Javafx 8 Listview Remove item behaviour [duplicate] - javafx

Question

i am trying to put elements on a listview and treeview with javafx, but both controls wont refresh theyre content. i am using an obvservable list to control the items and every time i delete one item, the listview or treeview removes it from the datasource. but the view is not updating. i am still seeing all the items. the only difference is, the removed item can not be selected any more. for example link 2 shows the collaped item list. image 1 shows the items before they are collaped. the items are collapsed but the old entry is still visible. does anybody know a solution for this problem. thank you all for helping me
link 1: treeview is not collapsed
link 2: treeview is collapsed but not updating old view
this is the custom cell factory i use to display a listview:
public ListCell<T> call(final ListView<T> param) {
ListCell<T> cell = new ListCell<T>(){
#Override
protected void updateItem(final T persistentObject, final boolean empty) {
super.updateItem(persistentObject, empty);
if(persistentObject instanceof POProcessStep){
POProcessStep poProcessStep = (POProcessStep) persistentObject;
if (persistentObject != null) {
super.setText(poProcessStep.getId() + " - " + poProcessStep.getTitle());
}
}else if(persistentObject instanceof POProcess){
POProcess poProcess = (POProcess) persistentObject;
if (persistentObject != null) {
super.setText(poProcess.getId() + " - " + poProcess.getTitle());
}
}else if(persistentObject instanceof POCategory){
POCategory poCategory = (POCategory) persistentObject;
if(persistentObject != null){
super.setText(poCategory.getId() + " - " + poCategory.getTitle());
}
}else if(persistentObject instanceof String){
if(persistentObject != null){
super.setText(String.valueOf(persistentObject));
}
}
super.setGraphic(null);
}
};
return cell;
}

Answer 1

Your cell factory's updateItem(...) needs to handle the case where the cell is empty. This will be exactly the scenario when an item is removed (or becomes empty because a node in the TreeView was collapsed) and the cell that previously showed an item is reused as an empty cell:
public ListCell<T> call(final ListView<T> param) {
ListCell<T> cell = new ListCell<T>(){
#Override
protected void updateItem(final T persistentObject, final boolean empty) {
super.updateItem(persistentObject, empty);
if (empty) {
setText(null);
setGraphic(null);
} else {
// ... rest of your code.
}
}
}
return cell ;
}