android 闪光效果TextView

public class ShimmerTextView extends TextView {

    //渲染器
    private LinearGradient mLinearGradient;
    //渲染范围
    private Matrix mGradientMatrix;
    //渲染的起始位置
    private int mViewWidth = 0;
    //渲染的终止距离
    private int mTranslate = 0;
    //是否启动动画
    private boolean mAnimating = true;
    //多少毫秒刷新一次
    private int speed = 50;
    private Paint mPaint;

    public ShimmerTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        mPaint = getPaint();
        mGradientMatrix = new Matrix();
    }

    @SuppressLint("DrawAllocation")
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        mViewWidth = getMeasuredWidth();
        mLinearGradient = new LinearGradient(0, 0, mViewWidth, 0, new int[] { Color.GRAY, Color.WHITE, Color.GRAY }, null, Shader.TileMode.CLAMP);
        mPaint.setShader(mLinearGradient);
    }

    @Override
    protecte