Battery Level Android App Using Android Studio

Introduction

 

In this article, I will show you how to create an Android app that shows the Battery Level of your device.A battery is an electrochemical cell (or enclosed and protected material) that can be charged electrically to provide a static potential for power or released electrical charge when needed.

 

Requirements

• Android Studio version 2.3.3
• Little bit XML and JAVA knowledge.
• Android Emulator (or) Android mobile
• Download link (Android Studio)

Steps to be followed

 

Follow these steps to create the app using Android Studio. I have attached the source code too.

 

Step 1

 

Open Android Studio and start a new Android Studio Project.

 

 

Step 2

 

You can choose your application name and choose where your project is stored. If you wish to use C++ for coding the project, mark the "Include C++ support", and click the "Next" button.

 

 

Step 3

 

Now, select the version of Android and select the target Android devices. We need to choose the SDK level which plays an important role to run the application.

 

 

Step 4

 

Now, add the activity and click the "Next" button.

 

 

Step 5

 

Add Activity name and click "Finish".

 

 

Step 6

 

Go to activity_main.xml. This XML file contains the designing code for the Android app.

 

 

The XML code is given below.

<?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:padding="16dp"
    tools:context=".MainActivity"
    android:background="#d5ebfa"
    >
    <ProgressBar
        android:id="@+id/pb"
        android:layout_width="150dp"
        android:layout_height="150dp"
        style="@android:style/Widget.ProgressBar.Horizontal"
     android:progressDrawable="@layout/progressbar_states"
        android:layout_centerInParent="true"
        />
    <TextView
        android:id="@+id/tv_percentage"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="25dp"
        android:textColor="#000"
        android:layout_centerInParent="true"
        />
    <TextView
        android:id="@+id/tv_info"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20dp"
        />
</RelativeLayout>

Step 7

 

Go to Main Activity.java. This Java program is the back-end language of Android.

 

 

The java code is given below.

package abu.battery;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.BatteryManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Window;
import android.widget.ProgressBar;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    private Context mContext;

    private TextView mTextViewInfo;
    private TextView mTextViewPercentage;
    private ProgressBar mProgressBar;
    private int mProgressStatus = 0;
    private BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {

            int scale = intent.getIntExtra(BatteryManager.EXTRA_SCALE,-1);

            mTextViewInfo.setText("Battery Scale : " + scale)

            int level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL,-1);
            mTextViewInfo.setText(mTextViewInfo.getText() + "\nBattery Level : " + level);
            float percentage = level/ (float) scale;
            mProgressStatus = (int)((percentage)*100);
            mTextViewPercentage.setText("" + mProgressStatus + "%");
            mTextViewInfo.setText(mTextViewInfo.getText() +
                    "\nPercentage : "+ mProgressStatus + "%");
            mProgressBar.setProgress(mProgressStatus);
        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        requestWindowFeature(Window.FEATURE_ACTION_BAR);
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mContext = getApplicationContext();
        IntentFilter iFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
        mContext.registerReceiver(mBroadcastReceiver,iFilter);
        mTextViewInfo = (TextView) findViewById(R.id.tv_info);
        mTextViewPercentage = (TextView) findViewById(R.id.tv_percentage);
        mProgressBar = (ProgressBar) findViewById(R.id.pb);
    }
}

Step 8

 

Go to (App ⇒ Res ⇒Layout⇒progressbar_states.xml).

 

 

The Progressbar_states.xml code is given below.

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="match_parent" android:layout_width="match_parent">
    <item android:id="@android:id/background">
        <shape
            android:shape="oval">
            <stroke
                android:width="5dp"
                android:color="#d0d4d7"
                />
            <solid android:color="#eef2f5"/>
        </shape>
    </item>
    <item android:id="@android:id/progress">
        <clip android:clipOrientation="vertical" android:gravity="bottom">
            <shape
                android:shape="oval">
                <stroke
                    android:width="5dp"
                    android:color="#ff0001"
                    />
                <gradient
                    android:startColor="#7fc97c"
                    android:endColor="#99f396"
                    android:centerColor="#89e386"
                    android:angle="270"
                    android:gradientRadius="50"
                    android:centerY=".50"
                    />
            </shape>
        </clip>
    </item>
</layer-list>

Step 9

 

Now, go to the menu bar and click "Make a project" or press ctrl+f9 to debug the error.

 

 

Step 10

 

Then, click the Run button or press shift+f10 to run the project. And, choose the virtual machine option and click OK.

 

 

Conclusion

 

We have successfully created an app that shows the battery level of our Android phone.