JavaFX tableview, my list is erased when I add a new object - list

Question

I've got an issue with Tableview in JavaFX.
Whenever I add a new row in my Tableview my list is deleted.
I pre-make a list with 4 objects in it
When i use my button to add a row, the row is added.
The thing is when the row is added. If I had text in one of my cell, all is erased.
Here's my main program :
package application;
import vue.*;
import domaine.Reponse;
import javafx.application.Application;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TableView;
import javafx.stage.Stage;
public class Mainfx extends Application {
public static final String nomApplication = "QCM-Builder";
private TableViewReponse tableauReponse;
private Button addButton;
public static void main(String[] args) {
launch(args);
}
public void start(Stage stage){
Scene scene = new Scene(new Group());
stage.setTitle("Table View Sample");
stage.setWidth(300);
stage.setHeight(500);
tableauReponse = new TableViewReponse();
tableauReponse.setTranslateX(130);
tableauReponse.setTranslateY(300);
tableauReponse.setColumnResizePolicy(TableView.CONSTRAINED_RESIZE_POLICY);
tableauReponse.setPrefHeight(150);
addButton = new Button("Add");
addButton.setTranslateX(400);
addButton.setTranslateY(400);
((Group) scene.getRoot()).getChildren().addAll(addButton);
addButton.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent e) {
ObservableList<Reponse> list = tableauReponse.getItems();
list.add(new Reponse("",false));
tableauReponse.setItems(list);
}
});
((Group) scene.getRoot()).getChildren().addAll(tableauReponse);
stage.setScene(scene);
stage.show();
}
}
And here's my custom Tableview
package vue;
import java.io.IOException;
import java.sql.SQLException;
import domaine.Reponse;
import javafx.beans.property.SimpleBooleanProperty;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.control.TableCell;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableColumn.CellDataFeatures;
import javafx.scene.control.TableColumn.CellEditEvent;
import javafx.scene.control.TablePosition;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.CheckBoxTableCell;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.control.cell.TextFieldTableCell;
import javafx.scene.layout.StackPane;
import javafx.util.Callback;
public class TableViewReponse extends TableView<Reponse> {
private TableColumn<Reponse, String> reponseCol;
private TableColumn<Reponse, Boolean> singleCol;
private final ObservableList<Reponse> list =
FXCollections.observableArrayList(
new Reponse("",false),
new Reponse("",false),
new Reponse("",false),
new Reponse("",false)
);
public TableViewReponse() {
super();
this.setEditable(true);
reponseCol = new TableColumn<Reponse, String>("Réponse");
singleCol = new TableColumn<Reponse, Boolean>("Correcte ?");
// ==== FULL NAME (TEXT FIELD) ===
reponseCol.setCellValueFactory(new PropertyValueFactory<Reponse, String>("reponse"));
reponseCol.setCellFactory(TextFieldTableCell.<Reponse>forTableColumn());
reponseCol.setMinWidth(200);
// On Cell edit commit (for FullName column)
reponseCol.setOnEditCommit((CellEditEvent<Reponse, String> event) -> {
TablePosition<Reponse, String> pos = event.getTablePosition();
int row = pos.getRow();
Reponse reponse = event.getTableView().getItems().get(row);
reponse.setLibelle(event.getNewValue());
try {
System.out.println("Bisous "+ reponse.toStringAMC());
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
});
// ==== SINGLE? (CHECK BOX) ===
singleCol.setCellValueFactory(new Callback<CellDataFeatures<Reponse, Boolean>, ObservableValue<Boolean>>() {
#Override
public ObservableValue<Boolean> call(CellDataFeatures<Reponse, Boolean> param) {
Reponse reponse = param.getValue();
SimpleBooleanProperty booleanProp = new SimpleBooleanProperty(reponse.estJuste());
// Note: singleCol.setOnEditCommit(): Not work for
// CheckBoxTableCell.
// When "Single?" column change.
booleanProp.addListener(new ChangeListener<Boolean>() {
#Override
public void changed(ObservableValue<? extends Boolean> observable, Boolean oldValue,
Boolean newValue) {
reponse.setJuste(newValue);
}
});
return booleanProp;
}
});
singleCol.setCellFactory(new Callback<TableColumn<Reponse, Boolean>, TableCell<Reponse, Boolean>>() {
#Override
public TableCell<Reponse, Boolean> call(TableColumn<Reponse, Boolean> p) {
CheckBoxTableCell<Reponse, Boolean> cell = new CheckBoxTableCell<Reponse, Boolean>();
cell.setAlignment(Pos.CENTER);
//cell.commitEdit(true);
return cell;
}
});
this.setItems(list);
this.getColumns().addAll(reponseCol, singleCol);
StackPane root = new StackPane();
root.setPadding(new Insets(5));
}
public void ajouterReponse() {
ObservableList<Reponse> list = this.getItems();
list.add(new Reponse("", false));
this.setItems(list);
}
public String getColReponse(int i) {
return reponseCol.getTableView().getItems().get(i).getLibelle();
}
public void viderColReponse(int i) {
reponseCol.getTableView().getItems().get(i).setLibelle(null);
}
public Boolean getColSingle(int i) {
return this.singleCol.getCellData(i);
}
}
Any ideas why ?
Thanks by advance

Answer 1

As you didn't show your Reponse class i can only assume but i think the problem may come from the mismatch cause by
reponseCol.setCellValueFactory(new PropertyValueFactory<Reponse, String>("reponse"));
and the fact you are doing:
reponseCol.setOnEditCommit((CellEditEvent<Reponse, String> event) -> {
//Some code
reponse.setLibelle(event.getNewValue());
//the rest
});
Assuming you are using the common naming system for setter/getter your Reponse
class shoud have a libelle field that you are updating on commiting the cell.
On the other side you are telling the column to search the value to display in a property named reponse (maybe another field of your class?).
Your are updating a different value than the one your ask to display on automatic refresh, that's why the column is clear when your add a new one.
To fix it you can either do:
reponseCol.setCellValueFactory(new PropertyValueFactory<Reponse, String>("libelle"));
to display the libelle or update the reponse field on commit instead.