/**
* Set the view as header.
*
* @param header The inflated header
* @param view The RecyclerView to set scroll listeners
*/
public void setParallaxHeader(View header, final RecyclerView view) {
mRecyclerView = view;
mHeader = new CustomRelativeWrapper(header.getContext(), mShouldClipView);
mHeader.setLayoutParams(
new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
mHeader.addView(
header,
new RelativeLayout.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
view.setOnScrollListener(
new RecyclerView.OnScrollListener() {
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
if (mHeader != null) {
translateHeader(
mRecyclerView.getLayoutManager().getChildAt(0) == mHeader
? mRecyclerView.computeVerticalScrollOffset()
: mHeader.getHeight());
}
}
});
}
/**
* 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);
}
}
