RecyclerView Widget 使用

時間 2019-12-04

標籤 recyclerview widget 使用简体版

原文原文鏈接

# recyclerView 使用場景：

加載列表
多類型 Item 適配加載列表
header footer 適配加載列表
上拉加載更多下拉刷新
分組列表
分組懸浮列表
拖拽排序
側滑展開Menu 菜單

加載列表

/** * RecyclerView.Adapter<T> 封裝 * 實現 基本的初始化 方法 增 刪 數據 */
public abstract class BaseAdapter<D extends Object, VH extends RecyclerView.ViewHolder> extends RecyclerView.Adapter<VH> {
        private Context mContext;
        private ArrayList<D> mds;
    
        public ArrayList<D> getMds() {
            return mds;
        }
    
        public Context getmContext() {
            return mContext;
        }
    
        public BaseAdapter(Context context) {
            mContext = context;
            this.mds = new ArrayList<>();
        }
    
        public BaseAdapter(Context context, ArrayList<D> mds) {
            mContext = context;
            this.mds = mds;
        }
    
        @Override
        @NonNull
        public VH onCreateViewHolder(ViewGroup parent, int viewType) {
            return onCreateChildViewHolder(parent, viewType);
        }
    
        protected abstract VH onCreateChildViewHolder(ViewGroup parent, int viewType);
    
        public void initMDatas(ArrayList<D> ds) {
            if (ds == null) return;
            if (ds.size() == 0) return;
            mds.clear();
            mds.addAll(ds);
            notifyDataSetChanged();
        }
    
        public void initMDatasToOne(ArrayList<D> ds) {
            if (ds == null) return;
            if (ds.size() == 0) return;
            mds.clear();
            mds.addAll(0, ds);
            notifyDataSetChanged();
        }
    
        public void initMData(D d) {
            if (d == null) return;
            mds.add(d);
            notifyDataSetChanged();
        }
    
        public void initMDataToOne(D d) {
            if (d == null) return;
            mds.add(0, d);
            notifyDataSetChanged();
        }
    
        public void addDataModel(ArrayList<D> ds) {
            if (ds == null || ds.size() == 0) return;
            mds.addAll(ds);
            notifyDataSetChanged();
        }
    
        public void addStartDataModel(ArrayList<D> ds) {
            if (ds == null || ds.size() == 0) return;
            mds.addAll(0, ds);
            notifyDataSetChanged();
        }
    
        public void addDataModel(D d) {
            if (d == null) return;
            mds.add(d);
            notifyDataSetChanged();
        }
    
        public void deleteMDatas() {
            mds.clear();
            notifyDataSetChanged();
        }
    
        @Override
        public int getItemCount() {
            return mds != null ? mds.size() : 0;
        }
    
        @Override
        public void onBindViewHolder(@NonNull VH holder, int position) {
            D d = mds.get(position);
            onBindDataViewHolder(holder, position, d);
        }
    
        protected abstract void onBindDataViewHolder(VH holder, int position, D d);
    }
    
    //初始化RecyclerView 
    //設置LayouerManager
    //綁定Adapter
    mRecyclerView.setHasFixedSize(true);
    mRecyclerView.setLayoutManager(new GridLayoutManager(this, 4));
    groupingAdapter = new GroupingAdapter(this);
    mRecyclerView.setAdapter(groupingAdapter);
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# 多類型 Item 適配加載列表

若是數據不肯定的狀況下須要自行組裝服務端返回的接口數據不一樣類型的數據須要設置不一樣的 ItemViewType java

/** * 設置Item 類型多樣化條目 */
    @Override
    public int getItemViewType(int position) {
        ArrayList<RecycleViewItemData> mds = getMds();
        if (mds != null && mds.size() > 0) {
            return mds.get(position).getItemType();
        } else
            return super.getItemViewType(position);
    }
    
    /** * 根據viewType * 設置 ViewHolder 多樣化條目 */
   @Override
    protected RecyclerView.ViewHolder onCreateChildViewHolder(ViewGroup parent, int viewType) {
        if (viewType == RecycleViewItemData.TYPE_ZERO)
            return new IndicatorViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.indicator_item, parent, false));
        if (viewType == RecycleViewItemData.TYPE_ONE)
            return new GroupingViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.grouping_item, parent, false));
        return null;
    }
    
    /** * 若是layoutManager 是GridLayoutManager 須要實現 * setSpanSizeLookup() 接口 返回 spanSize */
    @Override
    public void onAttachedToRecyclerView(@NonNull final RecyclerView recyclerView) {
        super.onAttachedToRecyclerView(recyclerView);
        RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
        if (layoutManager instanceof GridLayoutManager) {
            final GridLayoutManager gridManager = (GridLayoutManager) layoutManager;
            gridManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
                @Override
                public int getSpanSize(int position) {
                    if (getItemViewType(position) == RecycleViewItemData.TYPE_ONE)
                        return 1;
                    else
                        return 4;
                }
            });
        }
    }
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# 方法1：

利用多Item 類型將數據泛型多樣化git

# 方法2：

在 getItemCount() 方法返回多於展現列表的 position 0 header itemDatas.size()+1 footergithub

@Override
    public int getItemCount() {
        return mds != null ? mds.size() : 0;
    }
    
    @Override
    public int getItemCount() {
        return mds != null ? mds.size()+1 : 0; // header 
    }
    
    @Override
    public int getItemCount() {
        return mds != null ? mds.size()+2 : 0; // header footer
    }
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# header fooder 適配加載列表

# 上拉加載更多下拉刷新

添加Header 或者 fooder 和多Item 展現屬於一個套路下來刷新上啦加載更多須要預先加載 RefreshHeader FooderHeader 重寫RecyclerView 的touch 事件監聽 RecyclerView ScrollChangeapp

