Android - Creating a simple wallpaper app

In this post we will learn how to set images as wallpaper and develop a simple android application which sets images as wallpaper to our mobile devices. Here we take an image and save it in our drawable folder and use that image to set that as a wallpaper.

Firstly create a new android project,



click next  2 or 3 times until finish button appears.

Then first we desgin the layout i.e the xml part , here we have just one  image view and one button to set that image as wallpaper.

 We will set the image size to  200 * 200 (for the tutorial sake),

<ImageView
        android:layout_width="200dp"
        android:layout_height="200dp"
        android:id="@+id/imageView"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true" />

and one button ,

<Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Set as wallpaper"
        android:id="@+id/button"
        android:layout_below="@+id/imageView"
        android:layout_centerHorizontal="true" />

Now lets do the java part.

Firstly initialize the imageview and button we used in activity_man.xml file

ImageView iv = (ImageView) findViewById(R.id.imageView);
        Button button = (Button) findViewById(R.id.button);

now copy any image you want and paste in drawable folder , i haved named my image as cc.jpg

Now set this image as the resource for the imageview we used

iv.setImageResource(R.drawable.cc);

Now we the button  is clicked, this image will set as a wallpaper ,
here we convert the image into bitmap and then set that image as a wallpaper , for that we use BitmapFactory class.

First we take the input resource for the BitmapFactory , the input stream accepts only an int value as a paramater , so we store our image in an integer,

int wallpaper;

at the beginning , just above the onCreate activity
and later when button is clicked set this as

wallpaper = R.drawable.cc;

now when the button is clicked,

button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                InputStream is = getResources().openRawResource(wallpaper);
                Bitmap bm = BitmapFactory.decodeStream(is);
                WallpaperManager wallpaperManager = WallpaperManager.getInstance(MainActivity.this);
                try {
                    wallpaperManager.setBitmap(bm);
                    Toast toast = Toast.makeText(MainActivity.this, "Set wallpaper successfully!", Toast.LENGTH_LONG);
                    toast.show();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        });

This will set the image as a wallpaper,

The complete MainActivity.java file is ,

package com.blogspot.codingcorner999.wallpaperapp;

import android.app.WallpaperManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

import java.io.IOException;
import java.io.InputStream;


public class MainActivity extends ActionBarActivity {

    int wallpaper;

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

        ImageView iv = (ImageView) findViewById(R.id.imageView);
        Button button = (Button) findViewById(R.id.button);

        iv.setImageResource(R.drawable.cc);


        wallpaper = R.drawable.cc;
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                InputStream is = getResources().openRawResource(wallpaper);
                Bitmap bm = BitmapFactory.decodeStream(is);
                WallpaperManager wallpaperManager = WallpaperManager.getInstance(MainActivity.this);
                try {
                    wallpaperManager.setBitmap(bm);
                    Toast toast = Toast.makeText(MainActivity.this, "Set wallpaper successfully!", Toast.LENGTH_LONG);
                    toast.show();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        });


    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

For setting wallpaper we need to add a permission to set wallpaper in manifest file  as the android system must have all the information of the app before running the app. So all the activities , permissions must be included in manifest.xml file.

The permission we need is SET_WALLPAPER

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

The complete manifest file looks like,

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.blogspot.codingcorner999.wallpaperapp" >
    <uses-permission android:name="android.permission.SET_WALLPAPER"></uses-permission>
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

</manifest>

Thats it we are done.

OUTPUT :