项目中开发日历功能，需求是可以连续滑动多页，有列表的流畅。又要保持当前页居中显示。

参考文献：  http://www.open-open.com/lib/view/open1435026935638.html

                    http://mp.weixin.qq.com/s/DMksgHOuGWhztESGfDgucA?utm_source=tuicool&utm_medium=referral

效果图：

1.  继承自RecyclerView的ViewPager:

/** * Created by Administrator on 2017/6/9. * 基于RecyclerView实现的ViewPager，支持类似于gallary的fling操作 * http://www.open-open.com/lib/view/open1435026935638.html */public class RecyclerViewPager extends RecyclerView {    public static final boolean DEBUG = BuildConfig.DEBUG;

    private RecyclerViewPagerAdapter<?> mViewPagerAdapter;    private float mTriggerOffset = 0.25f;    private float mFlingFactor = 0.15f;    private float mMillisecondsPerInch = 25f;    private float mTouchSpan;    private List<OnPageChangedListener> mOnPageChangedListeners;    private int mSmoothScrollTargetPosition = -1;    private int mPositionBeforeScroll = -1;

    private boolean mSinglePageFling;    boolean isInertia; // inertia slide state    float minSlideDistance;    PointF touchStartPoint;

    boolean mNeedAdjust;    int mFisrtLeftWhenDragging;    int mFirstTopWhenDragging;    View mCurView;    int mMaxLeftWhenDragging = Integer.MIN_VALUE;    int mMinLeftWhenDragging = Integer.MAX_VALUE;    int mMaxTopWhenDragging = Integer.MIN_VALUE;    int mMinTopWhenDragging = Integer.MAX_VALUE;    private int mPositionOnTouchDown = -1;    private boolean mHasCalledOnPageChanged = true;    private boolean reverseLayout = false;    private float mLastY;

    public RecyclerViewPager(Context context) {        this(context, null);    }

    public RecyclerViewPager(Context context, AttributeSet attrs) {        this(context, attrs, 0);    }

    public RecyclerViewPager(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        initAttrs(context, attrs, defStyle);        setNestedScrollingEnabled(false);        ViewConfiguration viewConfiguration = ViewConfiguration.get(context);        minSlideDistance = viewConfiguration.getScaledTouchSlop();    }

    private void initAttrs(Context context, AttributeSet attrs, int defStyle) {        final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.RecyclerViewPager, defStyle,                0);        mFlingFactor = a.getFloat(R.styleable.RecyclerViewPager_rvp_flingFactor, 0.15f);        mTriggerOffset = a.getFloat(R.styleable.RecyclerViewPager_rvp_triggerOffset, 0.25f);        mSinglePageFling = a.getBoolean(R.styleable.RecyclerViewPager_rvp_singlePageFling, mSinglePageFling);        isInertia = a.getBoolean(R.styleable.RecyclerViewPager_rvp_inertia, false);        mMillisecondsPerInch = a.getFloat(R.styleable.RecyclerViewPager_rvp_millisecondsPerInch, 25f);        a.recycle();    }

    public void setFlingFactor(float flingFactor) {        mFlingFactor = flingFactor;    }

    public float getFlingFactor() {        return mFlingFactor;    }

    public void setTriggerOffset(float triggerOffset) {        mTriggerOffset = triggerOffset;    }

    public float getTriggerOffset() {        return mTriggerOffset;    }

    public void setSinglePageFling(boolean singlePageFling) {        mSinglePageFling = singlePageFling;    }

    public boolean isSinglePageFling() {        return mSinglePageFling;    }

    public boolean isInertia() {        return isInertia;    }

    public void setInertia(boolean inertia) {        isInertia = inertia;    }

    @Override    protected void onRestoreInstanceState(Parcelable state) {        try {            Field fLayoutState = state.getClass().getDeclaredField("mLayoutState");            fLayoutState.setAccessible(true);            Object layoutState = fLayoutState.get(state);            Field fAnchorOffset = layoutState.getClass().getDeclaredField("mAnchorOffset");            Field fAnchorPosition = layoutState.getClass().getDeclaredField("mAnchorPosition");            fAnchorPosition.setAccessible(true);            fAnchorOffset.setAccessible(true);            if (fAnchorOffset.getInt(layoutState) > 0) {                fAnchorPosition.set(layoutState, fAnchorPosition.getInt(layoutState) - 1);            } else if (fAnchorOffset.getInt(layoutState) < 0) {                fAnchorPosition.set(layoutState, fAnchorPosition.getInt(layoutState) + 1);            }            fAnchorOffset.setInt(layoutState, 0);        } catch (Throwable e) {            e.printStackTrace();        }        super.onRestoreInstanceState(state);    }

