Develop Reference

Android studio RecyclerView onCreateViewHolder layout inflation is so slow

I have a root recyclerview and each item is populated with this layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
>
<TextView
android:id="#+id/headerText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#drawable/accent_gradient"
android:ellipsize="end"
android:maxLines="1"
android:padding="8dp"
android:paddingStart="16dp"
android:text="My original"
android:textColor="#color/colorWhite"
android:textSize="14sp" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rootRecycler"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
/>
</LinearLayout>
As you can see, there is another recylcerview within each item. I wanted to achieve the effect of sectioned recyclerview with headers. (So Header > List Header > List)
Now each recyclerview is populated with this layout view:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content"
>
<TextView
android:layout_toStartOf="#id/relativeLayout3"
android:layout_marginStart="16dp"
android:layout_marginEnd="16dp"
android:id="#+id/foodName_fv"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="8dp"
android:text="Food name"
android:ellipsize="end"
android:maxLines="1"
android:textColor="#color/colorBlack"
android:textSize="18sp"
android:transitionName="Food_Name"/>
<TextView
android:layout_below="#id/foodName_fv"
android:layout_marginStart="16dp"
android:layout_marginEnd="16dp"
android:id="#+id/foodGrams_fv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingTop="8dp"
android:paddingBottom="8dp"
android:text="Grams"
android:textColor="#color/colorLightGrey"
android:textSize="15sp" />
<LinearLayout
android:id="#+id/relativeLayout3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="16dp"
android:orientation="vertical"
android:layout_alignParentEnd="true"
>
<TextView
android:id="#+id/foodCalories_fv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
android:text="Calories"
android:textColor="#color/colorBlack"
android:textSize="18sp"
android:transitionName="Food_Cal"/>
<TextView
android:layout_gravity="center"
android:id="#+id/calText_fv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
android:paddingBottom="8dp"
android:text="#string/calText_fv"
android:textColor="#color/colorLightGrey"
android:textSize="14sp" />
</LinearLayout>
</RelativeLayout>
This is a fairly simple layout but for some odd reason the child recyclerview takes soo much time to inflate these rows. I did some testings and it took (on average) 1200 ms to load 300 rows!
Now the weirdest thing is that before this code i had a plain listview (without any sections and headers, just a big list) and it loaded all these rows very fast. I have'nt changed nothing but this code (Converting it from listview with an adapter to recyclerview with an adapter) so it looks pretty strange to me, but i dont know i might be missing something here.
This is the onCreateViewHolder method:
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.food_view, parent, false);
return new ViewHolder(view);
}
In conclusion the child recyclerview takes too much time to do this work. And yes I am aware i can do "Lazy loading" but I want to figure out why the hell is it so slow?
EDIT 1:
Tried implementing it in a fresh new project, thought something with the broke somehow, but its still gave same results, also tried on my actual phone and not an emulator and still slow. I really want to figure out this one already because it seems very illogical.
EDIT 2:
Posting the adapters code for hamza khan:
Code for the root recyclerview:
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import java.util.ArrayList;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
public class SelectFoodRootRecyclerAdapter extends RecyclerView.Adapter<SelectFoodRootRecyclerAdapter.ViewHolder> {
private static final String TAG = "SelectFoodRootRecyclerAdapter";
private Context mContext;
private ArrayList<SectionedFoodGroup> items;
private ArrayList<SelectFoodChildRecyclerAdapter> adapters; //For filter use outside this class
RecyclerView.RecycledViewPool recycledViewPool;
public SelectFoodRootRecyclerAdapter(Context mContext) {
this.mContext = mContext;
items = new ArrayList<>();
adapters = new ArrayList<>();
recycledViewPool = new RecyclerView.RecycledViewPool();
SectionedFoodGroup section1 = new SectionedFoodGroup(mContext.getString(R.string.myFoods),
FoodsDBHelper.getAllFoodRows(Food.DBType.USER_CREATED_FOODS_DB.ordinal()));
SectionedFoodGroup section2 = new SectionedFoodGroup(mContext.getString(R.string.foods),
FoodsDBHelper.getAllFoodRows(Food.DBType.REGULAR_FOOD_DB.ordinal()));
addSection(section1);
addSection(section2);
}
private void addSection(SectionedFoodGroup sectionedFoodGroup){
if(sectionedFoodGroup.getFoods().size() > 0){
items.add(sectionedFoodGroup);
adapters.add(new SelectFoodChildRecyclerAdapter(mContext, sectionedFoodGroup.getFoods()));
}
}
public ArrayList<SelectFoodChildRecyclerAdapter> getAdapters(){
return adapters;
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_sfa_viewholder, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull ViewHolder holder, int position) {
SectionedFoodGroup sectionedFoodGroup = items.get(position);
holder.headerText.setText(sectionedFoodGroup.getHeaderName());
holder.foodsRecycler.setAdapter(adapters.get(position));
holder.foodsRecycler.setRecycledViewPool(recycledViewPool);
}
#Override
public int getItemCount() {
return items != null ? items.size() : 0;
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextView headerText;
RecyclerView foodsRecycler;
public ViewHolder(#NonNull View itemView) {
super(itemView);
headerText = itemView.findViewById(R.id.headerText);
foodsRecycler = itemView.findViewById(R.id.rootRecycler);
}
}
}
Code for the child recyclerview (the one containing all the actual rows):
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.TextView;
import java.text.DecimalFormat;
import java.util.ArrayList;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
public class SelectFoodChildRecyclerAdapter extends RecyclerView.Adapter<SelectFoodChildRecyclerAdapter.ViewHolder>{
private static final String TAG = "SelectFoodChildRecyclerAdapter";
private Context mContext;
private ArrayList<Food> original;
private DecimalFormat decimalFormat;
public SelectFoodChildRecyclerAdapter(Context mContext, ArrayList<Food> foods) {
this.mContext = mContext;
this.original = foods;
decimalFormat = new DecimalFormat("#.0");
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.food_view, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull ViewHolder holder, int foodPos) {
Food currFood = original.get(foodPos);
holder.foodName.setText(currFood.getName());
float grams = 100;
if(currFood.getAmount() != 0) grams = (float)currFood.getAmount();
int roundedGrams = (int)Math.round(grams);
holder.foodGrams.setText(roundedGrams +" "+ mContext.getResources().getString(R.string.gramsWord));
float caloriesToShow = (float)currFood.getCalories();
holder.foodCalories.setText(decimalFormat.format(caloriesToShow));
}
#Override
public int getItemCount() {
return original != null ? original.size() : 0;
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextView foodName;
TextView foodGrams;
TextView foodCalories;
public ViewHolder(View itemView) {
super(itemView);
foodName = itemView.findViewById(R.id.foodName_fv);
foodGrams = itemView.findViewById(R.id.foodGrams_fv);
foodCalories = itemView.findViewById(R.id.foodCalories_fv);
}
}
}
The calling activity onCreate method:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_select_food);
foodsRecyclerView = findViewById(R.id.rootRecycler);
selectFoodRootRecyclerAdapter = new SelectFoodRootRecyclerAdapter(this);
foodsRecyclerView.setAdapter(selectFoodRootRecyclerAdapter);
}
Again, as you can see all the code is fairly simple..
EDIT 3:
Ok so i've narrowed it down even more. I tried to do just one big recyclerview of the second layout and it worked fast. SOOO the problem must be with the first layout/the root recyclerview adapter code. but everything seems fine with it...
I really don't know what am I missing here!! Thanks for any kind of help!
Thanks!

