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Nested Recycler View, Child And Parent Remove Issue

I have created a Nested recycle rview with parent and child both dynamic.Addition to both Parent and Child is working fine.Deletion from child is working fine.I want to remove parent view when all the child views for the same is removed.Confused about how could i implement the same.
Here is the child Adapter
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
private List<ToDoModel> values;
private Context context;
//private OnEditListener onEditListener;
AlertDialog alertDialog;
/*public MyAdapter(List<ToDoModel> context) {
this.values = context;
this.onEditListener = onEditListener;
}*/
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView txtHeader;
public TextView txtFooter;
public ImageView mIcon;
public View layout;
public ImageView deleteItem;
public CheckBox doneButton;
public ImageView editItem;
public ViewHolder(View v) {
super(v);
layout = v;
txtHeader = (TextView) v.findViewById(R.id.firstLine);
txtFooter = (TextView) v.findViewById(R.id.secondLine);
mIcon = (ImageView) v.findViewById(R.id.icon);
deleteItem = (ImageView) v.findViewById(R.id.deleteButton);
doneButton = (CheckBox) v.findViewById(R.id.checkBox);
editItem = (ImageView) v.findViewById(R.id.editButton);
}
}
public void add(int position, ToDoModel item) {
values.add(position, item);
sort();
notifyDataSetChanged();
//notifyItemInserted(position);
}
public void replace(ToDoModel item)
{
int editPos;
editPos = values.indexOf(item);
values.set(editPos,item);
sort();
notifyDataSetChanged();
}
public void sort() {
if ((int) values.size() > 1) {
Collections.sort(values);
}
}
public void remove(int position) {
values.remove(position);
notifyDataSetChanged();
}
public MyAdapter(List<ToDoModel> myDataset) {
values = myDataset;
}
#Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
LayoutInflater inflater = LayoutInflater.from(
parent.getContext());
View v =
inflater.inflate(R.layout.todo_row_view, parent, false);
ViewHolder vh = new ViewHolder(v);
return vh;
}
#Override
public void onBindViewHolder(ViewHolder holder, final int position) {
final ToDoModel toDoModel = values.get(position);
switch ((String) toDoModel.task) {
case "To Go":
holder.mIcon.setImageResource(R.drawable.ic_explore24px);
break;
case "To Get":
holder.mIcon.setImageResource(R.drawable.ic_shoppingbag24px);
break;
case "To Do":
holder.mIcon.setImageResource(R.drawable.ic_todo);
break;
default:
break;
}
holder.txtHeader.setText(toDoModel.header);
holder.txtFooter.setText(toDoModel.task + " | " + toDoModel.tod + " | " + toDoModel.footer);
holder.doneButton.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if (buttonView.isChecked()) {
//holder.mIcon.setImageResource(R.drawable.ic_check_circle24px);
Toast.makeText(buttonView.getContext(), "Marked As Done", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(buttonView.getContext(), "Marked As UnDone", Toast.LENGTH_SHORT).show();
}
}
});
holder.deleteItem.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
AlertDialog.Builder builder = new AlertDialog.Builder(v.getContext());
View view = LayoutInflater.from(v.getContext()).inflate(R.layout.delete_promptdialog,null);
Button YesButton = (Button) view.findViewById(R.id.buttonYes);
Button NoButton = (Button) view.findViewById(R.id.buttonNo);
YesButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
remove(position);
Toast.makeText(v.getContext(), "List Item Removed", Toast.LENGTH_SHORT).show();
alertDialog.dismiss();
}
});
NoButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(v.getContext(), "Delete Canceled", Toast.LENGTH_SHORT).show();
alertDialog.dismiss();
}
});
builder.setView(view);
alertDialog=builder.create();
alertDialog.show();
/*remove(position);
