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I'd like to make an internal grid view added by clicking the button on the external recyclerview

I want to make an internal grid view(room) added by clicking the button on the external recycler view(floor). but Null pointer extension occurs in onBindViewHolder. please help me
public class FloorAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> implements OnFloorItemClickListener {
OnFloorItemClickListener listener;
static public ArrayList<FloorData> floors;
private Context context;
private LayoutInflater layoutInflater;
private OnItemClickListener mListener = null;
public FloorAdapter(ArrayList<FloorData> floors, Context context) {
this.floors = floors;
this.context = context;
this.layoutInflater = LayoutInflater.from(context);
}
public interface OnItemClickListener{
void onItemClick(View v, int pos);
}
public void setOnItemClickListener(OnItemClickListener listener) {
this.mListener = listener ;
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = layoutInflater.inflate(R.layout.signle_floor, parent, false);
return new GridViewHolder(view);
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
((GridViewHolder)holder).recyclerView.setAdapter(new RoomAdapter(context, floors.get(position).rooms));
((GridViewHolder)holder).recyclerView.setLayoutManager(new GridLayoutManager(context, 2));
((GridViewHolder)holder).recyclerView.setHasFixedSize(true);
((GridViewHolder)holder).tvFloorNum.setText(String.valueOf(floors.get(position).floorNum));
}
#Override
public int getItemCount() {
return floors.size();
}
#Override public void onItemClick(RecyclerView.ViewHolder holder, View view, int position) {
if(listener != null){
listener.onItemClick(holder,view,position);
}
}
#Override
public int getItemViewType(int position) {
return floors.get(position).id;
}
public class GridViewHolder extends RecyclerView.ViewHolder {
RecyclerView recyclerView;
TextView tvFloorNum;
Button btnPlusRoom;
public GridViewHolder(View itemView) {
super(itemView);
recyclerView = itemView.findViewById(R.id.rvRooms);
tvFloorNum = itemView.findViewById(R.id.tvRoomNumber);
btnPlusRoom = (Button)itemView.findViewById(R.id.btnPlusRoom);
btnPlusRoom.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v)
{
int pos = getAdapterPosition();
if (pos != RecyclerView.NO_POSITION)
{
if(mListener != null){
mListener.onItemClick(v, pos);
}
}
}
});
}
}
}
public class RoomAdapter extends RecyclerView.Adapter<RoomAdapter.CustomViewHolder> {
private Context context;
private ArrayList<RoomData> rooms;
private LayoutInflater inflater;
public RoomAdapter(Context context, ArrayList<RoomData> rooms) {
this.context = context;
this.rooms = rooms;
this.inflater = LayoutInflater.from(context);
}
#Override
public CustomViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view;
view = inflater.inflate(R.layout.single_room, parent, false);
return new CustomViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull CustomViewHolder holder, int position) {
RoomData room = rooms.get(position);
holder.tvRoomNum.setText(String.valueOf(room.roomNum));
}
#Override
public int getItemCount() {
return rooms.size();
}
public static class CustomViewHolder extends RecyclerView.ViewHolder {
public TextView tvRoomNum;
public CustomViewHolder(View itemView) {
super(itemView);
tvRoomNum = (TextView) itemView.findViewById(R.id.tvRoomNumber);
}
}
}
public class RoomActivity extends AppCompatActivity {
private RecyclerView rvFloor;
private FloorAdapter floorAdapter;
public ArrayList<FloorData> globalfloors;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_room);
globalfloors = prepareData();
rvFloor = findViewById(R.id.rvFloors);
floorAdapter = new FloorAdapter(globalfloors, RoomActivity.this);
LinearLayoutManager manager = new LinearLayoutManager(RoomActivity.this);
rvFloor.setLayoutManager(manager);
rvFloor.setAdapter(floorAdapter);
floorAdapter.setOnItemClickListener(new FloorAdapter.OnItemClickListener() {
#Override
public void onItemClick(View v, int position) {
FloorData floor = globalfloors.get(position);
RoomData newRoom = new RoomData();
floor.finalRoomNum++;
newRoom.roomNum = floor.finalRoomNum;
floor.rooms.add(newRoom);
rvFloor.setAdapter(floorAdapter);
}
});
}
private ArrayList<FloorData> prepareData() {
ArrayList<FloorData> floors = new ArrayList<FloorData>();
//첫번째 subject 추가
FloorData floor1 = new FloorData();
floor1.floorNum = 1;
RoomData room101 = new RoomData();
room101.roomNum = 101;
RoomData room102 = new RoomData();
room102.roomNum = 102;
RoomData room103 = new RoomData();
room103.roomNum = 103;
floor1.finalRoomNum = 103;
floor1.rooms.add(room101);
floor1.rooms.add(room102);
floor1.rooms.add(room103);
floors.add(floor1);
FloorData floor2 = new FloorData();
floor2.floorNum = 2;
floor2.finalRoomNum = 200;
floors.add(floor2);
return floors;
}
}
activity_room
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".tools.RewardActivity"
android:orientation="vertical">
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolBar_room"
android:layout_width="match_parent"
android:layout_gravity="center"
android:layout_height="60dp"
android:background="#color/colorPrimaryDark"
app:title="호실 등록"
android:theme="#style/ToolbarTheme" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rvFloors"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
single_floor
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<LinearLayout
android:orientation="vertical"
android:background="#FFFFFF"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="15dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<TextView
android:id="#+id/tvFloorNum"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="8dp"
android:textSize="30dp"
android:textColor="#000000" />
<Button
android:id="#+id/btnPlusRoom"
android:layout_width="40dp"
android:layout_height="40dp"
android:text="+"
android:textSize="30dp"
android:layout_marginTop="10dp"
android:background="#color/colorPrimaryDark"/>
</LinearLayout>
<androidx.recyclerview.widget.RecyclerView
android:columnCount="5"
android:id="#+id/rvRooms"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
</LinearLayout>
single_room
<LinearLayout 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="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="2dp">
<TextView
android:id="#+id/tvRoomNumber"
android:layout_width="70dp"
android:layout_height="70dp"
android:layout_marginBottom="5dp"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_marginTop="5dp"
android:ellipsize="end"
android:singleLine="true"
android:background="#color/colorAccent"
android:gravity="center"
android:textSize="30dp"
/>
</LinearLayout>
</LinearLayout>
error message describes "java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
at com.eos.parcelnoticemanager.tools.FloorAdapter.onBindViewHolder"

