【improve】 support head、footView

[xiaobaDev]

add custom headView、footView

public class HeadFootRecyclerAdapter<T> extends EfficientRecyclerAdapter<T> {
    private static final int HEAD_VIEW_TYPE = 3300;
    private static final int FOOT_VIEW_TYPE = HEAD_VIEW_TYPE + 1;

    private View mHeadView;
    private View mFootView;

    public HeadFootRecyclerAdapter(List<T> objects) {
        super(objects);
    }

    public HeadFootRecyclerAdapter(int layoutResId, Class<? extends EfficientViewHolder<? extends T>> viewHolderClass, List<T> objects) {
        super(layoutResId, viewHolderClass, objects);
    }

    public void setHeadView(View headView) {
        mHeadView = headView;
        notifyDataSetChanged();
    }

    public void setFootView(View footView) {
        mFootView = footView;
        notifyDataSetChanged();
    }

    public boolean hasHeadView() {
        return mHeadView != null;
    }

    public boolean hasFootView() {
        return mFootView != null;
    }

    public void removeHeadView() {
        if (!hasHeadView()) return;

        mHeadView = null;
        notifyDataSetChanged();
    }

    public void removeFootView() {
        if (!hasFootView()) return;

        mFootView = null;
        notifyDataSetChanged();
    }

    @Override
    public int getItemCount() {
        int count = super.getItemCount();

        if (mHeadView != null)
            count++;

        if (mFootView != null)
            count++;

        return count;
    }

    public int getRealCount() {
        return super.getItemCount();
    }

    public int getRealPosition(int position) {
        if (mHeadView != null) {
            position--;
        }

        return position;
    }

    @Override
    public int getItemViewType(int position) {
        if (mHeadView != null && position == 0) {
            return HEAD_VIEW_TYPE;
        }

        if (mFootView != null && position == getItemCount() - 1) {
            return FOOT_VIEW_TYPE;
        }

        return super.getItemViewType(position);
    }

    @Override
    public EfficientViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        if (viewType == HEAD_VIEW_TYPE && mHeadView != null) {
            return new EfficientViewHolder(mHeadView) {
                @Override
                protected void updateView(Context context, Object object) {

                }
            };
        }

        if (viewType == FOOT_VIEW_TYPE && mFootView != null) {
            return new EfficientViewHolder(mFootView) {
                @Override
                protected void updateView(Context context, Object object) {

                }
            };
        }

        return super.onCreateViewHolder(parent, viewType);
    }

    @Override
    public void onBindViewHolder(EfficientViewHolder viewHolder, int position) {
        int viewType = getItemViewType(position);

        if (viewType == HEAD_VIEW_TYPE || viewType == FOOT_VIEW_TYPE) return;


        position = getRealPosition(position);
        super.onBindViewHolder(viewHolder, position);
    }
}