Toast.makeText(v.getContext(), "List Item Removed", Toast.LENGTH_SHORT).show();*/
}
});
/* holder.editItem.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
onEditListener.onEditClick(values.get(position));
//Toast.makeText(v.getContext(), "List Edit", Toast.LENGTH_SHORT).show();
}
});*/
}
/*public interface OnEditListener {
void onEditClick(ToDoModel currentData);
}*/
#Override
public int getItemCount() {
return values.size();
}
}
Here is the Parent Adapter
public class ParentAdapter extends RecyclerView.Adapter<ParentAdapter.ParentViewHolder> {
private RecyclerView.RecycledViewPool viewPool = new RecyclerView.RecycledViewPool();
public List<TodoParent> parentList;
public TodoParent todayList;
public static long todayEpochDate;
public ParentAdapter(List<TodoParent> parentList, MainFragment mainFragment) {
this.parentList = parentList;
}
public void add(int position, TodoParent item) {
parentList.add(position, item);
sort();
notifyDataSetChanged();
//notifyItemInserted(position);
}
public void sort() {
if ((int) parentList.size() > 1) {
Collections.sort(parentList);
//if(!(todayList.ParentTitle.isEmpty())) Collections.swap(parentList, parentList.indexOf(todayList), 0);
}
/* if ( todayList )
{
System.out.println("Entering Swap");
setToday(todayList);
}*/
}
public void setToday(TodoParent item) {
int todayPos;
todayPos = parentList.indexOf(item);
parentList.remove(todayPos);
notifyDataSetChanged();
parentList.add(0,item);
notifyDataSetChanged();
}
#NonNull
#Override
public ParentAdapter.ParentViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.todo_parent_view,parent,false);
ParentViewHolder vh = new ParentViewHolder(view);
return vh;
}
#RequiresApi(api = Build.VERSION_CODES.N)
#Override
public void onBindViewHolder(#NonNull ParentViewHolder holder, int position) {
TodoParent todoParent = parentList.get(position);
todoParent.ParentId = position;
Calendar mCal;
mCal = Calendar.getInstance();
int mDay = mCal.get(Calendar.DAY_OF_MONTH);
int mMonth = mCal.get(Calendar.MONTH);
int mYear = mCal.get(Calendar.YEAR);
String dateString = mDay +"/"+ (mMonth+1) +"/" + mYear;
try {
todayEpochDate = new SimpleDateFormat("dd/MM/yyyy").parse(dateString).getTime()/1000;
} catch (ParseException e) {
e.printStackTrace();
}
if((long)todayEpochDate == (long)todoParent.EpochTime)
{
holder.mTitle.setText("Today");
todayList = todoParent;
System.out.println("todayE:"+todayEpochDate);
System.out.println("SelectedE:"+todoParent.EpochTime);
}
else
{
holder.mTitle.setText(todoParent.ParentTitle);
System.out.println("today:"+todayEpochDate);
System.out.println("Selected:"+todoParent.EpochTime);
}
LinearLayoutManager layoutManager = new LinearLayoutManager(holder.childView.getContext(),
LinearLayoutManager.VERTICAL,false);
layoutManager.setInitialPrefetchItemCount(todoParent.mChildList.size());
holder.childView.setLayoutManager(layoutManager);
MyAdapter myAdapter = new MyAdapter(todoParent.mChildList);
holder.childView.setAdapter(myAdapter);
holder.childView.setRecycledViewPool(viewPool);
}
#Override
public int getItemCount() {
return parentList.size();
}
public class ParentViewHolder extends RecyclerView.ViewHolder {
public TextView mTitle;
public RecyclerView childView;
public ParentViewHolder(#NonNull View itemView) {
super(itemView);
mTitle = itemView.findViewById(R.id.mParentTitle);
childView = itemView.findViewById(R.id.mChildView);
}
}
}
remove for child is working fine. How to remove Parent here when there are no more child views?

ExpandableRecyclerView - How to expand and collapse multiple CardViews simultaneously

Is it possible to expand and collapse multiple CardViews within a RecyclerView at the same time? I created a header (for my RecyclerView) with two buttons but I'm not sure what needs to go in the click event.
