自定义View实现手机qq5.X的抽屉特效和聊天界面联系人左滑功能

主要是ViewDragHelper的使用（ViewDragHelper: Google2013年IO大会提出的, 解决界面控件拖拽移动问题），就是把两个View叠加在一起拖动顶层View时加上一些伴随动画可实现抽屉特效。

效果图：

抽屉特效：

首先是抽屉特效的自定义View，为了方便使用就继承FrameLayout(继承FrameLayout的原因就是省事，因为FrameLayout自动测量和摆放位置了，而且FrameLayout是上下层叠关系，没有位置相对的关系，正是这样方便了使用)
自定义View（抽屉）代码：

public class DragLayout extends FrameLayout {

    private String TAG = DragLayout.class.getName();
    private ViewDragHelper mDragHelper;
    private ViewGroup mLeftContent;
    private ViewGroup mMainContent;
    private int mWidth;
    private int mHeight;
    private int mRange;

    public DragStatus getStatus() {
        return mStatus;
    }

    public void setStatus(DragStatus mStatus) {
        this.mStatus = mStatus;
    }

    public DragStatus mStatus = DragStatus.Close;
    public OnDragStatusChangeListener mDragChange;

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

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

    public DragLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        // a.初始化操作
        //参数2 最小敏感范围, 值越小, 越敏感
        mDragHelper = ViewDragHelper.create(this, 0.5f, mCallback);
    }
    public enum DragStatus {
        Close, Open, Draging;
    }


    public interface OnDragStatusChangeListener {
        void onOpen();

        void onClose();

        void onDraging(float percent);
    }

    public void setOnDragStatusChangeListener(OnDragStatusChangeListener mDragChange) {
        this.mDragChange = mDragChange;
    }

    ViewDragHelper.Callback mCallback = new ViewDragHelper.Callback() {

        // 根据返回结果决定是否可以拖拽
        @Override
        public boolean tryCaptureView(View child, int pointerId) {
            return true;
        }

        // 2. 根据建议值 修正将要移动到的(横向)位置
        @Override
        public int clampViewPositionHorizontal(View child, int left, int dx) {

            if (child == mMainContent) {
                left = fixLeft(left);
            }
            return left;
        }
// 返回拖拽的范围, 不对拖拽进行的限制. 只是动画执行速度
        @Override
        public int getViewHorizontalDragRange(View child) {

            return mRange;
        }

        // View已经发生了位置的改变，更新状态, 伴随动画, 重绘界面
        @Override
        public void onViewPositionChanged(View changedView, int left, int top, int dx, int dy) {
            super.onViewPositionChanged(changedView, left, top, dx, dy);
            int newLeft = left;
            if (changedView == mLeftContent) {
                newLeft = fixLeft(mMainContent.getLeft() + dx);
                mLeftContent.layout(0, 0, mWidth, mHeight);
                mMainContent.layout(newLeft, 0, mWidth + newLeft, mHeight);
            }

            // 更新状态,执行伴随动画
            dispatchDragEvent(newLeft);
        }


        // 4. 当View被释放的时候, 执行平滑动画
        @Override
        public void onViewReleased(View releasedChild, float xvel, float yvel) {
            super.onViewReleased(releasedChild, xvel, yvel);
            // 判断执行 关闭/开启
            Log.d(TAG, "onViewReleased:" + "xvel" + xvel);
            if (xvel == 0 && mMainContent.getLeft() > mRange / 2.0f) {
                open();
            } else if (xvel > 0) {
                open();
            } else {
                close();
            }
        }
    };

    private int fixLeft(int left) {
        if (left < 0) {
            return 0;
        } else if (left > mRange) {
            return mRange;
        }
        return left;
    }


    protected void dispatchDragEvent(int newLeft) {
        //主界面从开始到结束的百分比
        float percent = newLeft * 1.0f / mRange;
        if (mDragChange != null) {
            mDragChange.onDraging(percent);
        }
        // 更新状态, 执行回调
        DragStatus preStetus = mStatus;
        mStatus = upDateStetus(percent);
        if (mStatus != preStetus) {
            if (mStatus == DragStatus.Close) {
                if (mDragChange != null) {
                    mDragChange.onClose();
                }
            } else if (mStatus == DragStatus.Open) {
                if (mDragChange != null) {
                    mDragChange.onOpen();
                }
            }
        }

