Android仿IOS式越界回弹效果

前言：Android自带的越界样式是滑到两端发荧光，不过就个人而言觉得这还是挺丑的，一直比较喜欢ios那种越界回弹的效果，所以现在就做了个，效果下面看图。

一、SwipeMenuRecyclerView（支持item左右滑动和列表越界回弹的效果）

1.Item左右滑动

支持RecyclerView的Vertical布局并很好地解决了item左右滑动和列表上下滑动容易误触的问题，item向右滑自带回弹效果！

使用：itemView的布局文件仿照下面即可

<?xml version="1.0" encoding="utf-8"?><com.liuzhenlin.overscroll.SmoothScrollableLinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:orientation="horizontal">    <RelativeLayout        android:layout_width="match_parent"        android:layout_height="65dp"        android:background="@drawable/default_selector_recycler_item"        android:clickable="true">        <!-- child views -->        <ImageView            android:id="@+id/image_ssll_rl"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_centerVertical="true"            android:src="@mipmap/ic_launcher" />        <TextView            android:id="@+id/text_ssll_rl"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:layout_centerVertical="true"            android:layout_margin="5dp"            android:layout_toRightOf="@id/image_ssll_rl"            android:autoLink="web"            android:text="文本"            android:textSize="16sp" />    </RelativeLayout>    <LinearLayout        android:layout_width="150dp"        android:layout_height="match_parent"        android:orientation="horizontal">        <Button            android:id="@+id/button_top"            android:layout_width="0dp"            android:layout_height="match_parent"            android:layout_weight="1"            android:background="@color/orange"            android:gravity="center"            android:text="置顶"            android:textColor="@android:color/white"            android:textSize="16sp" />        <Button            android:id="@+id/button_delete"            android:layout_width="0dp"            android:layout_height="match_parent"            android:layout_weight="1"            android:background="@color/red"            android:gravity="center"            android:text="删除"            android:textColor="@android:color/white"            android:textSize="16sp" />        <!-- and can place more buttons here... -->    </LinearLayout></com.liuzhenlin.overscroll.SmoothScrollableLinearLayout>

SmoothScrollableLinearLayout用以实现itemView的平滑滚动，下面为其两个主要的方法：

    /**     * Smoothly scroll this view to a position relative to its old position.     *     * @param deltaX   The amount of pixels to scroll by horizontally.     *                 Positive numbers will scroll the view to the right.     * @param deltaY   The amount of pixels to scroll by vertically.     *                 Positive numbers will scroll the view up.     * @param duration duration of the scroll in milliseconds.     */    public void smoothScrollBy(int deltaX, int deltaY, int duration) {        if (deltaX != 0 || deltaY != 0) {            mOverScroller.startScroll(getScrollX(), getScrollY(), -deltaX, deltaY, duration);//            setScrollX(getScrollX() - deltaX);//            setScrollY(getScrollY() + deltaY);            invalidate();        }    }    /**     * Smoothly scroll this view to a position.     *     * @param desX     The x position to scroll to in pixels.     * @param desY     The y position to scroll to in pixels.     * @param duration duration of the scroll in milliseconds.     */    public void smoothScrollTo(int desX, int desY, int duration) {        if (-getScrollX() != desX || getScrollY() != desY) {            final int deltaX = getScrollX() - (desX > 0 ? desX : -desX);            final int deltaY = desY - getScrollY();            smoothScrollBy(deltaX, deltaY, duration);        }    }    @Override    public void computeScroll() {        // 重写computeScroll()方法，并在其内部完成平滑滚动的逻辑        if (mOverScroller.computeScrollOffset()) {            scrollTo(mOverScroller.getCurrX(), mOverScroller.getCurrY());            invalidate();        }    }

可在代码和xml文件中禁用此功能（Vertical布局下默认开启）

mSwipeMenuRecyclerView.setItemScrollingEnabled(false);

app:item_scrolling_enabled="false"

2.越界回弹 

列表越界回弹完美支持RecyclerView的 Vertical布局；对Horizontal布局的RecyclerView，最右端越界回弹暂时有bug，还没找到解决办法，如果有人有办法，欢迎能指正！

可在代码或布局文件中禁用此功能以使用默认的荧光效果

mSwipeMenuRecyclerView.setOverscrollEnabled(false);

app:overscroll_enabled="false"

