The proper way of getting the Activity or Fragment Manager from the Context.

ContextHelper.java

/*
 * Copyright 2016 Elmar Rhex Gomez.
 *
 * 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.
 */

import android.app.Activity;
import android.content.Context;
import android.content.ContextWrapper;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;

public class ContextHelper {

    /**
     * The method that unwraps the the Context inorder to
     * obtained the Fragment Manager.
     *
     * @param context the Context to unwrap.
     * @return the Fragment Manager. Otherwise it returns null if not found.
     */
    public static FragmentManager getFragmentManager(Context context) {
        Activity activity = getActivity(context);
        if (activity instanceof FragmentActivity) {
            return ((FragmentActivity) activity).getSupportFragmentManager();
        }
        return null;
    }

    /**
     * The method that unwraps the the Context inorder to
     * obtained the Activity.
     *
     * @param context the Context to unwrap.
     * @return the Activity. Otherwise it returns null if not found.
     */
    public static Activity getActivity(Context context) {
        if (context == null) {
            throw new NullPointerException("Context must not be null");
        }

        while (context instanceof ContextWrapper) {
            if (context instanceof Activity) {
                return (Activity) context;
            }
            context = ((ContextWrapper) context).getBaseContext();
        }
        
        throw new IllegalArgumentException("The Context is not an Activity context!");
    }

}