        //伴随动画:
        animViews(percent);
    }

    private DragStatus upDateStetus(float percent) {
        if (percent == 0f) {
            return DragStatus.Close;
        } else if (percent == 1.0f) {
            return DragStatus.Open;
        }
        return DragStatus.Draging;
    }

    private void animViews(float percent) {
        // 缩放动画
        mLeftContent.setScaleX(UiUtils.evaluate(percent, 0.5, 1.0f));
        mLeftContent.setScaleY(UiUtils.evaluate(percent, 0.5, 1.0f));
        // 平移动画: 
     mLeftContent.setTranslationX(UiUtils.evaluate(percent, -mWidth / 2.0f, 0f));
        // 透明度: 
        mLeftContent.setAlpha(UiUtils.evaluate(percent, 0.5, 1.0f));

        //  主界面: 缩放动画
        // 1.0f -> 0.8f
        mMainContent.setScaleX(UiUtils.evaluate(percent, 1.0, 0.8f));
        mMainContent.setScaleY(UiUtils.evaluate(percent, 1.0, 0.8f));

        // 背景动画: 亮度变化
        getBackground().setColorFilter((Integer) UiUtils.evaluateColor(percent, Color.BLACK, Color.TRANSPARENT), PorterDuff.Mode.SRC_OVER);
    }


    // 持续平滑动画
    @Override
    public void computeScroll() {
        super.computeScroll();
        if (mDragHelper.continueSettling(true)) {
            //  如果返回true, 动画还需要继续执行
            ViewCompat.postInvalidateOnAnimation(this);
        }
    }

    public void open() {
        open(true);
    }

    public void open(boolean isSmoot) {
        int fianlLeft = mRange;
        // 触发一个平滑动画
        if (isSmoot) {
            if (mDragHelper.smoothSlideViewTo(mMainContent, fianlLeft, 0)) {
                // 返回true代表还没有移动到指定位置, 需要刷新界面.
                // 参数传this(child所在的ViewGroup)
                ViewCompat.postInvalidateOnAnimation(this);
            }
        } else {
            mMainContent.layout(fianlLeft, 0, fianlLeft + mWidth, mHeight);
        }
    }

    public void close() {
        close(true);
    }

    public void close(boolean isSmoot) {
        int fianlLeft = 0;
        if (isSmoot) {
            if (mDragHelper.smoothSlideViewTo(mMainContent, fianlLeft, 0)) {
                ViewCompat.postInvalidateOnAnimation(this);
            }
        } else {
            mMainContent.layout(fianlLeft, 0, fianlLeft + mWidth, mHeight);
        }
    }

    // 传递触摸事件
    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        if (SwipeLayout.mStatus == SwipeLayout.SwipeStatus.Close) {
            return mDragHelper.shouldInterceptTouchEvent(ev);
        }
        return false;
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {

        try {
            mDragHelper.processTouchEvent(event);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return true;
    }

    //获取当前View的子View
    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();

        mLeftContent = (ViewGroup) getChildAt(0);
        mMainContent = (ViewGroup) getChildAt(1);

    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        // 当尺寸有变化的时候调用
        mWidth = getMeasuredWidth();
        mHeight = getMeasuredHeight();

        // 向右滑的范围
        mRange = (int) (mWidth * 0.6f);
    }


}

MainActivity代码：

public class MainActivity extends AppCompatActivity {

    private String TAG = MainActivity.class.getName();
    private MyLinearLayout mLayout;
    private DragLayout dl_layout;
    private ListView mMainList;
    private ImageView mHeaderImage;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setStatusBar();
        dl_layout = (DragLayout) findViewById(R.id.dl_layout);
        mMainList = (ListView) findViewById(R.id.lv_main);
        mHeaderImage = (ImageView) findViewById(R.id.iv_header);
        mLayout = (MyLinearLayout) findViewById(R.id.rl_main);
        mLayout.setmDragLayout(dl_layout);
        //打开或关闭抽屉的回调
        mHeaderImage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                dl_layout.open();
            }
        });

        dl_layout.setOnDragStatusChangeListener(new DragLayout.OnDragStatusChangeListener() {
            @Override
            public void onOpen() {
                UiUtils.showToast(MainActivity.this,"onOpen");
            }

