Gluon Connect DataProvider.retrieveList results in IllegalStateException - gluon

Question

Following code produces an IllegalStateException - not on FX application Thread - .
private void populateListView(){
GluonObservableList<MyClass> items = DataProvider.retrieveList(restClient.createListDataReader(MyClass.class));
listview.setItems(items);
}
I guess the reason for this is that the code which adds the elements from the Iterator to the GluonObservableList is not wrapped in Platform.runLater(), despite to the other calls in retrieveList()?

Answer 1

Updating a UI element (such as listview) must be done from the FX Application Thread.
If populateListView() is called from a background thread, the observableList updates in the background causing the listview to try to update from the background.
Setting the observableList to the listview using Platform.runLater occurs on the FX Thread but the observableList still updates in the background after it is loaded to the listview.
new Thread(()->{
GluonObservableList<MyClass> items = DataProvider.retrieveList(restClient.createListDataReader(MyClass.class));
//Option 1
//listview.setItems(items);
//Option 2
//Platform.runLater(()->listview.setItems(items));
//Option 3
//items.initializedProperty().addListener((obv,ov,nv)->{
// listview.setItems(items);
//});
//Option 4
items.stateProperty().addListener((obvs,ovs,nvs)->{
if (nvs.equals(ConnectState.SUCCEEDED)) {
listview.setItems(items);
}else if(nvs.equals(ConnectState.FAILED)){
MobileApplication.getInstance().showMessage("Rest API request failed");
}
});
}).start();
Option 1 and Option 2 update the listview before data is loaded to the observableList. Option 1 and 2 throw multiple exceptions (and option 1 is just ugly).
Both option 3 and option 4 trigger the listview update after the observableList has been loaded and are handled on the FX Application Thread.
Alternatively, you can wrap any call to populateListView() in Platform.runLater