Readding Checkbox property in a tableview in javafx

Question

I am new to JavaFx. I have designed a table thorugh scenebuilder where in column 1 I have a button and in column 2 I have a checkbox. What I want to get the checkbox property when I click the button. But the problem is I am always getting false as output. here is my code

Model.java

private boolean Active;     
    public boolean isActive() {
        return Active;
    }   
    public void setActive(boolean active) {
        Active = active;
    }

In my controller class I have designed the initialize() method below way

Controller.java

@FXML
private TableView<Model> tableBuilding;
@FXML
private TableColumn<Model,Boolean> colActive;
@FXML
private TableColumn<Model,Model> colAction; 
 @Override
        public void initialize(URL arg0, ResourceBundle arg1) {
//Containing the button         
colAction.setCellFactory(col -> {
                Button ShowButton = new Button("Show");

                TableCell<Model, Model> cell = new TableCell<Model, Model>() {
                    @Override
                    //Updating with the number of row 
                    public void updateItem(Model building, boolean empty) {
                        super.updateItem(building, empty);
                        if (empty) {
                            setGraphic(null);
                        } else {
                            setGraphic(ShowButton);
                        }
                    }              
                };                                          
                ShowButton.setOnAction(event -> {

                TableRow row = cell.getTableRow();
                    Model building=(Model) row.getItem();


                    ObservableList<Model> data = tableBuilding.getItems();

                    for (Model item : data){
                        //check the boolean value of each item to determine checkbox state
                        System.out.println(item.isActive());
                    }

                });

                return cell ;
            });
//Containing the checkbox
colActive.setCellValueFactory(new PropertyValueFactory<Model,Boolean>("Active"));
        colActive.setCellFactory(tc -> new CheckBoxTableCell<>());   

}

here System.out.println(item.isActive()); is always retunrning false as output. How can I get the actual property of that checkbox? Can anyone help me please?

Answer 1

I believe you can simplify your controller a bit. Try changing your controller code to:

public class Controller {

    @FXML
    private TableView<Model> tableBuilding;
    @FXML
    private TableColumn<Model, Boolean> colActive;
    @FXML
    private TableColumn<Model, Model> colAction;

    @FXML
    public void initialize() {

        // Sample List
        ObservableList<Model> models = FXCollections.observableArrayList();
        models.addAll(
                new Model(),
                new Model(),
                new Model()
        );

        tableBuilding.setItems(models);

        //Containing the button
        colAction.setCellFactory(col -> {
            Button ShowButton = new Button("Show");

            TableCell<Model, Model> cell = new TableCell<>() {
                @Override
                //Updating with the number of row
                public void updateItem(Model building, boolean empty) {
                    super.updateItem(building, empty);
                    if (empty) {
                        setGraphic(null);
                    } else {
                        setGraphic(ShowButton);
                    }
                }
            };

            ShowButton.setOnAction(event -> {

                TableRow row = cell.getTableRow();
                Model building = (Model) row.getItem();

                System.out.println(building.getActive());

            });

            return cell;
        });

        //Containing the checkbox
        colActive.setCellValueFactory(new PropertyValueFactory<>("active"));
        colActive.setCellFactory(col -> new CheckBoxTableCell<>());

    }
}

Specifically, the last two lines of code; you shouldn't need to specify your own TableCell as the CheckBoxTableCell handles the updating of the Model on its own.

However, the Model class needs to be changed to update the Active field to a true property; otherwise, the TableView cannot update it properly. The line in your controller colActive.setCellValueFactory(new PropertyValueFactory<Model,Boolean>("Active")); tells the cell's value to be bound to a JavaFX Property in your Model class named Active , but there is no such property.

Here's the proper way to define the property:

public class Model {

    private SimpleBooleanProperty active = new SimpleBooleanProperty(true);

    public boolean getActive() {
        return active.get();
    }

    public SimpleBooleanProperty activeProperty() {
        return active;
    }

    public void setActive(boolean active) {
        this.active.set(active);
    }
}

Interestingly, this seems to be one of those cases where it's important to follow proper Java coding practices. The Active property should be lowercase here as well, not capitalized.