android - actionbar dropdown not working when in fragment -

i have navigation menu bar , drop-down in action bar.the ui looks this:

for navigation different ui i’m using fragments.when click on top of drop-down should list out added items instead im getting exception:

    06-04 18:12:39.651  22359-22359/com.poliveira.apps.materialtests w/dalvikvm﹕ method landroid/support/v7/internal/widget/listviewcompat;.lookforselectableposition incorrectly overrides package-private method same name in landroid/widget/listview; 06-04 18:12:39.671  22359-22359/com.poliveira.apps.materialtests d/androidruntime﹕ shutting down vm 06-04 18:12:39.671  22359-22359/com.poliveira.apps.materialtests w/dalvikvm﹕ threadid=1: thread exiting uncaught exception (group=0x40ce5930) 06-04 18:12:39.671  22359-22359/com.poliveira.apps.materialtests e/androidruntime﹕ fatal exception: main     java.lang.nullpointerexception             @ android.widget.relativelayout.onmeasure(relativelayout.java:529)             @ android.view.view.measure(view.java:15535)             @ android.support.v7.internal.widget.listviewcompat.measureheightofchildrencompat(listviewcompat.java:294)             @ android.support.v7.widget.listpopupwindow.builddropdown(listpopupwindow.java:1200)             @ android.support.v7.widget.listpopupwindow.show(listpopupwindow.java:584)             @ android.support.v7.internal.widget.spinnercompat.performclick(spinnercompat.java:603)             @ android.view.view$performclick.run(view.java:17372)             @ android.os.handler.handlecallback(handler.java:725)             @ android.os.handler.dispatchmessage(handler.java:92)             @ android.os.looper.loop(looper.java:137)             @ android.app.activitythread.main(activitythread.java:5041)             @ java.lang.reflect.method.invokenative(native method)             @ java.lang.reflect.method.invoke(method.java:511)             @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:793)             @ com.android.internal.os.zygoteinit.main(zygoteinit.java:560)             @ dalvik.system.nativestart.main(native method) 

in mainactivity.java on-create i’m doing this:

mtoolbar = (toolbar) findviewbyid(r.id.toolbar_actionbar); setsupportactionbar(mtoolbar); getsupportactionbar().setdisplayshowhomeenabled(true); actionbar=getsupportactionbar(); actionbar.setdisplayshowtitleenabled(false);  // enabling spinner dropdown navigation actionbar.setnavigationmode(actionbar.navigation_mode_list); actionbar.setdisplayshowhomeenabled(true);  // spinner title navigation data navspinner = new arraylist<spinnernavitem>(); navspinner.add(new spinnernavitem("local", r.drawable.deviceonline)); navspinner.add(new spinnernavitem("my places", r.drawable.deviceonline)); navspinner.add(new spinnernavitem("checkins", r.drawable.deviceonline)); navspinner.add(new spinnernavitem("latitude", r.drawable.deviceonline));  // title drop down adapter adapter = new titlenavigationadapter(getapplicationcontext(), navspinner); // assigning spinner navigation actionbar.setlistnavigationcallbacks(adapter, this); 

i’m having fragment class called "refragment.java". code i'm using:

   @override     public view oncreateview(layoutinflater inflater, viewgroup container,             bundle savedinstancestate) {          view rootview;         display d =getactivity().getwindowmanager().getdefaultdisplay();         // set display size         thumbsize.setscreensize(d.getwidth(), d.getheight());         final int w = d.getwidth();         final int h = d.getheight();         final double ar = w > h ? (double) w / (double) h : (double) h / (double) w;          if (ar > 1.6) {             log.i(tag, "ar = " + ar + ", using extended layout.");             rootview= inflater.inflate(r.layout.rbox_extended, container, false);          } else {             log.i(tag, "ar = " + ar + ", normal layout.");             rootview= inflater.inflate(r.layout.rbox, container, false);          }        if (mviewflipper != null) {             mremoteview = mviewflipper.getchildat(0);             mmousepadview = mviewflipper.getchildat(1);             mgestureview = mviewflipper.getchildat(2);             mviewflipper.setdisplayedchild(0); // mremoteview         }         rootview.findviewbyid(android.r.id.content);         mremotecontroller = new      remotecontroller(getactivity().getapplicationcontext());         mconfigurationmanager = configurationmanager.getinstance(getactivity());         setupbuttons(rootview);         setupslider(ar,rootview,mmainactivitiycontext);          return rootview; }