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In android application RecyclerView view show only half of the phone with

Here in my activity_main.xml|
in my android RecyclerView show only half of the screen, I'm not able to find out the mistake. Help me guys. I was used different layout like relativelayout, constraintlayout, linearlayout. but I was getting only half of the screen RecyclerView with size.
<?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=".MainActivity">
<android.support.v7.widget.SearchView
android:id="#+id/search"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/colorPrimaryDark"
android:focusable="false"
android:visibility="gone"
app:iconifiedByDefault="false"
app:queryHint="Search Distributors..." />
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_below="#+id/search"
android:layout_centerInParent="true"
android:layout_height="match_parent" />
<Button
android:id="#+id/btnGet"
android:visibility="gone"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:layout_alignParentBottom="true"
android:text="get" />
</RelativeLayout>
Here I attach my MainActivity.java
package com.example.admin.recyclerview;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.SearchView;
import android.view.View;
import android.widget.Button;
import com.google.gson.Gson;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private List<Model> models;
RecyclerView recyclerView;
private RecyclerView.LayoutManager layoutManager;
public SearchView searchView;
private Button button;
private RecyclerViewAdapter recyclerViewAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = findViewById(R.id.recyclerView);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
searchView = findViewById(R.id.search);
button = findViewById(R.id.btnGet);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
List<Model> models1 = recyclerViewAdapter.getList();
System.out.println("final order list "+new Gson().toJson(models1));
}
});
searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
#Override
public boolean onQueryTextSubmit(String query) {
return false;
}
#Override
public boolean onQueryTextChange(String newText) {
if (recyclerViewAdapter != null) {
recyclerViewAdapter.getFilter().filter(newText);
}
return true;
}
});
//recyclerView.setHasFixedSize(true);
models = new ArrayList<>();
models.add(new Model("rajesh"));
models.add(new Model("deva"));
models.add(new Model("merlin"));
models.add(new Model("antony"));
models.add(new Model("giri"));
models.add(new Model("guru"));
System.out.println("get the position " +
models.get(0).getName());
System.out.println("json view "+new Gson().toJson(models));
recyclerViewAdapter = new
RecyclerViewAdapter(getApplicationContext(), models);
recyclerView.setAdapter(recyclerViewAdapter);
}
}
Here i bellow attach my adapter class
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.MyViewHolder> implements Filterable {
public Context context;
private List<Model> modelList;
private List<Model> myfilterList;
public RecyclerViewAdapter(Context context, List<Model> modelList) {
this.context = context;
this.modelList = modelList;
this.myfilterList = modelList;
}
#NonNull
#Override
public MyViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
LayoutInflater layoutInflater = LayoutInflater.from(context);
View view = layoutInflater.inflate(R.layout.recyclerview_items, null);
return new MyViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull MyViewHolder myViewHolder, int i) {
Model model = myfilterList.get(i);
myViewHolder.llMain.setTag(i);
myViewHolder.textView.setText(model.getName());
}
#Override
public int getItemCount() {
return myfilterList.size();
}
#Override
public Filter getFilter() {
return new Filter() {
#Override
protected FilterResults performFiltering(CharSequence constraint) {
String text = constraint.toString();
if (text.isEmpty()) {
myfilterList = modelList;
} else {
ArrayList<Model> filterable = new ArrayList<>();
for (Model model : modelList) {
System.out.println("check equal " + model.getName()
+ " " + text);
if (model.getName().toLowerCase().contains(text)) {
filterable.add(model);
}
}
myfilterList = filterable;
}
FilterResults filterResults = new FilterResults();
filterResults.values = myfilterList;
return filterResults;
}
#Override
protected void publishResults(CharSequence constraint, FilterResults results) {
myfilterList = (ArrayList<Model>) results.values;
notifyDataSetChanged();
}
};
}
class MyViewHolder extends RecyclerView.ViewHolder {
TextView textView;
Button btnAdd, btnMinus;
LinearLayout llMain;
MyViewHolder(#NonNull View itemView) {
super(itemView);
textView = itemView.findViewById(R.id.tvName);
btnAdd = itemView.findViewById(R.id.btnAdd);
btnMinus = itemView.findViewById(R.id.btnMinus);
llMain = itemView.findViewById(R.id.llMain);
btnAdd.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int pos = (Integer) llMain.getTag();
System.out.println("linear layout position details
"+pos);
myfilterList.add(pos+1, new Model("dummy"));
notifyItemChanged(pos+1);
notifyDataSetChanged();
}
});
}
}
public List<Model> getList()
{
return myfilterList;
}
}
Here I bellow attach my item xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/llMain"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="#+id/tvName"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textAlignment="center"
android:textSize="16sp"
android:layout_margin="5dp"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:id="#+id/btnAdd"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Add Items"/>
<Button
android:id="#+id/btnMinus"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Add Items"/>
</LinearLayout>
</LinearLayout>