RecyclerView adapter class
public class MyRecyclerAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private static final int TYPE_HEADER = 0;
private static final int TYPE_ITEM = 1;
public boolean isSupposedToBeCollapsed;
private Context mContext;
RecyclerViewHeader header;
List<RecyclerViewItem> listItems;
ValueAnimator mAnimator;
public MyRecyclerAdapter(Context context, RecyclerViewHeader header, List<RecyclerViewItem> listItems)
{
this.mContext = context;
this.header = header;
this.listItems = listItems;
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if(viewType == TYPE_HEADER)
{
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.recyclerview_header, parent, false);
return new MyRecyclerAdapter.VHHeader(v);
}
else if(viewType == TYPE_ITEM)
{
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.recyclerview_item, parent, false);
return new MyRecyclerAdapter.VHItem(v);
}
throw new RuntimeException("there is no type that matches the type " + viewType + " + make sure your using types correctly");
}
private RecyclerViewItem getItem(int position)
{
return listItems.get(position);
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
final Typeface iconFont = FontManager.getTypeface(mContext, FontManager.FONTAWESOME);
if (holder instanceof VHHeader)
{
final VHHeader vhHeader = (VHHeader)holder;
vhHeader.btnExpandAll.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(isSupposedToBeCollapsed){
// change visibility to 'VISIBLE'
txtB.setVisibility(View.VISIBLE);
// change direction of chevron to 'up'
txtExpandCollapse.setText(R.string.fa_icon_chevron_up);
// apply animation to the height of 'txtB'
mAnimator = slideAnimator(0, textBHeight);
// start the animation
mAnimator.start();
}
else{
}
}
});
vhHeader.btnCollapseAll.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(isSupposedToBeCollapsed){
// change visibility to 'VISIBLE'
txtB.setVisibility(View.VISIBLE);
// change direction of chevron to 'up'
txtExpandCollapse.setText(R.string.fa_icon_chevron_up);
// apply animation to the height of 'txtB'
mAnimator = slideAnimator(0, textBHeight);
// start the animation
mAnimator.start();
}
else{
}
}
});
}
else if (holder instanceof VHItem)
{
RecyclerViewItem currentItem = getItem(position-1);
final VHItem vhItem = (VHItem)holder;
vhItem.txtA.setText(currentItem.getTitle());
vhItem.txtB.setText(currentItem.getDescription());
vhItem.txtB.setVisibility(View.GONE);
vhItem.txtExpandCollapse.setText(R.string.fa_icon_chevron_down);
vhItem.txtExpandCollapse.setTypeface(iconFont);
//Add onPreDrawListener
vhItem.txtB.getViewTreeObserver().addOnPreDrawListener(
new ViewTreeObserver.OnPreDrawListener() {
#Override
public boolean onPreDraw() {
vhItem.txtB.getViewTreeObserver().removeOnPreDrawListener(this);
vhItem.txtB.setVisibility(View.GONE);
final int widthSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
final int heightSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
vhItem.txtB.measure(widthSpec, heightSpec);
vhItem.textBHeight = vhItem.txtB.getMeasuredHeight();
return true;
}
});
vhItem.cardView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(vhItem.txtB.getVisibility() == View.GONE){
vhItem.expand();
} else {
vhItem.collapse();
}
}
});
vhItem.mLinearLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(vhItem.txtB.getVisibility() == View.GONE){
vhItem.expand();
} else {
vhItem.collapse();
}
}
});
vhItem.txtExpandCollapse.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(vhItem.txtB.getVisibility() == View.GONE){
vhItem.expand();
} else {
vhItem.collapse();
}
}
});
}
}
// need to override this method
#Override
public int getItemViewType(int position) {
if(isPositionHeader(position))
return TYPE_HEADER;
return TYPE_ITEM;
}
private boolean isPositionHeader(int position)
{
return position == 0;
}
// increasing getItemcount to 1. This will be the row of header.
