Create style using Android Resources Tools

- Start Eclipse, create a new Android project.

- Right click /res/values/ in Package Explorer, click New -> Other....


- Expand Android, and select Android XML Values File, click Next.


- Enter file name, mystyle.xml.


- Click Finish.


- The generated file will be opened in Resources mode. Click the tab with file name, mystyle.xml, to view in edit mode. The wizard should have create a root of <resources> for you.


- Switch back to Resources mode by clicking on Resources tab.

- Click on the Add button.


- Select Style/Theme, and click OK.


- Enter "MyStyle" in the name field.


- Click on Add button.

- Select Item and click OK.


- Enter "android:layout_width" in Name field, and "wrap_content" in Value field.


- Click on mystyle.xml tab to view in edit mode. The wizard have already filled in the item.


- Repeat to fill in others.

<?xml version="1.0" encoding="utf-8"?>
<resources>
   <style name="MyStyle">
       <item name="android:layout_width">wrap_content</item>
       <item name="android:layout_height">wrap_content</item>
       <item name="android:textColor">#AAA</item>
       <item name="android:textSize">18dip</item>
       <item name="android:background">#222</item>
       <item name="android:padding">5dip</item>
   </style>

</resources>

- Save It.

- Modify main.xml to add a TextView using MyStyle.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:orientation="vertical" >

   <TextView
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"
       android:text="@string/hello" />
   <TextView
       style="@style/MyStyle"
       android:layout_width="fill_parent"
       android:text="it's text using style" />
  
</LinearLayout>

- Finished!



next:
- Create style inheriting properties from another style
- Apply style on whole application/activity as theme

Create your own London 2012 App

London 2012 Olympic is coming! Official site of the London 2012 Olympic (http://www.london2012.com/) have a very nice designed mobile version. You will be redirected to mobile version if you browse http://www.london2012.com/ using mobile device.

So, you can easily create your own London 2012 App for Android by embedding WebView.



Modify main.xml to embed a WebView.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:orientation="vertical" >
<RelativeLayout
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:orientation="vertical" >
  <TextView
      android:id="@+id/myblog"
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:text="@string/my_blog"
 android:padding="5dp"
 android:autoLink="web"
 android:gravity="center_horizontal"
      android:layout_alignParentBottom="true"/>
  <WebView
      android:id="@+id/webview"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:layout_alignParentTop="true"
      android:layout_above="@id/myblog"/>
</RelativeLayout>
</LinearLayout>

Modify /res/values/strings.xml to add String of "my_blog", to advertise me:)

<?xml version="1.0" encoding="utf-8"?>
<resources>

 <string name="hello">Hello World, MyLondon2012Activity!</string>
 <string name="app_name">MyLondon2012</string>
<string name="my_blog">http://android-coding.blogspot.com/</string>
</resources>

Modify main activity to handle WebView.

package android.coding.myLondon2012;

import android.app.Activity;
import android.os.Bundle;
import android.view.Window;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class MyLondon2012Activity extends Activity {

WebView webView;
final String London2012_URL = "http://www.london2012.com/";

 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     getWindow().requestFeature(Window.FEATURE_PROGRESS);
     setContentView(R.layout.main);
     webView = (WebView)findViewById(R.id.webview);
     webView.getSettings().setJavaScriptEnabled(true);
     webView.setWebViewClient(new MyWebViewClient());
     webView.loadUrl(London2012_URL);
  
     final Activity activity = this;
     webView.setWebChromeClient(new WebChromeClient() {
    
      public void onProgressChanged(WebView view, int progress) {
       // Activities and WebViews measure progress with different scales.
       // The progress meter will automatically disappear when we reach 100%
       activity.setProgress(progress * 100);
      }});
 }

public class MyWebViewClient extends WebViewClient {

@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
 view.loadUrl(url);
         return true;
}

}
}

Save the icon in /res/drawable/london2012.png


Modify AndroidManifest.xml to enable "android.permission.INTERNET".