I don't have privileges to add a comment, hence posting it here. Sorry in advance.
Your question is not quite clear, do you want your RecyclerView to occupy the whole screen(i.e. parent). If that's the case, With LinearLayout I guess if you add an attribute android:layout_weight in your RecyclerView will solve the problem.
Here's what the discription for the attribute on developer.android site:
LinearLayout also supports assigning a weight to individual children with the android:layout_weight attribute. This attribute assigns an "importance" value to a view in terms of how much space it should occupy on the screen. A larger weight value allows it to expand to fill any remaining space in the parent view. Child views can specify a weight value, and then any remaining space in the view group is assigned to children in the proportion of their declared weight. Default weight is zero.
Hope this link helps https://developer.android.com/guide/topics/ui/layout/linear
Also there's this question already asked by me : What is the connection between setVisibility and layout_weight in Linear Layout
Correct me if I'm wrong.

Try changing the RecyclerView element inside your activity_main.xml file with the following, remove center_in_parent and change android:layout_height="wrap_content"
<?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=".MainActivity">
<android.support.v7.widget.SearchView
android:id="#+id/search"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/colorPrimaryDark"
android:focusable="false"
android:visibility="gone"
app:iconifiedByDefault="false"
app:queryHint="Search Distributors..." />
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_below="#+id/search"
android:layout_height="wrap_content" />
<Button
android:id="#+id/btnGet"
android:visibility="gone"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:layout_alignParentBottom="true"
android:text="get" />
</RelativeLayout>
Edit 1 - Using ConstraintLayout, since after the RecyclerView you'd also like to display the button, you will need the ConstraintLayout inside the NestedScrollView
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView 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">
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.SearchView
android:id="#+id/search"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
android:background="#color/colorPrimaryDark"
android:focusable="false"
app:iconifiedByDefault="false"
app:queryHint="Search Distributors..." />
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
app:layout_constraintTop_toBottomOf="#+id/search"
android:layout_height="wrap_content" />
<Button
android:id="#+id/btnGet"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toBottomOf="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:layout_alignParentBottom="true"
android:text="get" />
</android.support.constraint.ConstraintLayout>
</android.support.v4.widget.NestedScrollView>

In your adapter where you are inflating the item in onCreateViewHolder, use this code block:
View rootView = LayoutInflater.from(context).inflate(R.layout.itemLayout, null, false);
RecyclerView.LayoutParams lp = new RecyclerView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
rootView.setLayoutParams(lp);
return new RecyclerViewHolder(rootView);

items.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/llMain"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="#+id/tvName"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textAlignment="center"
android:textSize="16sp"
android:text="fdfsfsdfsd"
android:layout_margin="5dp"/>
<Button
android:id="#+id/btnAdd"
android:layout_width="wrap_content"
android:layout_below="#+id/tvName"
android:layout_height="wrap_content"
android:text="Add Items"/>
<Button
android:layout_below="#+id/tvName"
android:id="#+id/btnMinus"
android:layout_alignParentEnd="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Add Items"/>
</RelativeLayout>
activity_main.xml
<android.support.v7.widget.SearchView
android:id="#+id/search"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/colorPrimaryDark"
android:focusable="false"
android:visibility="visible"
app:iconifiedByDefault="false"
app:queryHint="Search Distributors..." />
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_marginBottom="8dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/search" />
<Button
android:id="#+id/btnGet"
android:visibility="visible"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_alignParentBottom="true"
android:text="get" />
</android.support.constraint.ConstraintLayout>

