@Override
 public boolean onInterceptTouchEvent(MotionEvent ev) {
  ensureTarget();

  final int action = MotionEventCompat.getActionMasked(ev);

  if (mReturningToStart && action == MotionEvent.ACTION_DOWN) {
   mReturningToStart = false;
  }

  if (!isEnabled() || mReturningToStart || canChildScrollUp()
    || mRefreshing || mNestedScrollInProgress) {
   // Fail fast if we're not in a state where a swipe is possible
   return false;
  }

  switch (action) {
   case MotionEvent.ACTION_DOWN:
    setTargetOffsetTopAndBottom(mOriginalOffsetTop - mCircleView.getTop(), true);
    mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
    mIsBeingDragged = false;
    final float initialDownY = getMotionEventY(ev, mActivePointerId);
    if (initialDownY == -1) {
     return false;
    }
    mInitialDownY = initialDownY;
    break;

   case MotionEvent.ACTION_MOVE:
    if (mActivePointerId == INVALID_POINTER) {
     Log.e(LOG_TAG, "Got ACTION_MOVE event but don't have an active pointer id.");
     return false;
    }

    final float y = getMotionEventY(ev, mActivePointerId);
    if (y == -1) {
     return false;
    }
    final float yDiff = y - mInitialDownY;
    if (yDiff > mTouchSlop && !mIsBeingDragged) {
     mInitialMotionY = mInitialDownY + mTouchSlop;
     mIsBeingDragged = true;
     mProgress.setAlpha(STARTING_PROGRESS_ALPHA);
    }
    break;

   case MotionEventCompat.ACTION_POINTER_UP:
    onSecondaryPointerUp(ev);
    break;

   case MotionEvent.ACTION_UP:
   case MotionEvent.ACTION_CANCEL:
    mIsBeingDragged = false;
    mActivePointerId = INVALID_POINTER;
    break;
  }

  return mIsBeingDragged;
 }

 @Override
 public boolean onTouchEvent(MotionEvent ev) {
  
  ....

  switch (action) {
   case MotionEvent.ACTION_DOWN:
    mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
    mIsBeingDragged = false;
    break;

   case MotionEvent.ACTION_MOVE: {
    pointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
    if (pointerIndex < 0) {
     Log.e(LOG_TAG, "Got ACTION_MOVE event but have an invalid active pointer id.");
     return false;
    }

    final float y = MotionEventCompat.getY(ev, pointerIndex);
    final float overscrollTop = (y - mInitialMotionY) * DRAG_RATE;
    if (mIsBeingDragged) {
     if (overscrollTop > 0) {
      moveSpinner(overscrollTop);
     } else {
      return false;
     }
    }
    break;
   }
   ....
   case MotionEvent.ACTION_UP: {
    pointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
    if (pointerIndex < 0) {
     Log.e(LOG_TAG, "Got ACTION_UP event but don't have an active pointer id.");
     return false;
    }

    final float y = MotionEventCompat.getY(ev, pointerIndex);
    final float overscrollTop = (y - mInitialMotionY) * DRAG_RATE;
    mIsBeingDragged = false;
    finishSpinner(overscrollTop);
    mActivePointerId = INVALID_POINTER;
    return false;
   }
   case MotionEvent.ACTION_CANCEL:
    return false;
  }

  return true;
 } 

 <span style="font-size:18px;">private void moveSpinner(float overscrollTop) {
  mProgress.showArrow(true);
  float originalDragPercent = overscrollTop / mTotalDragDistance;

  float dragPercent = Math.min(1f, Math.abs(originalDragPercent));
  float adjustedPercent = (float) Math.max(dragPercent - .4, 0) * 5 / 3;
  float extraOS = Math.abs(overscrollTop) - mTotalDragDistance;
  float slingshotDist = mUsingCustomStart ? mSpinnerFinalOffset - mOriginalOffsetTop
    : mSpinnerFinalOffset;
  float tensionSlingshotPercent = Math.max(0, Math.min(extraOS, slingshotDist * 2)
    / slingshotDist);
  float tensionPercent = (float) ((tensionSlingshotPercent / 4) - Math.pow(
    (tensionSlingshotPercent / 4), 2)) * 2f;
  float extraMove = (slingshotDist) * tensionPercent * 2;

  int targetY = mOriginalOffsetTop + (int) ((slingshotDist * dragPercent) + extraMove);
  // where 1.0f is a full circle
  if (mCircleView.getVisibility() != View.VISIBLE) {
   mCircleView.setVisibility(View.VISIBLE);
  }
  if (!mScale) {
   ViewCompat.setScaleX(mCircleView, 1f);
   ViewCompat.setScaleY(mCircleView, 1f);
  }