#Override
public int getItemCount() {
return listItems.size()+1;
}
class VHHeader extends RecyclerView.ViewHolder{
Button btnCollapseAll, btnExpandAll;
public VHHeader(View headerView) {
super(headerView);
this.btnCollapseAll = headerView.findViewById(R.id.btn_collapseall);
this.btnExpandAll = headerView.findViewById(R.id.btn_expandall);
}
}
public class VHItem extends RecyclerView.ViewHolder{
CardView cardView;
LinearLayout mLinearLayout;
RecyclerView mRecyclerView;
RelativeLayout mRelativeLayout;
TextView txtExpandCollapse, txtA, txtB;
public int textBHeight;
public VHItem(View itemView) {
super(itemView);
this.cardView = itemView.findViewById(R.id.cv);
this.mLinearLayout = itemView.findViewById(R.id.cardview_tconnections_titlerow);
this.mRelativeLayout = itemView.findViewById(R.id.my_relativelayout);
this.mRecyclerView = itemView.findViewById(R.id.my_recyclerview);
this.txtExpandCollapse = itemView.findViewById(R.id.tv_expandcollapse);
this.txtA = itemView.findViewById(R.id.tv_A);
this.txtB = itemView.findViewById(R.id.tv_B);
}
private void expand() {
// change visibility to 'VISIBLE'
txtB.setVisibility(View.VISIBLE);
// change direction of chevron to 'up'
txtExpandCollapse.setText(R.string.fa_icon_chevron_up);
// apply animation to the height of 'txtB'
mAnimator = slideAnimator(0, textBHeight);
// start the animation
mAnimator.start();
}
private void collapse() {
// change direction of chevron to 'down'
txtExpandCollapse.setText(R.string.fa_icon_chevron_down);
int finalHeight = txtB.getHeight();
ValueAnimator mAnimator = slideAnimator(finalHeight, 0);
mAnimator.addListener(new Animator.AnimatorListener() {
#Override
public void onAnimationEnd(Animator animator) {
txtB.setVisibility(View.GONE);
}
#Override
public void onAnimationStart(Animator animator) {
}
#Override
public void onAnimationCancel(Animator animator) {
}
#Override
public void onAnimationRepeat(Animator animator) {
}
});
mAnimator.start();
}
public ValueAnimator slideAnimator(int start, int end) {
ValueAnimator animator = ValueAnimator.ofInt(start, end);
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
#Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
// update height
int value = (Integer) valueAnimator.getAnimatedValue();
ViewGroup.LayoutParams layoutParams = txtB.getLayoutParams();
layoutParams.height = value;
txtB.setLayoutParams(layoutParams);
}
});
return animator;
}
}
}
Fragment class
public class MyFragment extends android.support.v4.app.Fragment {
private MyRecyclerAdapter adapter;
public MyFragment() {}
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_rv, container, false);
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
View v = getView();
assert v != null;
recyclerView = v.findViewById(R.id.my_recyclerview);
linearLayoutManager = new LinearLayoutManager(getActivity());
MyRecyclerAdapter adapter = new MyRecyclerAdapter(getContext(), getHeader(), getListItems());
recyclerView.setLayoutManager(linearLayoutManager);
recyclerView.setAdapter(adapter);
super.onActivityCreated(savedInstanceState);
}
RecyclerView recyclerView;
LinearLayoutManager linearLayoutManager;
public RecyclerViewHeader getHeader()
{
return new RecyclerViewHeader();
}
public List<RecyclerViewItem> getListItems()
{
List<RecyclerViewItem> rvItems = new ArrayList<>();
RecyclerViewItem itemA = new RecyclerViewItem();
itemA.setConnectionMode("Item A");
itemA.setConnectionName("Feature A1");
rvItems.add(itemA);
RecyclerViewItem itemB = new RecyclerViewItem();
itemB.setConnectionMode("Item B");
itemB.setConnectionName("Feature B1\nFeature B2");
rvItems.add(itemB);
RecyclerViewItem itemC = new RecyclerViewItem();
itemC.setConnectionMode("Item C");
itemC.setConnectionName("Feature C1\nFeature C2\nFeature C3");
rvItems.add(itemC);
return rvItems;
}
}

What you can do is, set a variable(boolean) that stores the state of the card (expanded/collapsed) in the RecyclerAdapter code.
Then, in your onBindViewHolder code block, write a piece of code to check if the card should be expanded or collapsed using the above-mentioned variable and the required display code.
Example:
if(isSuppossedToBeCollapsed){
textView.setVisibility = false;
}
else{
textView.setVisibility = true;
}
You can then call notifyDatasetChanged in your RecyclerAdapter code to update the recycler views when you click the button which will redraw the views and reflect the state of the cards(expanded/collapsed) accordingly.
NotifyDatasetChanged Documentation

How to update Datamodel in RecyclerviewAdapter

i created a recyclerview where i can see all my chats. Every item contains the name, the lastmessage and a thumb. if the user send or receive a new message, it should be displayed there and the item should go to position 0. Now i have the problem that the message is displayed, but the chat item goes only to the first position if the position was not 0 before. So if i receive two new messages its not working anymore because the data model is the same like before. So how can i fit my data model to the current position of every item. Currently my adapter looks like this:
private static final String TAG = "CustomAdapter";
private Context context;
private Activity mActivity;
private List<MatchesObject> matchesList;
private String currentUid;
public matchadapterino(Activity mActivity, ArrayList<MatchesObject> mDataSet) {
this.mActivity = mActivity;
this.matchesList = mDataSet;
}
// Create new views (invoked by the layout manager)
#Override
public matchadapterino.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
// Create a new view.
