Understanding CheckBoxTableCell changelistener using setSelectedStateCallback - javafx

Question

I'm trying to follow: CheckBoxTableCell changelistener not working
The given code answer to that question is below and dependent on the model 'Trainee'
final CheckBoxTableCell<Trainee, Boolean> ctCell = new CheckBoxTableCell<>();
ctCell.setSelectedStateCallback(new Callback<Integer, ObservableValue<Boolean>>() {
#Override
public ObservableValue<Boolean> call(Integer index) {
return table.getItems().get(index).selectedProperty();
}
});
I would like to obtain that selected property value and add a listener to it, but I don't think I'm doing it right. I attempted to add all kind of listeners to it so that I know when the checkbox in each row is changed and I can add logic to each. I presume the code above allow ctCell to now observe changes and I can just call a change listener to it and detect selection per given row.
I tried some change properties here just to detect the changes:
ctCell.selectedStateCallbackProperty().addListener(change -> {
System.out.println("1Change happened in selected state property");
});
ctCell.selectedProperty().addListener(change -> {
System.out.println("2Change happened in selected property");
});
ctCell.itemProperty().addListener(change -> {
System.out.println("3Change happened in item property");
});
ctCell.indexProperty().addListener(change -> {
System.out.println("4Change happened in index property");
});
...but none seemed to be called.
This is the shorten set up that I have:
requestedFaxCol.setCellValueFactory(new PropertyValueFactory("clientHasRequestedFax"));
requestedFaxCol.setCellFactory(CheckBoxTableCell.forTableColumn(requestedFaxCol));
final CheckBoxTableCell<ClinicClientInfo, Boolean> ctCell = new CheckBoxTableCell<>();
ctCell.setSelectedStateCallback(new Callback<Integer, ObservableValue<Boolean>>() {
#Override
public ObservableValue<Boolean> call(Integer index) {
return clinicLinkTable.getItems().get(index).clientHasRequestedFaxProperty();}
});
Let me know if I need to provide a more information! What am I not understanding in terms of why I cannot bridge a change listener to my table cell check boxes? Or if someone can point out the a direction for me to try. Thanks!
UPDATE to depict the ultimate goal of this question
package testapp;
import javafx.application.Application;
import javafx.beans.property.BooleanProperty;
import javafx.beans.property.SimpleBooleanProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.scene.control.Button;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.CheckBoxTableCell;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import javafx.util.Callback;
public class TestApp extends Application {
private TableView<ClinicClientInfo> clientTable = new TableView<>();
private TableColumn<ClinicClientInfo, String> faxCol = new TableColumn<>("Fax");
private TableColumn<ClinicClientInfo, Boolean> requestedFaxCol = new TableColumn<>("Requested Fax");
#Override
public void start(Stage primaryStage) {
StackPane root = new StackPane();
ObservableList<ClinicClientInfo> list = FXCollections.observableArrayList(
new ClinicClientInfo("", false),
new ClinicClientInfo("945-342-4324", true));
root.getChildren().add(clientTable);
clientTable.getColumns().addAll(faxCol, requestedFaxCol);
clientTable.setItems(list);
clientTable.setEditable(true);
clientTable.setColumnResizePolicy(TableView.CONSTRAINED_RESIZE_POLICY);
faxCol.setCellValueFactory(new PropertyValueFactory<>("clinicFax"));
faxCol.setVisible(true);
requestedFaxCol.setCellValueFactory(new PropertyValueFactory("clientHasRequestedFax"));
requestedFaxCol.setCellFactory(CheckBoxTableCell.forTableColumn(requestedFaxCol));
requestedFaxCol.setVisible(true);
requestedFaxCol.setEditable(true);
//My attempt to connect the listener
//If user selects checkbox and the fax value is empty, the alert should prompt
CheckBoxTableCell<ClinicClientInfo, Boolean> ctCell = new CheckBoxTableCell<>();
ctCell.setSelectedStateCallback(new Callback<Integer, ObservableValue<Boolean>>() {
#Override
public ObservableValue<Boolean> call(Integer index) {
ObservableValue<Boolean> itemBoolean = clientTable.getItems().get(index).clientHasRequestedFaxProperty();
itemBoolean.addListener(change -> {
ClinicClientInfo item = clientTable.getItems().get(index);
if(item.getClinicFax().isEmpty() && item.getClientHasRequestedFax()){
Alert alert = new Alert(Alert.AlertType.WARNING);
alert.setTitle("Warning");
alert.show();
}
});
return itemBoolean;
}
});
Scene scene = new Scene(root, 300, 250);
primaryStage.setScene(scene);
primaryStage.show();
}
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
launch(args);
}
public class ClinicClientInfo {
private final StringProperty clinicFax;
private final BooleanProperty clientHasRequestedFax;
public ClinicClientInfo(String fax, boolean clientHasRequestedFax){
this.clinicFax = new SimpleStringProperty(fax);
this.clientHasRequestedFax = new SimpleBooleanProperty(clientHasRequestedFax);
}
public String getClinicFax(){
return clinicFax.get();
}
public void setClinicFax(String clinicFax){
this.clinicFax.set(clinicFax);
}
public StringProperty clinicFaxProperty(){
return clinicFax;
}
public boolean getClientHasRequestedFax(){
return clientHasRequestedFax.get();
}
public void setClientHasRequestedFax(boolean clientHasRequestedFax){
this.clientHasRequestedFax.set(clientHasRequestedFax);
}
public BooleanProperty clientHasRequestedFaxProperty(){
return clientHasRequestedFax;
}
}
}
The goal is to get a prompt when the user tries to select fax request when the fax string is empty.