Well, because no one was able to answer my question and I've found my answer then ill share it with other people who might look at this in the future and think, wow this is exactly what I need.
So.. It turns out using a RecyclerView within RecyclerView is a big no no. thats because the onCreateViewHolder method gets called as many times as your items array size, and thats very heavy, especially if you have a large list. (I think its the same as RecyclerView within a ScrollView) - So try to avoid using this type of implementation.
So what can you do?
Option 1 - Create a multi view RecylcerView adapter. that means that you have one adapter and it can handle multiple view types (perfect for what i wanted. 1 view type is a header and the second view type is another layout to act as my main row).
You can look it up in google to find good results on how to implement it but the main
So declare these variables:
private int VIEW_TYPE_HEADER = 0;
private int VIEW_TYPE_MAIN_ROW = 1;
Next override the next method, and what this basically does it gives each row a special int which we then can compare in onCreateViewHolder and decide which layout we want to inflate (e.g. If its going to be a header or a main row)
#Override
public int getItemViewType(int itemPos) {
if(items.get(itemPos) instanceof String){
return VIEW_TYPE_HEADER;
}
return VIEW_TYPE_MAIN_ROW;
}
On the onCreateViewHolder we can test to see what type of row we are dealing with and inflate accordingly.
#NonNull
#Override
public RecyclerView.ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
if(viewType == VIEW_TYPE_HEADER){
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.header)_layout, parent, false);
return new HeaderViewHolder(view);
}
//Else a regular row.
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.main_row, parent, false);
return new MainViewHolder(view);
}
And of course make a separate view holder for each type.
Option 2 - Because I need only 2-3 sections, what i could also do is just "hardcode" it like this:
Create a TextView to be the header and below it a RecyclerView AND again 2-3 times. this approach is obviously less flexible but it works if you want some small.
Hope this'll help someone one day.