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
 package="android.coding.myLondon2012"
 android:versionCode="1"
 android:versionName="1.0" >

 <uses-sdk android:minSdkVersion="8" />
 <uses-permission android:name="android.permission.INTERNET"/>

 <application
     android:icon="@drawable/london2012"
     android:label="@string/app_name" >
     <activity
         android:name=".MyLondon2012Activity"
         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>

Download Eclipse project of myLondon2012: http://goo.gl/tg18O
Download Installable APK Android package of myLondon2012: http://goo.gl/28tnz

Related Post:
- android.webkit.WebView
- More on WebView, override url loading
- Enable JavaScript and built-in zoom control of WebView
- Display Progress Bar on WebView when loading
- Handle the Back button in WebView, to back in history

Copy part of Bitmap

Last post Copy bitmap using getPixels() and setPixels() show how to copy a whole Bitmap using getPixels() and setPixels(). It can be used to copy part of a Bitmap.

package com.AndroidCopyBitmap;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.os.Bundle;
import android.widget.ImageView;

public class AndroidCopyBitmapActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        ImageView image1 = (ImageView)findViewById(R.id.image1);
        ImageView image2 = (ImageView)findViewById(R.id.image2);
        
        Bitmap oldBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
        
        int orgWidth = oldBitmap.getWidth();
        int orgHeight = oldBitmap.getHeight();
        
        int firstx, firsty;
        int halfWidth = orgWidth/2;
        int halfHeight = orgHeight/2;
        
        //Create a same size Bitmap
        Bitmap newBitmap = Bitmap.createBitmap(orgWidth, orgHeight, Bitmap.Config.ARGB_8888);
        //Create a pixel of 1/4 size, to copy part of the bitmap
        int[] pixels = new int[halfWidth * halfHeight];
        
        //Copy Upper-Left part to Bottom-Right
        oldBitmap.getPixels(pixels, 0, halfWidth, 0, 0, halfWidth, halfHeight);
        newBitmap.setPixels(pixels, 0, halfWidth, halfWidth, halfHeight, halfWidth, halfHeight);
         
        //Copy Bottom-Right to Upper-Left part
        oldBitmap.getPixels(pixels, 0, halfWidth, halfWidth, halfHeight, halfWidth, halfHeight);
        newBitmap.setPixels(pixels, 0, halfWidth, 0, 0, halfWidth, halfHeight);
        
        //Copy Bottom-Left part to Upper-Right
        oldBitmap.getPixels(pixels, 0, halfWidth, 0, halfHeight, halfWidth, halfHeight);
        newBitmap.setPixels(pixels, 0, halfWidth, halfWidth, 0, halfWidth, halfHeight);
         
        //Copy Upper-Right to Bottom-Left part
        oldBitmap.getPixels(pixels, 0, halfWidth, halfWidth, 0, halfWidth, halfHeight);
        newBitmap.setPixels(pixels, 0, halfWidth, 0, halfHeight, halfWidth, halfHeight);
         
        image1.setImageBitmap(oldBitmap);
        image2.setImageBitmap(newBitmap);
    }
}

Copy bitmap using getPixels() and setPixels()

Example of copy bitmap using Bitmap.getPixels() and Bitmap.setPixels().

package com.AndroidCopyBitmap;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.os.Bundle;
import android.widget.ImageView;

public class AndroidCopyBitmapActivity extends Activity {
   /** Called when the activity is first created. */
   @Override
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.main);
       ImageView image1 = (ImageView)findViewById(R.id.image1);
       ImageView image2 = (ImageView)findViewById(R.id.image2);
      
       Bitmap oldBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
      
       int orgWidth = oldBitmap.getWidth();
       int orgHeight = oldBitmap.getHeight();
       
       Bitmap newBitmap = Bitmap.createBitmap(orgWidth, orgHeight, Bitmap.Config.ARGB_8888);
       int[] pixels = new int[orgWidth * orgHeight];
       oldBitmap.getPixels(pixels, 0, orgWidth, 0, 0, orgWidth, orgHeight);
       newBitmap.setPixels(pixels, 0, orgWidth, 0, 0, orgWidth, orgHeight);
       
       image1.setImageBitmap(oldBitmap);
       image2.setImageBitmap(newBitmap);
   }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:orientation="vertical" >

   <TextView
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"
       android:text="@string/hello" />
   <ImageView
       android:id="@+id/image1"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content" />
   <ImageView
       android:id="@+id/image2"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content" />