3.支持addHeaderView和addFooterView

实现方法借鉴自csdn的一篇帖子：Android 优雅的为RecyclerView添加HeaderView和FooterView

    public static class HeaderAndFooterWrapper extends RecyclerView.Adapter {        protected static final int BASE_ITEM_TYPE_HEADER = 1000_0000;        protected static final int BASE_ITEM_TYPE_FOOTER = 2000_0000;        protected final SparseArray<View> mHeaderViews = new SparseArray<>();        protected final SparseArray<View> mFooterViews = new SparseArray<>();        private final RecyclerView.Adapter mInnerAdapter;        protected HeaderAndFooterWrapper(RecyclerView.Adapter adapter) {            mInnerAdapter = adapter;        }        @Override        public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {            if (mHeaderViews.get(viewType) != null) {                return new ViewHolder(mHeaderViews.get(viewType));            } else if (mFooterViews.get(viewType) != null) {                return new ViewHolder(mFooterViews.get(viewType));            }            return mInnerAdapter.onCreateViewHolder(parent, viewType);        }        @Override        public int getItemViewType(int position) {            if (isHeaderViewPos(position)) {                return mHeaderViews.keyAt(position);            } else if (isFooterViewPos(position)) {                return mFooterViews.keyAt(position - getHeaderCount() - getInitialItemCount());            }            return mInnerAdapter.getItemViewType(position - getHeaderCount());        }        @Override        public int getItemCount() {            return getHeaderCount() + getFooterCount() + getInitialItemCount();        }        protected int getInitialItemCount() {            return mInnerAdapter.getItemCount();        }        @Override        public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {            if (isHeaderViewPos(position)) {                return;            }            if (isFooterViewPos(position)) {                return;            }            mInnerAdapter.onBindViewHolder(holder, position - getHeaderCount());        }        @Override        public void onAttachedToRecyclerView(RecyclerView recyclerView) {            mInnerAdapter.onAttachedToRecyclerView(recyclerView);            RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();            if (layoutManager instanceof GridLayoutManager) {                final GridLayoutManager gridLayoutManager = (GridLayoutManager) layoutManager;                final GridLayoutManager.SpanSizeLookup spanSizeLookup = gridLayoutManager.getSpanSizeLookup();                gridLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {                    @Override                    public int getSpanSize(int position) {                        final int viewType = getItemViewType(position);                        if (mHeaderViews.get(viewType) != null) {                            return gridLayoutManager.getSpanCount();                        } else if (mFooterViews.get(viewType) != null) {                            return gridLayoutManager.getSpanCount();                        }                        if (spanSizeLookup != null)                            return spanSizeLookup.getSpanSize(position);                        return 1;                    }                });                gridLayoutManager.setSpanCount(gridLayoutManager.getSpanCount());            }        }        @Override        public void onViewAttachedToWindow(RecyclerView.ViewHolder holder) {            mInnerAdapter.onViewAttachedToWindow(holder);            final int position = holder.getLayoutPosition();            if (isHeaderViewPos(position) || isFooterViewPos(position)) {                ViewGroup.LayoutParams lp = holder.itemView.getLayoutParams();                if (lp != null && lp instanceof StaggeredGridLayoutManager.LayoutParams) {                    StaggeredGridLayoutManager.LayoutParams p = (StaggeredGridLayoutManager.LayoutParams) lp;                    p.setFullSpan(true);                }            }        }        protected boolean isHeaderViewPos(int position) {            return position < getHeaderCount();        }        protected boolean isFooterViewPos(int position) {            return position >= getHeaderCount() + getInitialItemCount();        }        public void addHeaderView(View view) {            mHeaderViews.put(BASE_ITEM_TYPE_HEADER + mHeaderViews.size(), view);        }        public void addFooterView(View view) {            mFooterViews.put(BASE_ITEM_TYPE_FOOTER + mFooterViews.size(), view);        }        public <V extends View> V getHeaderView(int position) {            return (V) mHeaderViews.valueAt(position);        }        public <V extends View> V getFooterView(int position) {            return (V) mFooterViews.valueAt(position - getHeaderCount());        }        public int getHeaderCount() {            return mHeaderViews.size();        }        public int getFooterCount() {            return mFooterViews.size();        }    }    public static class ViewHolder extends RecyclerView.ViewHolder {        private final SparseArray<View> mViews = new SparseArray<>();        public final View mConvertView;        public ViewHolder(View itemView) {            super(itemView);            mConvertView = itemView;            mViews.put(mConvertView.getId(), mConvertView);        }        /**         * 通过view的id获取控件         */        public <V extends View> V findViewById(@IdRes int id) {            V view = (V) mViews.get(id);            if (view == null) {                view = mConvertView.findViewById(id);                mViews.put(id, view);            }            return view;        }    }}

