Mortal で Activity を利用する場合の実装方法 ref: http://qiita.com/eccyan/items/58f0f3b6c8554c7bfd66

file0.txt

java.lang.ClassCastException: mortar.MortarContextWrapper cannot be cast to 
android.app.Activity

file1.java

    class WindowOwner extends Presenter<WindowOwner.Activity> {

        interface Activity {
            void addFragsToWindow(int flags);
        }

        public static class Config() {
            final private int flags;
            Config(int flags) { this.flags = flags; }
            public int getFlags() { return this.flags; }
        }

        private Config config;

        public void setConfig(Config config) {
            this.config = config;
            update();
        }

        private void update() {
             WindowOwner.Activity activity = getView();
             if (activity != null) {
                  activity.addFlagsToWindow(config.getFlags());
             }
        }

        @dagger.Module(injects = {}, library = true)
        public static class WindowOwnerModule {
             @Provides
             @Singleton
             WindowOwner provideWindowOwnerPersenter() { return new WindowOwner(); }
        }
    }

file2.java

     class AwesomeActivity extends Activity implements WindowOwner.Activity {
          @Inject WindowOwner windowOwner;

          @Override
          protected void onCreate(Bundle savedInstanceState) {
              Mortar.inject(this, this);
              this.windowOwner.takeView(this);
          }

          @Override
          void addFragsToWindow(int flags) {
              getWindow().addFlags(flags);
          }
     }