[移动开发]Android RecyclerView TV-滑动选中态背景

TV应用开发中，正常使用的是根据点击、焦点、selected换图片背景资源。但是效果看起来不怎么丝滑。

优化方案：
1、滑动过程中判断居中
2、选中态为滑动的。体验起来丝滑一些。
代码实现：

  private static final int ITEM_MOVE_TIME = 600;
    private static final int ANIM_VALUE = 60;

    private Paint mPaint;

    //四个目标坐标
    private int aimLeft;
    private int aimTop;
    private int aimBottom;
    private int aimRight;

    //目前的坐标
    private static int currLeft;
    private static int currTop;
    private int currBottom;
    private int currRight;

	//宽高
    private int width = 270;
    private int height  = 96;

    private RectF mRect;

    private ValueAnimator valueAnimator;

    public FocusBuoyView(Context context) {
        super(context);
    }

    public FocusBuoyView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public FocusBuoyView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public FocusBuoyView(Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        init();
        mRect.set(currLeft, currTop, currLeft + width, currTop + height);
        //画圆角矩形
        canvas.drawRoundRect(mRect, 14 , 14, mPaint);
    }

    private void init(){
        if (mPaint == null){
            mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
            mPaint.setColor(Color.parseColor("#DC6666"));
            mPaint.setStyle(Paint.Style.FILL);
        }
        if (mRect == null){
            mRect = new RectF();
        }
    }

    public void setBuoy(int left, int top , int right, int bottom){
        this.aimLeft = left;
        this.aimTop = top;
        this.aimRight = right;
        this.aimBottom = bottom;

        if (valueAnimator == null){
            valueAnimator = new ValueAnimator();
            valueAnimator.setIntValues(0, ANIM_VALUE);
        }
        valueAnimator.removeAllUpdateListeners();
        valueAnimator.cancel();
        valueAnimator.setDuration(ITEM_MOVE_TIME);
        valueAnimator.setTarget(null);
        valueAnimator.setInterpolator(new LinearInterpolator());
        valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                int index = (int) animation.getAnimatedValue();
                currLeft = currLeft + (int)((aimLeft - currLeft) * (double)((double)index / (double)ANIM_VALUE));
                currTop = currTop + (int)((aimTop - currTop) * (double)((double) index / (double)ANIM_VALUE ));
                invalidate();
            }
        });
        valueAnimator.start();
    }

使用：

  homeRVAdapter.setOnFocusClickInterface(new BaseCommonListRVAdapter.OnFocusClick() {
            @Override
            public void onFocus(View view, int position, Object object, boolean focused, boolean parentFocus) {
				//设置坐标、刷新
                focusView.setBuoy(view.getLeft() + firstRV.getLeft(),
                        view.getTop() + firstRV.getTop(),
                        view.getRight()+ firstRV.getRight(),
                        view.getBottom()+ firstRV.getBottom());
            }
        });