The GridViewHolder inside your FloorAdapter is pointing to the wrong XML Id tag for the TextView that's why it's throwing NullPointerException
Change this in your GridViewHolder
tvFloorNum = itemView.findViewById(R.id.tvRoomNumber);
to this
tvFloorNum = itemView.findViewById(R.id.tvFloorNumber);
Then it should work

RecyclerView Adapter return NullPointerException

I want to make double recyclerview to represent rooms on each floor. but NullPointerException occurs in floorAdapter.
public class FloorAdapter extends RecyclerView.Adapter<FloorAdapter.ViewHolder> {
public ArrayList<FloorData> floors;
private Context context;
private LayoutInflater layoutInflater;
public FloorAdapter(ArrayList<FloorData> floors, Context context) {
this.floors = floors;
this.context = context;
this.layoutInflater = LayoutInflater.from(context);
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = layoutInflater.inflate(R.layout.signle_floor, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.recyclerView.setAdapter(new RoomAdapter(context, floors.get(position).rooms));
holder.recyclerView.setLayoutManager(new LinearLayoutManager(context, LinearLayoutManager.HORIZONTAL, false));
holder.recyclerView.setHasFixedSize(true);
holder.tvFloorNum.setText(floors.get(position).floorNum);
}
#Override
public int getItemCount() {
return floors.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
RecyclerView recyclerView;
TextView tvFloorNum;
public ViewHolder(View itemView) {
super(itemView);
recyclerView = (RecyclerView) itemView.findViewById(R.id.rvFloors);
tvFloorNum = (TextView) itemView.findViewById(R.id.tvFloorNum);
}
}
}
public class RoomAdapter extends RecyclerView.Adapter<RoomAdapter.CustomViewHolder> {
private Context context;
private ArrayList<RoomData> rooms;
private LayoutInflater inflater;
public RoomAdapter(Context context, ArrayList<RoomData> rooms) {
this.context = context;
this.rooms = rooms;
this.inflater = LayoutInflater.from(context);
}
#Override
public CustomViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view;
view = inflater.inflate(R.layout.single_room, parent, false);
return new CustomViewHolder(view);
}
#Override
public void onBindViewHolder(CustomViewHolder holder, int position) {
RoomData room = rooms.get(position);
holder.tvRoomNum.setText(room.roomNum);
}
#Override
public int getItemCount() {
return rooms.size();
}
public class CustomViewHolder extends RecyclerView.ViewHolder {
public TextView tvRoomNum;
public CustomViewHolder(View itemView) {
super(itemView);
tvRoomNum = (TextView) itemView.findViewById(R.id.tvRoomNumber);
}
}
}
public class RoomActivity extends AppCompatActivity {
private RecyclerView rvFloor;
private FloorAdapter floorAdapter;
private ArrayList<FloorData> floors;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_room);
floors = prepareData();
rvFloor = findViewById(R.id.rvFloors);
floorAdapter = new FloorAdapter(floors, RoomActivity.this);
LinearLayoutManager manager = new LinearLayoutManager(RoomActivity.this);
rvFloor.setLayoutManager(manager);
rvFloor.setAdapter(floorAdapter);
}
private ArrayList<FloorData> prepareData() {
ArrayList<FloorData> floors = new ArrayList<FloorData>();
//첫번째 subject 추가
FloorData floor1 = new FloorData();
floor1.floorNum = 1;
floor1.rooms = new ArrayList<RoomData>();
RoomData room101 = new RoomData();
room101.roomNum = 101;
RoomData room102 = new RoomData();
room102.roomNum = 102;
RoomData room103 = new RoomData();
room103.roomNum = 103;
floor1.rooms.add(room101);
floor1.rooms.add(room102);
floor1.rooms.add(room103);
