Java tutorial
/*** Copyright (c) 2013 Jake Wharton Portions Copyright (c) 2013 CommonsWare, LLC Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0. Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. Covered in detail in the book _The Busy Coder's Guide to Android Development_ https://commonsware.com/Android */ // derived from https://gist.github.com/JakeWharton/2621173 package com.commonsware.android.eu4youtb; import android.app.Activity; import android.support.v4.app.ListFragment; public class ContractListFragment<T> extends ListFragment { private T contract; @SuppressWarnings("unchecked") @Override public void onAttach(Activity activity) { super.onAttach(activity); try { contract = (T) activity; } catch (ClassCastException e) { throw new IllegalStateException(activity.getClass().getSimpleName() + " does not implement contract interface for " + getClass().getSimpleName(), e); } } @Override public void onDetach() { super.onDetach(); contract = null; } public final T getContract() { return (contract); } }