Inflating a TextView and an ImageView within a LinearLayout from a RecyclerView

package com.example.android.popularmovies;
import android.content.ActivityNotFoundException;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import java.util.ArrayList;
public class MovieAdapter extends RecyclerView.Adapter<MovieAdapter.ViewHolder> {
private ArrayList<String> mTrailers;
private Context mContext;
// Provide a suitable constructor (depends on the kind of dataset)
public MovieAdapter(Context context, ArrayList<String> trailers) {
mTrailers = trailers;
mContext = context;
}
// Create new views (invoked by the layout manager)
#Override
public MovieAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
// create a new view
LinearLayout v = (LinearLayout)LayoutInflater.from(parent.getContext())
.inflate(R.layout.trailer_view, parent, false);
ViewHolder vh = new ViewHolder(v);
return vh;
}
public void watchYoutubeVideo(String id) {
Intent appIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("vnd.youtube:" + id));
Intent webIntent = new Intent(Intent.ACTION_VIEW,
Uri.parse("http://www.youtube.com/watch?v=" + id));
try {
mContext.startActivity(appIntent);
} catch (ActivityNotFoundException ex) {
mContext.startActivity(webIntent);
}
}
// Replace the contents of a view (invoked by the layout manager)
#Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
holder.mImageView.setImageResource(R.drawable.ic_play_arrow_black_24dp);
holder.mTextView.setText("Trailer " + (position + 1));
holder.mTextView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
watchYoutubeVideo(mTrailers.get(holder.getAdapterPosition()));
}
});
}
// Return the size of your dataset (invoked by the layout manager)
#Override
public int getItemCount() {
return mTrailers.size();
}
// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder
public static class ViewHolder extends RecyclerView.ViewHolder {
// each data item is just a string in this case
public TextView mTextView;
public ImageView mImageView;
public ViewHolder(View v) {
super(v);
mImageView = v.findViewById(R.id.play_button_image_view);
mTextView = v.findViewById(R.id.movie_text_view);
}
}
}
I want my UI to be like this
With my code however the app looks like this:
Here is my xml resource:
<?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="horizontal">
<ImageView
android:id="#+id/play_button_image_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:maxHeight="10dp"
android:maxWidth="10dp"
android:scaleType="centerInside"
android:src="#drawable/ic_play_arrow_black_24dp"
/>
<TextView
android:id="#+id/movie_text_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:gravity="center_horizontal"
android:padding="10dp"
android:textSize="16sp" />
</LinearLayout>
Is there a way to implement this without using different viewholders? Can it be done with a single ViewHolder?
I have seen ways to implement different View types with a RecyclerView, but I would prefer to keep my code as simple as possible.

change the height of LinearLayot to "wrap_content". and add gravity as "center_vertical"
change you item's layout like this
<?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="wrap_content"
android:gravity="center_vertical"
android:orientation="horizontal">
<ImageView
android:id="#+id/play_button_image_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:maxHeight="10dp"
android:maxWidth="10dp"
android:scaleType="centerInside"
android:src="#drawable/ic_play_arrow_black_24dp"
/>
<TextView
android:id="#+id/movie_text_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:gravity="center_horizontal"
android:padding="10dp"
android:textSize="16sp"/>
</LinearLayout>

Try android:layout_height="wrap_content", instead of match_parent in LinearLayout.

