Broadcast Receiver Exercise

//--------------------- AndroidManifest.xml -----------------------

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.sgl.broadcastreceiver">

    <uses-permission android:name="android.permission.READ_PHONE_STATE" />
    <uses-permission android:name="android.permission.READ_CALL_LOG" />

    <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"
        tools:ignore="GoogleAppIndexingWarning">
        <receiver
            android:name=".CallReceiver"
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.PHONE_STATE"/>
                <action android:name="android.intent.action.CALL_LOG"/>
            </intent-filter>
        </receiver>

        <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>


// --------------------------- MainActivity.java ----------------------------

package com.sgl.broadcastreceiver;

import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

import android.Manifest;
import android.app.Activity;
import android.content.Context;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.telephony.TelephonyManager;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.Set;

public class MainActivity extends AppCompatActivity {

    Context context;
    private ArrayList<String> callsList;
    private static final String SHARED_PREFERENCES = "sharedPreferences";
    private static int index = 0;
    private ListView incomingList;
    SharedPreferences sharedPreferences;
    SharedPreferences.Editor editor;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setPointer();
    }

    private void setPointer() {
        this.context = this;
        sharedPreferences = getSharedPreferences(SHARED_PREFERENCES, MODE_PRIVATE);
        editor = sharedPreferences.edit();
        callsList = new ArrayList<>();
        if((ContextCompat.checkSelfPermission(context, Manifest.permission.READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED) &&
           (ContextCompat.checkSelfPermission(context, Manifest.permission.READ_CALL_LOG) != PackageManager.PERMISSION_GRANTED)) {
                ActivityCompat.requestPermissions((Activity) context, new String[]{Manifest.permission.READ_PHONE_STATE}, 1);
                ActivityCompat.requestPermissions((Activity) context, new String[] {Manifest.permission.READ_CALL_LOG}, 1);
        } else {
            // Permission is already granted
            incomingList = findViewById(R.id.incoming_calls_list);
            if(index == 0) clearSPList();
            registerReceiver(new CallReceiver(), new IntentFilter(TelephonyManager.EXTRA_INCOMING_NUMBER));
            Bundle extras = getIntent().getExtras();
            if(extras != null) {
                String phNumber = extras.getString("phoneNumber");
                saveData(phNumber);
                loadData();
            }
            incomingList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                @Override
                public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                    if(sharedPreferences.getAll().size() > 0) {
                        editor.remove(((TextView)view.findViewById(R.id.callNumber)).getText().toString());
                        editor.commit();
                        index--;
                        loadData();
                    }
                }
            });
        }
    }

    private void saveData(String data) {
        int x = Integer.parseInt(sharedPreferences.getString(data, "0"));
        x += 1;
        editor.putString(data, Integer.toString(x));
        index++;
        editor.commit();
    }

    private void clearSPList() {
        editor.clear();
        editor.commit();
        callsList.clear();
    }

    private void loadData() {
        callsList.clear();
        callsList.addAll(sharedPreferences.getAll().keySet());
        for(int i = 0; i < callsList.size(); i++) {
            if(Integer.parseInt(sharedPreferences.getString(callsList.get(i), "-1")) > 1) {
                callsList.set(i, callsList.get(i) + " (" + sharedPreferences.getString(callsList.get(i), "-1") + ")");
            }
        }
        CallAdapter callAdapter = new CallAdapter(context, callsList);
        incomingList.setAdapter(callAdapter);
    }
}


// ---------------------- CallReceiver.java -----------------------------

package com.sgl.broadcastreceiver;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.telephony.TelephonyManager;

public class CallReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        if(intent.getStringExtra(TelephonyManager.EXTRA_STATE).equals(TelephonyManager.EXTRA_STATE_RINGING)) {
            String phNumber = intent.getStringExtra(TelephonyManager.EXTRA_INCOMING_NUMBER);
            if(phNumber == null) return;
            Intent intent1 = new Intent(context, MainActivity.class);
            intent1.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            intent1.putExtra("phoneNumber", phNumber);
            context.startActivity(intent1);
        }
    }
}


//------------------------ CallAdapter.java -----------------------------

package com.sgl.broadcastreceiver;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import java.util.ArrayList;

class CallAdapter extends BaseAdapter {

    Context context;
    ArrayList<String> callsList;

    public CallAdapter(Context context, ArrayList<String> callsList) {
        this.context = context;
        this.callsList = callsList;
    }

    @Override
    public int getCount() {
        return callsList.size();
    }

    @Override
    public Object getItem(int position) {
        return callsList.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        final View singleCall = LayoutInflater.from(context).inflate(R.layout.call_layout, null);
        final TextView number = singleCall.findViewById(R.id.callNumber);
        number.setText(callsList.get(position));
        return singleCall;
    }
}


// ------------------------ activity_main.xml ------------------------------------

<?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="match_parent"
    tools:context=".MainActivity">

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

        <TextView
            android:id="@+id/title"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="6"
            android:background="#3949AB"
            android:gravity="center"
            android:text="@string/call_receiver"
            android:textColor="#FAFFFFFF"
            android:textSize="36sp" />

        <ListView
            android:id="@+id/incoming_calls_list"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1" />
    </LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>


// ---------------------- call_layout.xml -----------------------------

<?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"
    android:id="@+id/call_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="20dp"
    android:background="#3C00ACC1"
    android:orientation="horizontal">

    <ImageView
        android:id="@+id/imgCall"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        android:layout_weight="1"
        android:contentDescription="@string/img_call"
        android:padding="5dp"
        app:srcCompat="@drawable/call" />

    <TextView
        android:id="@+id/callNumber"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_weight="3"
        android:gravity="center"
        android:text="@string/_5555555555"
        android:textSize="30sp" />
</LinearLayout>