adding set wallpaper sample code in ApiDemos.

samples/ApiDemos/AndroidManifest.xml

@@ -27,6 +27,7 @@
     <uses-permission android:name="android.permission.VIBRATE" />
     <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
     <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.SET_WALLPAPER" />
 
     <!-- We will request access to the camera, saying we require a camera
          of some sort but not one with autofocus capability. -->
@@ -187,6 +188,14 @@
         <activity android:name=".app.ReorderThree" />
         <activity android:name=".app.ReorderFour" />
         
+        <activity android:name=".app.SetWallpaperActivity"
+                  android:label="@string/activity_setwallpaper">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.SAMPLE_CODE" />
+            </intent-filter>
+        </activity>
+
         <!-- Intent Samples -->
 
         <activity android:name=".app.Intents" android:label="@string/activity_intents">

samples/ApiDemos/res/layout/wallpaper_2.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8"?>
+<FrameLayout 
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content">
+    <ImageView 
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:id="@+id/imageview" />
+    <LinearLayout
+        android:orientation="horizontal"
+        android:layout_width="wrap_content"
+        android:layout_height="fill_parent">
+        <Button 
+            android:id="@+id/randomize"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="Randomize"
+            android:layout_gravity="bottom" />
+        <Button
+            android:id="@+id/setwallpaper"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="Set Wallpaper"
+            android:layout_gravity="bottom" />
+    </LinearLayout>
+</FrameLayout>

samples/ApiDemos/res/values/strings.xml

@@ -39,6 +39,7 @@
             customized dialog, here with an ugly frame.</string>
 
     <string name="activity_wallpaper">App/Activity/Wallpaper</string>
+    <string name="activity_setwallpaper">App/Activity/SetWallpaper</string>
     
     <string name="activity_translucent">App/Activity/Translucent</string>
     <string name="translucent_background">Example of how you can make an

samples/ApiDemos/src/com/example/android/apis/app/SetWallpaperActivity.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.android.apis.app;
+
+// Need the following import to get access to the app resources, since this
+// class is in a sub-package.
+import com.example.android.apis.R;
+
+import java.io.IOException;
+
+import android.app.Activity;
+import android.app.WallpaperManager;
+import android.graphics.Color;
+import android.graphics.PorterDuff;
+import android.graphics.drawable.BitmapDrawable;
+import android.os.Bundle;
+import android.view.View;
+import android.view.WindowManager;
+import android.view.View.OnClickListener;
+import android.widget.Button;
+import android.widget.ImageView;
+
+/**
+ * <h3>SetWallpaper Activity</h3>
+ *
+ * <p>This demonstrates the how to write an activity that gets the current system wallpaper,
+ * modifies it and sets the modified bitmap as system wallpaper.</p>
+ */
+public class SetWallpaperActivity extends Activity {
+    /**
+     * Initialization of the Activity after it is first created.  Must at least
+     * call {@link android.app.Activity#setContentView setContentView()} to
+     * describe what is to be displayed in the screen.
+     */
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        // Be sure to call the super class.
+        super.onCreate(savedInstanceState);        
+        // See assets/res/layout/wallpaper2.xml for this
+        // view layout definition, which is being set here as
+        // the content of our screen.
+        setContentView(R.layout.wallpaper_2);
+        final WallpaperManager mWallpaperManager = WallpaperManager.getInstance(this);
+        final BitmapDrawable mWallpaperDrawable = (BitmapDrawable) mWallpaperManager.getDrawable();
+        final ImageView imageView = (ImageView) findViewById(R.id.imageview);
+        imageView.setDrawingCacheEnabled(true);
+        imageView.setImageDrawable(mWallpaperDrawable);
+
+        Button randomize = (Button) findViewById(R.id.randomize);
+        randomize.setOnClickListener(new OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                int mColor = (int) Math.floor(Math.random() * mColors.length);
+                mWallpaperDrawable.setColorFilter(mColors[mColor], PorterDuff.Mode.MULTIPLY);
+                imageView.setImageDrawable(mWallpaperDrawable);
+                imageView.invalidate();
+            }
+        });
+
+        Button setWallpaper = (Button) findViewById(R.id.setwallpaper);
+        setWallpaper.setOnClickListener(new OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                try {
+                    mWallpaperManager.setBitmap(imageView.getDrawingCache());
+                    finish();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+        });
+    }
+
+    final private int[] mColors =
+            {Color.BLUE, Color.GREEN, Color.RED, Color.LTGRAY, Color.MAGENTA, Color.CYAN,
+                    Color.YELLOW, Color.WHITE};
+}
+