    @Override    public void setAdapter(Adapter adapter) {        mViewPagerAdapter = ensureRecyclerViewPagerAdapter(adapter);        super.setAdapter(mViewPagerAdapter);    }

    @Override    public void swapAdapter(Adapter adapter, boolean removeAndRecycleExistingViews) {        mViewPagerAdapter = ensureRecyclerViewPagerAdapter(adapter);        super.swapAdapter(mViewPagerAdapter, removeAndRecycleExistingViews);    }

    @Override    public Adapter getAdapter() {        if (mViewPagerAdapter != null) {            return mViewPagerAdapter.mAdapter;        }        return null;    }

    public RecyclerViewPagerAdapter getWrapperAdapter() {        return mViewPagerAdapter;    }

    @Override    public void setLayoutManager(LayoutManager layout) {        super.setLayoutManager(layout);

        if (layout instanceof LinearLayoutManager) {            reverseLayout = ((LinearLayoutManager) layout).getReverseLayout();        }    }

    @Override    public boolean fling(int velocityX, int velocityY) {        boolean flinging = super.fling((int) (velocityX * mFlingFactor), (int) (velocityY * mFlingFactor));        if (flinging) {            if (getLayoutManager().canScrollHorizontally()) {                adjustPositionX(velocityX);            } else {                adjustPositionY(velocityY);            }        }

        if (DEBUG) {            Log.d("@", "velocityX:" + velocityX);            Log.d("@", "velocityY:" + velocityY);        }        return flinging;    }

    @Override    public void smoothScrollToPosition(int position) {        if (DEBUG) {            Log.d("@", "smoothScrollToPosition:" + position);        }

        if (mPositionBeforeScroll < 0) {            mPositionBeforeScroll = getCurrentPosition();        }        mSmoothScrollTargetPosition = position;        if (getLayoutManager() != null && getLayoutManager() instanceof LinearLayoutManager) {            // exclude item decoration            LinearSmoothScroller linearSmoothScroller =                    new LinearSmoothScroller(getContext()) {                        @Override                        public PointF computeScrollVectorForPosition(int targetPosition) {                            if (getLayoutManager() == null) {                                return null;                            }                            return ((LinearLayoutManager) getLayoutManager())                                    .computeScrollVectorForPosition(targetPosition);                        }

                        @Override                        protected void onTargetFound(View targetView, RecyclerView.State state, Action action) {                            if (getLayoutManager() == null) {                                return;                            }                            int dx = calculateDxToMakeVisible(targetView,                                    getHorizontalSnapPreference());                            int dy = calculateDyToMakeVisible(targetView,                                    getVerticalSnapPreference());                            if (dx > 0) {                                dx = dx - getLayoutManager()                                        .getLeftDecorationWidth(targetView);                            } else {                                dx = dx + getLayoutManager()                                        .getRightDecorationWidth(targetView);                            }                            if (dy > 0) {                                dy = dy - getLayoutManager()                                        .getTopDecorationHeight(targetView);                            } else {                                dy = dy + getLayoutManager()                                        .getBottomDecorationHeight(targetView);                            }                            final int distance = (int) Math.sqrt(dx * dx + dy * dy);                            final int time = calculateTimeForDeceleration(distance);                            if (time > 0) {                                action.update(-dx, -dy, time, mDecelerateInterpolator);                            }                        }

                        @Override                        protected float calculateSpeedPerPixel(DisplayMetrics displayMetrics) {                            return mMillisecondsPerInch / displayMetrics.densityDpi;                        }

                        @Override                        protected void onStop() {                            super.onStop();                            if (mOnPageChangedListeners != null) {                                for (OnPageChangedListener onPageChangedListener : mOnPageChangedListeners) {                                    if (onPageChangedListener != null) {                                        onPageChangedListener.OnPageChanged(mPositionBeforeScroll, mSmoothScrollTargetPosition);                                    }                                }                            }                            mHasCalledOnPageChanged = true;                        }                    };

            linearSmoothScroller.setTargetPosition(position);            if (position == RecyclerView.NO_POSITION) {                return;            }            getLayoutManager().startSmoothScroll(linearSmoothScroller);        } else {            super.smoothScrollToPosition(position);        }    }