            @Override
            public void onClose() {
                UiUtils.showToast(MainActivity.this, "onClose");

                ObjectAnimator mAnim = ObjectAnimator.ofFloat(mHeaderImage, "translationX", 25.0f);
                mAnim.setInterpolator(new CycleInterpolator(3));
                mAnim.setDuration(500);
                mAnim.start();
            }

            @Override
            public void onDraging(float percent) {
                // 更新图标的透明度
                // 1.0 -> 0.0
                mHeaderImage.setAlpha(1 - percent);
            }
        });
        mMainList.setAdapter(new MyAdapter(getApplicationContext()));

    }
    protected void setStatusBar() {
        StatusBarUtil.setTranslucentForImageView(this, 60, mLayout);
    }
}

聊天界面联系人左滑功能：
自定义View代码：

public class SwipeLayout extends FrameLayout {

    private View operateView;
    private View itmeView;
    private int mHeight;
    private int mWidth;
    private int mRange;
    private ViewDragHelper mDragHelper;
    private OnSwipeLayoutStateChangeListener onStateChangeListener;
    public static SwipeStatus mStatus = SwipeStatus.Close;

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

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

    public SwipeLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);

        mDragHelper = ViewDragHelper.create(this, 1f, mCallback);
    }

    ViewDragHelper.Callback mCallback = new ViewDragHelper.Callback() {

        @Override
        public boolean tryCaptureView(View child, int pointerId) {
            return true;
        }

        @Override
        public int clampViewPositionHorizontal(View child, int left, int dx) {
            // 限定移动范围
            if (child == itmeView) {
                if (left > 0) {
                    return 0;
                } else if (left < -mRange) {
                    return -mRange;
                }
            } else if (child == operateView) {
                if (left > mWidth) {
                    return mWidth;
                } else if (left < mWidth - mRange) {
                    return mWidth - mRange;
                }
            }
            return left;
        }

        @Override
        public void onViewPositionChanged(View changedView, int left, int top, int dx, int dy) {
            super.onViewPositionChanged(changedView, left, top, dx, dy);

            if(changedView == itmeView){
                operateView.offsetLeftAndRight(dx);
            }else if (changedView == operateView) {
                itmeView.offsetLeftAndRight(dx);
            }

            dispatchSwipeEvent();
        }
        @Override
        public void onViewReleased(View releasedChild, float xvel, float yvel) {
            super.onViewReleased(releasedChild, xvel, yvel);
            if (xvel == 0 && itmeView.getLeft() < -mRange / 2.0f) {
                open();
            } else if (xvel < 0) {
                open();
            } else {
                close();
            }
        }
    };

    public enum SwipeStatus {
        Close, Open, Draging;
    }

    public interface OnSwipeLayoutStateChangeListener {

        void onClose(SwipeLayout mSwipeLayout);

        void onOpen(SwipeLayout mSwipeLayout);

        void onDraging(SwipeLayout mSwipeLayout);

        // 准备关闭
        void onStartClose(SwipeLayout mSwipeLayout);

        // 准备开启
        void onStartOpen(SwipeLayout mSwipeLayout);
    }

    public void setOnSwipeLayoutStateChangeListener(OnSwipeLayoutStateChangeListener onStateChangeListener) {
        this.onStateChangeListener = onStateChangeListener;
    }

    private void dispatchSwipeEvent() {

        if (onStateChangeListener != null) {
            onStateChangeListener.onDraging(this);
        }

        SwipeStatus preStatus = mStatus;
        mStatus = upDateStatus();
        if (preStatus != mStatus && onStateChangeListener != null) {
            if (mStatus == SwipeStatus.Close) {
                onStateChangeListener.onClose(this);
            } else if (mStatus == SwipeStatus.Open) {
                onStateChangeListener.onOpen(this);
            } else if (mStatus == SwipeStatus.Draging) {
                if(preStatus == SwipeStatus.Close){
                    onStateChangeListener.onStartOpen(this);
                }else if (preStatus == SwipeStatus.Open) {
                    onStateChangeListener.onStartClose(this);
                }
            }
        }
    }

    private SwipeStatus upDateStatus() {
        int left = itmeView.getLeft();
        if (left == 0) {
            return SwipeStatus.Close;
        } else if (left == -mRange) {
            return SwipeStatus.Open;
        }
        return SwipeStatus.Draging;
    }