floors.add(floor1);
FloorData floor2 = new FloorData();
floor2.floorNum = 2;
floor2.rooms = new ArrayList<RoomData>();
RoomData room201 = new RoomData();
room201.roomNum = 201;
RoomData room202 = new RoomData();
room202.roomNum = 202;
RoomData room203 = new RoomData();
room203.roomNum = 203;
floor2.rooms.add(room201);
floor2.rooms.add(room202);
floor2.rooms.add(room203);
floors.add(floor2);
return floors;
}
}
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".tools.RewardActivity"
android:orientation="vertical">
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolBar_room"
android:layout_width="match_parent"
android:layout_gravity="center"
android:layout_height="60dp"
android:background="#color/colorPrimaryDark"
app:title="호실 등록"
android:theme="#style/ToolbarTheme" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rvFloors"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<LinearLayout
android:orientation="vertical"
android:background="#FFFFFF"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="15dp">
<TextView
android:id="#+id/tvFloorNum"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="8dp"
android:textSize="30dp"
android:textColor="#000000" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rvRooms"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
</LinearLayout>
<LinearLayout 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="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="2dp">
<TextView
android:id="#+id/tvRoomNumber"
android:layout_width="70dp"
android:layout_height="70dp"
android:layout_marginBottom="5dp"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_marginTop="5dp"
android:ellipsize="end"
android:singleLine="true"
android:background="#color/colorPrimary"
/>
</LinearLayout>
</LinearLayout>
Logcat explain
"java.lang.NullPointerException: Attempt to invoke virtual method
'void
androidx.recyclerview.widget.RecyclerView.setAdapter(androidx.recyclerview.widget.RecyclerView$Adapter)'
on a null object reference"
I refer to https://medium.com/#ashishkudale/android-list-inside-list-using-recyclerview-73cff2c4ea95. It's almost the same, but I don't know why the error is happening. please help me

two things.
First, in your FloorAdapter's ViewHolder's constructor, you are finding recycler view of activity instead of that of Adapter. Change your code to,
public ViewHolder(View itemView) {
super(itemView);
recyclerView = (RecyclerView) itemView.findViewById(R.id.rvRooms); //**This is rvFloors in your code**
tvFloorNum = (TextView) itemView.findViewById(R.id.tvFloorNum);
}
in FloorAdapter. This will resolve your crash.
But you will experience two more crashes here
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.recyclerView.setAdapter(new RoomAdapter(context, floors.get(position).rooms));
holder.recyclerView.setLayoutManager(new LinearLayoutManager(context, LinearLayoutManager.HORIZONTAL, false));
holder.recyclerView.setHasFixedSize(true);
holder.tvFloorNum.setText(floors.get(position).floorNum); // **Crash will be on this line**
}
and
#Override
public void onBindViewHolder(CustomViewHolder holder, int position) {
RoomData room = rooms.get(position);
holder.tvRoomNum.setText(room.roomNum);//**Crash will be on this line**
}
These will happen because setText method takes String as argument but you are passing either Integer or int.
So change both these lines to
holder.tvFloorNum.setText(String.valueOf(floors.get(position).floorNum));
holder.tvRoomNum.setText(String.valueOf(room.roomNum));
Hope this answer helps.