    @Override    public void scrollToPosition(int position) {        if (DEBUG) {            Log.d("@", "scrollToPosition:" + position);        }        mPositionBeforeScroll = getCurrentPosition();        mSmoothScrollTargetPosition = position;        super.scrollToPosition(position);

        getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {            @SuppressWarnings("deprecation")            @Override            public void onGlobalLayout() {                if (Build.VERSION.SDK_INT < 16) {                    getViewTreeObserver().removeGlobalOnLayoutListener(this);                } else {                    getViewTreeObserver().removeOnGlobalLayoutListener(this);                }

                if (mSmoothScrollTargetPosition >= 0 && mSmoothScrollTargetPosition < getItemCount()) {                    if (mOnPageChangedListeners != null) {                        for (OnPageChangedListener onPageChangedListener : mOnPageChangedListeners) {                            if (onPageChangedListener != null) {                                onPageChangedListener.OnPageChanged(mPositionBeforeScroll, getCurrentPosition());                            }                        }                    }                }            }        });    }

    private int getItemCount() {        return mViewPagerAdapter == null ? 0 : mViewPagerAdapter.getItemCount();    }

    /**     * get item position in center of viewpager     */    public int getCurrentPosition() {        int curPosition;        if (getLayoutManager().canScrollHorizontally()) {            curPosition = RecycleViewPagerUtils.getCenterXChildPosition(this);        } else {            curPosition = RecycleViewPagerUtils.getCenterYChildPosition(this);        }        if (curPosition < 0) {            curPosition = mSmoothScrollTargetPosition;        }        return curPosition;    }

    /***     * adjust position before Touch event complete and fling action start.     */    protected void adjustPositionX(int velocityX) {        if (reverseLayout) velocityX *= -1;

        int childCount = getChildCount();        if (childCount > 0) {            int curPosition = RecycleViewPagerUtils.getCenterXChildPosition(this);            int childWidth = getWidth() - getPaddingLeft() - getPaddingRight();            int flingCount = getFlingCount(velocityX, childWidth);            int targetPosition = curPosition + flingCount;            if (mSinglePageFling) {                flingCount = Math.max(-1, Math.min(1, flingCount));                targetPosition = flingCount == 0 ? curPosition : mPositionOnTouchDown + flingCount;                if (DEBUG) {                    Log.d("@", "flingCount:" + flingCount);                    Log.d("@", "original targetPosition:" + targetPosition);                }            }            targetPosition = Math.max(targetPosition, 0);            targetPosition = Math.min(targetPosition, getItemCount() - 1);            if (targetPosition == curPosition                    && (!mSinglePageFling || mPositionOnTouchDown == curPosition)) {                View centerXChild = RecycleViewPagerUtils.getCenterXChild(this);                if (centerXChild != null) {                    if (mTouchSpan > centerXChild.getWidth() * mTriggerOffset * mTriggerOffset && targetPosition != 0) {                        if (!reverseLayout) targetPosition--;                        else targetPosition++;                    } else if (mTouchSpan < centerXChild.getWidth() * -mTriggerOffset && targetPosition != getItemCount() - 1) {                        if (!reverseLayout) targetPosition++;                        else targetPosition--;                    }                }            }            if (DEBUG) {                Log.d("@", "mTouchSpan:" + mTouchSpan);                Log.d("@", "adjustPositionX:" + targetPosition);            }            smoothScrollToPosition(safeTargetPosition(targetPosition, getItemCount()));        }    }

    public void addOnPageChangedListener(OnPageChangedListener listener) {        if (mOnPageChangedListeners == null) {            mOnPageChangedListeners = new ArrayList<>();        }        mOnPageChangedListeners.add(listener);    }

    public void removeOnPageChangedListener(OnPageChangedListener listener) {        if (mOnPageChangedListeners != null) {            mOnPageChangedListeners.remove(listener);        }    }

    public void clearOnPageChangedListeners() {        if (mOnPageChangedListeners != null) {            mOnPageChangedListeners.clear();        }    }

