Develop Reference

How to implement nested RecycleView?

I am trying to implement a nested recycle view i read several post online, but i am still having a difficult time. This is what i did so far, i created a main layout which contains my main Recycle view, i then created the main recycle view row item. And populated it by creating an adapter and implementing it in my main activity. Secondly, i crated a layout with my child recycle view as well as the child recycle view row item. The problem arises when i am trying to access this recycle view, i am unsure as to how to go about doing this? I was able to access my parent recycle and implement the adapter in my main activity, but i am not sure as to how to access my child recycle view. Could someone assist me?
**Parent Recycle View**
<?xml version="1.0" encoding="utf-8"?>
<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">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rv_main"
android:layout_width="match_parent"
android:layout_height="match_parent">
</androidx.recyclerview.widget.RecyclerView>
</RelativeLayout>
**Parent Recycle View row**
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<androidx.cardview.widget.CardView
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/card_view_home"
android:layout_width="130dp"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:elevation="5dp"
app:cardUseCompatPadding="true">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageView
android:id="#+id/image_view_movie"
android:layout_width="130dp"
android:layout_height="170dp"
android:scaleType="fitXY"
/>
<LinearLayout
android:id="#+id/layout_mov"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/image_view_movie"
android:layout_margin="1dp"
android:orientation="vertical">
<TextView
android:id="#+id/tv_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:maxLines="1"
android:text="Mission Impossible"
android:textSize="12sp" />
<TextView
android:id="#+id/tv_genre"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ellipsize="end"
android:fontFamily="sans-serif"
android:maxLines="1"
android:text="Action,Comedy..."
android:textSize="12sp" />
</LinearLayout>
</RelativeLayout>
</androidx.cardview.widget.CardView>
</RelativeLayout>
**Child RecycleView**
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/relativeLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/tv_movie_category"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:layout_marginTop="10dp"
android:layout_marginBottom="10dp"
android:text="Movie Category"
android:textSize="14sp"
android:textStyle="bold" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/home_recycler_view_horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#id/tv_movie_category"
android:layout_marginLeft="10dp"
android:layout_marginBottom="15dp"
android:orientation="horizontal" />
<View
android:id="#+id/activityMainDivider"
android:layout_width="match_parent"
android:layout_height="1dp"
android:layout_below="#+id/home_recycler_view_horizontal"
android:layout_marginBottom="5dp"
android:background="#31C7C7CC" />
</RelativeLayout>
**Child recycle view row**
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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/constraintlayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="15dp">
<androidx.cardview.widget.CardView
android:id="#+id/cardView"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:background="#color/colorPrimary"
app:cardElevation="5dp"
app:cardUseCompatPadding="true"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageView
android:id="#+id/newsThumbNail"
android:layout_width="0dp"
android:layout_height="200dp"
android:scaleType="fitXY"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.448"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="1.0" />
<TextView