Multiple TextView in RecycleView. how to do that?

Hello I just started the Android and I do not understand how to put more TextView in a RecyclerView
I have already seen this solution but I do not understand: How to create RecyclerView with multiple view type?
I tried to make a table with multiple dimensions but it did not work.
Adapter:
public class DeviceRecyclerView extends RecyclerView.Adapter<DeviceRecyclerView.ViewHolder> {
private String[]data;
public DeviceRecyclerView(String[]data){
this.data = data;
}
#Override
public DeviceRecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
View view = inflater.inflate(R.layout.device_list_row, parent , false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
String name = data[position];
String rssi = data[position];
String uuid = data[position];
holder.DeviceNameTextView.setText(name);
holder.DeviceUUIDTextViewValue.setText(rssi);
holder.DeviceRSSIVTextViewValue.setText(uuid);
}
#Override
public int getItemCount() {
return data.length;
}
public class ViewHolder extends RecyclerView.ViewHolder{
TextView DeviceNameTextView;
TextView DeviceUUIDTextViewValue;
TextView DeviceRSSIVTextViewValue;
public ViewHolder (View itemView){
super(itemView);
DeviceNameTextView = itemView.findViewById(R.id.DeviceNameTextView);
DeviceUUIDTextViewValue = itemView.findViewById(R.id.DeviceUUIDTextViewValue);
DeviceRSSIVTextViewValue = itemView.findViewById(R.id.DeviceRSSIVTextViewValue);
}
}
MainActivity:
RecyclerView deviceList = (RecyclerView)findViewById(R.id.recycler_view_NoPaired);
deviceList.setLayoutManager(new LinearLayoutManager(this));
String[]names = {"Samsung64656"};
String[]rssi = {"ezez"};
String[]uuid = {"08:90:e5:90"};
deviceList.setAdapter(new DeviceRecyclerView(names));
My 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/frameLayout"
android:layout_width="match_parent"
android:layout_height="180dp"
android:gravity="center_vertical"
tools:layout_editor_absoluteX="30dp"
tools:layout_editor_absoluteY="81dp">
<View
android:id="#+id/ColoredRect"
android:layout_width="10dp"
android:layout_height="160dp"
android:layout_marginBottom="16dp"
android:layout_marginTop="16dp"
android:background="#E27F26"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="#+id/DeviceNameTextView"
android:layout_width="133dp"
android:layout_height="24dp"
android:layout_marginStart="20dp"
android:layout_marginTop="16dp"
android:text="#string/device_name_label"
android:textColor="#color/TextColor"
android:textSize="18sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="#+id/DeviceUUIDTv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="20dp"
android:layout_marginTop="8dp"
android:text="#string/deviceUUIDTextView"
android:textColor="#color/TextColor"
android:textSize="12sp"
app:layout_constraintBottom_toTopOf="#+id/DeviceUUIDTextViewValue"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/DeviceNameTextView" />
<TextView
android:id="#+id/DeviceUUIDTextViewValue"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="20dp"
android:layout_marginTop="14sp"
android:text=""
android:textColor="#color/TextColor"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/DeviceUUIDTv" />
<TextView
android:id="#+id/rssiLabelTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="20dp"
android:layout_marginTop="16dp"
android:text="#string/deviceRSSITextView"
android:textColor="#color/TextColor"
android:textSize="12sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/DeviceUUIDTextViewValue" />
<TextView
android:id="#+id/DeviceRSSIVTextViewValue"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="20dp"
android:layout_marginTop="14sp"
android:text=""
android:textColor="#color/TextColor"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/rssiLabelTextView" />
</android.support.constraint.ConstraintLayout>
Please explain me clearly how to do it. I am French sorry for spelling errors.