    /***     * adjust position before Touch event complete and fling action start.     */    protected void adjustPositionY(int velocityY) {        if (reverseLayout) velocityY *= -1;

        int childCount = getChildCount();        if (childCount > 0) {            int curPosition = RecycleViewPagerUtils.getCenterYChildPosition(this);            int childHeight = getHeight() - getPaddingTop() - getPaddingBottom();            int flingCount = getFlingCount(velocityY, childHeight);            int targetPosition = curPosition + flingCount;            if (mSinglePageFling) {                flingCount = Math.max(-1, Math.min(1, flingCount));                targetPosition = flingCount == 0 ? curPosition : mPositionOnTouchDown + flingCount;            }

            targetPosition = Math.max(targetPosition, 0);            targetPosition = Math.min(targetPosition, getItemCount() - 1);            if (targetPosition == curPosition                    && (!mSinglePageFling || mPositionOnTouchDown == curPosition)) {                View centerYChild = RecycleViewPagerUtils.getCenterYChild(this);                if (centerYChild != null) {                    if (mTouchSpan > centerYChild.getHeight() * mTriggerOffset && targetPosition != 0) {                        if (!reverseLayout) targetPosition--;                        else targetPosition++;                    } else if (mTouchSpan < centerYChild.getHeight() * -mTriggerOffset && targetPosition != getItemCount() - 1) {                        if (!reverseLayout) targetPosition++;                        else targetPosition--;                    }                }            }            if (DEBUG) {                Log.d("@", "mTouchSpan:" + mTouchSpan);                Log.d("@", "adjustPositionY:" + targetPosition);            }            smoothScrollToPosition(safeTargetPosition(targetPosition, getItemCount()));        }    }

    @Override    public boolean dispatchTouchEvent(MotionEvent ev) {        if (ev.getAction() == MotionEvent.ACTION_DOWN && getLayoutManager() != null) {            mPositionOnTouchDown = getLayoutManager().canScrollHorizontally()                    ? RecycleViewPagerUtils.getCenterXChildPosition(this)                    : RecycleViewPagerUtils.getCenterYChildPosition(this);            if (DEBUG) {                Log.d("@", "mPositionOnTouchDown:" + mPositionOnTouchDown);            }            mLastY = ev.getRawY();        }        return super.dispatchTouchEvent(ev);    }

    @Override    public boolean onTouchEvent(MotionEvent e) {        // recording the max/min value in touch track        if (e.getAction() == MotionEvent.ACTION_MOVE) {            if (mCurView != null) {                mMaxLeftWhenDragging = Math.max(mCurView.getLeft(), mMaxLeftWhenDragging);                mMaxTopWhenDragging = Math.max(mCurView.getTop(), mMaxTopWhenDragging);                mMinLeftWhenDragging = Math.min(mCurView.getLeft(), mMinLeftWhenDragging);                mMinTopWhenDragging = Math.min(mCurView.getTop(), mMinTopWhenDragging);            }        }        return super.onTouchEvent(e);    }

    @Override    public boolean onInterceptTouchEvent(MotionEvent e) {        if (isInertia) {            final float x = e.getRawX();            final float y = e.getRawY();            if (touchStartPoint == null)                touchStartPoint = new PointF();            switch (MotionEvent.ACTION_MASK & e.getAction()) {                case MotionEvent.ACTION_DOWN:                    touchStartPoint.set(x, y);                    break;                case MotionEvent.ACTION_MOVE:                    float tempDistance = (float) Math.sqrt(x*x+ y*y);                    float lastDistance = (float) Math.sqrt(touchStartPoint.x*touchStartPoint.x + touchStartPoint.y*touchStartPoint.y);

                    if (Math.abs(lastDistance - tempDistance) > minSlideDistance) {                        float k = Math.abs((touchStartPoint.y - y) / (touchStartPoint.x - x));                        // prevent tan 90° calc                        if (Math.abs(touchStartPoint.y - y) < 1)                            return getLayoutManager().canScrollHorizontally();                        if (Math.abs(touchStartPoint.x - x) < 1)                            return !getLayoutManager().canScrollHorizontally();                        return k < Math.tan(Math.toRadians(30F));                    }                    break;            }        }        return super.onInterceptTouchEvent(e);    }

