code: public void setCurrentItemShowing(int index, boolean animate) {
          if (index != HOUR_INDEX && index != MINUTE_INDEX) {
              Log.e(TAG, "TimePicker does not support view at index " + index);
              return;
          }
  
          int lastIndex = getCurrentItemShowing();
          mCurrentItemShowing = index;
  
          if (animate && (index != lastIndex)) {
              ObjectAnimator[] anims = new ObjectAnimator[4];
              if (index == MINUTE_INDEX) {
                  anims[0] = mHourRadialTextsView.getDisappearAnimator();
                  anims[1] = mHourRadialSelectorView.getDisappearAnimator();
                  anims[2] = mMinuteRadialTextsView.getReappearAnimator();
                  anims[3] = mMinuteRadialSelectorView.getReappearAnimator();
              } else if (index == HOUR_INDEX) {
                  anims[0] = mHourRadialTextsView.getReappearAnimator();
                  anims[1] = mHourRadialSelectorView.getReappearAnimator();
                  anims[2] = mMinuteRadialTextsView.getDisappearAnimator();
                  anims[3] = mMinuteRadialSelectorView.getDisappearAnimator();
              }
  
              if (mTransition != null && mTransition.isRunning()) {
                  mTransition.end();
              }
              mTransition = new AnimatorSet();
              mTransition.playTogether(anims);
              mTransition.start();
          } else {
              int hourAlpha = (index == HOUR_INDEX) ? 255 : 0;
              int minuteAlpha = (index == MINUTE_INDEX) ? 255 : 0;
              mHourRadialTextsView.setAlpha(hourAlpha);
              mHourRadialSelectorView.setAlpha(hourAlpha);
              mMinuteRadialTextsView.setAlpha(minuteAlpha);
              mMinuteRadialSelectorView.setAlpha(minuteAlpha);
          }
  
      }
docs: Set either minutes or hours as showing.
  
  @param animate True to animate the transition, false to show with no animation.