  if (mScale) {
   setAnimationProgress(Math.min(1f, overscrollTop / mTotalDragDistance));
  }
  if (overscrollTop < mTotalDragDistance) {
   if (mProgress.getAlpha() > STARTING_PROGRESS_ALPHA
     && !isAnimationRunning(mAlphaStartAnimation)) {
    // Animate the alpha
    startProgressAlphaStartAnimation();
   }
  } else {
   if (mProgress.getAlpha() < MAX_ALPHA && !isAnimationRunning(mAlphaMaxAnimation)) {
    // Animate the alpha
    startProgressAlphaMaxAnimation();
   }
  }
  float strokeStart = adjustedPercent * .8f;
  mProgress.setStartEndTrim(0f, Math.min(MAX_PROGRESS_ANGLE, strokeStart));
  mProgress.setArrowScale(Math.min(1f, adjustedPercent));

  float rotation = (-0.25f + .4f * adjustedPercent + tensionPercent * 2) * .5f;
  mProgress.setProgressRotation(rotation);
  setTargetOffsetTopAndBottom(targetY - mCurrentTargetOffsetTop, true /* requires update */);
 }</span>

 <span style="font-size:18px;">private void setTargetOffsetTopAndBottom(int offset, boolean requiresUpdate) {
  mCircleView.bringToFront();
  mCircleView.offsetTopAndBottom(offset);
  mCurrentTargetOffsetTop = mCircleView.getTop();
  if (requiresUpdate && android.os.Build.VERSION.SDK_INT < 11) {
   invalidate();
  }
 }</span>

 <span style="font-size:18px;">private void finishSpinner(float overscrollTop) {
  if (overscrollTop > mTotalDragDistance) {
   setRefreshing(true, true /* notify */);
  } else {
   // cancel refresh
   mRefreshing = false;
   mProgress.setStartEndTrim(0f, 0f);
   Animation.AnimationListener listener = null;
   if (!mScale) {
    listener = new Animation.AnimationListener() {

     @Override
     public void onAnimationStart(Animation animation) {
     }

     @Override
     public void onAnimationEnd(Animation animation) {
      if (!mScale) {
       startScaleDownAnimation(null);
      }
     }

     @Override
     public void onAnimationRepeat(Animation animation) {
     }

    };
   }
   animateOffsetToStartPosition(mCurrentTargetOffsetTop, listener);
   mProgress.showArrow(false);
  }
 }</span>

 <span style="font-size:18px;">private void animateOffsetToCorrectPosition(int from, AnimationListener listener) {
  mFrom = from;
  mAnimateToCorrectPosition.reset();
  mAnimateToCorrectPosition.setDuration(ANIMATE_TO_TRIGGER_DURATION);
  mAnimateToCorrectPosition.setInterpolator(mDecelerateInterpolator);
  if (listener != null) {
   mCircleView.setAnimationListener(listener);
  }
  mCircleView.clearAnimation();
  mCircleView.startAnimation(mAnimateToCorrectPosition);
 }

 private void animateOffsetToStartPosition(int from, AnimationListener listener) {
  if (mScale) {
   // Scale the item back down
   startScaleDownReturnToStartAnimation(from, listener);
  } else {
   mFrom = from;
   mAnimateToStartPosition.reset();
   mAnimateToStartPosition.setDuration(ANIMATE_TO_START_DURATION);
   mAnimateToStartPosition.setInterpolator(mDecelerateInterpolator);
   if (listener != null) {
    mCircleView.setAnimationListener(listener);
   }
   mCircleView.clearAnimation();
   mCircleView.startAnimation(mAnimateToStartPosition);
  }
 }</span>

 <span style="font-size:18px;">private Animation.AnimationListener mRefreshListener = new Animation.AnimationListener() {
  @Override
  public void onAnimationStart(Animation animation) {
  }

  @Override
  public void onAnimationRepeat(Animation animation) {
  }

  @Override
  public void onAnimationEnd(Animation animation) {
   if (mRefreshing) {
    // Make sure the progress view is fully visible
    mProgress.setAlpha(MAX_ALPHA);
    mProgress.start();
    if (mNotify) {
     if (mListener != null) {
      mListener.onRefresh();
     }
    }
    mCurrentTargetOffsetTop = mCircleView.getTop();
   } else {
    reset();
   }
  }
 };</span>

 <span style="font-size:18px;">listener = new Animation.AnimationListener() {


 @Override
 public void onAnimationStart(Animation animation) {
 }


 @Override
 public void onAnimationEnd(Animation animation) {
  if (!mScale) {
   startScaleDownAnimation(null);
  }
 }


 @Override
 public void onAnimationRepeat(Animation animation) {
 }


};</span>