</LinearLayout>

next:
- Copy part of Bitmap

Scale Bitmap

To scale bitmap, we can use the following code:
Matrix matrix = new Matrix();
matrix.postScale(xScale, yScale);
Bitmap newBitmap = Bitmap.createBitmap(oldBitmap, 0, 0, orgWidth, orgHeight, matrix, true);

example:

package com.AndroidScaleBitmap;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.os.Bundle;
import android.widget.ImageView;

public class AndroidScaleBitmapActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        ImageView image1 = (ImageView)findViewById(R.id.image1);
        ImageView image2 = (ImageView)findViewById(R.id.image2);
        
        Bitmap oldBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
        
        int orgWidth = oldBitmap.getWidth();
        int orgHeight = oldBitmap.getHeight();
        int newWidth = 300;
        int newHeight = 300;
        float xScale = newWidth/orgWidth;
        float yScale = newHeight/orgHeight;
        
        Matrix matrix = new Matrix();
        matrix.postScale(xScale, yScale);
        Bitmap newBitmap = Bitmap.createBitmap(oldBitmap, 0, 0, orgWidth, orgHeight, matrix, true);
        
        image1.setImageBitmap(oldBitmap);
        image2.setImageBitmap(newBitmap);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />
    <ImageView
        android:id="@+id/image1" 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <ImageView
        android:id="@+id/image2" 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

Dynamic change the content of Spinner

In the last post Apply List to Spinner, the content of Spinner is come from a List. We can change the List programmatically, to change the content of the Spinner, then call notifyDataSetChanged() of the ArrayAdapter to update the Spinner.

It's a example modify from the last post. There are two Spinner. When the Move button clicked, the current item of Spinner1 will be moved to Spinner2.

package com.AndroidListSpinner;
import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;

public class AndroidListSpinnerActivity extends Activity {
 
 Button btnMove;
 Spinner MySpinner1, MySpinner2;
 List<String> myList1, myList2;
 private ArrayAdapter<String> myAdapter1, myAdapter2;
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        btnMove = (Button)findViewById(R.id.move);
        MySpinner1 = (Spinner)findViewById(R.id.myspinner1);
        MySpinner2 = (Spinner)findViewById(R.id.myspinner2);
        
        initList();
        myAdapter1 = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, myList1);
        myAdapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        MySpinner1.setAdapter(myAdapter1);
        
        myAdapter2 = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, myList2);
        myAdapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        MySpinner2.setAdapter(myAdapter2);

        btnMove.setOnClickListener(MoveOnClickListener);
    }
    
    Button.OnClickListener MoveOnClickListener
    = new Button.OnClickListener(){

  @Override
  public void onClick(View arg0) {
   // TODO Auto-generated method stub
   int pos = MySpinner1.getSelectedItemPosition();
   
   if(pos != AdapterView.INVALID_POSITION){
    myList2.add(myList1.get(pos));
    myList1.remove(pos);
    myAdapter1.notifyDataSetChanged();
    myAdapter2.notifyDataSetChanged();
   }
  }};
    
    void initList(){
     myList1 = new ArrayList<String>();
     myList1.add("Sunday");
     myList1.add("Monday");
     myList1.add("Tuesday");
     myList1.add("Wednesday");
     myList1.add("Thursday");
     myList1.add("Friday");
     myList1.add("Saturday");
     
     myList2 = new ArrayList<String>();
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />
    <Spinner
        android:id="@+id/myspinner1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
    <Spinner
        android:id="@+id/myspinner2"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
    <Button
        android:id="@+id/move"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" 
        android:text="Move" />

</LinearLayout>

Apply List to Spinner

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />
    <Spinner
        android:id="@+id/myspinner"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

package com.AndroidListSpinner;
import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.Spinner;

public class AndroidListSpinnerActivity extends Activity {
 
 Spinner MySpinner;
 List<String> myList;
 private ArrayAdapter<String> myAdapter;
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        MySpinner = (Spinner)findViewById(R.id.myspinner);
        
        initList();
        myAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, myList);
        myAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        MySpinner.setAdapter(myAdapter);
    }
    
    void initList(){
     myList = new ArrayList<String>();
     myList.add("Sunday");
     myList.add("Monday");
     myList.add("Tuesday");
     myList.add("Wednesday");
     myList.add("Thursday");
     myList.add("Friday");
     myList.add("Saturday");
    }
}

