FULL PRODUCT VERSION :
java version "1.8.0_65"
Java(TM) SE Runtime Environment (build 1.8.0_65-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.65-b01, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
MacOS X El Capitan 10.11.1

A DESCRIPTION OF THE PROBLEM :
The class "Scene" has a field called scrollGesture which keeps a reference to the last target / node that was scrolled. If the target / node gets removed from the scene then it can not be garbage collected.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
- Create a list view with a list of items (e.g. "TestItem").
- Add the view to the scene.
- Scroll the view with a gesture (e.g. swipe down on Mac Magic Mouse)
- Remove the list view from the scene

When using jvisualvm you will see that the last list of TestItems will still be in memory / in the heap.

More details and screenshots on my blog at https://dlemmermann.wordpress.com/2016/01/29/javafx-scrollgesture-memory-leak/


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
All instances of TestItem should have been garbage collected.
ACTUAL -
All instances of TestItem are still there.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
No error log, this needs to be profiled. The heap has to be examined.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.ArrayList;
import java.util.List;

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.ListView;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;

public class MemoryLeakListViewApp extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception {
        BorderPane pane = new BorderPane();
        Scene scene = new Scene(pane);

        Button createButton = new Button("Create");
        createButton.setOnAction(evt -> {

            ListView<TestItem> listView = new ListView<>();

            List<TestItem> children = new ArrayList<>();
            for (int i = 0; i < 1000; i++) {
                children.add(new TestItem("Row " + i));
            }

            listView.getItems().setAll(children);
            pane.setCenter(listView);
        });

        Button deleteButton = new Button("Destroy");
        deleteButton.setOnAction(evt -> {
            pane.setCenter(null);
        });

        HBox box = new HBox();
        box.getChildren().addAll(createButton, deleteButton);
        pane.setTop(box);

        primaryStage.setScene(scene);
        primaryStage.setWidth(800);
        primaryStage.setHeight(800);
        primaryStage.show();
    }

    static class TestItem {

        private String name;

        public TestItem(String name) {
            this.name = name;
        }

        @Override
        public String toString() {
            return name;
        }
    }

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

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
None that I can think of right now.