protected void moveSharedElementsFromOverlay() {
    int numListeners = mGhostViewListeners.size();
    for (int i = 0; i < numListeners; i++) {
        GhostViewListeners listener = mGhostViewListeners.get(i);
        listener.removeListener();
    }
    mGhostViewListeners.clear();

    if (mWindow == null || !mWindow.getSharedElementsUseOverlay()) {
        return;
    }
    ViewGroup decor = getDecor();
    if (decor != null) {
        ViewGroupOverlay overlay = decor.getOverlay();
        int count = mSharedElements.size();
        for (int i = 0; i < count; i++) {
            View sharedElement = mSharedElements.get(i);
            GhostView.removeGhost(sharedElement);
        }
    }
}
 

public FastScroller(@NonNull ViewGroup view, @NonNull ViewHelper viewHelper,
                    @Nullable Rect padding, @NonNull Drawable trackDrawable,
                    @NonNull Drawable thumbDrawable, @NonNull Consumer<TextView> popupStyle,
                    @NonNull AnimationHelper animationHelper) {

    mMinTouchTargetSize = view.getResources().getDimensionPixelSize(
            R.dimen.afs_min_touch_target_size);
    Context context = view.getContext();
    mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();

    mView = view;
    mViewHelper = viewHelper;
    mUserPadding = padding;
    mAnimationHelper = animationHelper;

    mTrackWidth = trackDrawable.getIntrinsicWidth();
    mThumbWidth = thumbDrawable.getIntrinsicWidth();
    mThumbHeight = thumbDrawable.getIntrinsicHeight();

    mTrackView = new View(context);
    mTrackView.setBackground(trackDrawable);
    mThumbView = new View(context);
    mThumbView.setBackground(thumbDrawable);
    mPopupView = new AppCompatTextView(context);
    mPopupView.setLayoutParams(new FrameLayout.LayoutParams(
            ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
    popupStyle.accept(mPopupView);

    ViewGroupOverlay overlay = mView.getOverlay();
    overlay.add(mTrackView);
    overlay.add(mThumbView);
    overlay.add(mPopupView);

    postAutoHideScrollbar();
    mPopupView.setAlpha(0);

    mViewHelper.addOnPreDrawListener(this::onPreDraw);
    mViewHelper.addOnScrollChangedListener(this::onScrollChanged);
    mViewHelper.addOnTouchEventListener(this::onTouchEvent);
}
 

@RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)
    private void applyDim(Activity activity) {
        ViewGroup parent = (ViewGroup) activity.getWindow().getDecorView().getRootView();
        //activity跟布局
//        ViewGroup parent = (ViewGroup) parent1.getChildAt(0);
        Drawable dimDrawable = new ColorDrawable(mDimColor);
        dimDrawable.setBounds(0, 0, parent.getWidth(), parent.getHeight());
        dimDrawable.setAlpha((int) (255 * mDimValue));
        ViewGroupOverlay overlay = parent.getOverlay();
        overlay.add(dimDrawable);
    }
 

@RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)
private void applyDim(ViewGroup dimView) {
    Drawable dimDrawable = new ColorDrawable(mDimColor);
    dimDrawable.setBounds(0, 0, dimView.getWidth(), dimView.getHeight());
    dimDrawable.setAlpha((int) (255 * mDimValue));
    ViewGroupOverlay overlay = dimView.getOverlay();
    overlay.add(dimDrawable);
}
 

@RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)
    private void clearDim(Activity activity) {
        ViewGroup parent = (ViewGroup) activity.getWindow().getDecorView().getRootView();
        //activity跟布局
//        ViewGroup parent = (ViewGroup) parent1.getChildAt(0);
        ViewGroupOverlay overlay = parent.getOverlay();
        overlay.clear();
    }
 

static void applyDim(@NonNull ViewGroup parent){
    Drawable dim = new ColorDrawable(Color.BLACK);
    dim.setBounds(0, 0, parent.getWidth(), parent.getHeight());
    dim.setAlpha((int) (255 * 0.5));