下面是牛逼閃閃的XRecyclerView ↓↓↓↓↓↓↓↓↓↓↓↓↓ide

# XRecyclerView

下拉刷新上拉加載封裝自定義Refresh View
添加 Header Footer
拖動排序的接口封裝
等等

@Override
    public void onScrollStateChanged(int state) {
        super.onScrollStateChanged(state);
        if (state == RecyclerView.SCROLL_STATE_IDLE && mLoadingListener != null && !isLoadingData && loadingMoreEnabled) {
            LayoutManager layoutManager = getLayoutManager();
            int lastVisibleItemPosition; //最後item 的未知
            if (layoutManager instanceof GridLayoutManager) {
                lastVisibleItemPosition = ((GridLayoutManager) layoutManager).findLastVisibleItemPosition();
            } else if (layoutManager instanceof StaggeredGridLayoutManager) {
                int[] into = new int[((StaggeredGridLayoutManager) layoutManager).getSpanCount()];
                ((StaggeredGridLayoutManager) layoutManager).findLastVisibleItemPositions(into);
                lastVisibleItemPosition = findMax(into);
            } else {
                lastVisibleItemPosition = ((LinearLayoutManager) layoutManager).findLastVisibleItemPosition();
            }
            int adjAdapterItemCount = layoutManager.getItemCount() + getHeaders_includingRefreshCount();

            if (
                    layoutManager.getChildCount() > 0
                            && lastVisibleItemPosition >= adjAdapterItemCount - limitNumberToCallLoadMore
                            && adjAdapterItemCount >= layoutManager.getChildCount()
                            && !isNoMore
                            && mRefreshHeader.getState() < ArrowRefreshHeader.STATE_REFRESHING
            ) {
                //是不是最後一位Item
                isLoadingData = true;
                if (mFootView instanceof LoadingMoreFooter) {
                    ((LoadingMoreFooter) mFootView).setState(LoadingMoreFooter.STATE_LOADING);
                } else {
                    if (footerViewCallBack != null) {
                        footerViewCallBack.onLoadingMore(mFootView);
                    }
                }
                //調用接口 返回事件
                mLoadingListener.onLoadMore();
            }
        }
    }
    
    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        if (mLastY == -1) {
            mLastY = ev.getRawY();
        }
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mLastY = ev.getRawY();
                break;
            case MotionEvent.ACTION_MOVE:
                final float deltaY = ev.getRawY() - mLastY;
                mLastY = ev.getRawY();
                if (isOnTop() && pullRefreshEnabled && appbarState == AppBarStateChangeListener.State.EXPANDED) {
                    mRefreshHeader.onMove(deltaY / DRAG_RATE);
                    if (mRefreshHeader.getVisibleHeight() > 0 && mRefreshHeader.getState() < ArrowRefreshHeader.STATE_REFRESHING) {
                        return false;
                    }
                }
                break;
            default:
                mLastY = -1; // reset
                if (isOnTop() && pullRefreshEnabled && appbarState == AppBarStateChangeListener.State.EXPANDED) {
                    if (mRefreshHeader.releaseAction()) {
                        if (mLoadingListener != null) {
                            mLoadingListener.onRefresh();
                        }
                    }
                }
                break;
        }
        return super.onTouchEvent(ev);
    }
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更多詳情->post

XRecyclerView GitHubthis

# 分組摺疊列表

待續。。。spa

# 分組懸浮列表

待續。。。3d

# 拖拽排序

待續。。。code

# 側滑展開Menu 菜單

實現RecyclerView OnItemTouchListener 接口獲取 Item 的 Touch 事件

/** * An OnItemTouchListener allows the application to intercept touch events in progress at the * view hierarchy level of the RecyclerView before those touch events are considered for * RecyclerView's own scrolling behavior. * * <p>This can be useful for applications that wish to implement various forms of gestural * manipulation of item views within the RecyclerView. OnItemTouchListeners may intercept * a touch interaction already in progress even if the RecyclerView is already handling that * gesture stream itself for the purposes of scrolling.</p> * * @see SimpleOnItemTouchListener */
    public interface OnItemTouchListener {
        /** * Silently observe and/or take over touch events sent to the RecyclerView * before they are handled by either the RecyclerView itself or its child views. * * <p>The onInterceptTouchEvent methods of each attached OnItemTouchListener will be run * in the order in which each listener was added, before any other touch processing * by the RecyclerView itself or child views occurs.</p> * * @param e MotionEvent describing the touch event. All coordinates are in * the RecyclerView's coordinate system. * @return true if this OnItemTouchListener wishes to begin intercepting touch events, false * to continue with the current behavior and continue observing future events in * the gesture. */
        boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e);

        /** * Process a touch event as part of a gesture that was claimed by returning true from * a previous call to {@link #onInterceptTouchEvent}. * * @param e MotionEvent describing the touch event. All coordinates are in * the RecyclerView's coordinate system. */
        void onTouchEvent(RecyclerView rv, MotionEvent e);

        /** * Called when a child of RecyclerView does not want RecyclerView and its ancestors to * intercept touch events with * {@link ViewGroup#onInterceptTouchEvent(MotionEvent)}. * * @param disallowIntercept True if the child does not want the parent to * intercept touch events. * @see ViewParent#requestDisallowInterceptTouchEvent(boolean) */
        void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept);
    }
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實現接口

public static class OnSwipeItemTouchListener implements RecyclerView.OnItemTouchListener {
        private SwipeItemLayout mCaptureItem;
        private float mLastMotionX;
        private float mLastMotionY;
        private VelocityTracker mVelocityTracker;

        private int mActivePointerId;

        private int mTouchSlop;
        private int mMaximumVelocity;

        private boolean mDealByParent;
        private boolean mIsProbeParent;

        public OnSwipeItemTouchListener(Context context) {
            ViewConfiguration configuration = ViewConfiguration.get(context);
            mTouchSlop = configuration.getScaledTouchSlop();
            mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
            mActivePointerId = -1;
            mDealByParent = false;
            mIsProbeParent = false;
        }

