在 JavaFX 表视图中插入行并开始编辑无法正常工作

Question

我们正在运行一个 JavaFX 应用程序，其中包含一些可编辑的表视图。请求的新功能是：一个按钮，该按钮在当前选定的行下方添加新行，并立即开始编辑该行的第一个单元格。

我们实现了这个功能，它并不那么复杂，但是我们遇到了一个非常奇怪的行为，经过几天的调查，我们仍然不知道出了什么问题。

发生的情况是，当单击按钮时，它会添加一个新行，但开始编辑新创建行的第一个单元格，而不是新创建行，而是任意其他行。不幸的是，这个问题不是100%可复制的。有时它会按预期工作，但最常见的情况是，新添加的行下面的行会被编辑，但有时甚至会在当前选定的行之前和之后出现完全不同的行。

下面可以找到JavaFX TableView的精简版本的源代码，可以用来查看问题。正如已经提到的，它不是100%可复制的。要查看问题，必须多次添加新行。有时，当上下滚动表格几次时，问题会更频繁地发生。

任何帮助，不胜感激。

提示:我们已经对Platform.runlater()做了很多尝试，将按钮的动作实现放在runlater()中，但是尽管这个问题出现的频率较低，但它从未完全消失。

表视图：

package tableview;

import java.util.ArrayList;
import java.util.List;

import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
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.TableCell;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.VBox;
import javafx.scene.text.Font;
import javafx.stage.Stage;
import javafx.util.Callback;

@SuppressWarnings({ "rawtypes", "unchecked" })
public class SimpleTableViewTest extends Application {

    private final ObservableList<Person> data = FXCollections.observableArrayList(createData());

    private final TableView table = new TableView();

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

    private static List<Person> createData() {
        List<Person> data = new ArrayList<>();
        for (int i = 0; i < 100; i++) {
            data.add(new Person("Jacob", "Smith", "jacob.smith_at_example.com", "js_at_example.com"));
        }

        return data;
    }

    @Override
    public void start(Stage stage) {

        Scene scene = new Scene(new Group());
        stage.setTitle("Table View Sample");
        stage.setWidth(700);
        stage.setHeight(550);

        final Label label = new Label("Address Book");
        label.setFont(new Font("Arial", 20));

        // Create a customer cell factory so that cells can support editing.
        Callback<TableColumn, TableCell> cellFactory = (TableColumn p) -> {
            return new EditingCell();
        };

        // Set up the columns
        TableColumn firstNameCol = new TableColumn("First Name");
        firstNameCol.setMinWidth(100);
        firstNameCol.setCellValueFactory(new PropertyValueFactory<Person, String>("firstName"));
        firstNameCol.setCellFactory(cellFactory);

        TableColumn lastNameCol = new TableColumn("Last Name");
        lastNameCol.setMinWidth(100);
        lastNameCol.setCellValueFactory(new PropertyValueFactory<Person, String>("lastName"));
        lastNameCol.setCellFactory(cellFactory);
        lastNameCol.setEditable(true);

        TableColumn primaryEmailCol = new TableColumn("Primary Email");
        primaryEmailCol.setMinWidth(200);
        primaryEmailCol.setCellValueFactory(new PropertyValueFactory<Person, String>("primaryEmail"));
        primaryEmailCol.setCellFactory(cellFactory);
        primaryEmailCol.setEditable(false);

        TableColumn secondaryEmailCol = new TableColumn("Secondary Email");
        secondaryEmailCol.setMinWidth(200);
        secondaryEmailCol.setCellValueFactory(new PropertyValueFactory<Person, String>("secondaryEmail"));
        secondaryEmailCol.setCellFactory(cellFactory);

        // Add the columns and data to the table.
        table.setItems(data);
        table.getColumns().addAll(firstNameCol, lastNameCol, primaryEmailCol, secondaryEmailCol);
        table.setEditable(true);

