Android自定义View(四)侧滑布局

利用Scroller来写一个侧滑布局效果如下:

ezgif-5-2511a3329a.gif

1.自定义一个Viewgroup在构造方法初始化参数

        mScroller = new Scroller(context);
        //滑动临界值
        ViewConfiguration viewConfiguration = ViewConfiguration.get(context);
        mTouchSlop = ViewConfigurationCompat.getScaledPagingTouchSlop(viewConfiguration);

2.在onMeasure方法中测量子孩子大小

        if (!mIsMeasure) {
            for (int i = 0; i < getChildCount(); i++) {
                View view = getChildAt(i);
                measureChild(view, widthMeasureSpec, heightMeasureSpec);
            }
            mIsMeasure = true;
        }

3.在onLayout布局中初始化子孩子的位置里面有三个view分别是文本内容,置顶以及删除

  @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        for (int i = 0; i < getChildCount(); i++) {
            View view = getChildAt(i);
            if (i == 0) {
                mTextWidth = view.getMeasuredWidth();
                view.layout(0, 0, mTextWidth, view.getMeasuredHeight());
            } else if (i == 1) {
              //置顶文本的宽度
                mStickWidth = view.getMeasuredWidth();
                view.layout(mTextWidth, 0, mTextWidth + mStickWidth, view.getMeasuredHeight());

            } else if (i == 2) {
          //删除文本的宽度
                mDeleteWidth = view.getMeasuredWidth();
                view.layout(mTextWidth + mStickWidth, 0, mTextWidth + mStickWidth + mDeleteWidth, view.getMeasuredHeight());
            }
        }
    }

4.在onInterceptTouchEvent方法中处理滑动事件,如果是横向滑动我们就拦截事件自己去处理事件

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mDownX = (int) ev.getRawX();
                break;
            case MotionEvent.ACTION_MOVE:
                mMovex = (int) ev.getRawX();
                float diff = Math.abs(mMovex - mDownX);
                // 当手指拖动值大于TouchSlop值时，认为应该进行滚动，拦截子控件的事件
                mLastMove = mMovex;
                if (diff > mTouchSlop) {
                    return true;
                }
                break;
        }
        return super.onInterceptTouchEvent(ev);
    }

5.在onTouchEvent方法中处理滑动事件,用ScrollBy方法来移动控件,移动过程中对移动范围进行限制
move事件中:

               mMovex = (int) event.getX();
                scrollBy(mLastMove - mMovex, 0);
                if (getScrollX() <= 0) {
                    scrollTo(0, 0);
                    return true;
                }
                if (getScrollX() >= mDeleteWidth + mStickWidth) {
                    scrollTo(mDeleteWidth + mStickWidth, 0);
                    return true;
                }
                mLastMove = mMovex;

当手指抬起的时候根据移动的位置来判断是否是打开还是关闭getScrollX()方法可以得到移动的x值,大于置顶和删除文本宽度一半时就是打开状态否则就是关闭

 if (getScrollX() >= mDeleteWidth) {//open
      dx = mDeleteWidth + mStickWidth - getScrollX();
     if (mOnStateChangeListener != null) {
        mOnStateChangeListener.onOpen(this);
      }
   } else {//close
      dx = 0 - getScrollX();
       mOnStateChangeListener.onClose(this);
    }
 mScroller.startScroll(getScrollX(), 0, dx, 0);
 invalidate();

6.在配合Recycleview使用的时候要注意的地方:

在onTouchEvent方法中move事件要请求父控件不要拦截否则收不到up事件

 //请求父容器不要拦截事件
getParent().requestDisallowInterceptTouchEvent(true);

在侧滑时一个条目时其他条目都要关闭这里利用adapter进行对当前滑动条目的记录和已经打开的条目记录,然后在move的时候进行判断

 case MotionEvent.ACTION_MOVE:
    if (getAdapter().getOpenView() != null && getAdapter().getOpenView() != this) {
       getAdapter().getOpenView().close();
       getAdapter().setOpenView(null);
       return true;
       }
     if (getAdapter().getCurrentDeleteView() !=null && getAdapter().getCurrentDeleteView() != this) {
        return true;
     }

完整代码:

public class DeleteView extends ViewGroup {

    private Scroller mScroller;
    private int mDownX;
    private int mMovex;
    private int mTouchSlop;
    private boolean mIsMeasure = false;
    private int mTextWidth;
    private int mStickWidth;
    private int mDeleteWidth;
    private int mLastMove;

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

    public DeleteView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        mScroller = new Scroller(context);
        //滑动临界值
        ViewConfiguration viewConfiguration = ViewConfiguration.get(context);
        mTouchSlop = ViewConfigurationCompat.getScaledPagingTouchSlop(viewConfiguration);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        if (!mIsMeasure) {
            for (int i = 0; i < getChildCount(); i++) {
                View view = getChildAt(i);
                measureChild(view, widthMeasureSpec, heightMeasureSpec);
            }
            mIsMeasure = true;
        }
    }
    
    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        for (int i = 0; i < getChildCount(); i++) {
            View view = getChildAt(i);
            if (i == 0) {
                mTextWidth = view.getMeasuredWidth();
                view.layout(0, 0, mTextWidth, view.getMeasuredHeight());
            } else if (i == 1) {
                mStickWidth = view.getMeasuredWidth();
                view.layout(mTextWidth, 0, mTextWidth + mStickWidth, view.getMeasuredHeight());

            } else if (i == 2) {
                mDeleteWidth = view.getMeasuredWidth();
                view.layout(mTextWidth + mStickWidth, 0, mTextWidth + mStickWidth + mDeleteWidth, view.getMeasuredHeight());