android:id="#+id/newsTitle"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Dangerous fire is out of control at 24 and park"
android:textSize="17sp"
app:layout_constraintEnd_toEndOf="#+id/newsThumbNail"
app:layout_constraintStart_toStartOf="#+id/newsThumbNail"
app:layout_constraintTop_toBottomOf="#+id/newsThumbNail" />
<TextView
android:id="#+id/newsBody"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:text="Some text is here"
app:layout_constraintEnd_toEndOf="#+id/newsTitle"
app:layout_constraintStart_toStartOf="#+id/newsTitle"
app:layout_constraintTop_toBottomOf="#+id/newsTitle" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.cardview.widget.CardView>
</androidx.constraintlayout.widget.ConstraintLayout>
**Parent Adapter**
public class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.MessageViewHolder> {
private Context context;
private ArrayList<DataModel> userMessagesList;
public HomeAdapter(Context context, ArrayList<DataModel> userMessageList) {
this.context = context;
this.userMessagesList = userMessageList;
}
#NonNull
#Override
public MessageViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.inner_recycleview_row, viewGroup, false);
return new MessageViewHolder(view);
}
//Loads data into views
#Override
public void onBindViewHolder(#NonNull MessageViewHolder viewHolder, int i) {
// viewHolder.senderTextView.setText(message.getMessage());
viewHolder.senderTextView.setText(userMessagesList.get(i).getName());
viewHolder.receiverTextView.setText(userMessagesList.get(i).getAge());
}
#Override
public int getItemCount() {
return userMessagesList.size();
}
//links up ui elements
static class MessageViewHolder extends RecyclerView.ViewHolder {
private TextView senderTextView, receiverTextView;
public MessageViewHolder(#NonNull View itemView) {
super(itemView);
senderTextView = itemView.findViewById(R.id.tv_genre);
receiverTextView = itemView.findViewById(R.id.tv_title);
}
}
}
**Main Activity**
public class MainActivity extends AppCompatActivity {
private RecyclerView messagesRecycleView;
private ArrayList<DataModel> messageList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
messageList = new ArrayList<>();
initRecycleView();
populateArray();
}
public void populateArray(){
DataModel dataModel1= new DataModel("Bob","18");
messageList.add(dataModel1);
}
//set up RecycleView
public void initRecycleView() {
messagesRecycleView = findViewById(R.id.rv_main);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
linearLayoutManager.setStackFromEnd(true);
//linearLayoutManager.setReverseLayout(true);
messagesRecycleView.setLayoutManager(linearLayoutManager);
HomeAdapter homeAdapter = new HomeAdapter(MainActivity.this, messageList);
messagesRecycleView.setAdapter(homeAdapter);
}
}
public class NewsAdapter extends RecyclerView.Adapter<NewsAdapter.MessageViewHolder> {
private Context context;
private ArrayList<DataModel> userMessagesList;
public NewsAdapter(Context context, ArrayList<DataModel> userMessageList) {
this.context = context;
this.userMessagesList = userMessageList;
}
#NonNull
#Override
public MessageViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.news_feed_row, viewGroup, false);
return new MessageViewHolder(view);
}
//Loads data into views
#Override
public void onBindViewHolder(#NonNull MessageViewHolder viewHolder, int i) {
// viewHolder.senderTextView.setText(message.getMessage());
viewHolder.senderTextView.setText(userMessagesList.get(i).getName());
viewHolder.receiverTextView.setText(userMessagesList.get(i).getAge());
}
#Override
public int getItemCount() {
return userMessagesList.size();
}
//links up ui elements
static class MessageViewHolder extends RecyclerView.ViewHolder {
private TextView senderTextView, receiverTextView;
public MessageViewHolder(#NonNull View itemView) {
super(itemView);
senderTextView = itemView.findViewById(R.id.newsBody);
receiverTextView = itemView.findViewById(R.id.newsTitle);
}
}
}