RecyclerView scrolling laggy on newer android versions

My RecyclerView is pretty laggy whenever I start to scroll over the first items in a cold app start. This behavior happens for the latest android versions (tested on API level 27 and 28) but not older ones (tested on API level 22).
I tried both versions, the normal com.android.support:appcompat-v7:28.0.0 and androidx com.google.android.material:material:1.1.0-alpha03.
The test project is pretty simple:
MainActivity.java
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
RecyclerView recyclerView = findViewById(R.id.recyclerview);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setHasFixedSize(true);
recyclerView.setItemViewCacheSize(20);
ArrayList<String> list = new ArrayList<>();
for (int i = 0; i < 200; i++) {
list.add(String.valueOf(i));
}
MyAdapter adapter = new MyAdapter(MainActivity.this, list);
recyclerView.setAdapter(adapter);
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerview"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
android:layout_marginBottom="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
MyAdapter.java
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
List<String> mData;
Context context;
LayoutInflater mInflater;
public MyAdapter(Context context, List<String> data) {
this.mData = data;
this.context = context;
this.mInflater = LayoutInflater.from(context);
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
View view = mInflater.inflate(R.layout.recycler_item, viewGroup, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull ViewHolder viewHolder, int i) {
viewHolder.tv.setText(String.valueOf(i));
}
#Override
public int getItemCount() {
return mData.size();
}
public String getItem(int id) {
return mData.get(id);
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextView tv;
public ViewHolder(#NonNull View itemView) {
super(itemView);
tv = itemView.findViewById(R.id.item_tv);
}
}
}
recycler_item.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:tools="http://schemas.android.com/tools">
<TextView
android:id="#+id/item_tv"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
Any ideas for solving the problem or is it a library issue which can't be solved by myself (waiting for new official release)?

In you item layout the wrapper class is ConstraintLayout with wrap_content_height - it could cause problems while measuring.
Since you have a single itme inside you could just get rid of wrapper and keep just single TextView as a root element
If you still wants to get wrapper for the view - try to avoid wrap_content for RelativeLayout and/or ConstrainLayout, use fix size or simple layouts such as Frame/Linear.

get layoutInflaterfrom parent context so instead of
mInflater.inflate(R.layout.recycler_item, viewGroup, false);
use this
LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_item, viewGroup,
false);
Hope this will help

I solved the problem by setting the build variant to release after finding this comment: Performance of ConstraintLayout inside RecyclerView ViewHolder.
The example shared here is smoothly then and my application with Glide performs more smoothly, too, even without setting layout_width to ConstraintLayout.
But it's unclear to me why this lag appears in the debug mode and only on the latest android versions.

