TableVew - Edit cell when KeyEvent is thrown

Question

I have an event listener on a TableView that listens for keyboard event.

 // Add event listener to table
 table.setOnKeyTyped(event -> {
        TablePosition         


        

Answer 1

These get really tricky; I think anything "behavior-related" (i.e. standard controls reacting to user input) is hard to change and generally not well supported in JavaFX. Hopefully this is an area of the API that will be improved...

There seem to be a couple of different issues. I think that what is happening with the Enter key, is that although this generates an ActionEvent on the text field, which commits the edit, etc, the keyTyped event still propagates back to the table, causing it to re-enter editing mode. A fix for this seems to be to use a keyPressed handler on the table instead (though to be honest this doesn't feel very robust).

The code relies on the default onEditCommit handler on the table column to actually change the property value. The onEditCommit handler is invoked by the default table cell's commitEdit method. The problem with calling commitEdit(...) on losing focus is that the default commitEdit method first checks if the cell is in an editing state, and does nothing if it's not. It appears that when the cell loses focus, it is taken out of the editing state before the focusProperty listener is invoked, so the onEditCommit handler is never called. (As an aside, this also prevents example 13-11 "Alternative solution of cell editing" (sic) from working correctly in the JDK 8 u25 (the current version).)

The only fix I can see for this second issue is to directly update the property from the commitEdit(...) method. This requires the cell have a reference to the property, which breaks the nice separation between the cell and the cell value.

I rewrote the example using the usual Person example and incorporated these two fixes. This example works quite well, though as I said some parts feel as though they are not very robust:

import java.util.function.Function;

import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.scene.Scene;
import javafx.scene.control.ContentDisplay;
import javafx.scene.control.TableCell;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TablePosition;
import javafx.scene.control.TableView;
import javafx.scene.control.TextField;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;


public class TableViewEditOnType extends Application {


    @Override
    public void start(Stage primaryStage) {

        TableView<Person> table = new TableView<>();

        table.getSelectionModel().setCellSelectionEnabled(true);
        table.setEditable(true);

        table.getColumns().add(createColumn("First Name", Person::firstNameProperty));
        table.getColumns().add(createColumn("Last Name", Person::lastNameProperty));
        table.getColumns().add(createColumn("Email", Person::emailProperty));

        table.getItems().addAll(
                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")
        );

        table.setOnKeyPressed(event -> {
            TablePosition<Person, ?> pos = table.getFocusModel().getFocusedCell() ;
            if (pos != null) {
                table.edit(pos.getRow(), pos.getTableColumn());
            }
        });

        Scene scene = new Scene(new BorderPane(table), 880, 600);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    private TableColumn<Person, String> createColumn(String title, Function<Person, StringProperty> property) {
        TableColumn<Person, String> col = new TableColumn<>(title);
        col.setCellValueFactory(cellData -> property.apply(cellData.getValue()));

        col.setCellFactory(column -> new EditCell(property));

        return col ;
    }

    private static class EditCell extends TableCell<Person, String> {

        private final TextField textField = new TextField();

        private final Function<Person, StringProperty> property ;

        EditCell(Function<Person, StringProperty> property) {
            this.property = property ;

            textProperty().bind(itemProperty());
            setGraphic(textField);
            setContentDisplay(ContentDisplay.TEXT_ONLY);

            textField.setOnAction(evt -> {
                commitEdit(textField.getText());
            });
            textField.focusedProperty().addListener((obs, wasFocused, isNowFocused) -> {
                if (! isNowFocused) {
                    commitEdit(textField.getText());
                }
            });
        }

        @Override
        public void startEdit() {
            super.startEdit();
            textField.setText(getItem());
            setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
            textField.requestFocus();          
        }

        @Override
        public void cancelEdit() {
            super.cancelEdit();
            setContentDisplay(ContentDisplay.TEXT_ONLY);
        }

        @Override
        public void commitEdit(String text) {
            super.commitEdit(text);
            Person person = getTableView().getItems().get(getIndex()) ;
            StringProperty cellProperty = property.apply(person);
            cellProperty.set(text);
            setContentDisplay(ContentDisplay.TEXT_ONLY);
        }

    }

    public static class Person {
        private final StringProperty firstName = new SimpleStringProperty();
        private final StringProperty lastName = new SimpleStringProperty();
        private final StringProperty email = new SimpleStringProperty();

        public Person(String firstName, String lastName, String email) {
            setFirstName(firstName);
            setLastName(lastName);
            setEmail(email);
        }

        public final StringProperty firstNameProperty() {
            return this.firstName;
        }

        public final java.lang.String getFirstName() {
            return this.firstNameProperty().get();
        }

        public final void setFirstName(final java.lang.String firstName) {
            this.firstNameProperty().set(firstName);
        }

        public final StringProperty lastNameProperty() {
            return this.lastName;
        }

        public final java.lang.String getLastName() {
            return this.lastNameProperty().get();
        }

        public final void setLastName(final java.lang.String lastName) {
            this.lastNameProperty().set(lastName);
        }

        public final StringProperty emailProperty() {
            return this.email;
        }

        public final java.lang.String getEmail() {
            return this.emailProperty().get();
        }

        public final void setEmail(final java.lang.String email) {
            this.emailProperty().set(email);
        }


    }

    public static void main(String[] args) {
        launch(args);
    }
}