Bug in recycle grid. Changing UI without click randomly

I have a recycler inside fragment in view pager.
The problem that it put likes on user accounts in UI randomly but in DB everything is fine.
In logs, I see that random is not influence on BD. So the bug is only in UI part. After the refresh of the list, it can appear again and after that disappear.
I would like to share code but I already don't have an I idea where the problem could be. It might be in adapter/refresh list listener / XML or any other places. Please let me know what part of the code you need and I will provide it. Maybe it is a bug of recycler as itself and I can't fix it.
Adapter class code:
public class SearchAdapter extends RecyclerView.Adapter<SearchAdapter.UserViewHolder>{
private List<FsUser> fsUserList = new ArrayList<>();
private OnItemClickListener.OnItemClickCallback onItemClickCallback;
private OnItemClickListener.OnItemClickCallback onChatClickCallback;
private OnItemClickListener.OnItemClickCallback onLikeClickCallback;
private Context context;
public SearchAdapter(OnItemClickListener.OnItemClickCallback onItemClickCallback,
OnItemClickListener.OnItemClickCallback onChatClickCallback,
OnItemClickListener.OnItemClickCallback onLikeClickCallback) {
this.onItemClickCallback = onItemClickCallback;
this.onChatClickCallback = onChatClickCallback;
this.onLikeClickCallback = onLikeClickCallback;
}
public void addUsers(List<FsUser> userList) {
fsUserList.addAll(userList);
notifyItemRangeInserted(fsUserList.size() - userList.size(), fsUserList.size());
}
public void clearData(){
fsUserList.clear();
notifyDataSetChanged();
}
#NonNull
#Override
public UserViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
context = parent.getContext();
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_user, parent, false);
return new UserViewHolder(v);
}
#Override
public void onBindViewHolder(#NonNull UserViewHolder holder, int position) {
FsUser fsUser = fsUserList.get(position);
holder.bind(fsUser, position);
}
#Override
public int getItemCount() {
return fsUserList.size();
}
public String getLastItemId(){
return fsUserList.get(fsUserList.size() - 1).getUid();
}
class UserViewHolder extends RecyclerView.ViewHolder {
RelativeLayout container;
ImageView imageView, like, chat;
TextView name, country;
private LottieAnimationView animationView;
UserViewHolder(View itemView) {
super(itemView);
context = itemView.getContext();
container = itemView.findViewById(R.id.item_user_container);
imageView = itemView.findViewById(R.id.user_img);
like = itemView.findViewById(R.id.search_btn_like);
chat = itemView.findViewById(R.id.search_btn_chat);
name = itemView.findViewById(R.id.user_name);
country = itemView.findViewById(R.id.user_country);
animationView = itemView.findViewById(R.id.lottieAnimationView);
}
void bind(FsUser fsUser, int position){
ViewCompat.setTransitionName(imageView, fsUser.getName());
if (FirebaseUtils.isUserExist() && fsUser.getUid() != null) {
new FriendRepository().isLiked(fsUser.getUid(), flag -> {
if (flag) {
like.setBackground(ContextCompat.getDrawable(context, R.drawable.ic_favorite));
animationView.setVisibility(View.VISIBLE);
}
});
}
if(fsUser.getUid() != null) {
chat.setOnClickListener(new OnItemClickListener(position, onChatClickCallback));
like.setOnClickListener(new OnItemClickListener(position, onLikeClickCallback));
}
imageView.setOnClickListener(new OnItemClickListener(position, onItemClickCallback));
imageView.setScaleType(ImageView.ScaleType.FIT_XY);
if(fsUser.getImage().equals("default")){
Glide.with(context).load(context.getResources().getDrawable(R.drawable.default_avatar)).into(imageView);
} else {
Glide.with(context).load(fsUser.getImage()).thumbnail(0.5f).into(imageView);
}
name.setText(fsUser.getName());
country.setText(fsUser.getCountry());
ValueAnimator animator = ValueAnimator.ofFloat(0f, 1f).setDuration(500);
animator.addUpdateListener(valueAnimator ->
animationView.setProgress((Float) valueAnimator.getAnimatedValue()));
if (animationView.getProgress() == 0f) {
animator.start();
} else {
animationView.setProgress(0f);
}
}
}
}
And xml file of RecyclerView item:
<?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:id="#+id/item_user_container"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.CardView
android:layout_width="#dimen/user_cv_width"
android:layout_height="#dimen/user_cv_height"
android:layout_margin="#dimen/dp4"
android:elevation="#dimen/dp4">
<RelativeLayout
android:id="#+id/item_user_main_relative_container"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<RelativeLayout
android:id="#+id/item_user_top_relative_container"
android:layout_width="#dimen/user_rl_width"
android:layout_height="#dimen/user_rl_height">
<ImageView
android:id="#+id/user_img"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scaleType="centerCrop"
android:src="#drawable/default_avatar" />
<RelativeLayout
android:id="#+id/item_user_top_relative"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/user_item_bg"
android:orientation="vertical">
<TextView
android:id="#+id/user_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="#dimen/dp4"
android:textColor="#android:color/white"
android:textSize="#dimen/medium_text_size" />
<TextView
android:id="#+id/user_country"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#android:color/white"
android:layout_marginStart="#dimen/dp4"
android:textSize="#dimen/medium_text_size" />
</LinearLayout>
</RelativeLayout>
</RelativeLayout>
<RelativeLayout
android:id="#+id/item_user_bottom_relative_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:orientation="horizontal">
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="#dimen/dp12">
<ImageView
android:id="#+id/search_btn_like"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/heart_outline"
android:contentDescription="#string/search_btn_like_desc"/>
<com.airbnb.lottie.LottieAnimationView
android:id="#+id/lottieAnimationView"
android:visibility="gone"
android:layout_width="#dimen/lottie_animation_view_size"
android:layout_height="#dimen/lottie_animation_view_size"
app:lottie_loop="true"
app:lottie_autoPlay="true"
app:lottie_fileName="like.json"/>
</RelativeLayout>
<ImageView
android:id="#+id/search_btn_chat"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_margin="#dimen/dp12"
android:layout_weight="1"
android:src="#drawable/message_outline" />
</LinearLayout>
</RelativeLayout>
</RelativeLayout>
</android.support.v7.widget.CardView>
</RelativeLayout>