1) You need to change the height of the layout: android:layout_height="wrap_content"
2) For the ImageView set:
android:layout_width="10dp"
android:layout_height="10dp"
(very small)

You can also use ConstraintLayout like this
<?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:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageView
android:id="#+id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="32dp"
android:layout_marginLeft="32dp"
android:layout_marginTop="32dp"
android:layout_marginBottom="32dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:srcCompat="#drawable/ic_play_arrow_black_24dp" />
<TextView
android:id="#+id/textView"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginLeft="8dp"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"
android:text="Trailer 1"
app:layout_constraintBottom_toBottomOf="#+id/imageView"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="#+id/imageView"
app:layout_constraintTop_toTopOf="#+id/imageView" />
</androidx.constraintlayout.widget.ConstraintLayout>
That being said the easiest solution would be simply using "wrap_content" on your parent layout.

try this
<?xml version="1.0" encoding="utf-8"?><?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="wrap_content"
android:gravity="center_vertical"
android:orientation="horizontal">
<ImageView
android:id="#+id/play_button_image_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:scaleType="centerInside"
android:src="#drawable/ic_play_arrow_black_24dp" />
<TextView
android:id="#+id/movie_text_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Trailer 1"
android:layout_margin="5dp"
android:padding="10dp"
android:textSize="16sp" />
</LinearLayout>
Output

RecyclerView Margin

i am developing application for home security. One of the feature, that must be implemented is the ability to see connected devices (for sending notifications, blocking access, etc). So far, i've been able to create RecyclerView list of the devices, everything is perfect (for me), except that cards in this list have no spacing between them.
Screenshot of how it looks now
device_data_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:cardview="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="80dp"
android:layout_margin="8dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="80dp">
<ImageView
android:id="#+id/deviceIcon"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_alignParentLeft="true"
android:layout_centerVertical="true"
android:scaleType="centerCrop"
android:layout_marginLeft="8dp" />
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="80dp"
android:layout_alignBottom="#+id/deviceIcon"
android:layout_toEndOf="#+id/deviceIcon">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Username"
android:id="#+id/deviceUsername"
android:layout_gravity="center_vertical"
android:textColor="#000000"
android:layout_marginLeft="5dp" />
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="50dp"
android:layout_gravity="center_vertical"
android:gravity="center_vertical|center_horizontal">
<TextView
android:layout_width="wrap_content"
android:layout_height="25dp"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="Device Model"
android:gravity="center_vertical|right"
android:textColor="#000000"
android:id="#+id/deviceModel"
android:layout_marginLeft="5dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="25dp"
android:textColor="#000000"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="Device Version"
android:gravity="center_vertical|right"
android:id="#+id/deviceVersion"
android:layout_marginLeft="5dp" />
</LinearLayout>
</LinearLayout>
devices_list.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="#dimen/activity_vertical_margin">
<view
android:id="#+id/connectedDevicesList"
class="android.support.v7.widget.RecyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true" />
</RelativeLayout>
View Holder Code
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import com.exampleapp.R;
public class DeviceViewHolder extends RecyclerView.ViewHolder {
protected ImageView deviceIcon;
protected TextView deviceUsername;
protected TextView deviceModel;
protected TextView deviceVersion;
public DeviceViewHolder(View view) {
super(view);
this.deviceIcon = (ImageView) view.findViewById(R.id.deviceIcon);
this.deviceUsername = (TextView) view.findViewById(R.id.deviceUsername);
this.deviceModel = (TextView) view.findViewById(R.id.deviceModel);
this.deviceVersion = (TextView) view.findViewById(R.id.deviceVersion);
}
}
RecyclerView Adapter
import android.content.Context;
import android.support.v4.content.ContextCompat;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import java.util.List;
import com.exampleapp.API.AuthorizedDevice;
import com.exampleapp.R;
public class ConnectedDeviceAdapter extends RecyclerView.Adapter<DeviceViewHolder> {
private List<AuthorizedDevice> devices;
private Context mContext;
public ConnectedDeviceAdapter(Context context, List<AuthorizedDevice> devices) {
this.devices = devices;
this.mContext = context;
}
#Override
public DeviceViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.connected_devices_layout, null);
DeviceViewHolder viewHolder = new DeviceViewHolder(view);
return viewHolder;
}
#Override
public void onBindViewHolder(DeviceViewHolder deviceViewHolder, int i) {
AuthorizedDevice device = devices.get(i);
if (device.getDeviceId().equals("0")) {
deviceViewHolder.deviceIcon.setBackground(ContextCompat.getDrawable(mContext, R.drawable.android_icon));
} else {
deviceViewHolder.deviceIcon.setBackground(ContextCompat.getDrawable(mContext, R.drawable.apple_icon));
}
deviceViewHolder.deviceUsername.setText(device.getUsername());
deviceViewHolder.deviceModel.setText(device.getDeviceName());
deviceViewHolder.deviceVersion.setText(device.getDeviceVersion());
}
#Override
public int getItemCount() {
return (null != devices ? devices.size() : 0);
}
}
Can anyone please help me solve this problem? Thank you very much in advance!

