焦点改变为不同填充单元格的JavaFX可编辑单元格

Question

我需要JavaFX tableView的可编辑单元格。默认的TextFieldTableCell要求用户按enter提交更改。我认为一个典型的用户期望在单元格外单击时保留更改。我想要的所有功能包括：

1. 单击选择单元格并
2. 在选定的单元格中单击另一个单元格，或回车，开始编辑。
3. 双击单元格开始编辑。
4. 按enter提交对单元格的更改
5. 在单元格之外的任何地方更改鼠标焦点都将向单元格提交更改

我在这篇文章中发现了一个EditCell版本，它满足了前4个要求，并部分满足了第5个要求，但当用户单击表中另一个填充的单元格时，编辑更改将丢失。焦点侦听器被触发，但没有提交。单击空单元格或其他场景元素提交更改。

Answer 1

我可能来晚了一点，但现在开始了。

无法提交更改的单元格的值可能是由于TableCell中commitEdit方法的默认实现，因为它默认情况下将焦点丢失视为取消操作。

但是，用户James_D在这里创建了一个很好的解决方案

import java.util.function.Function;

import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.event.Event;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.input.KeyCode;
import javafx.scene.input.KeyEvent;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
import javafx.util.StringConverter;


public class TableViewCommitOnFocusLoss 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", "[e-mail]"),
                new Person("Isabella", "Johnson", "[e-mail]"),
                new Person("Ethan", "Williams", "[e-mail]"),
                new Person("Emma", "Jones", "[e-mail]"),
                new Person("Michael", "Brown", "[e-mail]")
        );

        Button showDataButton = new Button("Debug data");
        showDataButton.setOnAction(event -> table.getItems().stream()
                .map(p -> String.format("%s %s", p.getFirstName(), p.getLastName()))
                .forEach(System.out::println));

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

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

        col.setCellFactory(column -> EditCell.createStringEditCell());
        return col ;
    }

    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);
    }

}

class EditCell<S, T> extends TableCell<S, T> {

    // Text field for editing
    // TODO: allow this to be a plugable control.
    private final TextField textField = new TextField();

    // Converter for converting the text in the text field to the user type, and vice-versa:
    private final StringConverter<T> converter ;

    public EditCell(StringConverter<T> converter) {
        this.converter = converter ;

        itemProperty().addListener((obx, oldItem, newItem) -> {
            if (newItem == null) {
                setText(null);
            } else {
                setText(converter.toString(newItem));
            }
        });
        setGraphic(textField);
        setContentDisplay(ContentDisplay.TEXT_ONLY);

        textField.setOnAction(evt -> {
            commitEdit(this.converter.fromString(textField.getText()));
        });
        textField.focusedProperty().addListener((obs, wasFocused, isNowFocused) -> {
            if (! isNowFocused) {
                commitEdit(this.converter.fromString(textField.getText()));
            }
        });
        textField.addEventFilter(KeyEvent.KEY_PRESSED, event -> {
            if (event.getCode() == KeyCode.ESCAPE) {
                textField.setText(converter.toString(getItem()));
                cancelEdit();
                event.consume();
            } else if (event.getCode() == KeyCode.RIGHT) {
                getTableView().getSelectionModel().selectRightCell();
                event.consume();
            } else if (event.getCode() == KeyCode.LEFT) {
                getTableView().getSelectionModel().selectLeftCell();
                event.consume();
            } else if (event.getCode() == KeyCode.UP) {
                getTableView().getSelectionModel().selectAboveCell();
                event.consume();
            } else if (event.getCode() == KeyCode.DOWN) {
                getTableView().getSelectionModel().selectBelowCell();
                event.consume();
            }
        });
    }

    /**
     * Convenience converter that does nothing (converts Strings to themselves and vice-versa...).
     */
    public static final StringConverter<String> IDENTITY_CONVERTER = new StringConverter<String>() {

        @Override
        public String toString(String object) {
            return object;
        }

        @Override
        public String fromString(String string) {
            return string;
        }

    };

    /**
     * Convenience method for creating an EditCell for a String value.
     * @return
     */
    public static <S> EditCell<S, String> createStringEditCell() {
        return new EditCell<S, String>(IDENTITY_CONVERTER);
    }


    // set the text of the text field and display the graphic
    @Override
    public void startEdit() {
        super.startEdit();
        textField.setText(converter.toString(getItem()));
        setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
        textField.requestFocus();
    }

    // revert to text display
    @Override
    public void cancelEdit() {
        super.cancelEdit();
        setContentDisplay(ContentDisplay.TEXT_ONLY);
    }

    // commits the edit. Update property if possible and revert to text display
    @Override
    public void commitEdit(T item) {

        // This block is necessary to support commit on losing focus, because the baked-in mechanism
        // sets our editing state to false before we can intercept the loss of focus.
        // The default commitEdit(...) method simply bails if we are not editing...
        if (! isEditing() && ! item.equals(getItem())) {
            TableView<S> table = getTableView();
            if (table != null) {
                TableColumn<S, T> column = getTableColumn();
                TableColumn.CellEditEvent<S, T> event = new TableColumn.CellEditEvent<>(table,
                        new TablePosition<S,T>(table, getIndex(), column),
                        TableColumn.editCommitEvent(), item);
                Event.fireEvent(column, event);
            }
        }

        super.commitEdit(item);

        setContentDisplay(ContentDisplay.TEXT_ONLY);
    }

}