View v = LayoutInflater.from(viewGroup.getContext())
.inflate(R.layout.matchesitem, viewGroup, false);
return new matchadapterino.ViewHolder(v);
}
// Replace the contents of a view (invoked by the layout manager)
#Override
public void onBindViewHolder(final matchadapterino.ViewHolder viewHolder, final int position) {
viewHolder.getMatchname().setText(matchesList.get(position).getUsername());
if (!matchesList.get(position).getProfileImageUrl().equals("default")) {
Picasso.with(mActivity).load(matchesList.get(position).getProfileImageUrl()).into(viewHolder.getMatchImage());
getLastMSG(matchesList.get(position).getUserId(), viewHolder.getLastMSG(), position);
viewHolder.getMatchImage().setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(mActivity, UserDetailView.class);
//
i.putExtra("userId", matchesList.get(position).getUserId());
mActivity.startActivity(i);
}
});
} else {
viewHolder.getMatchImage().setImageResource(R.mipmap.ic_launcher_round);
}
viewHolder.getForeground().setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(mActivity, Chat.class);
Bundle b = new Bundle();
b.putString("matchId", matchesList.get(position).getUserId());
i.putExtras(b);
mActivity.startActivity(i);
}
});
}
#Override
public int getItemCount() {
return matchesList.size();
}
// Get element from your dataset at this position and replace the contents of the view
// with that element
public void removeItem(int position) {
matchesList.remove(matchesList.get(position));
notifyItemRemoved(position);
}
// Return the size of your dataset (invoked by the layout manager)
/**
* Provide a reference to the type of views that you are using (custom ViewHolder)
*/
public class ViewHolder extends RecyclerView.ViewHolder {
public TextView matchname, lastMSG;
public ImageView matchImage;
private RelativeLayout foreground;
private RelativeLayout background;
public ViewHolder(View v) {
super(v);
currentUid = FirebaseAuth.getInstance().getCurrentUser().getUid();
matchname = itemView.findViewById(R.id.matchname);
matchImage = itemView.findViewById(R.id.matchImages);
lastMSG = itemView.findViewById(R.id.lastmsg);
foreground = itemView.findViewById(R.id.foregroundmatch);
background = itemView.findViewById(R.id.backgroundmatch);
}
public RelativeLayout getForeground() {
return foreground;
}
public RelativeLayout getBackground() {
return background;
}
public TextView getLastMSG() {
return lastMSG;
}
public TextView getMatchname() {
return matchname;
}
public ImageView getMatchImage() {
return matchImage;
}
}
private void getLastMSG(final String userId, final TextView lastMSG, final int position) {
final String userid = FirebaseAuth.getInstance().getCurrentUser().getUid();
DatabaseReference ref = FirebaseDatabase.getInstance().getReference().child("Users").child(userid).child("connections").child("matches").child(userId);
ref.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
if (dataSnapshot.exists()) {
notifyItemMoved(0, position);
Toast.makeText(mActivity, "position changed" + position, Toast.LENGTH_LONG).show();
if (dataSnapshot.child("lastMsgBy").getValue().toString().equals(userid)) {
lastMSG.setTextColor(Color.parseColor("#d2403a3a"));
String lastMsg = dataSnapshot.child("lastMsg").getValue().toString();
lastMSG.setText(lastMsg);
} else {
lastMSG.setTextColor(Color.parseColor("#000000"));
String lastMsg = dataSnapshot.child("lastMsg").getValue().toString();
lastMSG.setText(lastMsg);
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
}

Add item on RecycleView Android

I'm trying to add an item on RecycleView like this:
I have an object called Image
public class Image{
public String name;
public String url;
}
When I click on the button to add a new item, my code is like this:
#Override
public void addItemOnList(String url) {
adapter.addItem(new ImageObject("aaaaaa", R.drawable.close_button));
}
That is my method which inserts on the list.
public void addItem(ImageObject imageObject) {
itemList.add(imageObject);
notifyDataSetChanged();
}
My problem is when I click for the first time in additem my onBindViewHolder doesn't iterate all the list but when I check in debug mod my getItemCount is correct! So If I try to add an item after the first time all work well.
