JavaFX - Incompatible parameter type with using TreeView.EditEvent in lambda - javafx

Question

In a JavaFX TreeView I'm using 'custom' classes which extend TreeItem. This makes me able to edit the items in the TreeView (I can double click them and edit the contents when running the application) but I can't seem to be able to set the .setOnEditCommit() method properly. I was hoping it'd work similar as the function in a tableview but I didn't have any luck yet.
This is my code in my controller in which I try to set the setOnEditCommit() method. In my TreeView called 'trvDivisies' I display football team divisions / competitions and one level lower I display all the teams that are in a certain division.
private void setUpTreeView() {
trvDivisies.setEditable(true);
trvDivisies.setShowRoot(false);
TreeItem<String> root = new TreeItem<>();
for (Divisie d : divisies) {
TreeItem<String> divisieTreeItem = d;
divisieTreeItem.valueProperty().set(d.getNaam());
for (VoetbalTeam vt : d.getVoetbalTeams()) {
TreeItem<String> voetbalTeamTreeItem = vt;
voetbalTeamTreeItem.valueProperty().setValue(vt.getTeamNaam());
divisieTreeItem.getChildren().add(voetbalTeamTreeItem);
}
root.getChildren().add(divisieTreeItem);
}
trvDivisies.setRoot(root);
trvDivisies.getSelectionModel().selectedItemProperty().addListener(new ChangeListener() {
#Override
public void changed(ObservableValue observable, Object oldValue, Object newValue) {
System.out.println(newValue);
}
});
trvDivisies.setCellFactory(TextFieldTreeCell.forTreeView());
// I get an error at the following line when compiling
trvDivisies.setOnEditCommit((TreeView.EditEvent p) -> {
TreeItem<String> selectedItem = p.getTreeItem();
if (selectedItem instanceof Divisie) {
updateDivisie((Divisie)selectedItem);
} else if (selectedItem instanceof VoetbalTeam) {
updateTeam((VoetbalTeam)selectedItem);
}
});
}
This is what my 'custom' classes look like.
public class Divisie extends TreeItem<String> {
private static int idCount = 0;
private int id;
private String naam;
private List<VoetbalTeam> voetbalTeams;
public int getId() {
return id;
}
public String getNaam() {
return naam;
}
public List<VoetbalTeam> getVoetbalTeams() {
return voetbalTeams;
}
public Divisie(int id, String naam) {
super(naam);
this.id = id;
this.naam = naam;
}
public Divisie(String naam) {
this.id = ++idCount;
this.naam = naam;
}
public void addTeam(VoetbalTeam toBeAdded) {
if (voetbalTeams == null) {
voetbalTeams = new LinkedList<>();
}
voetbalTeams.add(toBeAdded);
}
#Override
public String toString() {
return this.naam;
}
}
Second 'lower level' class
public class VoetbalTeam extends TreeItem<String> {
private static int idCount = 0;
private int id;
private String teamNaam;
private List<Speler> spelers;
public int getId() {
return id;
}
public String getTeamNaam() {
return teamNaam;
}
public List<Speler> getSpelers() {
return this.spelers;
}
public VoetbalTeam(int id, String teamNaam) {
super(teamNaam);
this.id = id;
this.teamNaam = teamNaam;
}
public VoetbalTeam(String teamNaam) {
super(teamNaam);
this.id = ++idCount;
this.teamNaam = teamNaam;
}
public void addSpeler(Speler nieuweSpeler) {
if (spelers == null) {
spelers = new LinkedList<>();
}
this.spelers.add(nieuweSpeler);
}
#Override
public String toString() {
return this.teamNaam;
}
}
When trying to run the application WITH the .setOnEditCommit() method I get an error saying:
Error:(97, 37) java: incompatible types: incompatible parameter types in lambda expression
I was hoping you guys can tell me what I need to change my TreeView.EditEvent lambda to or help me find an easier solution.

Answer 1

For a TreeView<T>, the signature of setOnEditCommit is
void setOnEditCommit(EventHandler<TreeView.EditEvent<T>> value)
Since you have (apparently) a TreeView<String>, you need
trvDivisies.setOnEditCommit((TreeView.EditEvent<String> p) -> {
// ...
});
Or, of course, you can just let the compiler do the work for you:
trvDivisies.setOnEditCommit(p -> {
// ...
});