        @Override
        public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent ev) {

            if (mIsProbeParent)
                return false;

            boolean intercept = false;
            final int action = ev.getActionMasked();

            if (mVelocityTracker == null) {
                mVelocityTracker = VelocityTracker.obtain();
            }
            mVelocityTracker.addMovement(ev);

            switch (action) {
                case MotionEvent.ACTION_DOWN: {
                    mActivePointerId = ev.getPointerId(0);
                    final float x = ev.getX();
                    final float y = ev.getY();
                    mLastMotionX = x;
                    mLastMotionY = y;

                    boolean pointOther = false;
                    SwipeItemLayout pointItem = null;
                    //首先知道ev針對的是哪一個item
                    View pointView = findTopChildUnder(rv, (int) x, (int) y);
                    if (pointView == null || !(pointView instanceof SwipeItemLayout)) {
                        //多是head view或bottom view
                        pointOther = true;
                    } else
                        pointItem = (SwipeItemLayout) pointView;

                    //此時的pointOther=true，意味着點擊的view爲空或者點擊的不是item
                    //尚未把點擊的是item可是不是capture item給過濾出來
                    if (!pointOther && (mCaptureItem == null || mCaptureItem != pointItem))
                        pointOther = true;

                    //點擊的是capture item
                    if (!pointOther) {
                        Mode touchMode = mCaptureItem.getTouchMode();

                        //若是它在fling，就轉爲drag
                        //須要攔截，而且requestDisallowInterceptTouchEvent
                        boolean disallowIntercept = false;
                        if (touchMode == Mode.FLING) {
                            mCaptureItem.setTouchMode(Mode.DRAG);
                            disallowIntercept = true;
                            intercept = true;
                        } else {//若是是expand的，就不容許parent攔截
                            mCaptureItem.setTouchMode(Mode.TAP);
                            if (mCaptureItem.isOpen())
                                disallowIntercept = true;
                        }

                        if (disallowIntercept) {
                            final ViewParent parent = rv.getParent();
                            if (parent != null)
                                parent.requestDisallowInterceptTouchEvent(true);
                        }
                    } else {//capture item爲null或者與point item不同
                        //直接將其close掉
                        if (mCaptureItem != null && mCaptureItem.isOpen()) {
                            mCaptureItem.close();
                            mCaptureItem = null;
                            intercept = true;
                        }

                        if (pointItem != null) {
                            mCaptureItem = pointItem;
                            mCaptureItem.setTouchMode(Mode.TAP);
                        } else
                            mCaptureItem = null;
                    }

                    //若是parent處於fling狀態，此時，parent就會轉爲drag。此時，應該將後續move都交給parent處理
                    mIsProbeParent = true;
                    mDealByParent = rv.onInterceptTouchEvent(ev);
                    mIsProbeParent = false;
                    if (mDealByParent)
                        intercept = false;
                    break;
                }

                case MotionEvent.ACTION_POINTER_DOWN: {
                    final int actionIndex = ev.getActionIndex();
                    mActivePointerId = ev.getPointerId(actionIndex);

                    mLastMotionX = ev.getX(actionIndex);
                    mLastMotionY = ev.getY(actionIndex);
                    break;
                }

                case MotionEvent.ACTION_POINTER_UP: {
                    final int actionIndex = ev.getActionIndex();
                    final int pointerId = ev.getPointerId(actionIndex);
                    if (pointerId == mActivePointerId) {
                        final int newIndex = actionIndex == 0 ? 1 : 0;
                        mActivePointerId = ev.getPointerId(newIndex);

                        mLastMotionX = ev.getX(newIndex);
                        mLastMotionY = ev.getY(newIndex);
                    }
                    break;
                }

                //down時，已經將capture item定下來了。因此，後面能夠安心考慮event處理
                case MotionEvent.ACTION_MOVE: {
                    final int activePointerIndex = ev.findPointerIndex(mActivePointerId);
                    if (activePointerIndex == -1)
                        break;

                    //在down時，就被認定爲parent的drag，因此，直接交給parent處理便可
                    if (mDealByParent) {
                        if (mCaptureItem != null && mCaptureItem.isOpen())
                            mCaptureItem.close();
                        return false;
                    }

                    final int x = (int) (ev.getX(activePointerIndex) + .5f);
                    final int y = (int) ((int) ev.getY(activePointerIndex) + .5f);

                    int deltaX = (int) (x - mLastMotionX);
                    int deltaY = (int) (y - mLastMotionY);
                    final int xDiff = Math.abs(deltaX);
                    final int yDiff = Math.abs(deltaY);

                    if (mCaptureItem != null && !mDealByParent) {
                        Mode touchMode = mCaptureItem.getTouchMode();

                        if (touchMode == Mode.TAP) {
                            //若是capture item是open的，下拉有兩種處理方式：
                            // 一、下拉後，直接close item
                            // 二、只要是open的，就攔截全部它的消息，這樣若是點擊open的，就只能滑動該capture item
                            //網易郵箱，在open的狀況下，下拉直接close
                            //QQ，在open的狀況下，下拉也是close。可是，作的不夠好，沒有達到該效果。
                            if (xDiff > mTouchSlop && xDiff > yDiff) {
                                mCaptureItem.setTouchMode(Mode.DRAG);
                                final ViewParent parent = rv.getParent();
                                parent.requestDisallowInterceptTouchEvent(true);

