How to style a table cell in JavaFX2 using CSS (without removing hover/selection etc.)

Question

I'm trying to style individual table cells in an JavaFX2 TableView (to indicate that a table cell value is changed, contains an error, etc). To achieve this, I have created a custom TableCell that sets the proper CSS class, based on it's content.

This works to some degree, but the problem is that I now lose all effects, the hover, the selection color gradient etc. (i.e. the pseudo classes).

How can I style a table cell using CSS, without requiring re-defining all the possible combinations of pseudo-classes?

I've read this answer but the solution does not work for me. If I set -fx-control-inner-background to the background color I want, I get hover and selection color like I want, but the initial color is transparent, which is obviously not what I want (I have commented out the attempts in the CSS below, you can uncomment and try for yourself). If you can explain why, and provide a solution, I'd be happy to accept that.

I've also seen this answer, but I really don't want to crate duplicate definitions for all the pseudo-classes (besides, it only seems to work with row selection).

Below is an SSCCE that demonstrates the issue.

Screen shot (this looks like what I want, except the hover and selection doesn't work):

TableViewSample.java (based on Table View tutorial code):

import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.geometry.Insets;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.SelectionMode;
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;

public class TableViewSample extends Application {

    public static final String CSS_ORIGINAL = "cell-renderer-original";
    public static final String CSS_CHANGED = "cell-renderer-changed";
    public static final String CSS_ERROR = "cell-renderer-error";
    public static final String CSS_ERROR_AND_CHANGED = "cell-renderer-error-and-changed";

    private TableView<Person> table = new TableView<>();
    private final ObservableList<Person> data =
            FXCollections.observableArrayList(
                    new Person("Jacob", "Smith", "[email protected]"),
                    new Person("Isabella", "Johnson", "[email protected]"),
                    new Person("Ethan", "Williams", "[email protected]"),
                    new Person("Emma", "Jones", "[email protected]"),
                    new Person("Michael", "Brown", "[email protected]")
            );

    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(500);

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

        table.setEditable(true);

        // Cell selection only (I need this)
        table.getSelectionModel().setCellSelectionEnabled(true);
        table.getSelectionModel().setSelectionMode(SelectionMode.MULTIPLE);

        TableColumn<Person, String> firstNameCol = new TableColumn<>("First Name");
        firstNameCol.setMinWidth(100);
        firstNameCol.setCellValueFactory(new PropertyValueFactory<Person, String>("firstName"));

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

        TableColumn<Person, String> emailCol = new TableColumn<>("Email");
        emailCol.setMinWidth(200);
        emailCol.setCellValueFactory(new PropertyValueFactory<Person, String>("email"));

        // Install custom cell renderer
        emailCol.setCellFactory(new Callback<TableColumn<Person, String>, TableCell<Person, String>>() {
            @Override public TableCell<Person, String> call(final TableColumn<Person, String> personStringTableColumn) {
                return new BackgroundTableCell();
            }
        });

        table.setItems(data);
        table.getColumns().addAll(firstNameCol, lastNameCol, emailCol);

        VBox vbox = new VBox();
        vbox.setSpacing(5);
        vbox.setPadding(new Insets(10, 0, 0, 10));
        vbox.getChildren().addAll(label, table);

        ((Group) scene.getRoot()).getChildren().addAll(vbox);

        scene.getStylesheets().add(getClass().getResource("/my.css").toExternalForm());

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

    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);
        }
    }

    // My custom background cell renderer
    private static class BackgroundTableCell extends TableCell<Person, String> {
        @Override protected void updateItem(final String item, final boolean empty) {
            super.updateItem(item, empty);

            setText(empty ? "" : item);

            getStyleClass().removeAll(CSS_ORIGINAL, CSS_CHANGED, CSS_ERROR, CSS_ERROR_AND_CHANGED);
            updateStyles(empty ? null : item);
        }

        private void updateStyles(String item) {
            if (item == null) {
                return;
            }

            if (item.startsWith("i") || item.startsWith("j")) {
                getStyleClass().add(CSS_CHANGED);
            }
            else if (item.startsWith("e")) {
                getStyleClass().add(CSS_ERROR);
            }
            else if (item.startsWith("m")) {
                getStyleClass().add(CSS_ERROR_AND_CHANGED);
            }
        }
    }
}

my.css:

.cell-renderer-changed {
    -fx-background-color: rgba(255, 248, 33, .4);
    /*-fx-control-inner-background: rgb(255, 248, 33);*/
    -fx-accent: derive(-fx-control-inner-background, -40%);
    -fx-cell-hover-color: #cce3f4;
    -fx-cell-focus-inner-border: #85b9de;
}

.cell-renderer-error {
    -fx-background-color: rgba(255, 159, 160, .4);
    /*-fx-control-inner-background: rgb(255, 159, 160);*/
    -fx-accent: derive(-fx-control-inner-background, -40%);
    -fx-cell-hover-color: #cce3f4;
    -fx-cell-focus-inner-border: #85b9de;
}

.cell-renderer-error-and-changed {
    -fx-background-color: rgba(255, 205, 158, .4);
    /*-fx-control-inner-background: rgb(255, 205, 158);*/
    -fx-accent: derive(-fx-control-inner-background, -40%);
    -fx-cell-hover-color: #cce3f4;
    -fx-cell-focus-inner-border: #85b9de;
}

Answer 1

While not exactly what I wanted, I eventually found a way to create a CSS that doesn't contain too much redundancy.

Many thanks to @James_D for helping out!

Here's the updated my.css:

.cell-renderer-changed {
    my-bg: rgba(255, 248, 33, .5);
    -fx-background-color: my-bg;
}

.cell-renderer-error {
    my-bg: rgba(255, 159, 160, .5);
    -fx-background-color: my-bg;
}

.cell-renderer-error-and-changed {
    my-bg: rgba(255, 205, 158, .5);
    -fx-background-color: my-bg;
}

/* Restore default behaviour from caspian.css */
.cell-renderer-changed:hover, .cell-renderer-error:hover, .cell-renderer-error-and-changed:hover {
    -fx-background-color: -fx-table-cell-border-color, -fx-cell-hover-color;
    -fx-background-insets: 0, 0 0 1 0;
}

.cell-renderer-changed:selected, .cell-renderer-error:selected, .cell-renderer-error-and-changed:selected {
    -fx-background: -fx-accent;
    -fx-background-color: -fx-selection-bar;
    -fx-text-fill: -fx-selection-bar-text;
    -fx-background-insets: 0 0 1 0;
}

.cell-renderer-changed:focused:selected, .cell-renderer-error:focused:selected, .cell-renderer-error-and-changed:focused:selected {
    -fx-background-color: -fx-focus-color, -fx-cell-focus-inner-border, -fx-selection-bar;
    -fx-background-insets: 0 1 0 0, 1 2 1 1, 2 3 2 2;
    -fx-background: -fx-accent;
    -fx-text-fill: -fx-selection-bar-text;
}

.cell-renderer-changed:focused, .cell-renderer-error:focused, .cell-renderer-error-and-changed:focused {
    -fx-background-color: -fx-focus-color, -fx-cell-focus-inner-border, my-bg;
    /*-fx-background-color: -fx-focus-color, -fx-cell-focus-inner-border, transparent;*/
    -fx-background-insets: 0 1 0 0, 1 2 1 1, 2 3 2 2;
}