title: Can android PopupWindow show another PopupWindow?
body: <p>Can android PopupWindow show another PopupWindow?
  How many PopupWindow can be opened in the same time? Only one?</p>
  
  <p>The first PopupWindow is displayed normally. But on button click (which is in the first PopupWindow contentview) i am having an exception:</p>
  
  <pre><code>08-13 16:28:38.682: ERROR/AndroidRuntime(11760): FATAL EXCEPTION: main
          android.view.WindowManager$BadTokenException: Unable to add window -- token android.view.ViewRootImpl$W@41286250 is not valid; is your activity running?
          at android.view.ViewRootImpl.setView(ViewRootImpl.java:600)
          at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:313)
          at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:215)
          at android.view.WindowManagerImpl$CompatModeWrapper.addView(WindowManagerImpl.java:140)
          at android.view.Window$LocalWindowManager.addView(Window.java:537)
          at android.widget.PopupWindow.invokePopup(PopupWindow.java:992)
          at android.widget.PopupWindow.showAsDropDown(PopupWindow.java:901)
          at org.example.qberticus.quickactions.BetterPopupWindow.showLikePopDownMenu(BetterPopupWindow.java:159)
          at org.example.qberticus.quickactions.BetterPopupWindow.showLikePopDownMenu(BetterPopupWindow.java:129)
          at name.antonsmirnov.android.popup.ui.MainActivity$1$1.run(MainActivity.java:44)
          at android.app.Activity.runOnUiThread(Activity.java:4170)
          at name.antonsmirnov.android.popup.ui.MainActivity$1.onClick(MainActivity.java:42)
          at android.view.View.performClick(View.java:3558)
          at android.view.View$PerformClick.run(View.java:14157)
          at android.os.Handler.handleCallback(Handler.java:605)
          at android.os.Handler.dispatchMessage(Handler.java:92)
          at android.os.Looper.loop(Looper.java:137)
          at android.app.ActivityThread.main(ActivityThread.java:4514)
          at java.lang.reflect.Method.invokeNative(Native Method)
          at java.lang.reflect.Method.invoke(Method.java:511)
          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790)
          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
          at dalvik.system.NativeStart.main(Native Method)
  </code></pre>
  
  <p>the code is:</p>
  
  <pre><code>    @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
  
      setContentView(R.layout.main);
      bindControls();
      initControls();
  }
  
  private Button button;
  
  private void bindControls() {
      button = (Button) findViewById(R.id.button);
  }
  
  private void initControls() {
      initButton(button);
  }
  
  private void initButton(final Button button) {
      button.setOnClickListener(new View.OnClickListener() {
          public void onClick(View view) {
              final BetterPopupWindow window = new BetterPopupWindow(button);
  
              View popupview = createPopupView();
              window.setContentView(popupview);
              runOnUiThread(new Runnable() {
                  public void run() {
                      window.showLikePopDownMenu();
                  }
              });
          }
      });
  }
  
  private View createPopupView() {
      View v = LayoutInflater.from(MainActivity.this).inflate(R.layout.window, null);
      Button popupButton = (Button) v.findViewById(R.id.popupbutton);
      initButton(popupButton);
      return v;
  }
  </code></pre>