Javafx, get the object referenced by a TableCell

Question

I have the following Callback listening on the selected Cell of a TableView:

        Callback<TableColumn<MyFTPFile,String>, TableCell<MyFTPFile,String>> cellFactory =
            new Callback<TableColumn<MyFTPFile,String>, TableCell<MyFTPFile,String>>() {
                public TableCell<MyFTPFile,String> call(TableColumn<MyFTPFile,String> p) {
                    TableCell<MyFTPFile,String> cell = new TableCell<MyFTPFile, String>() {
                        @Override
                        public void updateItem(String item, boolean empty) {
                            super.updateItem(item, empty);
                            setText(empty ? null : getString());
                            setGraphic(null);
                        }

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

                    cell.addEventFilter(MouseEvent.MOUSE_CLICKED, new EventHandler<MouseEvent>() {
                        @Override
                        public void handle(MouseEvent event) {
                            if (event.getClickCount() > 1) {
                                TableCell<MyFTPFile,String> c = (TableCell<MyFTPFile,String>) event.getSource();


                                ftpObservablelist = MyFTPClient.getInstance().getFtpObservableList(); 
                                ftpTable.setItems(ftpObservablelist);

                            }
                        }
                    });

Now, I would like to get the MyFTPFile object which is referenced by the cell, which is doubleclicked, so that i can pass it to another class and do stuff... Any Idea how to do that???

Thanks in advance.

Answer 1

The MyFTPFile object is associated with the cell's row, so, as the asker pointed out in his comment, it is retrievable via cell.getTableRow().getItem().

At first I thought this should be cell.getItem(), which returns the data value associated with the cell. However, most of the time, the cell data value will be a property of the backing item rather than the object itself (for example a filename field of a MyFTPFile object).

Executable sample for the curious:

import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.TableCell;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.control.cell.TextFieldTableCell;
import javafx.scene.input.MouseEvent;
import javafx.stage.Stage;
import javafx.util.Callback;

public class TableClickListener extends Application {

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

  class FTPTableCell<S, T> extends TextFieldTableCell<S, T> {
    FTPTableCell() {
      super();
      addEventFilter(MouseEvent.MOUSE_CLICKED, new EventHandler<MouseEvent>() {
        @Override
        public void handle(MouseEvent event) {
          if (event.getClickCount() > 1 && getItem() != null) {
            System.out.println("Sending " + getTableRow().getItem() + " to the FTP client");
          }
        }
      });
    }
  }

  final Callback<TableColumn<MyFTPFile, String>, TableCell<MyFTPFile, String>> FTP_TABLE_CELL_FACTORY =
      new Callback<TableColumn<MyFTPFile, String>, TableCell<MyFTPFile, String>>() {
        public TableCell<MyFTPFile, String> call(TableColumn<MyFTPFile, String> p) {
          return new FTPTableCell<>();
        }
      };

  @Override
  public void start(final Stage stage) {
    final TableView<MyFTPFile> table = new TableView<>();

    final TableColumn<MyFTPFile, String> filenameColumn = new TableColumn<>("Filename");
    filenameColumn.setCellValueFactory(new PropertyValueFactory<MyFTPFile, String>("filename"));
    filenameColumn.setCellFactory(FTP_TABLE_CELL_FACTORY);
    filenameColumn.setMinWidth(150);

    final TableColumn<MyFTPFile, String> ratingColumn = new TableColumn<>("Rating");
    ratingColumn.setCellValueFactory(new PropertyValueFactory<MyFTPFile, String>("rating"));
    ratingColumn.setCellFactory(FTP_TABLE_CELL_FACTORY);
    ratingColumn.setMinWidth(20);

    table.getColumns().setAll(filenameColumn, ratingColumn);

    table.getItems().setAll(
        new MyFTPFile("xyzzy.txt", 10),
        new MyFTPFile("management_report.doc", 1),
        new MyFTPFile("flower.png", 7)
    );

    table.setColumnResizePolicy(TableView.CONSTRAINED_RESIZE_POLICY);

    stage.setScene(new Scene(new Group(table)));
    stage.show();
  }

  public class MyFTPFile {
    private final String filename;
    private final int rating;

    MyFTPFile(String filename, int rating) {
      this.filename = filename;
      this.rating = rating;
    }

    public String getFilename() {
      return filename;
    }

    public int getRating() {
      return rating;
    }

    @Override
    public String toString() {
      return "MyFTPFile{" +
          "filename='" + filename + '\'' +
          ", rating=" + rating +
          '}';
    }
  }

}