When a listView backing list becomes empty after some items removals calling getSelectionModel().isEmpty() returns false.

One can use the following test case for recreate.

package javafx.scene.control;

import static org.junit.Assert.assertTrue;
import javafx.collections.FXCollections;
import javafx.embed.swing.JFXPanel;

import org.junit.Before;
import org.junit.Test;

public class ListViewTest {

@Before
public void init(){
// WAD for JFX8 to initialize the toolkit, otherwise java.lang.IllegalStateException: Toolkit not initialized
//
new JFXPanel();
}

@Test
public void testRemoveAll() {
ListView<String> listView = new ListView<String>(FXCollections.observableArrayList("one", "two", "three"));

listView.getSelectionModel().selectFirst();

listView.getItems().removeAll("one", "two", "three");

// notify the [null] element on the list
System.out.println(listView.getSelectionModel().getSelectedItems());

assertTrue(listView.getSelectionModel().isEmpty());
}
}

After a quick analysis of decompilled sources it looks like this behaviour is connected to the following part of code in

javafx.scene.control.MultipleSelectionModelBase.shiftSelection(int, int)

--------------------------------------------------------
} else if (shift < 0) {
            for (int i = position; i < selectedIndicesSize; i++) {
                if ((i + shift) < 0) continue; <--------- 1*
                boolean selected = selectedIndices.get(i + 1);
                selectedIndices.set(i + 1 + shift, selected); <--------- it will never update a 0th bit (in connection with [1*] (i+1+shift) > 0 ) in the selectedIndices BitSet so it will always
                                                                                                                       indicate 0th item as selected and thus:
                                                                                                                      -) never return true from isEmpty.
                                                                                                                      -) getSelectionModel().getSelectedItems() will return a collection with a null object inside
                                                                                                                      -) adding items to this listview will keep shifting this null item to the end
                                                                                                                      -) possibly will eventually break logic that depends on sizes of collections (e.g. replace)

                if (selected) {
                    perm[idx++] = i;
                }
            }
}
---------------------------------------------------------

The code is quite messy imho and I haven't analyzed it more than I needed but I might have come up with two possible fixes

1 - let the 0th bit be updated by modifying the mentioned code

//AS IS
if ((i + shift) < 0) continue;

//TO BE
if ((i + shift) < -1) continue;

2 - (BETTER) considering it's a border case - no more items in a list view - shiftSelection can be avoided by a simple check in

javafx.scene.control.ListView.ListViewBitSetSelectionModel.updateSelection(Change<? extends T>)

//AS IS
} else if (c.wasAdded() || c.wasRemoved()) {
              int shift = c.wasAdded() ? c.getAddedSize() : -c.getRemovedSize();
              shiftSelection(c.getFrom(), shift);
}

to :

//TO BE
} else if (c.wasAdded() || c.wasRemoved()) {
              shiftSelection(c.getFrom(), c.getAddedSize());
} else if (c.wasRemoved()) {
           if (getItemCount() == 0) {
                        // all items were removed from the model
                        clearSelection();
            } else {
                shiftSelection(c.getFrom(), -c.getRemovedSize());
            }
}

Please let me know what you think.

Thanks.