[JAVA] I made a lock pattern using the volume key with the Android app. Fragment edition

I wrote a code that unlocks when I type a command within 5 seconds using the volume button.

  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
                           Bundle savedInstanceState) {

    //Initialization of commands when changing volume
    mCommandTime = 0;
    mSuccessCommand = "";

    final View v = inflater.inflate(R.layout.fragment_recording, container, false);

    v.setOnKeyListener(new View.OnKeyListener() {
      @Override
      public boolean onKey(View v, int keyCode, KeyEvent event) {


        if (mCommandTime==0) {
          //Once pressed, timer will not start until mCommandTime is reset to 0 after 5 seconds
          mCommandTime++;

          final Handler handler = new Handler();
          handler.postDelayed(new Runnable() {
            @Override
            public void run() {
              Log.d(TAG, "Initialize openPass after 5 seconds");
              mSuccessCommand = "";
              //String the value only when the timer is on(mSuccessCommand)Can be added to
              Log.d(TAG, "The timer can be started after 5 seconds have passed.");
              mCommandTime= 0;
            }
          }, 5000);

        }else{
          Log.d(TAG,"comandTime"+mCommandTime+"And I can't use timer because it's been over 5 seconds");
        }

        if(event.getKeyCode() == KeyEvent.KEYCODE_VOLUME_UP){
          mSuccessCommand=mSuccessCommand+"1";
          Log.d(TAG,"To Command+1, the current command is"+mSuccessCommand);


        }else if(event.getKeyCode() == KeyEvent.KEYCODE_VOLUME_DOWN){
          mSuccessCommand=mSuccessCommand+"0";
          Log.d(TAG,"To Command+0, the current command is"+mSuccessCommand);

        }

        if (mSuccessCommand.equals("01101")) { 
          Log.i(TAG,"The life command has been lifted");
     
          Toast.makeText(getActivity(), "The lock has been released.", Toast.LENGTH_SHORT).show();
          
          //Here is the process for unlocking
      }
    });
    // View#It is important to set true in setFocusableInTouchMode
    v.setFocusableInTouchMode(true);
    return v;
  }
}

Although it is not written here, KeyEvent is called twice, "Down" and "Up", so it is good to make an if statement that can be entered only when "Down".

personally,

While making SNS etc. in the future, I would like to adjust the transparency of the application by unlocking the volume button. Have fun