    @Override    public void onScrollStateChanged(int state) {        super.onScrollStateChanged(state);        if (state == SCROLL_STATE_DRAGGING) {            mNeedAdjust = true;            mCurView = getLayoutManager().canScrollHorizontally() ? RecycleViewPagerUtils.getCenterXChild(this) :                    RecycleViewPagerUtils.getCenterYChild(this);            if (mCurView != null) {                if (mHasCalledOnPageChanged) {                    // While rvp is scrolling, mPositionBeforeScroll will be previous value.                    mPositionBeforeScroll = getChildLayoutPosition(mCurView);                    mHasCalledOnPageChanged = false;                }                if (DEBUG) {                    Log.d("@", "mPositionBeforeScroll:" + mPositionBeforeScroll);                }                mFisrtLeftWhenDragging = mCurView.getLeft();                mFirstTopWhenDragging = mCurView.getTop();            } else {                mPositionBeforeScroll = -1;            }            mTouchSpan = 0;        } else if (state == SCROLL_STATE_SETTLING) {            mNeedAdjust = false;            if (mCurView != null) {                if (getLayoutManager().canScrollHorizontally()) {                    mTouchSpan = mCurView.getLeft() - mFisrtLeftWhenDragging;                } else {                    mTouchSpan = mCurView.getTop() - mFirstTopWhenDragging;                }            } else {                mTouchSpan = 0;            }            mCurView = null;        } else if (state == SCROLL_STATE_IDLE) {            if (mNeedAdjust) {                int targetPosition = getLayoutManager().canScrollHorizontally() ? RecycleViewPagerUtils.getCenterXChildPosition(this) :                        RecycleViewPagerUtils.getCenterYChildPosition(this);                if (mCurView != null) {                    targetPosition = getChildAdapterPosition(mCurView);                    if (getLayoutManager().canScrollHorizontally()) {                        int spanX = mCurView.getLeft() - mFisrtLeftWhenDragging;                        // if user is tending to cancel paging action, don't perform position changing                        if (spanX > mCurView.getWidth() * mTriggerOffset && mCurView.getLeft() >= mMaxLeftWhenDragging) {                            if (!reverseLayout) targetPosition--;                            else targetPosition++;                        } else if (spanX < mCurView.getWidth() * -mTriggerOffset && mCurView.getLeft() <= mMinLeftWhenDragging) {                            if (!reverseLayout) targetPosition++;                            else targetPosition--;                        }                    } else {                        int spanY = mCurView.getTop() - mFirstTopWhenDragging;                        if (spanY > mCurView.getHeight() * mTriggerOffset && mCurView.getTop() >= mMaxTopWhenDragging) {                            if (!reverseLayout) targetPosition--;                            else targetPosition++;                        } else if (spanY < mCurView.getHeight() * -mTriggerOffset && mCurView.getTop() <= mMinTopWhenDragging) {                            if (!reverseLayout) targetPosition++;                            else targetPosition--;                        }                    }                }                smoothScrollToPosition(safeTargetPosition(targetPosition, getItemCount()));                mCurView = null;            } else if (mSmoothScrollTargetPosition != mPositionBeforeScroll) {                if (DEBUG) {                    Log.d("@", "onPageChanged:" + mSmoothScrollTargetPosition);                }                mPositionBeforeScroll = mSmoothScrollTargetPosition;            }            // reset            mMaxLeftWhenDragging = Integer.MIN_VALUE;            mMinLeftWhenDragging = Integer.MAX_VALUE;            mMaxTopWhenDragging = Integer.MIN_VALUE;            mMinTopWhenDragging = Integer.MAX_VALUE;        }    }

    @SuppressWarnings("unchecked")    @NonNull    protected RecyclerViewPagerAdapter ensureRecyclerViewPagerAdapter(Adapter adapter) {        return (adapter instanceof RecyclerViewPagerAdapter)                ? (RecyclerViewPagerAdapter) adapter                : new RecyclerViewPagerAdapter(this, adapter);

    }

    private int getFlingCount(int velocity, int cellSize) {        if (velocity == 0) {            return 0;        }        int sign = velocity > 0 ? 1 : -1;        return (int) (sign * Math.ceil((velocity * sign * mFlingFactor / cellSize)                - mTriggerOffset));    }

    private int safeTargetPosition(int position, int count) {        if (position < 0) {            return 0;        }        if (position >= count) {            return count - 1;        }        return position;    }

    public interface OnPageChangedListener {        /**         * Fires when viewpager changes it's page         * @param oldPosition old position         * @param newPosition new position         */        void OnPageChanged(int oldPosition, int newPosition);    }

    public float getlLastY() {        return mLastY;    }}

2.xml文件调用：

<你的包名.calender.activity.RecyclerViewPager    android:id="@+id/calender_pager"    android:layout_marginTop="10dp"    android:layout_marginBottom="20dp"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:paddingLeft="50dp"    android:paddingRight="50dp"    android:paddingStart="40dp"    android:paddingEnd="40dp"    app:rvp_triggerOffset="0.1"    app:rvp_singlePageFling="false"    android:clipToPadding="false"/>3.代码调用：