                                deltaX = deltaX > 0 ? deltaX - mTouchSlop : deltaX + mTouchSlop;
                            } else {// if(yDiff>mTouchSlop){
                                mIsProbeParent = true;
                                boolean isParentConsume = rv.onInterceptTouchEvent(ev);
                                mIsProbeParent = false;
                                if (isParentConsume) {
                                    //代表不是水平滑動，即不斷定爲SwipeItemLayout的滑動
                                    //可是，多是下拉刷新SwipeRefreshLayout或者RecyclerView的滑動
                                    //通常的下拉斷定，都是yDiff>mTouchSlop，因此，此處這麼寫不會出問題
                                    //這裏這麼作之後，若是斷定爲下拉，就直接close
                                    mDealByParent = true;
                                    mCaptureItem.close();
                                }
                            }
                        }

                        touchMode = mCaptureItem.getTouchMode();
                        if (touchMode == Mode.DRAG) {
                            intercept = true;
                            mLastMotionX = x;
                            mLastMotionY = y;

                            //對capture item進行拖拽
                            mCaptureItem.trackMotionScroll(deltaX);
                        }
                    }
                    break;
                }

                case MotionEvent.ACTION_UP:
                    if (mCaptureItem != null) {
                        Mode touchMode = mCaptureItem.getTouchMode();
                        if (touchMode == Mode.DRAG) {
                            final VelocityTracker velocityTracker = mVelocityTracker;
                            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
                            int xVel = (int) velocityTracker.getXVelocity(mActivePointerId);
                            mCaptureItem.fling(xVel);

                            intercept = true;
                        }
                    }
                    cancel();
                    break;

                case MotionEvent.ACTION_CANCEL:
                    if (mCaptureItem != null)
                        mCaptureItem.revise();
                    cancel();
                    break;
            }

            return intercept;
        }

        @Override
        public void onTouchEvent(RecyclerView rv, MotionEvent ev) {
            final int action = ev.getActionMasked();
            final int actionIndex = ev.getActionIndex();

            if (mVelocityTracker == null) {
                mVelocityTracker = VelocityTracker.obtain();
            }
            mVelocityTracker.addMovement(ev);

            switch (action) {
                case MotionEvent.ACTION_POINTER_DOWN:
                    mActivePointerId = ev.getPointerId(actionIndex);

                    mLastMotionX = ev.getX(actionIndex);
                    mLastMotionY = ev.getY(actionIndex);
                    break;

                case MotionEvent.ACTION_POINTER_UP:
                    final int pointerId = ev.getPointerId(actionIndex);
                    if (pointerId == mActivePointerId) {
                        final int newIndex = actionIndex == 0 ? 1 : 0;
                        mActivePointerId = ev.getPointerId(newIndex);

                        mLastMotionX = ev.getX(newIndex);
                        mLastMotionY = ev.getY(newIndex);
                    }
                    break;

                //down時，已經將capture item定下來了。因此，後面能夠安心考慮event處理
                case MotionEvent.ACTION_MOVE: {
                    final int activePointerIndex = ev.findPointerIndex(mActivePointerId);
                    if (activePointerIndex == -1)
                        break;

                    final float x = ev.getX(activePointerIndex);
                    final float y = (int) ev.getY(activePointerIndex);

                    int deltaX = (int) (x - mLastMotionX);

                    if (mCaptureItem != null && mCaptureItem.getTouchMode() == Mode.DRAG) {
                        mLastMotionX = x;
                        mLastMotionY = y;

                        //對capture item進行拖拽
                        mCaptureItem.trackMotionScroll(deltaX);
                    }
                    break;
                }

                case MotionEvent.ACTION_UP:
                    if (mCaptureItem != null) {
                        Mode touchMode = mCaptureItem.getTouchMode();
                        if (touchMode == Mode.DRAG) {
                            final VelocityTracker velocityTracker = mVelocityTracker;
                            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
                            int xVel = (int) velocityTracker.getXVelocity(mActivePointerId);
                            mCaptureItem.fling(xVel);
                        }
                    }
                    cancel();
                    break;

                case MotionEvent.ACTION_CANCEL:
                    if (mCaptureItem != null)
                        mCaptureItem.revise();

                    cancel();
                    break;

            }
        }

        @Override
        public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
        }

        void cancel() {
            mDealByParent = false;
            mActivePointerId = -1;
            if (mVelocityTracker != null) {
                mVelocityTracker.recycle();
                mVelocityTracker = null;
            }
        }

    }
複製代碼

SwipeItemLayout author:liyi

/** * Author： liyi * Date：2017/2/16. * description: 側滑 菜單 */
public class SwipeItemLayout extends ViewGroup {

    enum Mode {
        RESET, DRAG, FLING, TAP
    }

    private Mode mTouchMode;
    private ViewGroup mMainView;
    private ViewGroup mSideView;
    private ScrollRunnable mScrollRunnable;
    private int mScrollOffset;
    private int mMaxScrollOffset;
    private boolean mInLayout;
    private boolean mIsLaidOut;

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

    public SwipeItemLayout(Context context, AttributeSet attrs) {
        super(context, attrs);

        mTouchMode = Mode.RESET;
        mScrollOffset = 0;
        mIsLaidOut = false;
        mScrollRunnable = new ScrollRunnable(context);
    }

    public boolean isOpen() {
        return mScrollOffset != 0;
    }

    Mode getTouchMode() {
        return mTouchMode;
    }

    void setTouchMode(Mode mode) {
        switch (mTouchMode) {
            case FLING:
                mScrollRunnable.abort();
                break;
            case RESET:
                break;
        }

        mTouchMode = mode;
    }

    public void open() {
        if (mScrollOffset != -mMaxScrollOffset) {
            //正在open，不須要處理
            if (mTouchMode == Mode.FLING && mScrollRunnable.isScrollToLeft())
                return;

