FXML, JavaFX 8, TableView: Make a delete button in each row and delete the row accordingly - javafx-8

Question

I am working on a TableView (FXML) where I want to have all the rows accompanied with a delete button at the last column.
Here's a video that shows what I mean: YouTube Delete Button in TableView
Here's what I have in my main controller class:
public Button del() {
Button del = new Button();
del.setText("X");
del.setPrefWidth(30);
del.setOnAction(new EventHandler<ActionEvent>() {
public void handle(ActionEvent event) {
int i = index.get();
if(i > -1) {
goals.remove(i);
list.getSelectionModel().clearSelection();
}
}
});
return del;
}
private SimpleIntegerProperty index = new SimpleIntegerProperty();
#Override
public void initialize(URL location, ResourceBundle resources){
//DateFormat df = new SimpleDateFormat("dd MMM yyyy");
sdate.setValue(LocalDate.now());
edate.setValue(LocalDate.now());
seq.setCellValueFactory(new PropertyValueFactory<Goals, Integer>("id"));
gol.setCellValueFactory(new PropertyValueFactory<Goals, String>("goal"));
sdt.setCellValueFactory(new PropertyValueFactory<Goals, Date>("sdte"));
edt.setCellValueFactory(new PropertyValueFactory<Goals, Date>("edte"));
prog.setCellValueFactory(new PropertyValueFactory<Goals, Integer>("pb"));
del.setCellValueFactory(new PropertyValueFactory<Goals, Button>("x"));
list.setItems(goals);
list.getSelectionModel().selectedItemProperty().addListener(new ChangeListener<Object>() {
#Override
public void changed(ObservableValue<?> observable,
Object oldValue, Object newValue) {
index.set(goals.indexOf(newValue));
System.out.println("Index is: "+goals.indexOf(newValue));
}
});
}
Each time I launch the application, I will try to click the delete button from random rows but it always delete the first row. I guess the addListener method I use for list is not properly implemented and indexOf(newValue) is always 0 at every initialisation.
However, it will work if I click a row first and then click the delete button. But this is not what I want. I want users to be able to delete any row if they press the delete button without selecting the row.
Appreciate your help guys!

Answer 1

You need a custom cell factory defined for the column containing the delete button.
TableColumn<Person, Person> unfriendCol = new TableColumn<>("Anti-social");
unfriendCol.setCellValueFactory(
param -> new ReadOnlyObjectWrapper<>(param.getValue())
);
unfriendCol.setCellFactory(param -> new TableCell<Person, Person>() {
private final Button deleteButton = new Button("Unfriend");
#Override
protected void updateItem(Person person, boolean empty) {
super.updateItem(person, empty);
if (person == null) {
setGraphic(null);
return;
}
setGraphic(deleteButton);
deleteButton.setOnAction(
event -> getTableView().getItems().remove(person)
);
}
});
Here is a sample app. It doesn't use FXML, but you could adapt it to work with FXML very easily. Just click on an "Unfriend" button in the "Anti-social" column to delete a friend. Do it a lot and you will soon run out of friends.
import javafx.application.Application;
import javafx.beans.property.ReadOnlyObjectWrapper;
import javafx.beans.property.SimpleStringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.Priority;
import javafx.scene.layout.VBox;
import javafx.scene.text.Font;
import javafx.stage.Stage;
public class GestureEvents extends Application {
private TableView<Person> table = new TableView<>();
private final ObservableList<Person> data =
FXCollections.observableArrayList(
new Person("Jacob", "Smith"),
new Person("Isabella", "Johnson"),
new Person("Ethan", "Williams"),
new Person("Emma", "Jones"),
new Person("Michael", "Brown")
);
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage stage) {
final Label label = new Label("Friends");
label.setFont(new Font("Arial", 20));
final Label actionTaken = new Label();
TableColumn<Person, Person> unfriendCol = new TableColumn<>("Anti-social");
unfriendCol.setMinWidth(40);
unfriendCol.setCellValueFactory(param -> new ReadOnlyObjectWrapper<>(param.getValue()));
unfriendCol.setCellFactory(param -> new TableCell<Person, Person>() {
private final Button deleteButton = new Button("Unfriend");
#Override
protected void updateItem(Person person, boolean empty) {
super.updateItem(person, empty);
if (person == null) {
setGraphic(null);
return;
}
setGraphic(deleteButton);
deleteButton.setOnAction(event -> data.remove(person));
}
});
TableColumn<Person, String> firstNameCol = new TableColumn<>("First Name");
firstNameCol.setMinWidth(100);
firstNameCol.setCellValueFactory(
new PropertyValueFactory<>("firstName"));
TableColumn<Person, String> lastNameCol = new TableColumn<>("Last Name");
lastNameCol.setMinWidth(100);
lastNameCol.setCellValueFactory(
new PropertyValueFactory<>("lastName"));
table.setItems(data);
table.getColumns().addAll(unfriendCol, firstNameCol, lastNameCol);
table.setPrefHeight(250);
final VBox vbox = new VBox();
vbox.setSpacing(5);
vbox.setPadding(new Insets(10, 10, 10, 10));
vbox.getChildren().addAll(label, table, actionTaken);
VBox.setVgrow(table, Priority.ALWAYS);
stage.setScene(new Scene(vbox));
stage.show();
}
public static class Person {
private final SimpleStringProperty firstName;
private final SimpleStringProperty lastName;
private Person(String fName, String lName) {
this.firstName = new SimpleStringProperty(fName);
this.lastName = new SimpleStringProperty(lName);
}
public String getFirstName() {
return firstName.get();
}
public void setFirstName(String fName) {
firstName.set(fName);
}
public String getLastName() {
return lastName.get();
}
public void setLastName(String fName) {
lastName.set(fName);
}
}
}