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.
dependencies{
compile 'com.hgDendi:expandable-recyclerview-adapter:1.0.1'
}// !!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);
}
}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);
}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) {
}
});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);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);MIT