You just need to add some textView in you'r XML row (named device_list_row.xml), and init their in your adapter, like you have already did with 3 textview.
But's more easy with Object than use array of string, for data. for example in you'r case , make Device class object
Device.java
public class Device {
String name;
String rssi;
String uuid;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getRssi() {
return rssi;
}
public void setRssi(String rssi) {
this.rssi = rssi;
}
public String getUuid() {
return uuid;
}
public void setUuid(String uuid) {
this.uuid = uuid;
}
}
And adapter code ->
public class DeviceRecyclerView extends RecyclerView.Adapter<DeviceRecyclerView.ViewHolder> {
private ArrayList<Device> deviceList;
public DeviceRecyclerView(Arraylist<Device> deviceList){
this.deviceList= deviceList;
}
#Override
public DeviceRecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
View view = inflater.inflate(R.layout.device_list_row, parent , false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
Device device = deviceList.get(position);
holder.deviceNameTextView.setText(device.getName());
holder.deviceUUIDTextViewValue.setText(device.getUuid());
holder.deviceRSSIVTextViewValue.setText(device.getRssi());
}
#Override
public int getItemCount() {
return deviceList.length;
}
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
TextView deviceNameTextView, deviceUUIDTextViewValue, deviceRSSIVTextViewValue;
public ViewHolder(View itemView) {
super(itemView);
itemView.setOnClickListener(this);
deviceNameTextView = itemView.findViewById(R.id.DeviceNameTextView);
deviceUUIDTextViewValue = itemView.findViewById(R.id.DeviceUUIDTextViewValue);
deviceRSSIVTextViewValue = itemView.findViewById(R.id.DeviceRSSIVTextViewValue);
}
#Override
public void onClick(View v) {
Log.i("DEBUG","Item RecyclerView Cliqué");
}
}
With that, you init your Adapter with list of Device Object, who can have any variable has you want without need to pass more array or data to Adapter:-)
And for make a new Device, and use it in RV
Device device = new Device();
device.setName("Device Name 01");
device.setUuid("uuid value");
device.SetRssi("rssi value");
ArrayList<Device> deviceList = new ArrayList<>();
deviceList.add(device);
//Init adapter and fill it
DeviceRecyclerView deviceRecyclerView = new DeviceRecyclerView(deviceList);
LinearLayoutManager llm = new LinearLayoutManager(getContext());
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(llm);
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(deviceRecyclerView);

RecyclerView's height 'match_parent' not working as expected whereas fixed height (1000dp,2000dp) is working