    @Override
    public void computeScroll() {
        super.computeScroll();
        if (mDragHelper.continueSettling(true)) {
            ViewCompat.postInvalidateOnAnimation(this);
        }
    }

    public void open() {
        open(true);
    }

    private void open(boolean isSmooth) {
        int fianlLeft = -mRange;
        if (isSmooth) {
            if (mDragHelper.smoothSlideViewTo(itmeView, fianlLeft, 0)) {
                ViewCompat.postInvalidateOnAnimation(this);
            }
        } else {
            layoutContent(true);
        }
    }

    public void close() {
        close(true);
    }

    private void close(boolean isSmooth) {
        int fianlLeft = 0;
        if (isSmooth) {
            if (mDragHelper.smoothSlideViewTo(itmeView, fianlLeft, 0)) {
                ViewCompat.postInvalidateOnAnimation(this);
            }
        } else {
            layoutContent(false);
        }
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
        layoutContent(false);
    }

    private void layoutContent(boolean isOpen) {
        Rect itemRect = computeFrontViewRect(isOpen);

        itmeView.layout(itemRect.left, itemRect.top, itemRect.right, itemRect.bottom);
        Rect OperateRect = computeOperateViewFront(itemRect);
        operateView.layout(OperateRect.left, OperateRect.top, OperateRect.right, OperateRect.bottom);
        // 调整顺序, 把itemRect前置
        bringChildToFront(itmeView);
    }

    private Rect computeOperateViewFront(Rect itemRect) {

        int left = itemRect.right;
        return new Rect(left, 0, left + mRange, mHeight);
    }

    private Rect computeFrontViewRect(boolean isOpen) {
        int left = 0;
        if (isOpen) {
            left = -mRange;
        }
        return new Rect(left, 0, mWidth + left, mHeight);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        return mDragHelper.shouldInterceptTouchEvent(ev);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        try {
            mDragHelper.processTouchEvent(event);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return true;
    }

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

        operateView = getChildAt(0);
        itmeView = getChildAt(1);
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        mHeight = itmeView.getMeasuredHeight();
        mWidth = itmeView.getMeasuredWidth();

        mRange = operateView.getMeasuredWidth();
    }
}

listView的Adaper：

public class MyAdapter extends BaseAdapter {

    protected static final String TAG = "TAG";


    public MyAdapter(Context context) {
        super();
        this.context = context;

        opendItems = new ArrayList<>();
    }

    private Context context;
    private ArrayList<SwipeLayout> opendItems;

    @Override
    public int getCount() {
        return Cheeses.NAMES.length;
    }

    @Override
    public Object getItem(int position) {
        return NAMES[position];
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        View view = convertView;
        if(convertView == null){
            view = View.inflate(context, R.layout.item_list, null);

        }
        ViewHolder mHolder = ViewHolder.getHolder(view);

        SwipeLayout sl = (SwipeLayout)view;
        sl.setOnSwipeLayoutStateChangeListener(new SwipeLayout.OnSwipeLayoutStateChangeListener() {

            @Override
            public void onStartOpen(SwipeLayout mSwipeLayout) {
                Log.d(TAG, "onStartOpen");
            }

            @Override
            public void onStartClose(SwipeLayout mSwipeLayout) {
                Log.d(TAG, "onStartClose");
            }

            @Override
            public void onOpen(SwipeLayout mSwipeLayout) {
                Log.d(TAG, "onOpen");
            }
            @Override
            public void onDraging(SwipeLayout mSwipeLayout) {
            }

            @Override
            public void onClose(SwipeLayout mSwipeLayout) {
                Log.d(TAG, "onClose");
            }
        });
        return view;
    }

    static class ViewHolder {
        TextView tv_call;
        TextView tv_del;

        public static ViewHolder getHolder(View view) {
            Object tag = view.getTag();
            if(tag == null){
                ViewHolder viewHolder = new ViewHolder();
                viewHolder.tv_call = (TextView)view.findViewById(R.id.tv_call);
                viewHolder.tv_del = (TextView)view.findViewById(R.id.tv_del);
                tag = viewHolder;
                view.setTag(tag);
            }
            return (ViewHolder)tag;
        }
    }

}