ParallaxRecyclerAdapter.java 文件源码

/**
 * Translates the adapter in Y
 *
 * @param of offset in px
 */
public void translateHeader(float of) {
    float ofCalculated = of * mScrollMultiplier;
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB && of < mHeader.getHeight()) {
        mHeader.setTranslationY(ofCalculated);
    } else if (of < mHeader.getHeight()) {
        TranslateAnimation anim = new TranslateAnimation(0, 0, ofCalculated, ofCalculated);
        anim.setFillAfter(true);
        anim.setDuration(0);
        mHeader.startAnimation(anim);
    }
    mHeader.setClipY(Math.round(ofCalculated));
    if (mParallaxScroll != null) {
        final RecyclerView.ViewHolder holder = mRecyclerView.findViewHolderForAdapterPosition(0);
        float left;
        if (holder != null) {
            left = Math.min(1, ((ofCalculated) / (mHeader.getHeight() * mScrollMultiplier)));
        }else {
            left = 1;
        }
        mParallaxScroll.onParallaxScroll(left, of, mHeader);
    }
}