默认不启用，如要使用请在布局文件中指明

app:use_header_and_footer_wrapper="true"

也可在程序中设置，但需要在每次setAdapter(adapter)之前调用才有效

/** * Must be invoked before per invoking of {@link #setAdapter(Adapter)}, * or else it will not be valid unless you invoke that method later. */public void setUsingAdapterWrapper(boolean usingAdapterWrapper) {    isUsingAdapterWrapper = usingAdapterWrapper;}

注：如果使用该功能，SwipeMenuRecyclerView刷新itemView时需要这样使用

mSwipeMenuRecyclerView.getAdapterWrapper().notifyDataSetChanged();mSwipeMenuRecyclerView.getAdapterWrapper().notifyItemChanged(position);// position从第一个headerView开始计

RecyclerView的下列方法,获取的position也是从第一个headerView(如果存在)开始计

mSwipeMenuRecyclerView.getChildViewHolder(itemView).getAdapterPosition();mSwipeMenuRecyclerView.getChildViewHolder(itemView).getLayoutPosition();mSwipeMenuRecyclerView.getChildLayoutPosition(itemView);mSwipeMenuRecyclerView.getChildAdapterPosition(itemView);mSwipeMenuRecyclerView.getLayoutManager().getPosition(itemView);

二、OverScrollView（越界回弹滚动view）

为了让其他布局和view（比如LinearLayout、RelativeLayout、ImageView、TextView等）实现越界回弹，所以这里搞了个 越界回弹滚动view，效果和上面类似。

使用：按照ScrollView的使用方法即可

三、HorizontalOverScrollView（水平越界回弹滚动view）

满足一般控件水平方向越界回弹的需求

使用：和HorizontalScrollView相类似

注：OverScrollView和HorizontalOverScrollView同样可禁用越界回弹的功能（和SwipeMenuRecyclerView一样），OverScrollView还可以搭配HorizontalOverScrollView一起使用，实现四个方向的越界回弹。

四、OverScrollBase接口

对于ListView、GridView等带滚动条的view，OverScrollView和HorizontalOverScrollView可能不太适用，这种情况需要继承自相应控件并实现该接口的方法，再对控件的滑动事件做相应逻辑处理即可。

package com.liuzhenlin.overscroll;import android.support.annotation.IntDef;/** * Created on 2017/12/23. <br/> * Copyright (c) 2017 刘振林.All rights reserved. * * @author 刘振林 */public interface OverscrollBase {    // 在两端拉动时，每次所允许移动最大的像素点    int MAX_ABS_DELTA_DIST = 25; // px    // 回弹时间    int DURATION_SPRING_BACK = 250; // ms    int OVERSCROLL_EDGE_UNSPECIFIED = 0;    int OVERSCROLL_EDGE_TOP = 1 << 0;    int OVERSCROLL_EDGE_BOTTOM = 1 << 1;    int OVERSCROLL_EDGE_LEFT = 1 << 2;    int OVERSCROLL_EDGE_RIGHT = 1 << 3;    @IntDef({            OVERSCROLL_EDGE_UNSPECIFIED,            OVERSCROLL_EDGE_TOP,            OVERSCROLL_EDGE_BOTTOM,            OVERSCROLL_EDGE_TOP | OVERSCROLL_EDGE_BOTTOM,            OVERSCROLL_EDGE_LEFT,            OVERSCROLL_EDGE_RIGHT,            OVERSCROLL_EDGE_LEFT | OVERSCROLL_EDGE_RIGHT    })    @interface OverscrollEdge {    }    boolean isTendToScrollCurrView();    int computeOverscrollDeltaY();    int computeOverscrollDeltaX();    /**     * 是否向下拉时手指向上滑动或向上拉时手指向下滑动 或     * 向右拉时手指向左滑动或向左拉时手指向右滑动     */    boolean isPushingBack();    boolean isAtTheStart();    boolean isAtTheEnd();    void startHeaderOverscrollAnim(int from, int to, int duration);    void startFooterOverscrollAnim(int from, int to, int duration);    /**     * 回弹至初始位置     */    void smoothSpringBack();}

最后，送上整个项目的地址：Android仿IOS式越界回弹效果