カスタムビュー波

public class CustomView extends View{
    //     
    private Path mPath;
    private Paint mPaint;

    //       
    private int mScreenHeight;
    private int mScreenWidth;

    private int mOffset;

    public CustomView(Context context) {
        super(context);
        init(context);
    }

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

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

    private void init(Context context) {
            WindowManager win= (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        DisplayMetrics displayMetrics = new DisplayMetrics();
        win.getDefaultDisplay().getMetrics(displayMetrics);
        mScreenHeight = displayMetrics.heightPixels;
        mScreenWidth=displayMetrics.widthPixels;
        mPath=new Path();
        mPaint=new Paint(Paint.ANTI_ALIAS_FLAG);
        mPaint.setColor(Color.BLUE);
        mPaint.setStyle(Paint.Style.FILL);
        mPaint.setStrokeWidth(8);
        setViewanimator();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        mPath.reset();
        mPath.moveTo(-mScreenWidth+mOffset,mScreenHeight/2);
        for (int i=0;i<2;i++){
            mPath.quadTo(-mScreenWidth*3/4+(mScreenWidth*i)+mOffset, mScreenHeight / 2 - 100, -mScreenWidth / 2 + (mScreenWidth * i) + mOffset, mScreenHeight / 2);
            mPath.quadTo(-mScreenWidth / 4 + (mScreenWidth * i) + mOffset, mScreenHeight / 2 + 100, +(mScreenWidth * i) + mOffset, mScreenHeight / 2);
        }
        mPath.lineTo(mScreenWidth,mScreenHeight);
        mPath.lineTo(0,mScreenHeight);
        canvas.drawPath(mPath,mPaint);
    }

    private void setViewanimator() {
        ValueAnimator valueAnimator = ValueAnimator.ofInt(0, mScreenWidth);
        valueAnimator.setDuration(1200);
        valueAnimator.setRepeatCount(ValueAnimator.INFINITE);
        valueAnimator.setInterpolator(new LinearInterpolator());
        valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator valueAnimator) {
             mOffset= (int) valueAnimator.getAnimatedValue();
                invalidate();
            }
        });
        valueAnimator.start();