In your RecyclerView Adapter onCreateViewHolder:
replace:
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.connected_devices_layout, null);
with:
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.connected_devices_layout, viewGroup, false);
Or you can use RecyclerView.addItemDecoration(ItemDecoration decor).

how to make an expandable list of cardviews?

I searched a lot to find a direct and clear solution for I think a popular problem but unfortunately I couldn't find it.
We want to have a list of cardviews so each card bind to a specific data and each card has a list inside that shows meta or detail data about its parent.
So we have a nested list inside a cardview.
With a simple search, we know that we should use expanded list view which parents items are cardviews and we must have another layout for its child.
So when you click on cards a list of items appears below of your cards on the root.
But we want to show child list inside of cards?
And there is no access to the something like child list id or any other things to refer to a transition animation and change of layout.
So the clear question is how to add a listview inside a cardview?
i follow my work by using tablelayout and table row. and prefer not to use external libraries for stability and version problems.
this is what i mean.
Image that describe my question

If you don't want to use an external library, you can make your CardView expand like this:
Layout file for an expandable CardView
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
xmlns:card_view="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/cv"
android:layout_marginTop="5dp"
android:layout_marginLeft="5dp"
android:layout_marginRight="5dp"
card_view:cardCornerRadius="5dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:orientation="vertical">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="48dp"
>
<TextView
android:id="#+id/textView_name"
android:layout_marginTop="10dp"
android:layout_marginBottom="10dp"
android:textSize="18sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textStyle="bold" />
<!--My dropdown Button -->
<RelativeLayout
android:id="#+id/button"
android:layout_width="48dp"
android:layout_height="48dp"
android:layout_gravity="end"
android:layout_alignParentRight="true"
android:gravity="center"
>
<View
android:layout_width="12dp"
android:layout_height="12dp"
android:background="#drawable/triangle"
android:layout_alignParentRight="false"
android:layout_alignParentEnd="false" />
</RelativeLayout>
</RelativeLayout>
<!--The layout below is my ExpandableLayout -->
<LinearLayout
android:id="#+id/expandableLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
>
<android.support.v7.widget.AppCompatImageView
android:id="#+id/imageView_Owner"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:orientation="vertical">
<TextView
android:id="#+id/textView_Owner"
android:textSize="16sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="#+id/textView_OwnerUrl"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
</android.support.v7.widget.CardView>
My ExpandableRecyclerAdapter Class
import android.animation.ObjectAnimator;
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.util.SparseBooleanArray;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.LinearInterpolator;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.TextView;
import com.squareup.picasso.Picasso;
import java.util.List;
public class ExpandableRecyclerAdapter extends RecyclerView.Adapter<ExpandableRecyclerAdapter.ViewHolder> {
private List<Repo> repos;
private SparseBooleanArray expandState = new SparseBooleanArray();
private Context context;
public ExpandableRecyclerAdapter(List<Repo> repos) {
this.repos = repos;
//set initial expanded state to false
for (int i = 0; i < repos.size(); i++) {
expandState.append(i, false);
}
}
#Override
public ExpandableRecyclerAdapter.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
this.context = viewGroup.getContext();