I'm working to make a cool layout like this:
For this I'm using Android Parallax library from Github.
This library is creating all the views (as shown in picture) from xml itself.
But I want to create my own recyclerview, create adpaters, model classes and show them with cardview.
I tried using cardview and recyclerview.
Problem:
When I put RecyclerView's height as match_parent (android:layout_height="match_parent"), it gives UI like this:
Only first cardview is display with half part only. Other cardviews are overlapped somehow.
But when I give its height with fixed height like (1000dp, 2000dp), it shows the UI as expected (as shown in first figure). I think it is not a good solution to give its height fixed since data items may differ.
I don't understand what is wrong with my code. Please do suggest some solutions on this.
Following is my different views with my code.
activity_main.xml
<com.github.florent37.parallax.ScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:layout_width="match_parent"
android:layout_height="200dp"
android:scaleType="centerCrop"
android:src="#drawable/background"
android:tag="parallax=0.3" />
<TextView
style="#style/MyTitle"
android:layout_width="match_parent"
android:layout_height="160dp"
android:gravity="center"
android:tag="parallax=0.5"
android:text="My awesome title" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="150dp"
android:orientation="vertical">
<android.support.v7.widget.RecyclerView
android:id="#+id/my_recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical" />
</LinearLayout>
</FrameLayout>
</com.github.florent37.parallax.ScrollView>
card_view.xml
<?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:orientation="vertical">
<android.support.v7.widget.CardView
android:id="#+id/card_view"
android:layout_width="fill_parent"
android:layout_height="100dp"
android:layout_gravity="center"
android:layout_margin="5dp"
card_view:cardCornerRadius="2dp"
card_view:contentPadding="10dp">
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:text="Hello"
android:textStyle="bold" />
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/textView"
android:layout_marginTop="10dp"
android:text="world" />
</RelativeLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
My Adapter class is like this:
public class MyRecyclerViewAdapter extends RecyclerView
.Adapter<MyRecyclerViewAdapter
.DataObjectHolder> {
private ArrayList<ContactsModel> mDataset;
private static MyClickListener myClickListener;
public static class DataObjectHolder extends RecyclerView.ViewHolder
implements View
.OnClickListener {
TextView label;
TextView dateTime;
public DataObjectHolder(View itemView) {
super(itemView);
label = (TextView) itemView.findViewById(R.id.textView);
dateTime = (TextView) itemView.findViewById(R.id.textView2);
itemView.setOnClickListener(this);
}
#Override
public void onClick(View v) {
//myClickListener.onItemClick(getAdapterPosition(), v);
}
}
public void setOnItemClickListener(MyClickListener myClickListener) {
this.myClickListener = myClickListener;
}
public MyRecyclerViewAdapter(ArrayList<ContactsModel> myDataset) {
mDataset = myDataset;
}
#Override
public DataObjectHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.card_view, parent, false);
DataObjectHolder dataObjectHolder = new DataObjectHolder(view);
return dataObjectHolder;
}
#Override
public void onBindViewHolder(DataObjectHolder holder, int position) {
holder.label.setText(mDataset.get(position).getmText1());
holder.dateTime.setText(mDataset.get(position).getmText2());
}
public void addItem(ContactsModel dataObj, int index) {
mDataset.add(index, dataObj);
notifyItemInserted(index);
}
public void deleteItem(int index) {
mDataset.remove(index);
notifyItemRemoved(index);
}
#Override
public int getItemCount() {
return mDataset.size();
}
public interface MyClickListener {
public void onItemClick(int position, View v);
}
}
In MainActivity, I have written code like this:
public class MainActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);
mRecyclerView.setHasFixedSize(true);
mLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(mLayoutManager);
mAdapter = new MyRecyclerViewAdapter(getDataSet());
mRecyclerView.setAdapter(mAdapter);
Fabric.with(this, new Crashlytics());
}
private ArrayList<ContactsModel> getDataSet() {
ArrayList results = new ArrayList<ContactsModel>();
for (int index = 0; index < 20; index++) {
ContactsModel obj = new ContactsModel("Some Primary Text " + index,
"Secondary " + index);
results.add(index, obj);
}
return results;
}
}
Model class is like:
public class ContactsModel {
private String mText1;
private String mText2;
ContactsModel (String text1, String text2){
mText1 = text1;
mText2 = text2;
}
public String getmText1() {
return mText1;
}
public void setmText1(String mText1) {
this.mText1 = mText1;
}
public String getmText2() {
return mText2;
}
public void setmText2(String mText2) {
this.mText2 = mText2;
}
}
Apologies for the very long bulk of code.
Thanks!

You have a RecyclerView (which is scrollable) within a Scrollable Layout.
Replace your ScrollView tag with "android.support.v4.widget.NestedScrollView". This will allow the RecyclerView to properly expand.
<android.support.v4.widget.NestedScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
...
<android.support.v7.widget.RecyclerView
android:id="#+id/my_recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical" />
</android.support.v4.widget.NestedScrollView>

After Replaceing your ScrollView with NestedScrollView you can just add this line into the NestedScrollView
android:fillViewport="true"

I was having a same problem in my NestedScrollView.
Just added one line inside NestedScrollView and my problem solved.
android:fillViewport="true"