            //當前正在向右滑，abort
            if (mTouchMode == Mode.FLING /*&& !mScrollRunnable.mScrollToLeft*/)
                mScrollRunnable.abort();

            mScrollRunnable.startScroll(mScrollOffset, -mMaxScrollOffset);
        }
    }

    public void close() {
        if (mScrollOffset != 0) {
            //正在close，不須要處理
            if (mTouchMode == Mode.FLING && !mScrollRunnable.isScrollToLeft())
                return;

            //當前正向左滑，abort
            if (mTouchMode == Mode.FLING /*&& mScrollRunnable.mScrollToLeft*/)
                mScrollRunnable.abort();

            mScrollRunnable.startScroll(mScrollOffset, 0);
        }
    }

    void fling(int xVel) {
        mScrollRunnable.startFling(mScrollOffset, xVel);
    }

    void revise() {
        if (mScrollOffset < -mMaxScrollOffset / 2)
            open();
        else
            close();
    }

    boolean trackMotionScroll(int deltaX) {
        if (deltaX == 0)
            return false;

        boolean over = false;
        int newLeft = mScrollOffset + deltaX;
        if ((deltaX > 0 && newLeft > 0) || (deltaX < 0 && newLeft < -mMaxScrollOffset)) {
            over = true;
            newLeft = Math.min(newLeft, 0);
            newLeft = Math.max(newLeft, -mMaxScrollOffset);
        }

        offsetChildrenLeftAndRight(newLeft - mScrollOffset);
        mScrollOffset = newLeft;
        return over;
    }

    private boolean ensureChildren() {
        int childCount = getChildCount();

        if (childCount != 2)
            return false;

        View childView = getChildAt(0);
        if (!(childView instanceof ViewGroup))
            return false;
        mMainView = (ViewGroup) childView;

        childView = getChildAt(1);
        if (!(childView instanceof ViewGroup))
            return false;
        mSideView = (ViewGroup) childView;
        return true;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        if (!ensureChildren())
            throw new RuntimeException("SwipeItemLayout的子視圖不符合規定");

        int widthMode = MeasureSpec.getMode(widthMeasureSpec);
        int widthSize = MeasureSpec.getSize(widthMeasureSpec);
        int heightMode = MeasureSpec.getMode(heightMeasureSpec);
        int heightSize = MeasureSpec.getSize(heightMeasureSpec);

        MarginLayoutParams lp = null;
        int horizontalMargin, verticalMargin;
        int horizontalPadding = getPaddingLeft() + getPaddingRight();
        int verticalPadding = getPaddingTop() + getPaddingBottom();

        lp = (MarginLayoutParams) mMainView.getLayoutParams();
        horizontalMargin = lp.leftMargin + lp.rightMargin;
        verticalMargin = lp.topMargin + lp.bottomMargin;
        measureChildWithMargins(mMainView,
                widthMeasureSpec, horizontalMargin + horizontalPadding,
                heightMeasureSpec, verticalMargin + verticalPadding);

        if (widthMode == MeasureSpec.AT_MOST)
            widthSize = Math.min(widthSize, mMainView.getMeasuredWidth() + horizontalMargin + horizontalPadding);
        else if (widthMode == MeasureSpec.UNSPECIFIED)
            widthSize = mMainView.getMeasuredWidth() + horizontalMargin + horizontalPadding;

        if (heightMode == MeasureSpec.AT_MOST)
            heightSize = Math.min(heightSize, mMainView.getMeasuredHeight() + verticalMargin + verticalPadding);
        else if (heightMode == MeasureSpec.UNSPECIFIED)
            heightSize = mMainView.getMeasuredHeight() + verticalMargin + verticalPadding;

        setMeasuredDimension(widthSize, heightSize);

        //side layout大小爲自身實際大小
        lp = (MarginLayoutParams) mSideView.getLayoutParams();
        verticalMargin = lp.topMargin + lp.bottomMargin;
        mSideView.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
                MeasureSpec.makeMeasureSpec(getMeasuredHeight() - verticalMargin - verticalPadding, MeasureSpec.EXACTLY));
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        if (!ensureChildren())
            throw new RuntimeException("SwipeItemLayout的子視圖不符合規定");

        mInLayout = true;

        int pl = getPaddingLeft();
        int pt = getPaddingTop();
        int pr = getPaddingRight();
        int pb = getPaddingBottom();

        MarginLayoutParams mainLp = (MarginLayoutParams) mMainView.getLayoutParams();
        MarginLayoutParams sideParams = (MarginLayoutParams) mSideView.getLayoutParams();

        int childLeft = pl + mainLp.leftMargin;
        int childTop = pt + mainLp.topMargin;
        int childRight = getWidth() - (pr + mainLp.rightMargin);
        int childBottom = getHeight() - (mainLp.bottomMargin + pb);
        mMainView.layout(childLeft, childTop, childRight, childBottom);

        childLeft = childRight + sideParams.leftMargin;
        childTop = pt + sideParams.topMargin;
        childRight = childLeft + sideParams.leftMargin + sideParams.rightMargin + mSideView.getMeasuredWidth();
        childBottom = getHeight() - (sideParams.bottomMargin + pb);
        mSideView.layout(childLeft, childTop, childRight, childBottom);

        mMaxScrollOffset = mSideView.getWidth() + sideParams.leftMargin + sideParams.rightMargin;
        mScrollOffset = mScrollOffset < -mMaxScrollOffset / 2 ? -mMaxScrollOffset : 0;

        offsetChildrenLeftAndRight(mScrollOffset);
        mInLayout = false;
        mIsLaidOut = true;
    }

    void offsetChildrenLeftAndRight(int delta) {
        ViewCompat.offsetLeftAndRight(mMainView, delta);
        ViewCompat.offsetLeftAndRight(mSideView, delta);
    }

    @Override
    public void requestLayout() {
        if (!mInLayout) {
            super.requestLayout();
        }
    }

    @Override
    protected LayoutParams generateDefaultLayoutParams() {
        return new MarginLayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
    }