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.expandable_card_row, viewGroup, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(final ExpandableRecyclerAdapter.ViewHolder viewHolder, final int i) {
viewHolder.setIsRecyclable(false);
viewHolder.tvName.setText(repos.get(i).getName());
viewHolder.tvOwnerLogin.setText("Owner: " +repos.get(i).getOwner().getLogin());
viewHolder.tvOwnerUrl.setText(repos.get(i).getOwner().getUrl());
Picasso.with(context)
.load(repos.get(i).getOwner().getImageUrl())
.resize(500, 500)
.centerCrop()
.into(viewHolder.ivOwner);
//check if view is expanded
final boolean isExpanded = expandState.get(i);
viewHolder.expandableLayout.setVisibility(isExpanded?View.VISIBLE:View.GONE);
viewHolder.buttonLayout.setRotation(expandState.get(i) ? 180f : 0f);
viewHolder.buttonLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(final View v) {
onClickButton(viewHolder.expandableLayout, viewHolder.buttonLayout, i);
}
});
}
#Override
public int getItemCount() {
return repos.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
private TextView tvName,tvOwnerLogin, tvOwnerUrl;
private ImageView ivOwner;
public RelativeLayout buttonLayout;
public LinearLayout expandableLayout;
public ViewHolder(View view) {
super(view);
tvName = (TextView)view.findViewById(R.id.textView_name);
tvId = (TextView)view.findViewById(R.id.textView_id);
tvUrl = (TextView)view.findViewById(R.id.textView_url);
tvOwnerLogin = (TextView)view.findViewById(R.id.textView_Owner);
tvOwnerUrl = (TextView)view.findViewById(R.id.textView_OwnerUrl);
ivOwner = (ImageView) view.findViewById(R.id.imageView_Owner);
buttonLayout = (RelativeLayout) view.findViewById(R.id.button);
expandableLayout = (LinearLayout) view.findViewById(R.id.expandableLayout);
}
}
private void onClickButton(final LinearLayout expandableLayout, final RelativeLayout buttonLayout, final int i) {
//Simply set View to Gone if not expanded
//Not necessary but I put simple rotation on button layout
if (expandableLayout.getVisibility() == View.VISIBLE){
createRotateAnimator(buttonLayout, 180f, 0f).start();
expandableLayout.setVisibility(View.GONE);
expandState.put(i, false);
}else{
createRotateAnimator(buttonLayout, 0f, 180f).start();
expandableLayout.setVisibility(View.VISIBLE);
expandState.put(i, true);
}
}
//Code to rotate button
private ObjectAnimator createRotateAnimator(final View target, final float from, final float to) {
ObjectAnimator animator = ObjectAnimator.ofFloat(target, "rotation", from, to);
animator.setDuration(300);
animator.setInterpolator(new LinearInterpolator());
return animator;
}
}
In your Activity/Fragment, set up RecyclerView like this
private RecyclerView recyclerView;
private List<Repo> data;
recyclerView = (RecyclerView)findViewById(R.id.card_recycler_view);
recyclerView.setHasFixedSize(true);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getApplicationContext());
recyclerView.setLayoutManager(layoutManager);
//fetch data and on ExpandableRecyclerAdapter
recyclerView.setAdapter(new ExpandableRecyclerAdapter(data));
So, its quite simple to create an expandable CardView without external Library. The code is almost exactly the same as using a normal CardView with RecyclerView, the main change is setting the View.GONE/View.VISIBLE on button click.

You can use ExpandLayout,and then add it in cardview.
<com.kyo.expandablelayout.ExpandableLayout
android:id="#+id/expandlayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="12dp" >
<ImageView
android:id="#+id/imageview"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:contentDescription="#null"
android:scaleType="centerCrop"
android:src="#drawable/parent" />
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="6dp"
android:contentDescription="#null"
android:scaleType="centerCrop"
android:src="#drawable/child"
app:canExpand="true" />
</com.kyo.expandable.ExpandableLayout>

how to remove empty list item in recycler views?