Override this two methods inside your adapter
#Override
public long getItemId(int position) {
return position;
}
#Override
public int getItemViewType(int position) {
return position;
}

Why UI not displaying properly?

I am making an android cv app but I want to implement the UI shown in the screenshot.
screenshot of ui I want
below current UI from real device
current ui
The XML layout where I have implemented my UI, which consists of an ImageView and some TextViews which shows subjects. I have implemented all the tasks but UI is not showing how I want it to show.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/colorBlust"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:baselineAligned="false"
android:orientation="horizontal">
<ImageView
android:id="#+id/educationImage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginStart="5dp"
android:layout_marginLeft="5dp"
android:src="#drawable/education_information"
tools:ignore="ContentDescription" />
<TextView
android:id="#+id/education_info"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginStart="10dp"
android:layout_marginLeft="10dp"
android:text="#string/education_information"
android:textColor="#color/colorWhite"
android:textSize="20sp" />
</LinearLayout>
<TextView
android:id="#+id/duration"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginStart="12dp"
android:layout_marginLeft="12dp"
android:text="#string/text_duration"
android:textColor="#color/colorWhite"
android:textSize="16sp" />
<TextView
android:id="#+id/institution"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginStart="12dp"
android:layout_marginLeft="12dp"
android:text="#string/text_institution"
android:textColor="#color/colorWhite"
android:textSize="16sp" />
<TextView
android:id="#+id/degree"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:layout_marginStart="12dp"
android:layout_marginLeft="12dp"
android:text="#string/text_degree"
android:textColor="#color/colorWhite"
android:textSize="16sp" />
<Space
android:layout_width="50dp"
android:layout_height="50dp" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<ImageView
android:id="#+id/subjectImage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginStart="20dp"
android:layout_marginLeft="20dp"
android:src="#drawable/university_subjects"
tools:ignore="ContentDescription" />
<TextView
android:id="#+id/subjects"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginStart="100dp"
android:layout_marginLeft="100dp"
android:text="#string/university_subjects"
android:textColor="#color/colorWhite"
android:textSize="20sp" />
<include
layout="#layout/subject_list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#+id/subjects"
android:layout_marginTop="60dp" />
</RelativeLayout>
</LinearLayout>
</LinearLayout>
I have created another adapter and created dummy data in subjectivity
below adapter class
public class SubjectAdapter extends RecyclerView.Adapter<SubjectAdapter.ViewHolder> {
private SubjectActivity subjectActivity;
private int [] subjectImage;
String[] subjectText;
List<FakeData> fakeData;
public class ViewHolder extends RecyclerView.ViewHolder {
public TextView subjects;
public ImageView subjectImage;
public ViewHolder(View view) {
super(view);
subjectImage = (ImageView) view.findViewById(R.id.subjectImage);
subjects = (TextView) view.findViewById(R.id.subjects);
}
}
public SubjectAdapter(SubjectActivity subjectActivity, int []subjectImage, String [] subjectText, List<FakeData> fakeData){
this.subjectActivity = subjectActivity;
this.subjectImage = subjectImage;
this.subjectText = subjectText;
this.fakeData = fakeData;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.subject_list, parent, false);
return new ViewHolder(itemView);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
FakeData fake = fakeData.get(position);
Picasso.get().load(fake.getImage()).
into(holder.subjectImage);
holder.subjects.setText(fake.getSubjects());
}
// TODO Auto-generated constructor stub
#Override
public int getItemCount() {
return fakeData.size() ;
}
}
below subject XML where I have hosted RecyclerView
<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.support.v7.widget.RecyclerView
