeft(foodTree) ;

        Scene scene = new Scene(b_pane, 300, 200) ;

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

    public TreeItem<String> makeBranch(String title, TreeItem<String> parent) 
    {
        TreeItem<String> item = new TreeItem<>(title) ;
        item.setExpanded(false) ;

        parent.getChildren().add(item) ;

        return item ;
    }   
}

I wish to know how to delete a TreeItem from the TreeView - how can I delete Mangoes so that it's not displayed in the TreeView ?

Answer 1

To remove a tree item, you need to remove it from the list returned by its parent's getChildren() method. If you have a reference to the item to be removed, this is straightforward. For example, if you do

// makeBranch("Mangoes", fruits) ;
TreeItem<String> mangoes = makeBranch("Mangoes", fruits) ;

then later you can simply remove the item from its parent:

mangoes.getParent().getChildren().remove(mangoes);

In this case, since you know the parent, you could also just do

fruits.getChildren().remove(mangoes);

You can also use any of the standard methods defined in List on the parent's getChildren() , eg

// remove any items from fruits whose value is "Mangoes":
fruits.getChildren().removeIf(treeItem -> treeItem.getValue().equals("Mangoes"));
// remove the first child from fruits:
fruits.getChildren().remove(0);