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<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.it.lec10_v3permissions">
<uses-permission android:name="android.permission.READ_CONTACTS"/>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        Dexter.withActivity(this)
                .withPermission(Manifest.permission.CAMERA)
                .withListener(new PermissionListener() {
                    @Override public void onPermissionGranted(PermissionGrantedResponse response) {
                        ContactsAdapter contactsAdapter = new ContactsAdapter(readContacts(),MainActivity.this);
                        RecyclerView recyclerView = findViewById(R.id.contactsRecycler);
                        recyclerView.setAdapter(contactsAdapter);
                        //readContacts();
                    }
                    @Override public void onPermissionDenied(PermissionDeniedResponse response) {
                        finish();
                    }
                    @Override public void onPermissionRationaleShouldBeShown(PermissionRequest permission, PermissionToken token) {
                        token.continuePermissionRequest();
                    }
                }).check();

    }

    public ArrayList<Contact> readContacts(){

        ArrayList<Contact> data = new ArrayList<>();

        ContentResolver cr = getContentResolver();
        Cursor cur = cr.query(ContactsContract.Contacts.CONTENT_URI, null, null, null, null);
        if (cur.getCount() > 0) {
            while (cur.moveToNext()) {
                String id = cur.getString(cur.getColumnIndex(ContactsContract.Contacts._ID));
                String name = cur.getString(cur.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
                String phoneNumber = "";
                if (Integer.parseInt(cur.getString(cur.getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER))) > 0) {

                    Cursor pCur = cr.query(
                            ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
                            null,
                            ContactsContract.CommonDataKinds.Phone.CONTACT_ID +" = ?",
                            new String[]{id}, null);

                    while (pCur.moveToNext()) {
                        int phoneType = pCur.getInt(pCur.getColumnIndex(
                                ContactsContract.CommonDataKinds.Phone.TYPE));
                        phoneNumber = pCur.getString(pCur.getColumnIndex(
                                ContactsContract.CommonDataKinds.Phone.NUMBER));
                        switch (phoneType) {
                            case ContactsContract.CommonDataKinds.Phone.TYPE_MOBILE:
                                Log.e(name + "(mobile number)", phoneNumber);
                                break;
                            case ContactsContract.CommonDataKinds.Phone.TYPE_HOME:
                                Log.e(name + "(home number)", phoneNumber);
                                break;
                            case ContactsContract.CommonDataKinds.Phone.TYPE_WORK:
                                Log.e(name + "(work number)", phoneNumber);
                                break;
                            case ContactsContract.CommonDataKinds.Phone.TYPE_OTHER:
                                Log.e(name + "(other number)", phoneNumber);
                                break;
                            default:
                                break;
                        }
                    }

                    pCur.close();
                }

                data.add(new Contact(id,name,phoneNumber));
            }
        }
        return data;
    }

}

public class Contact {
    private String id;
    private String name;
    private String numbers;

    public Contact(String id, String name, String numbers) {
        this.id = id;
        this.name = name;
        this.numbers = numbers;
    }
}

public class ContactsAdapter extends RecyclerView.Adapter<ContactsAdapter.MyViewHolder> {

    ArrayList<Contact> data;
    Activity activity;

    public ContactsAdapter(ArrayList<Contact> data, Activity activity) {
        this.data = data;
        this.activity = activity;
    }

    @NonNull
    @Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        View itemView = (View) LayoutInflater.from(activity).inflate(R.layout.contact_item, viewGroup, false);
        return new MyViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(@NonNull MyViewHolder myViewHolder, int i) {

        myViewHolder.tvID.setText(data.get(i).getId() + "");
        myViewHolder.tvName.setText(data.get(i).getName());
        myViewHolder.tvNumbers.setText(data.get(i).getNumbers());


    }

    @Override
    public int getItemCount() {
        return data.size();
    }

    public class MyViewHolder extends RecyclerView.ViewHolder {

        public TextView tvID;
        public TextView tvName;
        public TextView tvNumbers;

        public MyViewHolder(@NonNull View itemView) {
            super(itemView);
            tvID = itemView.findViewById(R.id.tvID);
            tvName = itemView.findViewById(R.id.tvName);
            tvNumbers = itemView.findViewById(R.id.tvNumbers);
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/linear"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <android.support.v7.widget.CardView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_margin="10dp"
        android:elevation="20dp">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical"
            android:textAlignment="center">

            <TextView
                android:id="@+id/tvID"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="TextView"
                android:textAlignment="center" />

            <TextView
                android:id="@+id/tvName"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="TextView"
                android:textAlignment="center" />

            <TextView
                android:id="@+id/tvNumbers"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="TextView"
                android:textAlignment="center" />


        </LinearLayout>


    </android.support.v7.widget.CardView>
</LinearLayout>

<?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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/contactsRecycler"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

dependencies{
    implementation 'com.karumi:dexter:5.0.0'
}

public MyActivity extends Activity {
	@Override public void onCreate() {
		super.onCreate();
		Dexter.withActivity(activity)
			.withPermission(permission)
			.withListener(listener)
			.check();
	}
}

Dexter.withActivity(this)
	.withPermission(Manifest.permission.CAMERA)
	.withListener(new PermissionListener() {
		@Override public void onPermissionGranted(PermissionGrantedResponse response) {/* ... */}
		@Override public void onPermissionDenied(PermissionDeniedResponse response) {/* ... */}
		@Override public void onPermissionRationaleShouldBeShown(PermissionRequest permission, PermissionToken token) {/* ... */}
	}).check();