android:id="#+id/list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_alignParentStart="true">
</android.support.v7.widget.RecyclerView>
below subject_list.xml where I have host items
<?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:background="#color/colorBlust"
android:orientation="horizontal" >
<ImageView
android:id="#+id/icon"
android:layout_width="60dp"
android:layout_marginLeft="10dp"
android:layout_height="60dp"
android:padding="5dp"
android:src="#drawable/computer_science"
android:layout_marginStart="10dp" />
<LinearLayout android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="#+id/item"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/computers_science"
android:textAppearance="?android:attr/textAppearanceMedium"
android:layout_marginLeft="10dp"
android:layout_marginTop="5dp"
android:padding="2dp"
android:textColor="#color/colorWhite" />
</LinearLayout>
I have created fake data in order to host other images and texts
below fakeModel class
public class FakeData {
public String getImage() {
return image;
}
public void setImage(String image) {
this.image = image;
}
public String getSubjects() {
return subjects;
}
public void setSubjects(String subjects) {
this.subjects = subjects;
}
String image;
String subjects;
}
below adapter class where I have extended with RecyclerView
public class SubjectAdapter extends RecyclerView.Adapter {
private SubjectActivity subjectActivity;
private int [] subjectImage;
String[] subjectText;
List<FakeData> fakeData;
public class ViewHolder extends RecyclerView.ViewHolder {
public TextView subjects;
public ImageView subjectImage;
public ViewHolder(View view) {
super(view);
subjectImage = (ImageView) view.findViewById(R.id.subjectImage);
subjects = (TextView) view.findViewById(R.id.subjects);
}
}
public SubjectAdapter(SubjectActivity subjectActivity, int []subjectImage, String [] subjectText, List<FakeData> fakeData){
this.subjectActivity = subjectActivity;
this.subjectImage = subjectImage;
this.subjectText = subjectText;
this.fakeData = fakeData;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.subject_list, parent, false);
return new ViewHolder(itemView);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
FakeData fake = fakeData.get(position);
Picasso.get().load(fake.getImage()).
into(holder.subjectImage);
holder.subjects.setText(fake.getSubjects());
}
// TODO Auto-generated constructor stub
#Override
public int getItemCount() {
return fakeData.size() ;
}
}
below My Subject class where I have implemented fake images and data
public class SubjectActivity extends Activity {
List<FakeData> fakeData;
int [] subjectImage = {R.drawable.computer_science,
R.drawable.data_structure,
};
ListView list;
String[] subjectText = {
"Computer Science",
"Data Structure",
};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.subject);
RecyclerView recyclerView= (RecyclerView) findViewById(R.id.list);
SubjectAdapter adapter = new SubjectAdapter(SubjectActivity.this, subjectImage,
subjectText, fakeData);
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
recyclerView.setLayoutManager(mLayoutManager);
recyclerView.setAdapter(adapter);
}
}

This looks like you only have used Android Studio's drag and drop feature to position the UI elements. The problem is, Android Studio shows those UI elements in a generic device, which wont match all devices. When I was starting off with Android, this document helped me a lot to understand how elements in the UI must be placed.
https://developer.android.com/studio/write/layout-editor

You XML is malformed. Your LinearLayout orientation is wrong:
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
It should be vertical.
Then validate its content. You have multiple RelativeLayout with orientation attribute.
It should be LinearLayout instead. RelativeLayouts don’t have orientation.
Besides those errors, your layout is very complex and have a deep hierarchy. This will lead to performance issues. My suggestion to you is to learn how to use ConstraintLayout.
The learning curve is a bit high, but it will be worth it!