I was facing same problem and solved by using recyclerview within nested scroll view. like below code:
<androidx.core.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbarSize="5dp"
android:scrollbars="vertical"
android:layout_above="#id/ListBannerAds">
<androidx.recyclerview.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical"
android:scrollbarSize="5dp"
android:nestedScrollingEnabled="false"
android:id="#+id/ZaboorListRecyclerview"/>
</androidx.core.widget.NestedScrollView>

How do I not recycle only the first 2 views of my recyclerview or any items?

I am using a recyclerview for displaying and broadcasting videos of users. However, when I scroll through the recycler view, I see my first view, which has my video gets recycled hence why it's not visible to other users. Is there a way I can make sure that the first view is not recycled so I dont have to worry about my video view getting resetrecycled every single time I scroll through my list?
Here's my code :
In my fragment...
...
<android.support.v7.widget.RecyclerView
android:id="#+id/videoList"
android:layout_width="0dp"
android:layout_height="0dp"
android:visibility="invisible"
app:layout_constraintBottom_toTopOf="#+id/myButtonContainer"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="#+id/myoldContainer">
...
and the corresponding adapter...
public class GroupAdapter extends RecyclerView.Adapter<GroupAdapter.myViewHolder> {
private CopyOnWriteArrayList<Person> persons;
private Context mContext;
public GroupAdapter(#NonNull final CopyOnWriteArrayList<Person> persons , Context context) {
this.persons = persons;
this.mContext= context;
for (Person person : this.persons) {
//get names
}
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
final View layout = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_person, parent, false);
final MyViewHolder viewHolder = new MyViewHolder(layout);
return viewHolder;
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
final Person person = person.get(position);
final Participant participant = person.getParticipant();
if (person.getName() != null) {
holder.personName.setText(person.getName());
}
if (person.getImage() != null) {
holder.personImage.setImageBitmap(person.getImage());
} else {
holder.personImage.setImageResource(R.drawable.default_profile);
}
holder.personImage.setVisibility(View.INVISIBLE);
holder.personImage.setVisibility(View.VISIBLE);
final VideoView videoView;
if (participant.isMe) {
videoView = participant.videoStreamer.videoView;
} else {
videoView = participant.videoPlayer.videoView;
}
if (holder.personVideo.getChildCount() != 0) {
holder.personVideo.removeAllViews();
}
if (videoView.getParent() != null) {
ViewGroup parent = (ViewGroup) videoView.getParent();
parent.removeView(videoView);
}
holder.personVideo.addView(videoView, myViewHolder.videoLayoutParams);
if (person.isVideoPaused()) {
holder.personVideo.setVisibility(View.INVISIBLE);
holder.personImage.setVisibility(View.VISIBLE);
} else {
holder.personVideo.setVisibility(View.VISIBLE);
holder.personImage.setVisibility(View.INVISIBLE);
}
}
#Override
public int getItemCount() {
return persons.size();
}
public static final class MyViewHolder extends RecyclerView.ViewHolder {
#BindView(R.id.personVideo)
public ViewGroup personVideo;
#BindView(R.id.personImage)
public ImageView personImage;
#BindView(R.id.personName)
public TextView personName;
protected static FrameLayout.LayoutParams videoLayoutParams = new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT
);
public MyViewHolder(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
}
}
}
Here's how I am setting it in my fragment:
LinearLayoutManager manager = new LinearLayoutManager(getActivity(), LinearLayoutManager.HORIZONTAL, false);
videoAdapter = new VideoAdapter(myHelper.getPeople(), getContext());
videoList.setLayoutManager(manager);
videoList.setAdapter(videoAdapter);
item_person:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginTop="0dp"
android:background="#drawable/person_border"
xmlns:app="http://schemas.android.com/apk/res-auto">
<RelativeLayout
android:id="#+id/personContainer"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintDimensionRatio="1:1"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent">
<FrameLayout
android:id="#+id/personVideo"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/black" />
<ImageView
android:id="#+id/personImage"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/black"
android:src="#drawable/default_profile" />
<TextView
android:id="#+id/personName"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#AA555555"
android:gravity="center_horizontal|bottom"
android:textColor="#color/green"
android:textSize="12sp"
android:lines="1"
android:ellipsize="end"
tools:text="androiduser#gmail.com"
android:layout_alignParentBottom="true" />
</RelativeLayout>
</android.support.constraint.ConstraintLayout>
fragment with recycle view: xml
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools">
<RelativeLayout>
....
</RelativeLayout>
<include containers>...</include>
...
<android.support.v7.widget.RecyclerView
android:id="#+id/personList"
android:layout_width="0dp"
android:layout_height="0dp"
android:visibility="invisible"
>
</android.support.v7.widget.RecyclerView>
</android.support.constraint.ConstraintLayout>