I'm using recycler view to show items with multiple views. whenever I launch the app some white space is being showed. which is exactly equal to my list items.
I provided the screenshot please go through it.
I think there is no problem with my code.
following is my code
recyclerview
<?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"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".activities.GroupView">
<android.support.v7.widget.RecyclerView
android:id="#+id/recycler_view_group_content"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical" >
</android.support.v7.widget.RecyclerView>
</RelativeLayout>
adapter code
import android.content.Context;
import android.support.v7.widget.CardView;
import android.support.v7.widget.RecyclerView;
import android.text.TextUtils;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import java.util.List;
import java.util.Objects;
import pdfshare.hemanthreddy.com.pdfshare.R;
import pdfshare.hemanthreddy.com.pdfshare.pojo.PdfItemHolder;
import pdfshare.hemanthreddy.com.pdfshare.pojo.RequestPojo;
public class GroupContentAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
final int PDF = 0,REQUEST = 1;
List<Object> list;
OnClickListener onClickListener;
Context context;
public GroupContentAdapter(List<Object> list, OnClickListener onClickListener, Context context) {
this.list = list;
this.onClickListener = onClickListener;
this.context = context;
}
public class PdfHolder extends RecyclerView.ViewHolder {
TextView pdfName,pdfDescription,Helped,uploadedBy;
Button downloadPdf,viewPdf;
View container;
CardView cardView;
public PdfHolder(View itemView) {
super(itemView);
container = itemView;
uploadedBy = (TextView) itemView.findViewById(R.id.pdf_info_uplodedby);
pdfName = (TextView) itemView.findViewById(R.id.pdf_name);
pdfDescription = (TextView) itemView.findViewById(R.id.pdf_description);
Helped = (TextView) itemView.findViewById(R.id.helped);
downloadPdf = (Button) itemView.findViewById(R.id.download_pdf);
viewPdf = (Button) itemView.findViewById(R.id.view_pdf);
cardView = (CardView) itemView.findViewById(R.id.card_view_pdf_row);
}
}
public class RequestHolder extends RecyclerView.ViewHolder {
View container;
TextView name,request;
public RequestHolder(View itemView) {
super(itemView);
container = itemView;
name = (TextView) itemView.findViewById(R.id.requested_name);
request = (TextView) itemView.findViewById(R.id.request);
}
}
public interface OnClickListener{
public void OnItemClick(View view,int position);
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
RecyclerView.ViewHolder viewHolder;
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
switch (viewType) {
case PDF:
View v1 = inflater.inflate(R.layout.pdf_row_view,parent,false);
viewHolder = new PdfHolder(v1);
break;
case REQUEST:
View v2 = inflater.inflate(R.layout.group_request_row_view,parent,false);
viewHolder = new RequestHolder(v2);
break;
default:
View v3 = inflater.inflate(R.layout.pdf_row_view,parent,false);
viewHolder = new PdfHolder(v3);
}
return viewHolder;
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {
if(holder.getItemViewType() == PDF)
{
PdfItemHolder pdfItemHolder = (PdfItemHolder) list.get(position);
PdfHolder pdfHolder = (PdfHolder) holder;
if(!TextUtils.isEmpty(pdfItemHolder.getPdfName())) {
pdfHolder.pdfName.setText(pdfItemHolder.getPdfName());
pdfHolder.pdfDescription.setText(pdfItemHolder.getPdfDescription());
pdfHolder.Helped.setText(pdfItemHolder.getHelped());
pdfHolder.uploadedBy.setText(pdfItemHolder.getUplodedBy());
pdfHolder.downloadPdf.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(context, "downloading pdf bitch", Toast.LENGTH_LONG).show();
}
});
pdfHolder.container.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
onClickListener.OnItemClick(v, position);
}
});
}
else
{
Toast.makeText(context,"empty",Toast.LENGTH_LONG).show();
Log.e("empty","empty");
pdfHolder.container.setVisibility(View.GONE);
pdfHolder.pdfName.setVisibility(View.GONE);
pdfHolder.pdfDescription.setVisibility(View.GONE);
pdfHolder.Helped.setVisibility(View.GONE);
pdfHolder.downloadPdf.setVisibility(View.GONE);
pdfHolder.uploadedBy.setVisibility(View.GONE);
pdfHolder.viewPdf.setVisibility(View.GONE);
}
}
else
{
RequestHolder requestHolder = (RequestHolder) holder;
RequestPojo requestPojo = (RequestPojo) list.get(position);
requestHolder.name.setText(requestPojo.getName());
requestHolder.request.setText(requestPojo.getRequest());
}
}
#Override
public int getItemCount() {
return list.size();
}
#Override