        // --- Here comes the interesting part! ---
        //
        // A button that adds a row below the currently selected one
        // and immediatly starts editing it.
        Button addAndEdit = new Button("Add and edit");
        addAndEdit.setOnAction((ActionEvent e) -> {
            int idx = table.getSelectionModel().getSelectedIndex() + 1;

            data.add(idx, new Person());
            table.getSelectionModel().select(idx);
            table.edit(idx, firstNameCol);
        });

        final VBox vbox = new VBox();
        vbox.setSpacing(5);
        vbox.getChildren().addAll(label, table, addAndEdit);
        vbox.setPadding(new Insets(10, 0, 0, 10));
        ((Group) scene.getRoot()).getChildren().addAll(vbox);

        stage.setScene(scene);
        stage.show();
    }

}

可编辑的表格单元格:

package tableview;

import javafx.event.EventHandler;
import javafx.scene.control.ContentDisplay;
import javafx.scene.control.TableCell;
import javafx.scene.control.TextField;
import javafx.scene.input.KeyCode;
import javafx.scene.input.KeyEvent;

public class EditingCell extends TableCell<Person, String> {
    private TextField textField;

    public EditingCell() {
    }

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

    @Override
    public void startEdit() {
        super.startEdit();
        if (textField == null) {
            createTextField();
        }
        setGraphic(textField);
        setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
    }

    @Override
    public void updateItem(String item, boolean empty) {
        super.updateItem(item, empty);
        if (empty) {
            setText(null);
            setGraphic(null);
        } else {
            if (isEditing()) {
                if (textField != null) {
                    textField.setText(getString());
                }
                setGraphic(textField);
                setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
            } else {
                setText(getString());
                setContentDisplay(ContentDisplay.TEXT_ONLY);
            }
        }
    }

    private void createTextField() {
        textField = new TextField(getString());
        textField.setMinWidth(this.getWidth() - this.getGraphicTextGap() * 2);
        textField.setOnKeyPressed(new EventHandler<KeyEvent>() {
            @Override
            public void handle(KeyEvent t) {
                if (t.getCode() == KeyCode.ENTER) {
                    commitEdit(textField.getText());
                } else if (t.getCode() == KeyCode.ESCAPE) {
                    cancelEdit();
                }
            }
        });
    }

    private String getString() {
        return getItem() == null ? "" : getItem().toString();
    }
}

数据豆：

package tableview;

import javafx.beans.property.SimpleStringProperty;

public class Person {
    private final SimpleStringProperty firstName;
    private final SimpleStringProperty lastName;
    private final SimpleStringProperty primaryEmail;
    private final SimpleStringProperty secondaryEmail;

    public Person() {
        this(null, null, null, null);
    }

    public Person(String firstName, String lastName, String primaryEmail, String secondaryEmail) {
        this.firstName = new SimpleStringProperty(firstName);
        this.lastName = new SimpleStringProperty(lastName);
        this.primaryEmail = new SimpleStringProperty(primaryEmail);
        this.secondaryEmail = new SimpleStringProperty(secondaryEmail);
    }

    public SimpleStringProperty firstNameProperty() {
        return firstName;
    }

    public String getFirstName() {
        return firstName.get();
    }

    public String getLastName() {
        return lastName.get();
    }

    public String getPrimaryEmail() {
        return primaryEmail.get();
    }

    public SimpleStringProperty getPrimaryEmailProperty() {
        return primaryEmail;
    }

    public String getSecondaryEmail() {
        return secondaryEmail.get();
    }

    public SimpleStringProperty getSecondaryEmailProperty() {
        return secondaryEmail;
    }

    public SimpleStringProperty lastNameProperty() {
        return lastName;
    }

    public void setFirstName(String firstName) {
        this.firstName.set(firstName);
    }

    public void setLastName(String lastName) {
        this.lastName.set(lastName);
    }

    public void setPrimaryEmail(String primaryEmail) {
        this.primaryEmail.set(primaryEmail);
    }

    public void setSecondaryEmail(String secondaryEmail) {
        this.secondaryEmail.set(secondaryEmail);
    }
}

Answer 1

按钮动作实现的正确代码如下所示。修复所述问题的重要一行是“table.layout（）”。非常感谢fabian！

addAndEdit.setOnAction((ActionEvent e) -> {
    int idx = table.getSelectionModel().getSelectedIndex() + 1;

    data.add(idx, new Person());
    table.getSelectionModel().select(idx);

    table.layout();

    table.edit(idx, firstNameCol);
 });