    @Override
    protected LayoutParams generateLayoutParams(LayoutParams p) {
        return p instanceof MarginLayoutParams ? p : new MarginLayoutParams(p);
    }

    @Override
    protected boolean checkLayoutParams(LayoutParams p) {
        return p instanceof MarginLayoutParams && super.checkLayoutParams(p);
    }

    @Override
    public LayoutParams generateLayoutParams(AttributeSet attrs) {
        return new MarginLayoutParams(getContext(), attrs);
    }

    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();

        if (mScrollOffset != 0 && mIsLaidOut) {
            offsetChildrenLeftAndRight(-mScrollOffset);
            mScrollOffset = 0;
        } else
            mScrollOffset = 0;
    }

    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();

        if (mScrollOffset != 0 && mIsLaidOut) {
            offsetChildrenLeftAndRight(-mScrollOffset);
            mScrollOffset = 0;
        } else
            mScrollOffset = 0;
        removeCallbacks(mScrollRunnable);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        final int action = ev.getActionMasked();
        //click main view，可是它處於open狀態，因此，不須要點擊效果，直接攔截不調用click listener
        switch (action) {
            case MotionEvent.ACTION_DOWN: {
                final int x = (int) ev.getX();
                final int y = (int) ev.getY();
                View pointView = findTopChildUnder(this, x, y);
                if (pointView != null && pointView == mMainView && mScrollOffset != 0)
                    return true;
                break;
            }

            case MotionEvent.ACTION_MOVE:
            case MotionEvent.ACTION_CANCEL:
                break;

            case MotionEvent.ACTION_UP: {
                final int x = (int) ev.getX();
                final int y = (int) ev.getY();
                View pointView = findTopChildUnder(this, x, y);
                if (pointView != null && pointView == mMainView && mTouchMode == Mode.TAP && mScrollOffset != 0)
                    return true;
            }
        }

        return false;
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        final int action = ev.getActionMasked();
        //click main view，可是它處於open狀態，因此，不須要點擊效果，直接攔截不調用click listener
        switch (action) {
            case MotionEvent.ACTION_DOWN: {
                final int x = (int) ev.getX();
                final int y = (int) ev.getY();
                View pointView = findTopChildUnder(this, x, y);
                if (pointView != null && pointView == mMainView && mScrollOffset != 0)
                    return true;
                break;
            }

            case MotionEvent.ACTION_MOVE:
            case MotionEvent.ACTION_CANCEL:
                break;

            case MotionEvent.ACTION_UP: {
                final int x = (int) ev.getX();
                final int y = (int) ev.getY();
                View pointView = findTopChildUnder(this, x, y);
                if (pointView != null && pointView == mMainView && mTouchMode == Mode.TAP && mScrollOffset != 0) {
                    close();
                    return true;
                }
            }
        }

        return false;
    }

    @Override
    protected void onVisibilityChanged(View changedView, int visibility) {
        super.onVisibilityChanged(changedView, visibility);
        if (getVisibility() != View.VISIBLE) {
            mScrollOffset = 0;
            invalidate();
        }
    }

    private static final Interpolator sInterpolator = new Interpolator() {
        @Override
        public float getInterpolation(float t) {
            t -= 1.0f;
            return t * t * t * t * t + 1.0f;
        }
    };

    class ScrollRunnable implements Runnable {
        private static final int FLING_DURATION = 200;
        private Scroller mScroller;
        private boolean mAbort;
        private int mMinVelocity;
        private boolean mScrollToLeft;

        ScrollRunnable(Context context) {
            mScroller = new Scroller(context, sInterpolator);
            mAbort = false;
            mScrollToLeft = false;

            ViewConfiguration configuration = ViewConfiguration.get(context);
            mMinVelocity = configuration.getScaledMinimumFlingVelocity();
        }

        void startScroll(int startX, int endX) {
            if (startX != endX) {
                Log.e("scroll - startX - endX", "" + startX + " " + endX);
                setTouchMode(Mode.FLING);
                mAbort = false;
                mScrollToLeft = endX < startX;
                mScroller.startScroll(startX, 0, endX - startX, 0, 400);
                ViewCompat.postOnAnimation(SwipeItemLayout.this, this);
            }
        }

        void startFling(int startX, int xVel) {
            Log.e("fling - startX", "" + startX);

            if (xVel > mMinVelocity && startX != 0) {
                startScroll(startX, 0);
                return;
            }

            if (xVel < -mMinVelocity && startX != -mMaxScrollOffset) {
                startScroll(startX, -mMaxScrollOffset);
                return;
            }

            startScroll(startX, startX > -mMaxScrollOffset / 2 ? 0 : -mMaxScrollOffset);
        }

        void abort() {
            if (!mAbort) {
                mAbort = true;
                if (!mScroller.isFinished()) {
                    mScroller.abortAnimation();
                    removeCallbacks(this);
                }
            }
        }

        //是否正在滑動須要另外判斷
        boolean isScrollToLeft() {
            return mScrollToLeft;
        }

