BannerAutoScrollRecyclerView

BannerAutoScrollRecyclerView.java

public class BannerAutoScrollRecyclerView extends RecyclerView {
    private static final int AUTO_SCROLL_PERIOD_MILLIS = 3500;
    private static final int SCROLL_WHAT = 1;
    private boolean mAutoScrollEnabled;
    private boolean mAutoScrolling;
    private ScrollHandler mHandler;
    
    private static class ScrollHandler extends Handler {
        private final WeakReference<BannerAutoScrollRecyclerView> mRecyclerViewWeakReference;

        ScrollHandler(BannerAutoScrollRecyclerView bannerAutoScrollRecyclerView) {
            this.mRecyclerViewWeakReference = new WeakReference(bannerAutoScrollRecyclerView);
        }

        public void handleMessage(Message message) {
            super.handleMessage(message);
            if (message.what == 1) {
                BannerAutoScrollRecyclerView bannerAutoScrollRecyclerView = (BannerAutoScrollRecyclerView) this.mRecyclerViewWeakReference.get();
                if (bannerAutoScrollRecyclerView != null) {
                    bannerAutoScrollRecyclerView.smoothScrollingToNextPosition();
                }
            }
        }
    }

    public BannerAutoScrollRecyclerView(Context context) {
        super(context);
    }

    public BannerAutoScrollRecyclerView(Context context, AttributeSet attributeSet) {
        super(context, attributeSet);
    }

    public BannerAutoScrollRecyclerView(Context context, AttributeSet attributeSet, int i) {
        super(context, attributeSet, i);
    }

    public void startAutoScroll(boolean z) {
        if (!this.mAutoScrollEnabled) {
            this.mAutoScrollEnabled = true;
            this.mHandler = new ScrollHandler(this);
            startAutoScrolling(z);
        }
    }

    public void stopAutoScroll() {
        if (this.mAutoScrollEnabled) {
            this.mAutoScrollEnabled = false;
            this.mAutoScrolling = false;
            stopAutoScrolling();
            this.mHandler = null;
        }
    }

    private void startAutoScrolling(boolean z) {
        sendScrollMessage(z);
    }

    private void stopAutoScrolling() {
        if (this.mHandler != null) {
            this.mHandler.removeMessages(1);
        }
    }

    public void onScrollStateChanged(int i) {
        super.onScrollStateChanged(i);
        switch (i) {
            case 0:
                if (this.mAutoScrollEnabled != 0 && this.mAutoScrolling == 0) {
                    startAutoScrolling(false);
                }
                this.mAutoScrolling = false;
                break;
            case 1:
                if (this.mAutoScrollEnabled != 0 && this.mAutoScrolling == 0) {
                    stopAutoScrolling();
                    return;
                }
            default:
                break;
        }
    }

    public void sendScrollMessage(boolean z) {
        if (this.mHandler != null) {
            this.mHandler.removeMessages(1);
            if (z) {
                this.mHandler.sendEmptyMessage(1);
                return;
            }
            this.mHandler.sendEmptyMessageDelayed(1, 3500);
        }
    }

    private void smoothScrollingToNextPosition() {
        if (getAdapter() == null || !(getAdapter() instanceof InfiniteBannerAdapter)) {
            throw new IllegalStateException("Adapter == null or Adapter class not InfiniteBannerAdapter");
        }
        InfiniteBannerAdapter infiniteBannerAdapter = (InfiniteBannerAdapter) getAdapter();
        LayoutManager layoutManager = getLayoutManager();
        if (layoutManager instanceof LinearLayoutManager) {
            int findLastCompletelyVisibleItemPosition = ((LinearLayoutManager) layoutManager).findLastCompletelyVisibleItemPosition() + 1;
            if (findLastCompletelyVisibleItemPosition == infiniteBannerAdapter.getItemCount() - 1) {
                int sameBannerInCenterPosition = infiniteBannerAdapter.getSameBannerInCenterPosition(findLastCompletelyVisibleItemPosition);
                this.mAutoScrolling = true;
                scrollToPosition(sameBannerInCenterPosition);
                findLastCompletelyVisibleItemPosition = sameBannerInCenterPosition + 1;
            }
            this.mAutoScrolling = true;
            smoothScrollToPosition(findLastCompletelyVisibleItemPosition);
            sendScrollMessage(false);
            return;
        }
        throw new IllegalStateException("LinearLayoutManager has not been found");
    }
}