java - Get Checkbox value in a table in JavaFX

Question

I have a table and it has a column with checkboxes.

On a button click I want to find out which checkboxes are checked and which are not. So far I managed to create checkboxes in a table. The code is as follows.

public class TTEs implements Initializable {

    @FXML
    private TableView<TestObject> tableReport;

    @FXML
    private TableColumn<TestObject, String> name;

    @FXML
    private TableColumn<TestObject, Boolean> checkbox;

    @FXML
    public void getValues() {        
        //the method will get what check boxes are checked (this part is the problem)
    }

    @Override
    public void initialize(URL arg0, ResourceBundle arg1) { 
        ObservableList<TestObject> data = FXCollections.observableArrayList();
        data.add(new TestObject("Test 1", true));
        data.add(new TestObject("Test 2", false));

        tableReport.setItems(data);

        name.setCellValueFactory(new PropertyValueFactory<TestObject, String>("name"));
        checkbox.setCellValueFactory(new PropertyValueFactory<TestObject, Boolean>("checked"));

        checkbox.setCellFactory(new Callback<TableColumn<TestObject, Boolean>,
            TableCell<TestObject, Boolean>>() {

            public TableCell<TestObject, Boolean> call(TableColumn<TestObject, Boolean> p) {
                return new CheckBoxTableCell<TestObject, Boolean>();
            }
        });
    }

    //CheckBoxTableCell for creating a CheckBox in a table cell
    public static class CheckBoxTableCell<S, T> extends TableCell<S, T> {
        private final CheckBox checkBox;
        private ObservableValue<T> ov;

        public CheckBoxTableCell() {
            this.checkBox = new CheckBox();
            this.checkBox.setAlignment(Pos.CENTER);

            setAlignment(Pos.CENTER);
            setGraphic(checkBox);
        } 

        @Override public void updateItem(T item, boolean empty) {
            super.updateItem(item, empty);
            if (empty) {
                setText(null);
                setGraphic(null);
            } else {
                setGraphic(checkBox);
                if (ov instanceof BooleanProperty) {
                    checkBox.selectedProperty().unbindBidirectional((BooleanProperty) ov);
                }
                ov = getTableColumn().getCellObservableValue(getIndex());
                if (ov instanceof BooleanProperty) {
                    checkBox.selectedProperty().bindBidirectional((BooleanProperty) ov);
                }
            }
        }
    }
}

When I debug, I find that:

        ov = getTableColumn().getCellObservableValue(getIndex());
        if (ov instanceof BooleanProperty) {
            checkBox.selectedProperty().bindBidirectional((BooleanProperty) ov);
        }

In the above condition, it never goes inside the if statement, meaning that the ov is not an instance of BooleanProperty. But when I print the class of ov,

System.out.println(ov.getClass().getName());

it prints as

javafx.beans.property.ReadOnlyObjectWrapper

ReadOnlyObjectWrapper is a subclass of BooleanProperty, so why is the instanceof check not working?

Answer 1

Tested on Java 8.
Only 4 simple things.

1) Make CheckBoxCellFactory class. Put somewhere in your project.

public class CheckBoxCellFactory implements Callback {
    @Override
    public TableCell call(Object param) {
        CheckBoxTableCell<Person,Boolean> checkBoxCell = new CheckBoxTableCell();
        return checkBoxCell;
    }
}

2) Your model class. Person for example.

public static class Person {
   private SimpleBooleanProperty checked = new SimpleBooleanProperty(false);
   // other columns here

    public SimpleBooleanProperty checkedProperty() {
        return this.checked;
    }

    public java.lang.Boolean getChecked() {
        return this.checkedProperty().get();
    }

    public void setChecked(final java.lang.Boolean checked) {
        this.checkedProperty().set(checked);
    }

    // getter/setter for other columns

}

3) Made modifications in your fxml file. The section of your TableView -> TableColumn gonna look like this:

<TableColumn fx:id="checkBoxTableColumn" maxWidth="34.0" minWidth="26.0" prefWidth="34.0" resizable="false" sortable="false">   
<cellValueFactory><PropertyValueFactory property="checked" /></cellValueFactory>
<cellFactory><partarch.fx.CheckBoxCellFactory /></cellFactory>
</TableColumn>

4) If you want to make your checkbox being editable

• 4.1 Open fxml in the Scene Builder.
• 4.2 Select checkBox column and then check "Editable" property in the Properties pane.
• 4.3 Select TableView containing your checkbox and do the same(check "Editable" property in the Properties pane).

Implementation in binaries on SF and source on GitHub