Adding hover listener to cells of a specific column in javafx table

Question

I want to create a OnMouseOver Listener to cells of a specific column of a TableView, such that a popup window should appeared with some message, when I hover to it's cells. This is how I am creating a table and its columns.

private TableView<Stock> stockTable = new TableView<>();
ObservableList columns = stockTable.getColumns();

public TableColumn createTextColumn(String columnName, String columnCaption,BooleanProperty editingStarted) {
    TableColumn column = new TableColumn(columnCaption);
    column.setCellValueFactory(new PropertyValueFactory<>(columnName));
    column.setCellFactory(TextFieldTableCell.forTableColumn());
    return column;
}

final TableColumn nameColumn 
                         = createTextColumn("name", "Product Name", editingStarted);
columns.add(nameColumn);

So is it possible to do it. I know how to create listeners for rows. But I found nothing on internet on listening to cells of table. Thanks in advance for any help.

Answer 1

The above example also displays the label when it's empty. This small change will fix this ...

                    if (event.getEventType() == MouseEvent.MOUSE_EXITED) {
                        popup.hide();
                    } else if (event.getEventType() == MouseEvent.MOUSE_ENTERED) {
                        if(result.getText() != null) {
                            if (!"".equals(result.getText())) {
                                popup.show(result, event.getScreenX() + 10, event.getScreenY());
                            }
                        }
                    }

Answer 2

You already used the TextFieldTableCell.forTableColumn() which you need to rewrite to suit your needs

import javafx.event.EventHandler;
import javafx.scene.control.Label;
import javafx.scene.control.TableCell;
import javafx.scene.control.TableColumn;
import javafx.scene.control.cell.TextFieldTableCell;
import javafx.scene.input.MouseEvent;
import javafx.stage.Popup;
import javafx.util.Callback;
import javafx.util.StringConverter;
import javafx.util.converter.DefaultStringConverter;

public final class CustomTextFieldTableCell<S, T> extends TextFieldTableCell<S, T> {

    public static <S> Callback<TableColumn<S, String>, TableCell<S, String>> forTableColumn() {
        return forTableColumn(new DefaultStringConverter());
    }

    public static <S, T> Callback<TableColumn<S, T>, TableCell<S, T>> forTableColumn(final StringConverter<T> converter) {
        return new Callback<TableColumn<S, T>, TableCell<S, T>>() {
            @Override
            public TableCell<S, T> call(TableColumn<S, T> list) {
                final TextFieldTableCell<S, T> result = new TextFieldTableCell<S, T>(converter);
                final Popup popup = new Popup();
                popup.setAutoHide(true);

                final EventHandler<MouseEvent> hoverListener = new EventHandler<MouseEvent>() {

                    @Override
                    public void handle(MouseEvent event) {
                        final Label popupContent = new Label("this is a popup showing the content = '" + result.getText() + "'");
                        popupContent.setStyle("-fx-background-color: #64b5f6; -fx-border-color: #000000; -fx-border-width: 1px; -fx-padding: 5px; -fx-text-fill: white;");

                        popup.getContent().clear();
                        popup.getContent().addAll(popupContent);

                        if (event.getEventType() == MouseEvent.MOUSE_EXITED) {
                            popup.hide();
                        } else if (event.getEventType() == MouseEvent.MOUSE_ENTERED) {
                            popup.show(result, event.getScreenX() + 10, event.getScreenY());                
                        }
                    }
                };

                result.setOnMouseEntered(hoverListener);
                result.setOnMouseExited(hoverListener);
                return result;
            }
        };
    }
}

To use it you need to change your code to

column.setCellFactory(CustomTextFieldTableCell.forTableColumn());

The result looks like this