        @Override
        public void run() {
            Log.e("abort", Boolean.toString(mAbort));
            if (!mAbort) {
                boolean more = mScroller.computeScrollOffset();
                int curX = mScroller.getCurrX();
                Log.e("curX", "" + curX);

                boolean atEdge = trackMotionScroll(curX - mScrollOffset);
                if (more && !atEdge) {
                    ViewCompat.postOnAnimation(SwipeItemLayout.this, this);
                    return;
                }

                if (atEdge) {
                    removeCallbacks(this);
                    if (!mScroller.isFinished())
                        mScroller.abortAnimation();
                    setTouchMode(Mode.RESET);
                }

                if (!more) {
                    setTouchMode(Mode.RESET);
                    //絕對不會出現這種意外的！！！能夠註釋掉
                    if (mScrollOffset != 0) {
                        if (Math.abs(mScrollOffset) > mMaxScrollOffset / 2)
                            mScrollOffset = -mMaxScrollOffset;
                        else
                            mScrollOffset = 0;
                        ViewCompat.postOnAnimation(SwipeItemLayout.this, this);
                    }
                }
            }
        }
    }

    public static class OnSwipeItemTouchListener implements RecyclerView.OnItemTouchListener {
        private SwipeItemLayout mCaptureItem;
        private float mLastMotionX;
        private float mLastMotionY;
        private VelocityTracker mVelocityTracker;

        private int mActivePointerId;

        private int mTouchSlop;
        private int mMaximumVelocity;

        private boolean mDealByParent;
        private boolean mIsProbeParent;

        public OnSwipeItemTouchListener(Context context) {
            ViewConfiguration configuration = ViewConfiguration.get(context);
            mTouchSlop = configuration.getScaledTouchSlop();
            mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
            mActivePointerId = -1;
            mDealByParent = false;
            mIsProbeParent = false;
        }

        @Override
        public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent ev) {

            if (mIsProbeParent)
                return false;

            boolean intercept = false;
            final int action = ev.getActionMasked();

            if (mVelocityTracker == null) {
                mVelocityTracker = VelocityTracker.obtain();
            }
            mVelocityTracker.addMovement(ev);

            switch (action) {
                case MotionEvent.ACTION_DOWN: {
                    mActivePointerId = ev.getPointerId(0);
                    final float x = ev.getX();
                    final float y = ev.getY();
                    mLastMotionX = x;
                    mLastMotionY = y;

                    boolean pointOther = false;
                    SwipeItemLayout pointItem = null;
                    //首先知道ev針對的是哪一個item
                    View pointView = findTopChildUnder(rv, (int) x, (int) y);
                    if (pointView == null || !(pointView instanceof SwipeItemLayout)) {
                        //多是head view或bottom view
                        pointOther = true;
                    } else
                        pointItem = (SwipeItemLayout) pointView;

                    //此時的pointOther=true，意味着點擊的view爲空或者點擊的不是item
                    //尚未把點擊的是item可是不是capture item給過濾出來
                    if (!pointOther && (mCaptureItem == null || mCaptureItem != pointItem))
                        pointOther = true;

                    //點擊的是capture item
                    if (!pointOther) {
                        Mode touchMode = mCaptureItem.getTouchMode();

                        //若是它在fling，就轉爲drag
                        //須要攔截，而且requestDisallowInterceptTouchEvent
                        boolean disallowIntercept = false;
                        if (touchMode == Mode.FLING) {
                            mCaptureItem.setTouchMode(Mode.DRAG);
                            disallowIntercept = true;
                            intercept = true;
                        } else {//若是是expand的，就不容許parent攔截
                            mCaptureItem.setTouchMode(Mode.TAP);
                            if (mCaptureItem.isOpen())
                                disallowIntercept = true;
                        }

                        if (disallowIntercept) {
                            final ViewParent parent = rv.getParent();
                            if (parent != null)
                                parent.requestDisallowInterceptTouchEvent(true);
                        }
                    } else {//capture item爲null或者與point item不同
                        //直接將其close掉
                        if (mCaptureItem != null && mCaptureItem.isOpen()) {
                            mCaptureItem.close();
                            mCaptureItem = null;
                            intercept = true;
                        }

                        if (pointItem != null) {
                            mCaptureItem = pointItem;
                            mCaptureItem.setTouchMode(Mode.TAP);
                        } else
                            mCaptureItem = null;
                    }

                    //若是parent處於fling狀態，此時，parent就會轉爲drag。此時，應該將後續move都交給parent處理
                    mIsProbeParent = true;
                    mDealByParent = rv.onInterceptTouchEvent(ev);
                    mIsProbeParent = false;
                    if (mDealByParent)
                        intercept = false;
                    break;
                }

                case MotionEvent.ACTION_POINTER_DOWN: {
                    final int actionIndex = ev.getActionIndex();
                    mActivePointerId = ev.getPointerId(actionIndex);

                    mLastMotionX = ev.getX(actionIndex);
                    mLastMotionY = ev.getY(actionIndex);
                    break;
                }

                case MotionEvent.ACTION_POINTER_UP: {
                    final int actionIndex = ev.getActionIndex();
                    final int pointerId = ev.getPointerId(actionIndex);
                    if (pointerId == mActivePointerId) {
                        final int newIndex = actionIndex == 0 ? 1 : 0;
                        mActivePointerId = ev.getPointerId(newIndex);

                        mLastMotionX = ev.getX(newIndex);
                        mLastMotionY = ev.getY(newIndex);
                    }
                    break;
                }

                //down時，已經將capture item定下來了。因此，後面能夠安心考慮event處理
                case MotionEvent.ACTION_MOVE: {
                    final int activePointerIndex = ev.findPointerIndex(mActivePointerId);
                    if (activePointerIndex == -1)
                        break;

                    //在down時，就被認定爲parent的drag，因此，直接交給parent處理便可
                    if (mDealByParent) {
                        if (mCaptureItem != null && mCaptureItem.isOpen())
                            mCaptureItem.close();
                        return false;
                    }

                    final int x = (int) (ev.getX(activePointerIndex) + .5f);
                    final int y = (int) ((int) ev.getY(activePointerIndex) + .5f);

                    int deltaX = (int) (x - mLastMotionX);
                    int deltaY = (int) (y - mLastMotionY);
                    final int xDiff = Math.abs(deltaX);
                    final int yDiff = Math.abs(deltaY);

                    if (mCaptureItem != null && !mDealByParent) {
                        Mode touchMode = mCaptureItem.getTouchMode();