MultiListView displays only one TextView

I am writing a ListView with 2 TextViews per row, but when I execute I get only one TextView.
Here is my adapter extending Base adapter
public class GlossaryListViewAdapter extends BaseAdapter {
List<Glossary_Entry> glossary_entryList;
Context context;
public GlossaryListViewAdapter(Context context,List<Glossary_Entry> glossary_entryList){
this.glossary_entryList = glossary_entryList;
this.context = context;
}
#Override
public int getCount() {
return glossary_entryList.size();
}
#Override
public Object getItem(int postion) {
return glossary_entryList.get(postion);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View view, ViewGroup viewGroup) {
ViewHolder viewHolder;
if(view == null){
view = LayoutInflater.from(context).inflate(R.layout.glossary_single_row,viewGroup,false);
viewHolder = new ViewHolder(view);
view.setTag(viewHolder);
}else{
viewHolder = (ViewHolder)view.getTag();
}
viewHolder.titleTextView.setText(glossary_entryList.get(position).getTitle());
viewHolder.definitionTextView.setText(glossary_entryList.get(position).getDefinition());
return view;
}
private static class ViewHolder{
TextView titleTextView;
TextView definitionTextView;
public ViewHolder(View view){
titleTextView = (TextView)view.findViewById(R.id.glossary_title_textview);
definitionTextView = (TextView)view.findViewById(R.id.glossary_word_definition_textview);
}
}
}
Here is my Activity code
public class GlossaryAcvtivity extends AppCompatActivity {
ListView glossaryListView;
ListAdapter listAdapter;
List<Glossary_Entry> glossary_entryList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_glossary);
/**
* Sample data
*/
glossary_entryList = new ArrayList<>();
glossary_entryList.add( new Glossary_Entry("Force","This is a push or push on an object.They can be duew to a phenomenon such as gravity, magnetism, or anything that might cause a mass to accelerate."));
glossary_entryList.add( new Glossary_Entry("Motion","Change in position of an object over time, described in terms of displacement,distance,velocity,acceleration,time and speed"));
glossary_entryList.add( new Glossary_Entry("Quantum Leap","An Abrupt transition of an electron,atom, or molecule from one quantum state to another,with the absorption or emission of a quantum"));
glossary_entryList.add( new Glossary_Entry("Force","This is a push or push on an object.They can be duew to a phenomenon such as gravity, magnetism, or anything that might cause a mass to accelerate."));
glossaryListView = (ListView)findViewById(R.id.glossary_list_view);
listAdapter = new GlossaryListViewAdapter(getApplicationContext(),glossary_entryList);
glossaryListView.setAdapter(listAdapter);
}
}
The source of my data is an Entry class
public class Glossary_Entry {
public String title;
public String definition;
public String getTitle() {
return title;
}
public String getDefinition() {
return definition;
}
public Glossary_Entry(String title,String definition){
this.title = title;
this.definition = definition;
}
}
Here is my glossary_single_row.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_marginTop="10dp"
android:layout_marginLeft="10dp"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/app_name"
android:textColor="#color/blue"
android:textStyle="bold"
android:textSize="16sp"
android:layout_margin="4dp"
android:id="#+id/glossary_title_textview"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/app_description"
android:layout_margin="4dp"
android:textSize="12sp"
android:id="#+id/glossary_word_definition_textview"/>
</LinearLayout>
Here is my glossary_activity.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
android:layout_height="match_parent"
android:layout_width="match_parent"
android:background="#color/white"
xmlns:android="http://schemas.android.com/apk/res/android">
<android.support.v7.widget.Toolbar
android:layout_width="match_parent"
android:id="#+id/glossary_toolbar"
android:background="#color/colorPrimary"
android:layout_height="?attr/actionBarSize">
</android.support.v7.widget.Toolbar>
<ListView
android:layout_width="match_parent"
android:id="#+id/glossary_list_view"
android:layout_margin="8dp"
android:layout_below="#+id/glossary_toolbar"
android:layout_height="wrap_content">
</ListView>
</RelativeLayout>
Please help when I execute I get only one TextView per row...

Apparently, I needed to change the text color to black in the second TextView. The text was there just not visible.
<LinearLayout xmlns:android="http:// schemas.android.com/apk/res/android" 
android:orientation="vertical"
android:layout_marginTop="10dp" 
android:layout_marginLeft="10dp"
  android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView android:layout_width="match_parent" 
android:layout_height="wrap_content" 
android:text="#string/app_name"
android:textColor="#color/blue" 
android:textStyle="bold" 
android:textSize="16sp" android:layout_margin="4dp"
android:id="#+id/glossary_title_textview"/>
<TextView 
android:layout_width="match_parent" 
android:layout_height="wrap_content" 
android:text="#string/app_description"
android:layout_margin="4dp" 
android:textSize="12sp" 
android:textColor="#color/black"
android:id="#+id/glossary_word_definition_textview"/>
</LinearLayout