            }

        }
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mDownX = (int) ev.getRawX();
                break;
            case MotionEvent.ACTION_MOVE:
                mMovex = (int) ev.getRawX();
                float diff = Math.abs(mMovex - mDownX);
                // 当手指拖动值大于TouchSlop值时，认为应该进行滚动，拦截子控件的事件
                mLastMove = mMovex;
                if (diff > mTouchSlop) {
                    return true;
                }
                break;
        }
        return super.onInterceptTouchEvent(ev);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()) {

            case MotionEvent.ACTION_MOVE:
                if (getAdapter().getOpenView() != null && getAdapter().getOpenView() != this) {
                    getAdapter().getOpenView().close();
                    getAdapter().setOpenView(null);
                    return true;
                }
                if (getAdapter().getCurrentDeleteView() !=null && getAdapter().getCurrentDeleteView() != this) {
                    return true;
                }
                getAdapter().setCurrentDeleteView(this);
                //请求父容器不要拦截事件
                getParent().requestDisallowInterceptTouchEvent(true);
                mMovex = (int) event.getX();
                scrollBy(mLastMove - mMovex, 0);
                if (getScrollX() <= 0) {
                    scrollTo(0, 0);
                    return true;
                }
                if (getScrollX() >= mDeleteWidth + mStickWidth) {
                    scrollTo(mDeleteWidth + mStickWidth, 0);
                    return true;
                }
                mLastMove = mMovex;
                break;
            case MotionEvent.ACTION_UP:
                LogUtils.LogE("up");
                int dx = 0;
                if (getScrollX() >= mDeleteWidth) {//open
                    dx = mDeleteWidth + mStickWidth - getScrollX();
                    if (mOnStateChangeListener != null) {
                        mOnStateChangeListener.onOpen(this);
                    }
                } else {//close
                    dx = 0 - getScrollX();
                    mOnStateChangeListener.onClose(this);
                }

                mScroller.startScroll(getScrollX(), 0, dx, 0);
                invalidate();
                getAdapter().setCurrentDeleteView(null);
                break;
        }
        return true;
    }

    @Override
    public void computeScroll() {
        if (mScroller.computeScrollOffset()) {
            scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
            invalidate();
        }

    }

    public interface onStateChangeListener {
        void onOpen(DeleteView deleteView);

        void onClose(DeleteView deleteView);
    }

    private onStateChangeListener mOnStateChangeListener;

    public void setOnStateChangeListener(onStateChangeListener onStateChangeListener) {
        mOnStateChangeListener = onStateChangeListener;
    }

    public void open() {
        scrollTo(mStickWidth + mDeleteWidth, 0);
    }

    public void close() {
        scrollTo(0, 0);
    }

    /**
     * 得到适配器
     *
     * @return
     */
    private DeleteAdapter getAdapter() {
        return (DeleteAdapter) ((RecyclerView) getParent()).getAdapter();
    }

Adapter代码：

public class DeleteAdapter extends RecyclerView.Adapter {


    private List<CartModel> mDatas;

    private DeleteView mDeleteView;
    private DeleteView mOpenView;

    public DeleteAdapter(List<CartModel> list) {
        mDatas = list;
    }


    public void setData(List<CartModel> list) {
        mDatas = list;
        notifyDataSetChanged();
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_delete, parent, false);
        MyHolder holder = new MyHolder(view);

        return holder;
    }

    @Override
    public void onBindViewHolder(final RecyclerView.ViewHolder holder, final int position) {
        MyHolder myHolder = (MyHolder) holder;
        myHolder.setItem(position);

        ((DeleteView) holder.itemView).setOnStateChangeListener(new DeleteView.onStateChangeListener() {
            @Override
            public void onOpen(DeleteView deleteView) {
                mOpenView = deleteView;
            }

            @Override
            public void onClose(DeleteView deleteView) {

            }
        });

        myHolder.delete.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(v.getContext(),"删除"+position,Toast.LENGTH_SHORT).show();
                mDatas.remove(position);
                getOpenView().close();
                notifyDataSetChanged();
            }
        });
        myHolder.stick.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                CartModel cartModel = mDatas.get(position);
                Toast.makeText(v.getContext(),"置顶"+position,Toast.LENGTH_SHORT).show();
                mDatas.remove(cartModel);
                mDatas.add(0,cartModel);
                getOpenView().close();
                notifyDataSetChanged();
            }
        });
    }

    /**
     * 得到当前滑动的view
     *
     * @return
     */
    public DeleteView getCurrentDeleteView() {
        return mDeleteView;
    }

    /**
     * 得到当前滑动的view
     *
     * @return
     */
    public void setCurrentDeleteView(DeleteView deleteView) {
        this.mDeleteView = deleteView;
    }

    public DeleteView getOpenView() {
        return mOpenView;
    }

    public void setOpenView(DeleteView openView) {
        mOpenView = openView;
    }

    @Override
    public int getItemCount() {//加的一是脚步局
        return mDatas.size();
    }


    class MyHolder extends RecyclerView.ViewHolder {
        TextView title;
        TextView stick;
        TextView delete;

        public MyHolder(View itemView) {
            super(itemView);
            title = itemView.findViewById(R.id.tv_title);
            stick = itemView.findViewById(R.id.tv_stick);
            delete = itemView.findViewById(R.id.tv_delete);

        }

        public void setItem(int position) {
            CartModel cartModel = mDatas.get(position);
            title.setText(cartModel.getName());

        }
    }
}