    ViewGroupOverlay overlay = parent.getOverlay();
    overlay.add(dim);
}
 

public FastScroller(AbsListView listView, int styleResId) {
    mList = listView;
    mOldItemCount = listView.getCount();
    mOldChildCount = listView.getChildCount();

    final Context context = listView.getContext();
    mScaledTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
    mScrollBarStyle = listView.getScrollBarStyle();

    mScrollCompleted = true;
    mState = STATE_VISIBLE;
    mMatchDragPosition =
            context.getApplicationInfo().targetSdkVersion >= Build.VERSION_CODES.HONEYCOMB;

    mTrackImage = new ImageView(context);
    mTrackImage.setScaleType(ScaleType.FIT_XY);
    mThumbImage = new ImageView(context);
    mThumbImage.setScaleType(ScaleType.FIT_XY);
    mPreviewImage = new View(context);
    mPreviewImage.setAlpha(0f);

    mPrimaryText = createPreviewTextView(context);
    mSecondaryText = createPreviewTextView(context);

    mMinimumTouchTarget = listView.getResources().getDimensionPixelSize(
            com.android.internal.R.dimen.fast_scroller_minimum_touch_target);

    setStyle(styleResId);

    final ViewGroupOverlay overlay = listView.getOverlay();
    mOverlay = overlay;
    overlay.add(mTrackImage);
    overlay.add(mThumbImage);
    overlay.add(mPreviewImage);
    overlay.add(mPrimaryText);
    overlay.add(mSecondaryText);

    getSectionsFromIndexer();
    updateLongList(mOldChildCount, mOldItemCount);
    setScrollbarPosition(listView.getVerticalScrollbarPosition());
    postAutoHide();
}
 

@RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)
private void clearDim(ViewGroup dimView) {
    ViewGroupOverlay overlay = dimView.getOverlay();
    overlay.clear();
}
 

static void clearDim(@NonNull ViewGroup parent) {
    ViewGroupOverlay overlay = parent.getOverlay();
    overlay.clear();
}
 

public static void reveal(Activity activity, View view, View sourceView, int colorRes) {
  if (activity == null || view == null || sourceView == null) return;
  if (isLollipop()) {
    final ViewGroupOverlay groupOverlay =
        (ViewGroupOverlay) activity.getWindow().getDecorView().getOverlay();

    final Rect displayRect = new Rect();
    view.getGlobalVisibleRect(displayRect);

    // Make reveal cover the display and status bar.
    final View revealView = new View(activity);
    revealView.setTop(displayRect.top);
    revealView.setBottom(displayRect.bottom);
    revealView.setLeft(displayRect.left);
    revealView.setRight(displayRect.right);
    revealView.setBackgroundColor(ContextCompat.getColor(activity, colorRes));
    groupOverlay.add(revealView);

    final int[] clearLocation = new int[2];
    sourceView.getLocationInWindow(clearLocation);
    clearLocation[0] += sourceView.getWidth() / 2;
    clearLocation[1] += sourceView.getHeight() / 2;

    final int revealCenterX = clearLocation[0] - revealView.getLeft();
    final int revealCenterY = clearLocation[1] - revealView.getTop();

    final double x1_2 = Math.pow(revealView.getLeft() - revealCenterX, 2);
    final double x2_2 = Math.pow(revealView.getRight() - revealCenterX, 2);
    final double y_2 = Math.pow(revealView.getTop() - revealCenterY, 2);
    final float revealRadius = (float) Math.max(Math.sqrt(x1_2 + y_2), Math.sqrt(x2_2 + y_2));

    try {
      final Animator revealAnimator =
          ViewAnimationUtils.createCircularReveal(revealView,
              revealCenterX, revealCenterY, 0.0f, revealRadius);
      revealAnimator.setDuration(
          activity.getResources().getInteger(android.R.integer.config_mediumAnimTime));

      final Animator alphaAnimator = ObjectAnimator.ofFloat(revealView, View.ALPHA, 0.0f);
      alphaAnimator.setDuration(
          activity.getResources().getInteger(android.R.integer.config_shortAnimTime));
      alphaAnimator.addListener(new AnimatorListenerAdapter() {
        @Override public void onAnimationEnd(Animator animation) {
          super.onAnimationEnd(animation);
          view.startAnimation(AnimationUtils.loadAnimation(activity, R.anim.abc_fade_in));
          view.setVisibility(View.VISIBLE);
        }
      });

      final AnimatorSet animatorSet = new AnimatorSet();
      animatorSet.play(revealAnimator).before(alphaAnimator);
      animatorSet.setInterpolator(new AccelerateDecelerateInterpolator());
      animatorSet.addListener(new AnimatorListenerAdapter() {
        @Override public void onAnimationEnd(Animator animator) {
          groupOverlay.remove(revealView);
        }
      });

      animatorSet.start();
    } catch (IllegalStateException e) {
      Timber.i("View is detached - not animating");
    }
  } else {
    view.setVisibility(View.VISIBLE);
  }
}