RoundCornersDrawable.java 文件源码

@Override
protected void onBoundsChange(Rect bounds) {
    super.onBoundsChange(bounds);
    mRect.set(mMargin, mMargin, bounds.width() - mMargin, bounds.height() - mMargin);

    if (USE_VIGNETTE) {
        RadialGradient vignette = new RadialGradient(
                mRect.centerX(), mRect.centerY() * 1.0f / 0.7f, mRect.centerX() * 1.3f,
                new int[] { 0, 0, 0x7f000000 }, new float[] { 0.0f, 0.7f, 1.0f },
                Shader.TileMode.CLAMP);

        Matrix oval = new Matrix();
        oval.setScale(1.0f, 0.7f);
        vignette.setLocalMatrix(oval);

        mPaint.setShader(
                new ComposeShader(mBitmapShader, vignette, PorterDuff.Mode.SRC_OVER));
    }
}