I'm using AndroidStudio3.2.1. I'm designing a recycler view, when running it using emulator, it does not fill the whole width of the activity. Why is this happening?
I tried "fill_parent", "layout_weight" but none of that worked. I have a CardView that contains the components that should appear in the view holder.
The layout of the main activity
<?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/linearLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerView"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
The layout of list_items that will be displayed in each ViewHolder
<?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:id="@+id/linearLayout3"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<android.support.v7.widget.CardView
android:id="@+id/cardView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="10dp"
android:layout_marginLeft="10dp"
android:layout_marginTop="10dp"
android:layout_marginEnd="10dp"
android:layout_marginRight="10dp"
android:layout_marginBottom="10dp"
android:layout_weight="0"
app:cardBackgroundColor="@color/colorPrimary"
app:cardCornerRadius="5dp"
app:cardElevation="6dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:orientation="vertical">
<TextView
android:id="@+id/textViewTeacher"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView"
android:textSize="18sp" />
<TextView
android:id="@+id/textViewID"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Section 1"
android:textSize="18sp" />
<TextView
android:id="@+id/textViewName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Database 1"
android:textSize="18sp" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="2"
android:gravity="center"
android:orientation="vertical">
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />
</LinearLayout>
</LinearLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
The code for MainActivity.java
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private RecyclerView recyclerView;
private SectionAdapter adapter;
private List<Section> sectionList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = findViewById(R.id.recyclerView);
sectionList = new ArrayList<Section>();
LinearLayoutManager layoutManager = new LinearLayoutManager(this);
layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
recyclerView.setLayoutManager(layoutManager);
Section sec = null;
sec = new Section("Database 1", "Section 1", "John Stanford");
sectionList.add (sec);
sec = new Section("Database 1", "Section 1", "John Stanford");
sectionList.add (sec);
sec = new Section("Database 1", "Section 1", "John Stanford");
sectionList.add (sec);
sec = new Section("Database 1", "Section 1", "John Stanford");
sectionList.add (sec);
sec = new Section("Database 1", "Section 1", "John Stanford");
sectionList.add (sec);
sec = new Section("Database 1", "Section 1", "John Stanford");
sectionList.add (sec);
sec = new Section("Database 1", "Section 1", "John Stanford");
sectionList.add (sec);
adapter = new SectionAdapter(this,sectionList);
recyclerView.setHasFixedSize(true);
recyclerView.setAdapter(adapter);
}
}
The code for the Adapter
import android.content.Context;
import android.support.annotation.NonNull;
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.TextView;
import android.widget.Toast;
import java.util.List;
public class SectionAdapter extends RecyclerView.Adapter<SectionAdapter.SectionViewHolder> {
private Context context;
private List<Section> sectionList;
public SectionAdapter(Context context, List<Section> sectionList) {
this.context = context;
this.sectionList = sectionList;
}
@NonNull
@Override
public SectionViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(context);
View view = inflater.inflate(R.layout.list_layout,null);
return new SectionViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull SectionViewHolder holder, int position) {
Section sec = sectionList.get(position);
holder.setValues(sec);
}
@Override
public int getItemCount() {
return sectionList.size();
}
class SectionViewHolder extends RecyclerView.ViewHolder
{
private TextView nameTV;
private TextView idTV;
private TextView teacherTV;
public SectionViewHolder(View itemView) {
super(itemView);
nameTV = itemView.findViewById(R.id.textViewName);
idTV = itemView.findViewById(R.id.textViewID);
teacherTV = itemView.findViewById(R.id.textViewTeacher);
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
int pos = getAdapterPosition();
Toast.makeText(context, "Laptop "+pos+" has been clicked", Toast.LENGTH_LONG).show();
}
});
}
public void setValues(Section sec)
{
nameTV.setText(sec.getName());
idTV.setText(sec.getId());
teacherTV.setText(sec.getTeacher());
}
}
}
The code for Section.java
public class Section {
private String name;
private String id;
private String teacher;
public Section(String name, String id, String teacher) {
this.name = name;
this.id = id;
this.teacher = teacher;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getTeacher() {
return teacher;
}
public void setTeacher(String teacher) {
this.teacher = teacher;
}
}