public int getItemViewType(int position)
{
if(list.get(position) instanceof PdfItemHolder)
return PDF;
else if(list.get(position) instanceof RequestPojo)
return REQUEST
;
return -1;
}
}
also I checked stack overflow to remove spaces and I added some code to adapter to check wheather the data is empty or not, it didn't worked well.
following Is code of row views`group_row_view code
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:text="Requested By : "
android:id="#+id/textView7" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Name"
android:id="#+id/requested_name"
android:layout_alignParentTop="true"
android:layout_toRightOf="#+id/textView7"
android:layout_toEndOf="#+id/textView7" />
<View
android:layout_width="fill_parent"
android:layout_height="2dp"
android:background="#c0c0c0"
android:id="#+id/view1"
android:layout_below="#+id/textView7"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:text="Medium Text"
android:id="#+id/request"
android:lines="2"
android:layout_below="#+id/view1"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"/>
</RelativeLayout>
</android.support.v7.widget.CardView>
code of Pdf_row_view
</LinearLayout>`
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:card_view="http://schemas.android.com/apk/res-auto">
<android.support.v7.widget.CardView
android:id="#+id/card_view_pdf_row"
android:layout_gravity="center"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp"
card_view:cardCornerRadius="3dp"
card_view:contentPadding="2dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="250dp"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="pdfName"
android:id="#+id/pdf_name"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:textSize="25dp"
android:lines="1" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="pdf descriptionl"
android:id="#+id/pdf_description"
android:layout_below="#+id/pdf_name"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:lines="2" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="View Pdf"
android:id="#+id/view_pdf"
android:layout_alignTop="#+id/download_pdf"
android:layout_toRightOf="#+id/pdf_info_uplodedby"
android:layout_toEndOf="#+id/pdf_info_uplodedby" />
<Button
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Download Pdf"
android:id="#+id/download_pdf"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_below="#+id/pdf_description" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="helped"
android:id="#+id/helped"
android:textSize="15dp"
android:layout_alignBottom="#+id/view_pdf"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<View
android:layout_width="fill_parent"
android:layout_height="2dp"
android:background="#c0c0c0"
android:layout_alignTop="#+id/view_pdf"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:id="#+id/view" />
<View
android:layout_width="fill_parent"
android:layout_height="2dp"
android:background="#c0c0c0"
android:id="#+id/view1"
android:layout_below="#+id/view_pdf"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:text="Upladed by : "
android:id="#+id/pdf_info_uplodedby"
android:layout_below="#+id/view_pdf"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
</RelativeLayout>
</android.support.v7.widget.CardView>
</RelativeLayout>
please help me.. thank you

In all of your list item layout files:
pdf_row_view.xml, group_request_row_view.xml, pdf_row_view.xml
set layout_height="wrap_content" of their root layout

Remove the match_parent and set wrap_content as the layout_height instead in the root of your layout of your list items.
For example your pdf_row_view.xml should look like this
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:card_view="http://schemas.android.com/apk/res-auto">
<android.support.v7.widget.CardView
android:id="#+id/card_view_pdf_row"
android:layout_gravity="center"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp"
card_view:cardCornerRadius="3dp"
card_view:contentPadding="2dp">
<!-- Other elements in your layout -->
</android.support.v7.widget.CardView>
</RelativeLayout>
See, I've set the android:layout_height="wrap_content" in the root RelativeLayout of your pdf_row_view list item.
Do the same for the other list item layouts.

Just set the height of the rootView of specific viewHolder to 0 like this -
RecyclerView.LayoutParams layoutParams = new RecyclerView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
layoutParams.height = 0;
rootView.setLayoutParams(layoutParams);
where rootView is same as this -
ViewHolder(View view) {
super(view);
rootView = view;
}
Let me know if you want more clarity on this.