Related Post:
- Apply array to Spinner
- Dynamic change the content of Spinner

Remove from DownloadManager

Modify from last post Download using DownloadManager, the downloaded SUCCESSFUL id can be removed using downloadManager.remove(downloadID).

package com.AndroidDownload;

import java.io.FileNotFoundException;

import android.app.Activity;
import android.app.DownloadManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.os.ParcelFileDescriptor;
import android.preference.PreferenceManager;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class AndroidDownloadActivity extends Activity {
 
 String Download_path = "http://goo.gl/Mfyya";
 String Download_ID = "DOWNLOAD_ID";
 
 SharedPreferences preferenceManager;
 DownloadManager downloadManager;
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        preferenceManager = PreferenceManager.getDefaultSharedPreferences(this);
        downloadManager = (DownloadManager)getSystemService(DOWNLOAD_SERVICE);
        
        Button btnDownload = (Button)findViewById(R.id.download);
        btnDownload.setOnClickListener(new Button.OnClickListener(){

   @Override
   public void onClick(View arg0) {
    // TODO Auto-generated method stub
    Uri Download_Uri = Uri.parse(Download_path);
    DownloadManager.Request request = new DownloadManager.Request(Download_Uri);
    long download_id = downloadManager.enqueue(request);
    
    //Save the download id
    Editor PrefEdit = preferenceManager.edit();
    PrefEdit.putLong(Download_ID, download_id);
    PrefEdit.commit();
   }});
    }
    
 @Override
 protected void onResume() {
  // TODO Auto-generated method stub
  super.onResume();
  
  IntentFilter intentFilter = new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE);
  registerReceiver(downloadReceiver, intentFilter);
 }

 @Override
 protected void onPause() {
  // TODO Auto-generated method stub
  super.onPause();
  
  unregisterReceiver(downloadReceiver);
 }

 private BroadcastReceiver downloadReceiver = new BroadcastReceiver() {

  @Override
  public void onReceive(Context arg0, Intent arg1) {
   // TODO Auto-generated method stub
   DownloadManager.Query query = new DownloadManager.Query();
   query.setFilterById(preferenceManager.getLong(Download_ID, 0));
   Cursor cursor = downloadManager.query(query);
   
   if(cursor.moveToFirst()){
    int columnIndex = cursor.getColumnIndex(DownloadManager.COLUMN_STATUS);
    int status = cursor.getInt(columnIndex);
    int columnReason = cursor.getColumnIndex(DownloadManager.COLUMN_REASON);
    int reason = cursor.getInt(columnReason);
    
    if(status == DownloadManager.STATUS_SUCCESSFUL){
     //Retrieve the saved download id
     long downloadID = preferenceManager.getLong(Download_ID, 0);
     
     ParcelFileDescriptor file;
     try {
      file = downloadManager.openDownloadedFile(downloadID);
      Toast.makeText(AndroidDownloadActivity.this, 
        "File Downloaded: " + file.toString(), 
        Toast.LENGTH_LONG).show();
     } catch (FileNotFoundException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
      Toast.makeText(AndroidDownloadActivity.this, 
        e.toString(), 
        Toast.LENGTH_LONG).show();
     }
     
     downloadManager.remove(downloadID);
     
    }else if(status == DownloadManager.STATUS_FAILED){
     Toast.makeText(AndroidDownloadActivity.this, 
       "FAILED!\n" + "reason of " + reason, 
       Toast.LENGTH_LONG).show();
    }else if(status == DownloadManager.STATUS_PAUSED){
     Toast.makeText(AndroidDownloadActivity.this, 
       "PAUSED!\n" + "reason of " + reason, 
       Toast.LENGTH_LONG).show();
    }else if(status == DownloadManager.STATUS_PENDING){
     Toast.makeText(AndroidDownloadActivity.this, 
       "PENDING!", 
       Toast.LENGTH_LONG).show();
    }else if(status == DownloadManager.STATUS_RUNNING){
     Toast.makeText(AndroidDownloadActivity.this, 
       "RUNNING!", 
       Toast.LENGTH_LONG).show();
    }
   }
  }
  
 };

}

Download using DownloadManager

The class android.app.DownloadManager (Since: API Level 9) is a system service that handles long-running HTTP downloads. Clients may request that a URI be downloaded to a particular destination file. The download manager will conduct the download in the background, taking care of HTTP interactions and retrying downloads after failures or across connectivity changes and system reboots.