Answer 1

This is already fully explained in the question you already linked, so I don't know what more I can add here other than just to restate it.
The check boxes in the cell are bidirectionally bound to the property that is returned by the selectedStateCallback. If no selectedStateCallback is set, and the cell is attached to a column whose cellValueFactory returns a BooleanProperty (which covers almost all use cases), then the check box's state is bidirectionally bound to that property.
In your code sample, I don't understand what ctCell is for. You just create it, set a selectedStateCallBack on it, and then don't do anything with it. It has nothing to do with your table and nothing to do with the cell factory you set.
So in your case, no selected state callback is set on the cells produced by your cell factory, and the cell value factory returns a boolean property, so the default applies, and the check box state is bidirectionally bound to the property returned by the cell value factory. All you have to do is register a listener with those properties.
import javafx.application.Application;
import javafx.beans.property.BooleanProperty;
import javafx.beans.property.SimpleBooleanProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.CheckBoxTableCell;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
public class CheckBoxTableCellTestApp extends Application {
private TableView<ClinicClientInfo> clientTable = new TableView<>();
private TableColumn<ClinicClientInfo, String> faxCol = new TableColumn<>("Fax");
private TableColumn<ClinicClientInfo, Boolean> requestedFaxCol = new TableColumn<>("Requested Fax");
#Override
public void start(Stage primaryStage) {
StackPane root = new StackPane();
ObservableList<ClinicClientInfo> list = FXCollections.observableArrayList(
new ClinicClientInfo("", false),
new ClinicClientInfo("945-342-4324", true));
// add listeners to boolean properties:
for (ClinicClientInfo clinic : list) {
clinic.clientHasRequestedFaxProperty().addListener((obs, faxWasRequested, faxIsNowRequested) ->{
System.out.printf("%s changed fax request from %s to %s %n",
clinic.getClinicFax(), faxWasRequested, faxIsNowRequested);
});
}
root.getChildren().add(clientTable);
clientTable.getColumns().addAll(faxCol, requestedFaxCol);
clientTable.setItems(list);
clientTable.setEditable(true);
clientTable.setColumnResizePolicy(TableView.CONSTRAINED_RESIZE_POLICY);
faxCol.setCellValueFactory(new PropertyValueFactory<>("clinicFax"));
faxCol.setVisible(true);
requestedFaxCol.setCellValueFactory(new PropertyValueFactory<>("clientHasRequestedFax"));
requestedFaxCol.setCellFactory(CheckBoxTableCell.forTableColumn(requestedFaxCol));
requestedFaxCol.setVisible(true);
requestedFaxCol.setEditable(true);
Scene scene = new Scene(root, 300, 250);
primaryStage.setScene(scene);
primaryStage.show();
}
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
launch(args);
}
public class ClinicClientInfo {
private final StringProperty clinicFax;
private final BooleanProperty clientHasRequestedFax;
public ClinicClientInfo(String fax, boolean clientHasRequestedFax){
this.clinicFax = new SimpleStringProperty(fax);
this.clientHasRequestedFax = new SimpleBooleanProperty(clientHasRequestedFax);
}
public String getClinicFax(){
return clinicFax.get();
}
public void setClinicFax(String clinicFax){
this.clinicFax.set(clinicFax);
}
public StringProperty clinicFaxProperty(){
return clinicFax;
}
public boolean getClientHasRequestedFax(){
return clientHasRequestedFax.get();
}
public void setClientHasRequestedFax(boolean clientHasRequestedFax){
this.clientHasRequestedFax.set(clientHasRequestedFax);
}
public BooleanProperty clientHasRequestedFaxProperty(){
return clientHasRequestedFax;
}
}
}