【中文 README】

Customized recyclerViewAdapter which shows items in a 2-level list.

It encapsulates the expand and fold operation in abstract class BaseExpandableListAdapter,which makes it flexible.

See the usage below , all you need to do is just extending the class and overriding these 6 methods:

• getGroupCount
• getGroupItem
• onCreateGroupViewHolder
• onCreateChildViewHolder
• onBindGroupViewHolder
• onBindChildViewHolder

As onCreateViewHolder & onBindViewHolder are compulsive methods which need developers to override. All your extra work is overriding getGroupCount & getGroupPosition. In most conditions , it is just a one-line-method.

Gradle

dependencies{
    compile 'com.hgDendi:expandable-recyclerview-adapter:1.0.1'
}

Usage

// !!Notice the generics here
public class SampleAdapter extends BaseExpandableRecyclerViewAdapter
<SampleGroupBean, SampleChildBean, SampleAdapter.GroupVH, SampleAdapter.ChildVH>

    @Override
    public int getGroupCount() {
        //return the size of group
    }

    @Override
    public GroupBean getGroupItem(int groupIndex) {
        //return the bean according to the groupIndex
    }

    @Override
    public GroupVH onCreateGroupViewHolder(ViewGroup parent, int groupViewType) {
    }

    @Override
    public ChildVH onCreateChildViewHolder(ViewGroup parent, int childViewType) {
    }

    @Override
    public void onBindGroupViewHolder(GroupVH holder, SampleGroupBean sampleGroupBean, boolean isExpand) {
    }

    @Override
    public void onBindChildViewHolder(ChildVH holder, SampleGroupBean sampleGroupBean, int childIndex) {
    }
}

Relating classes:

class SampleGroupBean implements BaseExpandableRecyclerViewAdapter.BaseGroupBean<SampleChildBean> {
    @Override
    public int getChildCount() {
        return mList.size();
    }

    // whether this group is expandable
    @Override
    public boolean isExpandable() {
        return getChildCount() > 0;
    }

      @Override
    public SampleChildBean getChildAt(int index) {
        return mList.size() <= index ? null : mList.get(index);
    }
}

public class SampleChildBean {
}

static class GroupVH extends BaseExpandableRecyclerViewAdapter.BaseGroupViewHolder {
    GroupVH(View itemView) {
        super(itemView);
    }

    // this method is used for partial update.Which means when expand status changed,only a part of this view need to invalidate
    @Override
    protected void onExpandStatusChanged(RecyclerView.Adapter relatedAdapter, boolean isExpanding) {
    }
}

static class ChildVH extends RecyclerView.ViewHolder {
    ChildVH(View itemView) {
        super(itemView);
        nameTv = (TextView) itemView.findViewById(R.id.child_item_name);
    }
}

ExtraUsage

SetListener

Use Adapter#setListener() to add Callback

public interface ExpandableRecyclerViewOnClickListener<GroupBean extends BaseGroupBean, ChildBean> {
    /**
    * called when group item is long clicked
    *
    * @param groupItem
    * @return
    */
    boolean onGroupLongClicked(GroupBean groupItem);

    /**
    * called when an expandable group item is clicked
    *
    * @param groupItem
    * @param isExpand
    * @return whether intercept the click event
    */
    boolean onInterceptGroupExpandEvent(GroupBean groupItem, boolean isExpand);

    /**
    * called when an unexpandable group item is clicked
    *
    * @param groupItem
    */
    void onGroupClicked(GroupBean groupItem);

    /**
    * called when child is clicked
    *
    * @param groupItem
    * @param childItem
    */
    void onChildClicked(GroupBean groupItem, ChildBean childItem);
}

ShowEmptyView

Show empty view when list is empty.

adapter.setEmptyViewProducer(new ViewProducer() {
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent) {
        View emptyView = LayoutInflater.from(parent.getContext()).inflate(R.layout.empty, parent, false);
        return new DefaultEmptyViewHolder(emptyView);
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder) {
    }
});

VariousGroup&Child

Override getGroupType & getChildType.

Override onCreateViewHolder to generate different ViewHolder.(The same as original RecyclerViewAdapter)

protected int getGroupType(GroupBean groupBean) {
    return 0;
}

abstract public GroupViewHolder onCreateGroupViewHolder(ViewGroup parent, int groupViewType);

protected int getChildType(GroupBean groupBean, ChildBean childBean) {
    return 0;
}

abstract public ChildViewHolder onCreateChildViewHolder(ViewGroup parent, int childViewType);

AddHeaderView

adapter.setEmptyViewProducer(new ViewProducer() {
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent) {
        View emptyView = LayoutInflater.from(parent.getContext()).inflate(R.layout.header, parent, false);
        return new DefaultEmptyViewHolder(emptyView);
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder) {
    }
},false);

License

MIT

https://rem.mit-license.org/