It's a basic code to download file from internet using DownloadManager.

package com.AndroidDownload;

import java.io.FileInputStream;
import java.io.FileNotFoundException;

import android.app.Activity;
import android.app.DownloadManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.os.ParcelFileDescriptor;
import android.preference.PreferenceManager;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class AndroidDownloadActivity extends Activity {
 
 String Download_path = "http://goo.gl/Mfyya";
 String Download_ID = "DOWNLOAD_ID";
 
 SharedPreferences preferenceManager;
 DownloadManager downloadManager;
 
   /** Called when the activity is first created. */
   @Override
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.main);
      
       preferenceManager = PreferenceManager.getDefaultSharedPreferences(this);
       downloadManager = (DownloadManager)getSystemService(DOWNLOAD_SERVICE);
      
       Button btnDownload = (Button)findViewById(R.id.download);
       btnDownload.setOnClickListener(new Button.OnClickListener(){

   @Override
   public void onClick(View arg0) {
    // TODO Auto-generated method stub
    Uri Download_Uri = Uri.parse(Download_path);
    DownloadManager.Request request = new DownloadManager.Request(Download_Uri);
    long download_id = downloadManager.enqueue(request);
    
    //Save the download id
    Editor PrefEdit = preferenceManager.edit();
    PrefEdit.putLong(Download_ID, download_id);
    PrefEdit.commit();
   }});
   }
  
 @Override
 protected void onResume() {
  // TODO Auto-generated method stub
  super.onResume();
  
  IntentFilter intentFilter = new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE);
  registerReceiver(downloadReceiver, intentFilter);
 }

 @Override
 protected void onPause() {
  // TODO Auto-generated method stub
  super.onPause();
  
  unregisterReceiver(downloadReceiver);
 }

 private BroadcastReceiver downloadReceiver = new BroadcastReceiver() {

  @Override
  public void onReceive(Context arg0, Intent arg1) {
   // TODO Auto-generated method stub
   DownloadManager.Query query = new DownloadManager.Query();
   query.setFilterById(preferenceManager.getLong(Download_ID, 0));
   Cursor cursor = downloadManager.query(query);
   
   if(cursor.moveToFirst()){
    int columnIndex = cursor.getColumnIndex(DownloadManager.COLUMN_STATUS);
    int status = cursor.getInt(columnIndex);
    int columnReason = cursor.getColumnIndex(DownloadManager.COLUMN_REASON);
    int reason = cursor.getInt(columnReason);
    
    if(status == DownloadManager.STATUS_SUCCESSFUL){
     //Retrieve the saved download id
     long downloadID = preferenceManager.getLong(Download_ID, 0);
     
     ParcelFileDescriptor file;
     try {
      file = downloadManager.openDownloadedFile(downloadID);
      Toast.makeText(AndroidDownloadActivity.this,
        "File Downloaded: " + file.toString(),
        Toast.LENGTH_LONG).show();
     } catch (FileNotFoundException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
      Toast.makeText(AndroidDownloadActivity.this,
        e.toString(),
        Toast.LENGTH_LONG).show();
     }
     
    }else if(status == DownloadManager.STATUS_FAILED){
     Toast.makeText(AndroidDownloadActivity.this,
       "FAILED!\n" + "reason of " + reason,
       Toast.LENGTH_LONG).show();
    }else if(status == DownloadManager.STATUS_PAUSED){
     Toast.makeText(AndroidDownloadActivity.this,
       "PAUSED!\n" + "reason of " + reason,
       Toast.LENGTH_LONG).show();
    }else if(status == DownloadManager.STATUS_PENDING){
     Toast.makeText(AndroidDownloadActivity.this,
       "PENDING!",
       Toast.LENGTH_LONG).show();
    }else if(status == DownloadManager.STATUS_RUNNING){
     Toast.makeText(AndroidDownloadActivity.this,
       "RUNNING!",
       Toast.LENGTH_LONG).show();
    }
   }
  }
  
 };

}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:orientation="vertical" >

   <TextView
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"
       android:text="@string/hello" />
   <Button
       android:id="@+id/download"
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"
       android:text="Start Download" />

</LinearLayout>

remark: "android.permission.INTERNET" is needed in AndroidManifest.xml.

next: Remove from DownloadManager

Download using DownloadManager

The class android.app.DownloadManager (Since: API Level 9) is a system service that handles long-running HTTP downloads. Clients may request that a URI be downloaded to a particular destination file. The download manager will conduct the download in the background, taking care of HTTP interactions and retrying downloads after failures or across connectivity changes and system reboots.