Using Intent to move from one activity to other takes alongtime and show blank screen

I am showing all mp3 files of my device in recyclerview.On click of item of recyclerview,i am moving to other activity but it shows blank screen for few seconds and then moves to next activity.
Adapter class of my recyclerview is as follos:
public class SongsAdapter extends RecyclerView.Adapter<SongsAdapter.MyViewHolder>{
Context context;
ArrayList<HashMap<String, String>> songList;
public SongsAdapter(ArrayList<HashMap<String, String>> songList,Context context) {
this.songList = songList;
this.context=context;
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);
return new MyViewHolder(view,context);
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
holder.textView.setText(songList.get(position).get("file_name"));
}
#Override
public int getItemCount() {
return songList.size();
}
public class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
private TextView textView;
Context context;
public MyViewHolder(View itemView, Context context){
super(itemView);
this.context = context;
textView=(TextView)itemView.findViewById(R.id.listitemtextview);
itemView.setOnClickListener(this);
}
#Override
public void onClick(View v) {
int position=getAdapterPosition();
Intent intent=new Intent(context,FinalActivity.class);
intent.putExtra("NAME",songList.get(position).get("file_name"));
intent.putExtra("POSITION",position);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(intent);
}
}
}
xml of Final Activity
<?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"
tools:context="pritish.sawant.com.musicplayer.FinalActivity">
<ImageView
android:id="#+id/finalactivityimageview"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="20dp" />
<ImageButton
android:id="#+id/shuffle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/finalactivityimageview"
android:layout_marginLeft="120dp"
android:background="#android:color/white"
android:src="#mipmap/repeat" />
<ImageButton
android:id="#+id/repeat"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="#+id/shuffle"
android:layout_below="#+id/finalactivityimageview"
android:layout_marginLeft="50dp"
android:layout_toRightOf="#+id/shuffle"
android:background="#android:color/white"
android:src="#mipmap/shuffle" />
<LinearLayout
android:id="#+id/linear"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/repeat"
android:layout_marginTop="30dp"
android:orientation="horizontal">
<TextView
android:id="#+id/currentTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/shuffle"
android:layout_marginLeft="30dp"
tools:text="Hi" />
<TextView
android:id="#+id/finalTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/repeat"
android:layout_marginLeft="300dp"
tools:text="Hi" />
</LinearLayout>
<SeekBar
android:id="#+id/seekbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/linear"
android:layout_marginLeft="30dp"
android:layout_marginRight="30dp"
android:layout_marginTop="20dp" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/seekbar"
android:layout_marginTop="30dp"
android:orientation="horizontal">
<ImageButton
android:id="#+id/previous"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content"
android:background="#android:color/white"
android:src="#mipmap/previous"
/>
<ImageButton
android:id="#+id/rewind"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content"
android:background="#android:color/white"
android:src="#mipmap/rewind" />
<ImageButton
android:id="#+id/play"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content"
android:background="#android:color/white"
android:src="#mipmap/play" />
<ImageButton
android:id="#+id/forward"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content"
android:background="#android:color/white"
android:src="#mipmap/forward" />
<ImageButton
android:id="#+id/next"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content"
android:background="#android:color/white"
android:src="#mipmap/next" />
</LinearLayout>
</RelativeLayout>
I am using AsyncTask to retrieve all mp3 files but even displaying mp3 files on my recycler view takes time

Its because you started the intent in your MyViewHolder class. Try this:
public class MyViewHolder extends RecyclerView.ViewHolder {
public TextView textView;//make public
View mView;// make a view here
public MyViewHolder(View itemView, Context context){
super(itemView);
this.context = context;
textView=(TextView)itemView.findViewById(R.id.listitemtextview);
mView = itemView;//--note-- make mView = iteem view
}
//dont set on click listner methods in here
}
Now our onBindViewHolder you set the listners here from the holder parameter:
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
//--note replace DataItem with your Class/Model/
final DataItem itemSong = songList.get(position);
try {
//this will bind to your recyclerView textView not sure why there is
//a string that says file_name should be itemSong.getFileName();
holder.textView.setText(songList.get("file_name"));
}
} catch (Exception e) {
e.printStackTrace();
}
//clicking of the recyclycleView
holder.mView.setOnClickListener(new View.OnClickListener() {//getting viewholder class and ctor
#Override
public void onClick(View v) {
Intent intent = new Intent(context,FinalActivity.class));
//--note create a static constant string at top of class
// public static final String ITEM_KEY ="item_id_key";
intent.putExtra(ITEM_KEY,itemSong);
context.startActivity(intent);
}
});
know to recive the intent in your final activity just call:
final DataItemSongs itemSong = getIntent().getExtras().getParcelable(SongsAdapter.ITEM_KEY);
From here you can use the itemSong Object and call its properties and set in views ex
nameTxt.setText(itemSong.name);

