JavaFX TableView TableRow focus behaves strangely - focus

Question

I'm using JDK 1.7.0_51 if that matters. I have the following adapted example code to demonstrate the unusual behaviour that I'm seeing.
I've programmatically selected row 0 in the table, then insert added rows at the 0 position. I'd expect the selected row to shift down by one, but instead it is dropping by two. In addition, when I monitor the focus property on the table row, I see that it changes quite a bit during this addition of a single row. And when it is finished inserting, row 2 has the dark blue background indicating selection, but row 3 has a blue highlighted border. I'm not sure what that is indicating.
I'm currently doing data validation when a table row focus is lost so that I can prevent users from leaving the current entry until it is correctly formed. But this selection and focus behaviour is causing my application to misbehave. This is the simplest test case I was able to create that shows what's happening.
import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.collections.ListChangeListener;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TablePosition;
import javafx.scene.control.TableRow;
import javafx.scene.control.TableView;
import javafx.scene.control.TextField;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;
import javafx.scene.text.Font;
import javafx.stage.Stage;
import javafx.util.Callback;
public class TableViewTest extends Application
{
private final TableView< Person > table = new TableView< Person >();
private final ObservableList< Person > data =
FXCollections.observableArrayList(
new Person( "Jacob", "Smith", "jacob.smith#example.com" ),
new Person( "Isabella", "Johnson", "isabella.johnson#example.com" ),
new Person( "Ethan", "Williams", "ethan.williams#example.com" ),
new Person( "Emma", "Jones", "emma.jones#example.com" ),
new Person( "Michael", "Brown", "michael.brown#example.com" ) );
final HBox hb = new HBox();
public static void main( String[] args )
{
launch( args );
}
#Override
public void start( Stage stage )
{
Scene scene = new Scene( new Group() );
stage.setTitle( "Table View Sample" );
stage.setWidth( 450 );
stage.setHeight( 550 );
final Label label = new Label( "Address Book" );
label.setFont( new Font( "Arial", 20 ) );
table.setEditable( true );
table.setRowFactory( getRowFactory() );
TableColumn firstNameCol = new TableColumn( "First Name" );
firstNameCol.setMinWidth( 100 );
firstNameCol.setCellValueFactory(
new PropertyValueFactory< Person, String >( "firstName" ) );
TableColumn lastNameCol = new TableColumn( "Last Name" );
lastNameCol.setMinWidth( 100 );
lastNameCol.setCellValueFactory(
new PropertyValueFactory< Person, String >( "lastName" ) );
TableColumn emailCol = new TableColumn( "Email" );
emailCol.setMinWidth( 200 );
emailCol.setCellValueFactory(
new PropertyValueFactory< Person, String >( "email" ) );
table.setItems( data );
table.getColumns().addAll( firstNameCol, lastNameCol, emailCol );
table.getSelectionModel().select( 0 );
table.getSelectionModel().getSelectedCells().addListener( new ListChangeListener< TablePosition >()
{
#Override
public void onChanged( final ListChangeListener.Change< ? extends TablePosition > c )
{
if ( !c.getList().isEmpty() )
{
for ( TablePosition pos : c.getList() )
{
System.out.println( "Row " + String.valueOf( pos.getRow() ) + " selected" );
}
}
else
{
System.out.println( "Row unselected" );
}
}
} );
final TextField addFirstName = new TextField();
addFirstName.setPromptText( "First Name" );
addFirstName.setMaxWidth( firstNameCol.getPrefWidth() );
final TextField addLastName = new TextField();
addLastName.setMaxWidth( lastNameCol.getPrefWidth() );
addLastName.setPromptText( "Last Name" );
final TextField addEmail = new TextField();
addEmail.setMaxWidth( emailCol.getPrefWidth() );
addEmail.setPromptText( "Email" );
final Button addButton = new Button( "Add" );
addButton.setOnAction( new EventHandler< ActionEvent >()
{
#Override
public void handle( ActionEvent e )
{
data.add( 0, new Person(
addFirstName.getText(),
addLastName.getText(),
addEmail.getText() ) );
addFirstName.clear();
addLastName.clear();
addEmail.clear();
}
} );
hb.getChildren().addAll( addFirstName, addLastName, addEmail, addButton );
hb.setSpacing( 3 );
final VBox vbox = new VBox();
vbox.setSpacing( 5 );
vbox.setPadding( new Insets( 10, 0, 0, 10 ) );
vbox.getChildren().addAll( label, table, hb );
( ( Group ) scene.getRoot() ).getChildren().addAll( vbox );
stage.setScene( scene );
stage.show();
}
private Callback< TableView< Person >, TableRow< Person >> getRowFactory()
{
return new Callback< TableView< Person >, TableRow< Person >>()
{
#Override
public TableRow< Person > call( final TableView< Person > arg0 )
{
return new DataTableRow();
}
};
}
public class DataTableRow extends TableRow< Person >
{
private final ChangeListener< Boolean > focusListener = new ChangeListener< Boolean >()
{
#Override
public void changed( final ObservableValue< ? extends Boolean > unused, final Boolean arg1,
final Boolean focused )
{
System.out.println( "Row " + getIndex() + " Focus: " + focused );
}
};
public DataTableRow()
{
focusedProperty().addListener( this.focusListener );
}
}
public static class Person
{
private final SimpleStringProperty firstName;
private final SimpleStringProperty lastName;
private final SimpleStringProperty email;
private Person( String fName, String lName, String email )
{
this.firstName = new SimpleStringProperty( fName );
this.lastName = new SimpleStringProperty( lName );
this.email = new SimpleStringProperty( email );
}
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 );
}
public String getEmail()
{
return email.get();
}
public void setEmail( String fName )
{
email.set( fName );
}
}
}
The output I get from running this and adding a single row is:
Row unselected
Row 1 selected
Row 0 Focus: false
Row 1 Focus: true
Row 1 Focus: false
Row 2 Focus: true
Row unselected
Row unselected
Row 2 selected
Row 2 Focus: false
Row 3 Focus: true
Row 3 Focus: true
Can anyone help me understand what is going on here and whether this is correct behaviour?

Answer 1

What IDE are you using? Have you tried it on IntelliJ? I don't have the focus problem you reported when I run your Class in IntelliJ at all. I'm using jdk 8u20. When I go to a new row, the previous row get de-focused and the new row gets focused. See below:
Row 0 Focus: true
Row 0 Focus: false
Row 1 Focus: true
Row 1 selected
Row 1 Focus: false
Row 2 Focus: true
Row 2 selected
Row unselected
Row 3 selected
Row 2 Focus: false
Row 3 Focus: true
Row 3 Focus: false
Row 4 Focus: true
Row 1 Focus: true
Row 4 Focus: false
Row 1 selected
Row 1 Focus: false
Row 5 Focus: true
Row 5 selected
Row 3 Focus: true
Row 5 Focus: false
Row 3 selected
Row 0 Focus: true
Row 3 Focus: false
Row 0 selected
Row 0 Focus: false
Row 1 Focus: true
Row 1 selected
Row 1 Focus: false
Row 2 Focus: true
Row 2 selected
Row 2 Focus: false
Row 3 Focus: true
Row 3 selected
Row 0 Focus: true
Row 3 Focus: false
Row 0 selected