如何有条件地格式化 JavaFX ComboBoxTableCell 标签

How to conditionally format JavaFX ComboBoxTableCell label

我认为可以根据以下 JavaFX 11 文档项目有条件地格式化 JavaFX ComboBoxTableCell 标签

By default, the ComboBoxTableCell is rendered as a Label when not being edited [...].

Sets the value of the property textFill.

如果我的假设是正确的,我想知道如何修改以下 SSCCE,以便将任何 ComboBoxTableCell 标签 textFill 属性 设置为以下 Paint 值.谢谢!

  1. Color.Red 如果其值无效

  1. Color.Blue 如果它的值是为不同的行设置的。

public class PersonInRoom extends Application
{
    private final ObservableList<Person> data = FXCollections.observableArrayList(
        new Person("Jacob"   , "Kitchen"),
        new Person("Isabella", "Bedroom"),
        new Person("Ethan"   , "Attic"));

    TableView<Person> table ;

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

    @Override
    public void start(Stage stage)
    {
        TableColumn nameCol = new TableColumn("Name");
        nameCol.setCellValueFactory(new PropertyValueFactory<Person, String>("name"));

        TableColumn roomCol = new TableColumn("Room");
        roomCol.setCellValueFactory(new PropertyValueFactory<Person, String>("room"));
        roomCol.setCellFactory(ComboBoxTableCell.forTableColumn("Bathroom", "Bedroom", "Kitchen"));
        roomCol.setOnEditCommit((EventHandler<CellEditEvent<Person, String>>) t -> t.getTableView().getItems().get(t.getTablePosition().getRow()).setRoom(t.getNewValue()));

        table = new TableView<>();
        table.setEditable(true);
        table.setItems(data);
        table.getColumns().addAll(nameCol, roomCol);

        VBox vbox = new VBox();
        vbox.getChildren().addAll(table);

        Scene scene = new Scene(vbox);
        stage.setScene(scene);
        stage.show();
    }

    public static class Person
    {
        private final SimpleStringProperty name;
        private final SimpleStringProperty room;
        private Person(String name, String room)
        {
            this.name = new SimpleStringProperty(name);
            this.room = new SimpleStringProperty(room);
        }
        public String getName()         {return name.get();}
        public String getRoom()         {return room.get();}
        public void   setRoom(String r) {room.set(r);}
    }
}

根据 kleopatra2020-09-28 中的建议 03:30:59Z 评论此问题顶部提出的问题页数:

You need a custom cell and override updateItem to set the color depending on context.

...我创建了一个自定义单元格(准确地说是 ComboBoxTableCell)并覆盖了它的 updateItem 方法。

随意 re-use 它(见下面的源代码)但请注意 kleopatra2020 上针对此答案发表的评论-09-2803:30:59Z:

You are probably aware that the logic itself doesn't belong into the view (aka: cell) - it should be handled "near" the model, including a notification path (vs. hacking around by calling refresh).

public class PersonInRoom extends Application
{
    private final ObservableList<Person> data = FXCollections.observableArrayList(
        new Person("Jacob", "Kitchen"),
        new Person("Isabella", "Bedroom"),
        new Person("Ethan", "Attic"));
    TableView<Person> table;

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

    @Override
    public void start(Stage stage)
    {
        TableColumn nameCol = new TableColumn("Name");
        nameCol.setCellValueFactory(new PropertyValueFactory<Person, String>("name"));

        TableColumn roomCol = new TableColumn("Room");
        roomCol.setCellValueFactory(new PropertyValueFactory<Person, String>("room"));

        roomCol.setCellFactory(new Callback<TableColumn<Person, String>, ComboBoxTableCell<Person, String>>()
        {
            @Override
            public ComboBoxTableCell<Person, String> call(TableColumn<Person, String> personStringTableColumn)
            {
                String rooms[] = {"Bathroom", "Bedroom", "Kitchen"};
                return new ComboBoxTableCell<>(rooms)
                {
                    @Override
                    public void updateItem(String item, boolean empty)
                    {
                        super.updateItem(item, empty);
                        if (!empty) {
                            setText(item);
                            boolean found = false;
                            for (int i = 0; i < rooms.length; i++) {
                                if (rooms[i].equals(item)) {
                                    found = true;
                                    break;
                                }
                            }
                            if (!found) {
                                setTextFill(Color.RED);
                                return;
                            }
                            int count = 0;
                            for (int i = 0; i < data.size(); i++) {
                                if (data.get(i).getRoom().equals(item)) {
                                    if (++count > 1) {
                                        setTextFill(Color.BLUE);
                                        return;
                                    }
                                }
                            }
                            setTextFill(Color.BLACK);
                        }
                    }

                };
            }
        });

        roomCol.setOnEditCommit(new EventHandler<CellEditEvent<Person, String>>()
        {
            @Override
            public void handle(CellEditEvent<Person, String> cellEditEvent)
            {
                cellEditEvent.getTableView().getItems().get(cellEditEvent.getTablePosition().getRow()).setRoom(cellEditEvent.getNewValue());
                table.refresh();
            }
        });


        table = new TableView<>();
        table.setEditable(true);
        table.setItems(data);
        table.getColumns().addAll(nameCol, roomCol);

        VBox vbox = new VBox();
        vbox.getChildren().addAll(table);

        Scene scene = new Scene(vbox);
        stage.setScene(scene);
        stage.show();
    }


    public static class Person
    {
        private final SimpleStringProperty name;
        private final SimpleStringProperty room;

        private Person(String name, String room)
        {
            this.name = new SimpleStringProperty(name);
            this.room = new SimpleStringProperty(room);
        }

        public String getName()       {return name.get();}
        public String getRoom()       {return room.get();}
        public void setRoom(String r) {room.set(r);}
    }
}