Android Studio RecyclerView Adapter loop getItemViewType() - android-studio

Question

My recyclerview's adapter continuously calls getItemViewType() and seems to be no sign to stop.
I also print log in onBindViewHolder(), onCreateViewHolder(), and viewHolder's bind function, but only getItemViewType get called infinitely.
How can I solve this problem?
My Fragment:
I added log in each function, and didn't see any function be called continuously.
public class Fragment{
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (presenter == null) {
presenter = new Presenter(this);
}
initViewModel();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
setRecyclerView();
//this will modify adapter
loadData();
return rootView;
}
void initViewModel(){
messageViewModel = new ViewModelProvider(this).get(messageViewModel.class);
final Observer<ArrayList<WallPost>> wallPostObserver = wallPostList -> {
//this will modify adapter
updateRecyclerView(wallPostList);
};
messageViewModel.getWallPostsLiveData().observe(this, wallPostObserver);
}
public void setRecyclerView() {
layoutManager = new LinearLayoutManager(getContext());
recyclerView.setLayoutManager(layoutManager);
adapter = new Adapter(getContext(), new ArrayList<>(), Repository.getInstance().getMemberData().getValue(), getType());
recyclerView.setAdapter(adapter);
recyclerView.addOnScrollListener(scrollListener);
}
}
My Adapter getItemViewType(int position) function:
Adapter getItemCount() be called continuously same as getItemViewType(int position).
#Override
public int getItemViewType(int position) {
if (wallPostList.size() == 0) {
return VIEW1;
}else if(position >= wallPostList.size()){
return VIEW7;
}
WallPost wallPost = wallPostList.get(position);
Log.d("Adapter","position:"+position);
if(wallPost.getStatus().equals(POST_STATUS_REVOKE)){
return VIEW8;
}
switch (wallPost.getType()) {
case azz:
return VIEW5;
case axx:
return VIEW6;
case ayy:
default:
if(wallPost.getMsgItemList().size() > 0){
return VIEW4;
}else if(StringUtils.checkHasLink(wallPost.getContent())){
return VIEW3;
}else {
return VIEW2;
}
}
}
Update: cause problem's code
I found the problem cause this, I solve this problem by add a flag in my customize view to restrict not repeat onMeansure, but I don't know why this will make adapter repeat call getItemViewType(int position) and getItemCount().
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if(type.equals(SINGLE)){
info.post(()->{
halfWidth = (info.getMeasuredWidth()- arrowImageView.getMeasuredWidth())/2;
name.setMaxWidth(halfWidth-image.getMeasuredWidth());
tvNoticeTime.setMaxWidth(halfWidth-image.getMeasuredWidth());
});
}
else if(type.equals(MULTI)){
info.post(()->{
name.setMaxWidth(info.getMeasuredWidth()-image.getMeasuredWidth() - (int)PixelUtil.convertDpToPixel(8,context));
});
}
else{
int dis = (int)PixelUtil.convertDpToPixel(8,context);
info.post(()->{
name.setMaxWidth(info.getMeasuredWidth()-image.getMeasuredWidth()-dis-
infoImageView.getMeasuredWidth()-dis);
});
}
}

Answer 1

The problem you are facing is that you update your RecyclerView based on the wallPostObserver that looks for changes in the wallPostList. There could be a problem regaring this because if the List changes there is a chnage in the recycler View and the getItemViewType method is called. If you made it so that the recyclerView is only updated once the user chooes to or in fix intervals you wouldn't have the problem. You could fix that by creating a Method that triggers if the List changes (without using an Observer) there you could define the max update interval and make is so that you dont always throw away your entire list.