onCreateViewHolder not called RecyclerView

I am using Recyclerview and my onCreateViewHolder and onBindViewHolder are not called. I am getting the data but it is not displaying.
My adapter class
public class DishesAdapter extends RecyclerView.Adapter<DishesAdapter.MyViewHolder> {
private Context mContext;
List<List> DialogList = new ArrayList<List>();
public class MyViewHolder extends RecyclerView.ViewHolder {
public TextView dishnames;
public RatingBar dishratings;
public ImageView dishimages;
private ImageLoader mLoader;
public MyViewHolder(View view) {
super(view);
Log.d("follower2","hi");
dishnames = (TextView)view.findViewById(R.id.dishname);
dishimages = (ImageView)view.findViewById(R.id.dishimage);
dishratings=(RatingBar)view.findViewById(R.id.dishrating);
}
}
public DishesAdapter(Context mContext, List objects) {
super();
Log.d("follower1","hi");
this.mContext = mContext;
this.DialogList = objects;
Log.d("follower1",objects.toString());
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(mContext)
.inflate(R.layout.recipe_list, parent, false);
Log.d("follower","hi");
return new MyViewHolder(itemView);
}
#Override
public void onBindViewHolder(final MyViewHolder holder, int position) {
final int i=position;
Log.d("follower","hi");
List dialog = DialogList.get(i);
Log.d("follower",dialog.toString());
String dishid = dialog.get(0).toString();
final String dishname = dialog.get(1).toString();
//byte[] dishimage = Base64.decode(dialog.get(2).toString(), Base64.DEFAULT);
String dishimage=dialog.get(2).toString();
String rating=dialog.get(3).toString();
holder.dishnames.setText(dishname);
holder.dishratings.setRating(Float.parseFloat(rating));
holder.mLoader.DisplayImage(dishimage.replaceAll(" ", "%20"),holder.dishimages);
}
#Override
public int getItemCount() {
return DialogList.size();
}}
Recyclerview
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getActivity());
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(mLayoutManager);
xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:tools="http://schemas.android.com/tools"
tools:context="mealplanner.com.main.mealplanner.MainActivity"
>
<android.support.v7.widget.RecyclerView
android:id="#+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipToPadding="false"
android:scrollbars="vertical" />
</LinearLayout>
Row List
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#FFFFFF"
card_view:cardUseCompatPadding="true"
card_view:cardElevation="4dp"
card_view:cardCornerRadius="3dp"
android:id="#+id/cv">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
>
<ImageView
android:id="#+id/dishimage"
android:layout_width="150dp"
android:layout_height="150dp"
android:layout_marginRight="6dip"
android:adjustViewBounds="true"
android:scaleType="fitXY"
android:layout_margin="10dp"
android:src="#drawable/portraitlanding"
/>
<TextView
android:id="#+id/dishname"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="40dp"
android:layout_toRightOf="#+id/dishimage"
android:textColor="#000000"
android:textSize="20dp"
android:layout_gravity="center"
android:text="Andrew" />
<RatingBar
android:id="#+id/dishrating"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
style="?android:attr/ratingBarStyleSmall"
android:isIndicator="true"
android:numStars="5"
android:stepSize="0.1"
android:layout_marginTop="10dp"
android:layout_gravity="center"
android:layout_below="#+id/dishname"
android:layout_toRightOf="#+id/dishimage"
/>
</RelativeLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
DishesAdapter constructor is being called. I am getting follower1 log along with the list of items.