I don't think that "not recycling" the video view will actually stop it from being destroyed when you scroll. It's not the recycling is the problem but the view unbinding.
I think such complex component such as VideoView should not be inside the RecyclerView at all.. You can try adding it as a static content on top, which most likely will solve the issue. You can use a NestedScrollView for that. Take a look here: Recyclerview inside scrollview- How to scroll whole content?
If you still think you want to keep it in the RecyclerView and disable the recycling, do the following.
Create a separate view type for your video view items. Here is an example:
https://stackoverflow.com/a/26573338/3086818. Treat your video view item as a header view from the example.
Once you do this, there is a RecycledViewPool class which manages the recycling of items inside a RecyclerView. You can tell it which views to recycle and which not. By default it recycles all views. To disable recycling for your video view items use your new view type like this:
recyclerView.getRecycledViewPool().setMaxRecycledViews(TYPE_VIDEO_VIEW, 0);
where TYPE_VIDEO_VIEW is the new type that you created using the previous example. The number 0 tells the RecyclerView how many items to recycle - in this case it's 0, meaning "do not recycle". More info about this here: https://stackoverflow.com/a/36313437/3086818.
I hope this helps.. Good luck!

The answer is yes, you can actually do that.
Since you said "The first item" so you simply add a check.
if(position == 0)
{
holder.setIsRecyclable(false); //This line prevents the row from recycling
}

RecyclerView scrolling issue (Child items far away from each other)

Goodd day.I have simple recycler view with simplest dummy datas for test purpose,thus i have an weird issue to which the google did not find any solution or even an issue at all.On first launch the view is all good but as soon as i start to scrool,the child items are being as far from each other as no one can image...Really very and very far.But the issue is that the actual child items layout parameters are correct,only issue is that i dont know why RecyclerView decides to have each item heaps far away from each other.Please can you give me an help?Posting full code of my RecyclerView.
The view for recyclerView
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:context="com.ink.activities.HomeActivity"
tools:showIn="#layout/app_bar_home">
<android.support.v7.widget.RecyclerView
android:id="#+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical" />
</RelativeLayout>
The Adapter.
public class FeedAdapter extends RecyclerView.Adapter<FeedAdapter.ViewHolder> {
private List<FeedModel> feedList;
private Context mContext;
public class ViewHolder extends RecyclerView.ViewHolder {
public TextView title, content;
public ViewHolder(View view) {
super(view);
title = (TextView) view.findViewById(R.id.feedTitle);
content = (TextView) view.findViewById(R.id.feedContent);
}
}
public FeedAdapter(List<FeedModel> feedList, Context context) {
mContext = context;
this.feedList = feedList;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.feed_single_view, parent, false);
return new ViewHolder(itemView);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
FeedModel feedModel = feedList.get(position);
holder.title.setText(feedModel.getTitle());
holder.content.setText(feedModel.getContent());
// animate(holder);
}
public void animate(RecyclerView.ViewHolder viewHolder) {
final Animation animAnticipateOvershoot = AnimationUtils.loadAnimation(mContext, R.anim.bounce_interpolator);
viewHolder.itemView.setAnimation(animAnticipateOvershoot);
}
#Override
public int getItemCount() {
return feedList.size();
}
}
I guess you won`t need holder as no view initiated with it.
The single child item view of RecyclerView adapter.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.v7.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:clickable="true"
android:foreground="?android:attr/selectableItemBackground"
app:cardCornerRadius="5dp"
app:cardElevation="10dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/feedTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_marginTop="10dp"
android:fontFamily="#string/appFont"
android:text="loading...."
android:textColor="#000000"
android:textSize="20sp" />
<TextView
android:id="#+id/feedContent"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/feedTitle"
android:layout_marginLeft="2dp"
android:layout_marginRight="2dp"
android:layout_marginTop="10dp" />
</RelativeLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
The initiation of actual parameters.
mRecyclerView = (RecyclerView) findViewById(R.id.recycler_view);
mAdapter = new FeedAdapter(mFeedModelArrayList, this);
RecyclerView.ItemAnimator itemAnimator = new DefaultItemAnimator();
itemAnimator.setAddDuration(500);
itemAnimator.setRemoveDuration(500);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
mRecyclerView.setItemAnimator(itemAnimator);
This code is as simple as it can get and it is important to mention that i am initiation all this inside the default NAVIGATION DRAWER ACTIVITY of android studio (the default templae inside content_main layout).So plaese can you give me any hint about the issue?

