sPFApp/src/main/java/it/polimi/spf/app/view/TagsPicker.java
public void setChangeListener(OnChangeListener listener) {
        changeListener = listener;
        if (changeListener != null) {
            // add a listener to TagViewer for removed tags events
            tv.setOnRemovedTagListener(new TagsViewer.OnRemovedListener() {
                @Override
                public void onRemovedTag(String tag) {
                    notifyChangeListener();
                }
            });
        }
    }
public void setChangeListener(OnChangeListener listener) {
        changeListener = listener;
        if (changeListener != null) {
            // add a listener to TagViewer for removed tags events
            tv.setOnRemovedTagListener(new TagsViewer.OnRemovedListener() {
                @Override
                public void onRemovedTag(String tag) {
                    notifyChangeListener();
                }
            });
        }
    }
Set the change listener.

@param listener