RecyclerViewPager calenderPager= (RecyclerViewPager) head.findViewById(R.id.calender_pager);

        LinearLayoutManager layout = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL,                false);        calenderPager.setLayoutManager(layout);        pagerAdapter = new LayoutAdapter(this,calenderDataList);        calenderPager.setAdapter(pagerAdapter);        calenderPager.setHasFixedSize(true);        calenderPager.setLongClickable(true);        calenderPager.setSinglePageFling(false);        calenderPager.addOnScrollListener(new RecyclerView.OnScrollListener() {            @Override            public void onScrollStateChanged(RecyclerView recyclerView, int scrollState) {//                updateState(scrollState);            }

            @Override            public void onScrolled(RecyclerView recyclerView, int i, int i2) {                int childCount = calenderPager.getChildCount();                int width = calenderPager.getChildAt(0).getWidth();                int padding = (calenderPager.getWidth() - width) / 2;                for (int j = 0; j < childCount; j++) {                    View v = recyclerView.getChildAt(j);                    //往左 从 padding 到 -(v.getWidth()-padding) 的过程中，由大到小                    float rate = 0;                    ;                    if (v.getLeft() <= padding) {                        if (v.getLeft() >= padding - v.getWidth()) {                            rate = (padding - v.getLeft()) * 1f / v.getWidth();                        } else {                            rate = 1;                        }                        v.setScaleY(1 - rate * 0.1f);                        v.setScaleX(1 - rate * 0.1f);

                    } else {                        //往右 从 padding 到 recyclerView.getWidth()-padding 的过程中，由大到小                        if (v.getLeft() <= recyclerView.getWidth() - padding) {                            rate = (recyclerView.getWidth() - padding - v.getLeft()) * 1f / v.getWidth();                        }                        v.setScaleY(0.9f + rate * 0.1f);                        v.setScaleX(0.9f + rate * 0.1f);                    }                }            }        });        calenderPager.addOnPageChangedListener(new RecyclerViewPager.OnPageChangedListener() {            @Override            public void OnPageChanged(int oldPosition, int newPosition) {                if (currentMonth==newPosition){//第一次进入，                    return;                }                if (oldPosition==newPosition){//没有滑动出当前item                    return;                }                currentMonth=newPosition;                //刷新绑定状态                updatMarkerButton();                //刷新事件列表                //旧数据清除                List list=  adapter.getData();                if (list.size()>0) {                    for (int i = 0; i < calenderDataList.get(oldPosition).getData().size(); i++) {                        adapter.notifyItemRemoved(i+1);                    }                    list.clear();                    adapter.notifyItemRangeRemoved(1, calenderDataList.get(oldPosition).getData().size() - 2);                }

                //新数据插入                List<CalenderDayBean> newList=calenderDataList.get(newPosition).getData();                for (int i = 0; i < newList.size(); i++) {                    dayList.add(newList.get(i));                    adapter.notifyItemInserted(1);                    adapter.notifyItemRangeChanged(1, newList.size()-2);                }

            }        });

        calenderPager.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {            @Override            public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {                if (calenderPager.getChildCount() < 3) {                    if (calenderPager.getChildAt(1) != null) {                        if (calenderPager.getCurrentPosition() == 0) {                            View v1 = calenderPager.getChildAt(1);                            v1.setScaleY(0.9f);                            v1.setScaleX(0.9f);                        } else {                            View v1 = calenderPager.getChildAt(0);                            v1.setScaleY(0.9f);                            v1.setScaleX(0.9f);                        }                    }                } else {                    if (calenderPager.getChildAt(0) != null) {                        View v0 = calenderPager.getChildAt(0);                        v0.setScaleY(0.9f);                        v0.setScaleX(0.9f);                    }                    if (calenderPager.getChildAt(2) != null) {                        View v2 = calenderPager.getChildAt(2);                        v2.setScaleY(0.9f);                        v2.setScaleX(0.9f);                    }                }

            }        });

        calenderPager.scrollToPosition(currentMonth);    }