如何通过功能调用启用浮动操作按钮？

我正在使用android sipmanager实现一个简单的sip调用。在两个座席之间建立呼叫后，我想在屏幕上显示下面列出的浮动操作按钮。但是有些代码永远不会激活，因此无法在成功调用后使该按钮可见。它确实显示日志。任何帮助将不胜感激

SipAudioCall.Listener listener = new SipAudioCall.Listener() {

        /**
         * Name: onCallEstablished
         * Description: onCallEstablished is called when the
         * user establishes a call. This method
         * will enable the User to talk to the
         * person on the opposite line.
         */


       @Override
        public void onCallEstablished(SipAudioCall call) {



           super.onCallEstablished(call);

           call.startAudio();
           call.setSpeakerMode(true);
           //it does shows log in console 
           Log.e("$$", "Manager was instantiated");  

          // it doesnt change floating action button to visible
           View view7 =findViewById(R.id.fab6);
           view7.setVisibility(View.VISIBLE);

           setText("Call ESTABLISEHED");

            if (call.isMuted()) {
                call.toggleMute();
            }

}