MainActivity
public class MainActivity extends AppCompatActivity implements RecyclerViewClickListener, OnStartDragListener {
private RecyclerViewAdapter adapter;
private ArrayList<ImageObject> listViewItems;
private RecyclerView recyclerView;
private ItemTouchHelper itemTouchHelper;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
recyclerView.setHasFixedSize(true);
StaggeredGridLayoutManager staggeredLayoutManager = new StaggeredGridLayoutManager(3, 1);
recyclerView.setLayoutManager(staggeredLayoutManager);
List<ImageObject> staggered = getListItemData();
adapter = new RecyclerViewAdapter(this, staggered);
recyclerView.setAdapter(adapter);
ItemTouchHelper.Callback callback = new SimpleItemTouchHelperCallback(adapter);
itemTouchHelper = new ItemTouchHelper(callback);
itemTouchHelper.attachToRecyclerView(recyclerView);
}
private List<ImageObject> getListItemData() {
listViewItems = new ArrayList<ImageObject>();
listViewItems.add(new ImageObject("Alkane", R.drawable.one));
listViewItems.add(new ImageObject("Ethane", R.drawable.two));
listViewItems.add(new ImageObject("Alkyne", R.drawable.three));
listViewItems.add(new ImageObject("Benzene", R.drawable.four));
listViewItems.add(new ImageObject("Alkane", R.drawable.one));
listViewItems.add(new ImageObject("Ethane", R.drawable.two));
listViewItems.add(new ImageObject("Alkyne", R.drawable.three));
listViewItems.add(new ImageObject("Benzene", R.drawable.four));
listViewItems.add(new ImageObject("Alkane", R.drawable.one));
listViewItems.add(new ImageObject("Ethane", R.drawable.two));
listViewItems.add(new ImageObject("Alkyne", R.drawable.three));
listViewItems.add(new ImageObject("Benzene", R.drawable.four));
return listViewItems;
}
#Override
public void addButtonClicked() {
FragmentManager fm = getSupportFragmentManager();
AlertFragment.newInstance(this).show(fm, "dialog");
}
#Override
public void addItemOnList(String url) {
adapter.addItem(new ImageObject("aaaaaa", R.drawable.close_button));
}
#Override
public void onStartDrag(RecyclerView.ViewHolder viewHolder) {
itemTouchHelper.startDrag(viewHolder);
}
}
My Adapter
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolders> implements ItemTouchHelperAdapter {
private List<ImageObject> itemList;
private MainActivity mainActivity;
private RecyclerViewClickListener recycleListener;
private OnStartDragListener dragStartListener;
public RecyclerViewAdapter(MainActivity mainActivity, List<ImageObject> itemList) {
this.itemList = itemList;
this.mainActivity = mainActivity;
this.recycleListener = mainActivity;
this.dragStartListener = mainActivity;
}
#Override
public ViewHolders onCreateViewHolder(ViewGroup parent, int viewType) {
View layoutView;
switch (viewType) {
case 1:
layoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.add_item_list, null);
break;
default:
layoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_list, null);
break;
}
return new ViewHolders(layoutView);
}
#Override
public void onBindViewHolder(final ViewHolders holder, final int position) {
switch (holder.getItemViewType()) {
case 1:
configureViewHolderAddItem(holder, position);
break;
case 0:
configureDefaultViewHolder(holder, position);
break;
}
}
private void configureViewHolderAddItem(final ViewHolders holder, final int position) {
holder.addItemLayout = holder.itemView.findViewById(R.id.add_item_layout);
holder.addItemLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
recycleListener.addButtonClicked();
}
});
}
private void configureDefaultViewHolder(final ViewHolders holder, final int position) {
Log.e("test", "position - " + position);
Log.e("test", "name - " + itemList.get(position).getName());
holder.itemLayout = holder.itemView.findViewById(R.id.main_layout);
holder.removeItemButton = holder.itemView.findViewById(R.id.remove_item_button);
holder.itemLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
itemList.remove(holder.getLayoutPosition());
notifyItemRemoved(holder.getLayoutPosition());
notifyItemRangeChanged(holder.getLayoutPosition(), itemList.size());
}
});
holder.itemLayout.setBackgroundResource(itemList.get(position).getPhoto());
holder.itemLayout.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
dragStartListener.onStartDrag(holder);
}
return false;
}
});
//resizeTheFirstPosition(holder, position);
}
private void resizeTheFirstPosition(ViewHolders holder, int position) {
if (position == 0) {