You're using
android:layout_width="match_parent"
android:layout_height="match_parent"
on your child item views. As of Support Library 23.2:
The RecyclerView widget provides an advanced and flexible base for creating lists and grids as well as supporting animations. This release brings an exciting new feature to the LayoutManager API: auto-measurement! This allows a RecyclerView to size itself based on the size of its contents. This means that previously unavailable scenarios, such as using WRAP_CONTENT for a dimension of the RecyclerView, are now possible. You’ll find all built in LayoutManagers now support auto-measurement.
Due to this change, make sure to double check the layout parameters of your item views: previously ignored layout parameters (such as MATCH_PARENT in the scroll direction) will now be fully respected.
Change your layout_height to wrap_content if you only want your items to be as large as needed. match_parent means they will be as large as the screen.

Android displaying text when ListView is empty

I'm setting a TextView with the id #android:id/empty to display a message when there are no items in the ListView. However, this TextView gets displayed even if there are items in the ListView, right before the items show up.
How can I make it such that it only gets displayed when there are no elements in the ListView?
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ListView
android:id="#android:id/list"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:dividerHeight="1dp" >
</ListView>
<TextView
android:id="#android:id/empty"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/empty_list" />
</LinearLayout>
PS: I'm using a Loader and a SimpleCursorAdapter with a ListFragment.

I'm guessing you are using a regular Fragment or Activity with a ListView inside of it. If you are, you must add the empty layout to the ListView manually.
E.g.
ListView lv = (ListView)findViewById(android.R.id.list);
TextView emptyText = (TextView)findViewById(android.R.id.empty);
lv.setEmptyView(emptyText);
Then your ListView will automatically use this view when its adapter is empty
If you are using a ListActivity you do not need to call setEmptyView() on the ListView since the ListActivity automatically manages that for you.

Set a TextView and assign to it whatever you want to display when the ListView is empty:
ProjectListAdapter projectListAdapter = new ProjectListAdapter();
TextView empty=(TextView)findViewById(R.id.empty);
projectsListView.setEmptyView(empty);
And in my xml file we write the below code
<TextView
android:id="#+id/empty"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:gravity="center"
android:text="Your text here"
android:textColor="#FFFFFF" />

I had this problem. You have to set the emptyView explicitly in your code.
Change your TextView:
<TextView
android:id="#+id/emptyResults"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/empty_list" />
Then in the onCreate():
listViewResults = (ListView) findViewById(R.id.list);
listViewResults.setEmptyView((LinearLayout) findViewById(R.id.emptyResults));
This code above assumes your ListView is in a LinearLayout.

I used ListFragment and had the same issue. I tried all variants from this answers, but the problem wasn't solved.
So I found my variant, to override setEmptyText():
public class NewsFragment extends ListFragment{
private TextView emptyText;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
//...
emptyText = (TextView)view.findViewById(android.R.id.empty);
//...
}
#Override
public void setEmptyText(CharSequence text) {
emptyText.setText(text);
}
}
Hope it will be helpful for somebody.

