Javafx tableview with data from multiple classes

Question

I have no problem filling my tableview with diffrent data from 1 class. But it does not work for me with multiple classes. Any idea how to solve that? I have checked out similar questions on stackoverflow. But none of them could help me. If you suggest anything with the "Callback" class, please provide me the full import, because there are a couple of Callback classes out there.

public class MainViewController implements Initializable {

    @FXML
    private TableColumn<TaskControl, Boolean> colErledigt;

    @FXML
    private TableColumn<TaskControl, Character> colPrioritaet;

    @FXML
    private TableColumn<TaskControl, String> colBeschreibung;


    @FXML
    private TableColumn<ProjectControl, String> colProjekt;


    @FXML
    private TableView<TaskControl> tblView;





    public final void initialize(final URL location,
            final ResourceBundle resources) {

        initializeTableElements();

    }


    public final void initializeTableElements() {
        colBeschreibung
                .setCellValueFactory(new PropertyValueFactory<>("description"));

        colPrioritaet
                .setCellValueFactory(new PropertyValueFactory<>("priority"));


        colProjekt.setCellValueFactory(new PropertyValueFactory<>("name"));


        colErledigt.setMaxWidth(50);
        colErledigt.setCellValueFactory(
                new PropertyValueFactory<TaskControl, Boolean>("isDone"));
        colErledigt
                .setCellFactory(CheckBoxTableCell.forTableColumn(colErledigt));
        colErledigt.setEditable(true);

        try {
            tblView.setItems(getObsTasks());
        } catch (IDNotValidException | StringNotValidException e1) {
            System.out.print("FEHLER beim getObsTasks");
        }

        tblView.setEditable(true);
    }


    public ObservableList<TaskControl> getObsTasks()
            throws IDNotValidException, StringNotValidException {

        ObservableList<TaskControl> obsTasks = FXCollections
                .observableArrayList();

        Map<Context, Set<Task>> test = TasksContextUtility.INSTANCE
                .getAllContextsAndTasks();

        test.values().forEach(v -> {
            v.forEach(b -> obsTasks.add((TaskControl) b));
        });

        return obsTasks;
    }

Further question: How can I show a certain Attribute of an Instance in a HashSet in a TableCell. So I have in my TaskControl class a HashSet. In that HashSet there are Instances of the class "ProjectControl". Every instance of ProjectControl has attributes like "name" or "id" etc.

And I want to represent all the names of the project instances in 1 single table cell if possible. Maybe as a string seperated with commas (project1,project2,project3...).

Task class (shortened a lot) my TaskControl Class inherits from this class

public abstract class Task
  implements Serializable, IDValidatable
{
  private int id;
  private char priority = ' ';
  private final Set<Project> projects = new HashSet();

  public Task(int oid)
    throws IDNotValidException
  {
    if (isIDValid(oid)) {
      this.id = oid;
    } else {
      throw new IDNotValidException("The ID you have specified is not valid!")
      {
        private static final long serialVersionUID = 99044660889990790L;
      };
    }
  }

  public final void setId(int oid)
    throws IDNotValidException
  {
    if (isIDValid(oid)) {
      this.id = oid;
    } else {
      throw new IDNotValidException("The ID you have specified is not valid!")
      {
        private static final long serialVersionUID = 99044660889990790L;
      };
    }
  }

  public final int getId()
  {
    return this.id;
  }

  public final Collection<Context> getContexts()
  {
    return this.contexts;
  }

  public final void addContext(Context context)
    throws ContextNotValidException
  {
    this.contexts.add(context);
  }

  public final void removeContext(Context context)
    throws ContextNotValidException
  {
    this.contexts.remove(context);
  }

  public final Collection<Project> getProjects()
  {
    return this.projects;
  }

  public final void addProject(Project project)
    throws ProjectNotValidException
  {
    this.projects.add(project);
  }

  public final void removeProject(Project project)
    throws ProjectNotValidException
  {
    this.projects.remove(project);
  }

  public final Map<String, String> getAddons()
  {
    return this.addons;
  }
}

Answer 1

In my opition you only have one nice solution for this.

You need a extra Class that holds your TaskControl, ContextControl and ProjectControl.

Your Code can look something like that.

class Wrapper{
 private TaskControl taskControl;
 private ContextControl contextControl;
 private ProjectControl projectControl;
 ...
 public Boolean isDone(){
   return taskControl != null ? taskControl.isDone() : null;
  }
}


@FXML
private TableView<Wrapper> tblView;

@FXML
private TableColumn<Wrapper, Boolean> colErledigt;

colErledigt.setCellValueFactory(
            new PropertyValueFactory<Wrapper, Boolean>("isDone"));

Answer 2

Solved it by adding an additional String to my TaskControl, that contains the names of all the projects it contains. It gets the names through a function that I call just before I create the ObservableList for the Table Column.

private String projectsAsString;
    ...
public final void convertProjectsToString() {

    String projects = "";

    for (Project p : this.getProjects()) {
        ProjectControl pp = (ProjectControl) p;
        projects += pp.getName() + ", ";
    }
    if (projects != null && projects != "" && projects.length() > 4) {
        projects = projects.substring(0, projects.length() - 2);
    }
    this.projectsAsString = projects;
}

Thank you guys anyways for helping me.