int dimensionInDp = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
200, mainActivity.getResources().getDisplayMetrics());
holder.itemLayout.getLayoutParams().height = dimensionInDp;
holder.itemLayout.getLayoutParams().width = dimensionInDp;
holder.itemLayout.requestLayout();
}
}
public void addItem(ImageObject imageObject) {
itemList.add(imageObject);
notifyDataSetChanged();
}
#Override
public int getItemViewType(int position) {
return position == itemList.size() - 1 ? 1 : 0;
}
#Override
public int getItemCount() {
return this.itemList.size();
}
#Override
public boolean onItemMove(int fromPosition, int toPosition) {
Collections.swap(itemList, fromPosition, toPosition);
notifyItemMoved(fromPosition, toPosition);
return true;
}
#Override
public void onItemDismiss(int position) {
itemList.remove(position);
notifyItemRemoved(position);
}
public class ViewHolders extends RecyclerView.ViewHolder implements View.OnClickListener,
ItemTouchHelperViewHolder {
private ImageView removeItemButton;
private ImageView addItemButton;
private FrameLayout addItemLayout;
private RelativeLayout itemLayout;
public ViewHolders(View itemView) {
super(itemView);
}
#Override
public void onClick(View view) {
itemList.remove(getLayoutPosition());
//notifyItemRemoved(getLayoutPosition());
notifyItemRangeChanged(getLayoutPosition(), itemList.size());
Toast.makeText(mainActivity, "Removed item- " + getLayoutPosition(), Toast.LENGTH_SHORT).show();
}
#Override
public void onItemSelected() {
itemView.setBackgroundColor(Color.LTGRAY);
}
#Override
public void onItemClear() {
itemView.setBackgroundColor(0);
}
}

Finally, I fixed this. I don't know why but I change how I insert on the list
Old code:
public void addItem(ImageObject imageObject) {
itemList.add(imageObject);
notifyDataSetChanged();
}
New code:
public void addItem(ImageObject imageObject) {
itemList.add(itemList.size() - 1, imageObject);
notifyDataSetChanged();
}

notifydatasetchanged() not working after onbackpressed()

My recyclerview is not updating correctly after the back button is
pressed.
The recyclerview works fine before the back button is pressed
The data is properly updated (seen in the log) but the recyclerview does not reflect the change
The purpose of the handler is to poll the database for a notification (working fine)
The notification toast is displayed everytime
I am not receiving any errors
If I can provide any other information to help do not hesitate to ask.
Main:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_chat_room);
recView = (RecyclerView) findViewById(R.id.recyclerViewMessages);
linearLayoutManager = new LinearLayoutManager(this) {};
linearLayoutManager.setReverseLayout(true);
recView.setLayoutManager(linearLayoutManager);
listData = (ArrayList) MessagingData.getMessageListData();
adapter = new RecyclerViewAdapterMessaging(listData, this);
recView.setAdapter(adapter);
adapter.setItemClickCallback(this);
final Handler h = new Handler();
final int delay = 2000; //milliseconds
h.postDelayed(new Runnable(){
public void run(){
Notify_Message_Async notify_message_async = new Notify_Message_Async(ctx);
notify_message_async.execute(NOTIFICATION, message_id);
System.out.println(global.getNotification());
if(global.getNotification()==1){
Toast.makeText(ctx, "Notified",
Toast.LENGTH_LONG).show();
try {
refresh_receive();
} catch (ExecutionException e) {
Toast.makeText(ctx, "catch",
Toast.LENGTH_LONG).show();
e.printStackTrace();
} catch (InterruptedException e) {
Toast.makeText(ctx, "catch",
Toast.LENGTH_LONG).show();
e.printStackTrace();
}
}
h.postDelayed(this, delay);
}
}, delay);
}
public void refresh_receive() throws ExecutionException, InterruptedException {
String method = "receive_message";
Receive_Live_Message_Async receive_live_message_async = new Receive_Live_Message_Async(this);
receive_live_message_async.execute(method, message_id).get();// Setup the message
adapter.setListData((ArrayList)MessagingData.getMessageListData());
adapter.notifyDataSetChanged();
global.setNotification(0);//reset notification
}
Adapter:
public class RecyclerViewAdapterMessaging extends RecyclerView.Adapter<RecyclerViewAdapterMessaging.Holder> {
private View v;
private List<List_Item_Messaging> listData;
private LayoutInflater inflater;
Global global = new Global();
private ItemClickCallback itemClickCallback;
Context context;
public interface ItemClickCallback {
void onItemClick(View v, int p);