I know this is kind of late, but for it to work from XML, you need to put a weight on your ListView and have your TextView match_parent
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ListView
android:id="#android:id/list"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_weight="1"
android:dividerHeight="1dp" >
</ListView>
<TextView
android:id="#android:id/empty"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="#string/empty_list" />
</LinearLayout>

There's a good example of how to do it which works awesome:
When you want to show a message to the user when the ListView is
empty, you have to keep in mind the following 3 steps:
In the xml where the ListView is declared, create a TextView (the TextView can be inside a LinearLayout if you want) right
below the ListView
Set the TextView’s id as “emptyElement”
And inside the activity, set the setEmptyView() property to the ListView
1- Create an xml which will hold the ListView and name it
“my_activity”
and an activity called “MyActivity”.
Now, in the just created xml “my_activity”, you will have to set the ListView. And right below the ListView, you will have to add
a TextView. This will be used to display the empty message.
Important: The TextView must have as id the following name: “emptyElement”. This name is mandatory. The message won’t be displayed
if you use another name.
This is how “my_activity” xml should look like:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context=".MyActivity">
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/listView"/>
<TextView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/emptyElement"
android:text="The list is empty"
android:textStyle="bold"
android:textSize="15sp"
android:visibility="gone"
android:layout_centerInParent="true"
android:textColor="#android:color/darker_gray"/>
</RelativeLayout>
Create an xml for displaying items (when the list is not empty), and name it “list_item”.
<TextView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/list_item_text_view"
android:textSize="20sp"
android:padding="10dp"
android:layout_marginLeft="5dp"/>
Create a new Java class for the custom adapter which will be used by the ListView and name “MyCustomAdapter”. The code for the adapter
is written below:
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
import java.util.ArrayList;
public class MyCustomAdapter extends BaseAdapter {
private ArrayList<String> mListItems;
private LayoutInflater mLayoutInflater;
public MyCustomAdapter(Context context, ArrayList<String> arrayList){
mListItems = arrayList;
//get the layout inflater
mLayoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
#Override
public int getCount() {
//getCount() represents how many items are in the list
return mListItems.size();
}
#Override
//get the data of an item from a specific position
//i represents the position of the item in the list
public Object getItem(int i) {
return null;
}
#Override
//get the position id of the item from the list
public long getItemId(int i) {
return 0;
}
#Override
public View getView(int position, View view, ViewGroup viewGroup) {
// create a ViewHolder reference
ViewHolder holder;
//check to see if the reused view is null or not, if is not null then reuse it
if (view == null) {
holder = new ViewHolder();
view = mLayoutInflater.inflate(R.layout.list_item, null);
holder.itemName = (TextView) view.findViewById(R.id.list_item_text_view);
// the setTag is used to store the data within this view
view.setTag(holder);
} else {
// the getTag returns the viewHolder object set as a tag to the view
holder = (ViewHolder)view.getTag();
}
//get the string item from the position "position" from array list to put it on the TextView
String stringItem = mListItems.get(position);
if (stringItem != null) {
if (holder.itemName != null) {
//set the item name on the TextView
holder.itemName.setText(stringItem);
}
}
//this method must return the view corresponding to the data at the specified position.
return view;
}
/**
* Static class used to avoid the calling of "findViewById" every time the getView() method is called,
* because this can impact to your application performance when your list is too big. The class is static so it
* cache all the things inside once it's created.
*/
private static class ViewHolder {
protected TextView itemName;
}
}
Now go to MyActivity class and add the code below:
import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;
import java.util.ArrayList;
import java.util.List;
public class MyActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.my_activity);
ListView listView = (ListView) findViewById(R.id.listView);
// Create an empty array list of strings
List<String> items = new ArrayList<String>();
// Set the adapter
MyCustomAdapter adapter = new MyCustomAdapter(items);
listView.setAdapter(adapter);
// Set the emptyView to the ListView
listView.setEmptyView(findViewById(R.id.emptyElement));
}
}

TextView tv=(TextView) view.findViewById(R.id.empty);
tv.setVisibiliy(View.GONE);