                        if (touchMode == Mode.TAP) {
                            //若是capture item是open的，下拉有兩種處理方式：
                            // 一、下拉後，直接close item
                            // 二、只要是open的，就攔截全部它的消息，這樣若是點擊open的，就只能滑動該capture item
                            //網易郵箱，在open的狀況下，下拉直接close
                            //QQ，在open的狀況下，下拉也是close。可是，作的不夠好，沒有達到該效果。
                            if (xDiff > mTouchSlop && xDiff > yDiff) {
                                mCaptureItem.setTouchMode(Mode.DRAG);
                                final ViewParent parent = rv.getParent();
                                parent.requestDisallowInterceptTouchEvent(true);

                                deltaX = deltaX > 0 ? deltaX - mTouchSlop : deltaX + mTouchSlop;
                            } else {// if(yDiff>mTouchSlop){
                                mIsProbeParent = true;
                                boolean isParentConsume = rv.onInterceptTouchEvent(ev);
                                mIsProbeParent = false;
                                if (isParentConsume) {
                                    //代表不是水平滑動，即不斷定爲SwipeItemLayout的滑動
                                    //可是，多是下拉刷新SwipeRefreshLayout或者RecyclerView的滑動
                                    //通常的下拉斷定，都是yDiff>mTouchSlop，因此，此處這麼寫不會出問題
                                    //這裏這麼作之後，若是斷定爲下拉，就直接close
                                    mDealByParent = true;
                                    mCaptureItem.close();
                                }
                            }
                        }

                        touchMode = mCaptureItem.getTouchMode();
                        if (touchMode == Mode.DRAG) {
                            intercept = true;
                            mLastMotionX = x;
                            mLastMotionY = y;

                            //對capture item進行拖拽
                            mCaptureItem.trackMotionScroll(deltaX);
                        }
                    }
                    break;
                }

                case MotionEvent.ACTION_UP:
                    if (mCaptureItem != null) {
                        Mode touchMode = mCaptureItem.getTouchMode();
                        if (touchMode == Mode.DRAG) {
                            final VelocityTracker velocityTracker = mVelocityTracker;
                            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
                            int xVel = (int) velocityTracker.getXVelocity(mActivePointerId);
                            mCaptureItem.fling(xVel);

                            intercept = true;
                        }
                    }
                    cancel();
                    break;

                case MotionEvent.ACTION_CANCEL:
                    if (mCaptureItem != null)
                        mCaptureItem.revise();
                    cancel();
                    break;
            }

            return intercept;
        }

        @Override
        public void onTouchEvent(RecyclerView rv, MotionEvent ev) {
            final int action = ev.getActionMasked();
            final int actionIndex = ev.getActionIndex();

            if (mVelocityTracker == null) {
                mVelocityTracker = VelocityTracker.obtain();
            }
            mVelocityTracker.addMovement(ev);

            switch (action) {
                case MotionEvent.ACTION_POINTER_DOWN:
                    mActivePointerId = ev.getPointerId(actionIndex);

                    mLastMotionX = ev.getX(actionIndex);
                    mLastMotionY = ev.getY(actionIndex);
                    break;

                case MotionEvent.ACTION_POINTER_UP:
                    final int pointerId = ev.getPointerId(actionIndex);
                    if (pointerId == mActivePointerId) {
                        final int newIndex = actionIndex == 0 ? 1 : 0;
                        mActivePointerId = ev.getPointerId(newIndex);

                        mLastMotionX = ev.getX(newIndex);
                        mLastMotionY = ev.getY(newIndex);
                    }
                    break;

                //down時，已經將capture item定下來了。因此，後面能夠安心考慮event處理
                case MotionEvent.ACTION_MOVE: {
                    final int activePointerIndex = ev.findPointerIndex(mActivePointerId);
                    if (activePointerIndex == -1)
                        break;

                    final float x = ev.getX(activePointerIndex);
                    final float y = (int) ev.getY(activePointerIndex);

                    int deltaX = (int) (x - mLastMotionX);

                    if (mCaptureItem != null && mCaptureItem.getTouchMode() == Mode.DRAG) {
                        mLastMotionX = x;
                        mLastMotionY = y;

                        //對capture item進行拖拽
                        mCaptureItem.trackMotionScroll(deltaX);
                    }
                    break;
                }

                case MotionEvent.ACTION_UP:
                    if (mCaptureItem != null) {
                        Mode touchMode = mCaptureItem.getTouchMode();
                        if (touchMode == Mode.DRAG) {
                            final VelocityTracker velocityTracker = mVelocityTracker;
                            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
                            int xVel = (int) velocityTracker.getXVelocity(mActivePointerId);
                            mCaptureItem.fling(xVel);
                        }
                    }
                    cancel();
                    break;

                case MotionEvent.ACTION_CANCEL:
                    if (mCaptureItem != null)
                        mCaptureItem.revise();

                    cancel();
                    break;

            }
        }

        @Override
        public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
        }

        void cancel() {
            mDealByParent = false;
            mActivePointerId = -1;
            if (mVelocityTracker != null) {
                mVelocityTracker.recycle();
                mVelocityTracker = null;
            }
        }

    }

    static View findTopChildUnder(ViewGroup parent, int x, int y) {
        final int childCount = parent.getChildCount();
        for (int i = childCount - 1; i >= 0; i--) {
            final View child = parent.getChildAt(i);
            if (x >= child.getLeft() && x < child.getRight()
                    && y >= child.getTop() && y < child.getBottom()) {
                return child;
            }
        }
        return null;
    }

    public static void closeAllItems(RecyclerView recyclerView) {
        for (int i = 0; i < recyclerView.getChildCount(); i++) {
            View child = recyclerView.getChildAt(i);
            if (child instanceof SwipeItemLayout) {
                SwipeItemLayout swipeItemLayout = (SwipeItemLayout) child;
                if (swipeItemLayout.isOpen())
                    swipeItemLayout.close();
            }
        }
    }

}
複製代碼