void onSecondaryIconClick(int p);
}
public void setItemClickCallback(final ItemClickCallback itemClickCallback) {
this.itemClickCallback = itemClickCallback;
}
public RecyclerViewAdapterMessaging(List<List_Item_Messaging> listData, Context c) {
inflater = LayoutInflater.from(c);
context = c;
this.listData = listData;
}
#Override
public int getItemViewType(int position) {//0 for self... /1 for Other
List_Item_Messaging item = listData.get(position);
//ENSURE GLOBAL USERNAME NOT NULL
String other_username = item.getMessage_username();
if (other_username == null) {
((Activity) context).finish();
}
if (item.getMessage_username().trim().equals(global.getUserName())) {
System.out.println("The usernames are the same");
return 0;
} else {
System.out.println("The usernames are the NOT same");
return 1;
}
}
#Override
public Holder onCreateViewHolder(ViewGroup parent, int viewType) {
switch (viewType) {
case 0:
View view = inflater.inflate(R.layout.chat_thread, parent, false);// Self
v = view;
break;
case 1:
View view2 = inflater.inflate(R.layout.chat_thread_other, parent, false);// Not self
int width2 = global.getScreenWidth();
v = view2;
break;
}
return new Holder(v);
}
#Override
public void onBindViewHolder(Holder holder, int position) {
List_Item_Messaging item = listData.get(position);
holder.conversation.setText(item.getMessage_conversation());
}
public void setListData(ArrayList<List_Item_Messaging> exerciseList) {
this.listData.clear();
this.listData.addAll(exerciseList);
}
#Override
public int getItemCount() {
return listData.size();
}
class Holder extends RecyclerView.ViewHolder implements View.OnClickListener {
ImageView thumbnail;
//ImageView secondaryIcon;
TextView conversation;
View message_container;
public Holder(View itemView) {
super(itemView);
conversation = (TextView) itemView.findViewById(R.id.conversation_textview);
message_container = itemView.findViewById(R.id.message_container);
message_container.setOnClickListener(this);
}
#Override
public void onClick(View v) {
if (v.getId() == R.id.message_container) {
itemClickCallback.onItemClick(v, getAdapterPosition());
} else {
itemClickCallback.onSecondaryIconClick(getAdapterPosition());
}
}
}
public void clearItems() {
listData.clear();
this.notifyDataSetChanged();
}
}
I have referenced the following to no solution:
notifyDataSetChanged not working on RecyclerView
smoothScrollToPosition after notifyDataSetChanged not working in android
adapter.notifyDataSetChange() not working after called from onResume()

change a little in your code
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_chat_room);
recView = (RecyclerView) findViewById(R.id.recyclerViewMessages);
linearLayoutManager = new LinearLayoutManager(this) {};
linearLayoutManager.setReverseLayout(true);
recView.setLayoutManager(linearLayoutManager);
// change here
if (listData != null)
listData.clear();
else listData = new <> ArrayList();
listData.addAdd((ArrayList)MessagingData.getMessageListData());
adapter = new RecyclerViewAdapterMessaging(listData, this);
recView.setAdapter(adapter);
adapter.setItemClickCallback(this);
final Handler h = new Handler();
final int delay = 2000; //milliseconds
then make a small change here
public void refresh_receive() throws ExecutionException, InterruptedException {
String method = "receive_message";
Receive_Live_Message_Async receive_live_message_async = new Receive_Live_Message_Async(this);
receive_live_message_async.execute(method, message_id).get();// Setup the message
// changing here
dataList.clear();
dataList.addAdd((ArrayList)MessagingData.getMessageListData())
adapter.setListData(dataList);
adapter.notifyDataSetChanged();
global.setNotification(0);//reset notification
}
another problem in your code, you are using receive_live_message_async AsyncTask
put your update code in onPostExecute
public class receive_live_message_async extends AsyncTask {
#Override
protected Object doInBackground(Object[] objects) {
return null;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected void onPostExecute(Object o) {
// call your refresh_receive(); here
super.onPostExecute(o);
}
}
similarly when you are call receive_live_message_async.execute(); update your recyclerView in onPostExecute
#Override
protected void onPostExecute(Object o) {
dataList.clear();
dataList.addAll((ArrayList)MessagingData.getMessageListData());
adapter.notifyDataSetChanged();
super.onPostExecute(o);
}