It's a basic code to download file from internet using DownloadManager.

package com.AndroidDownload;

import java.io.FileInputStream;
import java.io.FileNotFoundException;

import android.app.Activity;
import android.app.DownloadManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.os.ParcelFileDescriptor;
import android.preference.PreferenceManager;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class AndroidDownloadActivity extends Activity {
 
 String Download_path = "http://goo.gl/Mfyya";
 String Download_ID = "DOWNLOAD_ID";
 
 SharedPreferences preferenceManager;
 DownloadManager downloadManager;
 
   /** Called when the activity is first created. */
   @Override
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.main);
      
       preferenceManager = PreferenceManager.getDefaultSharedPreferences(this);
       downloadManager = (DownloadManager)getSystemService(DOWNLOAD_SERVICE);
      
       Button btnDownload = (Button)findViewById(R.id.download);
       btnDownload.setOnClickListener(new Button.OnClickListener(){

   @Override
   public void onClick(View arg0) {
    // TODO Auto-generated method stub
    Uri Download_Uri = Uri.parse(Download_path);
    DownloadManager.Request request = new DownloadManager.Request(Download_Uri);
    long download_id = downloadManager.enqueue(request);
    
    //Save the download id
    Editor PrefEdit = preferenceManager.edit();
    PrefEdit.putLong(Download_ID, download_id);
    PrefEdit.commit();
   }});
   }
  
 @Override
 protected void onResume() {
  // TODO Auto-generated method stub
  super.onResume();
  
  IntentFilter intentFilter = new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE);
  registerReceiver(downloadReceiver, intentFilter);
 }

 @Override
 protected void onPause() {
  // TODO Auto-generated method stub
  super.onPause();
  
  unregisterReceiver(downloadReceiver);
 }

 private BroadcastReceiver downloadReceiver = new BroadcastReceiver() {

  @Override
  public void onReceive(Context arg0, Intent arg1) {
   // TODO Auto-generated method stub
   DownloadManager.Query query = new DownloadManager.Query();
   query.setFilterById(preferenceManager.getLong(Download_ID, 0));
   Cursor cursor = downloadManager.query(query);
   
   if(cursor.moveToFirst()){
    int columnIndex = cursor.getColumnIndex(DownloadManager.COLUMN_STATUS);
    int status = cursor.getInt(columnIndex);
    int columnReason = cursor.getColumnIndex(DownloadManager.COLUMN_REASON);
    int reason = cursor.getInt(columnReason);
    
    if(status == DownloadManager.STATUS_SUCCESSFUL){
     //Retrieve the saved download id
     long downloadID = preferenceManager.getLong(Download_ID, 0);
     
     ParcelFileDescriptor file;
     try {
      file = downloadManager.openDownloadedFile(downloadID);
      Toast.makeText(AndroidDownloadActivity.this,
        "File Downloaded: " + file.toString(),
        Toast.LENGTH_LONG).show();
     } catch (FileNotFoundException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
      Toast.makeText(AndroidDownloadActivity.this,
        e.toString(),
        Toast.LENGTH_LONG).show();
     }
     
    }else if(status == DownloadManager.STATUS_FAILED){
     Toast.makeText(AndroidDownloadActivity.this,
       "FAILED!\n" + "reason of " + reason,
       Toast.LENGTH_LONG).show();
    }else if(status == DownloadManager.STATUS_PAUSED){
     Toast.makeText(AndroidDownloadActivity.this,
       "PAUSED!\n" + "reason of " + reason,
       Toast.LENGTH_LONG).show();
    }else if(status == DownloadManager.STATUS_PENDING){
     Toast.makeText(AndroidDownloadActivity.this,
       "PENDING!",
       Toast.LENGTH_LONG).show();
    }else if(status == DownloadManager.STATUS_RUNNING){
     Toast.makeText(AndroidDownloadActivity.this,
       "RUNNING!",
       Toast.LENGTH_LONG).show();
    }
   }
  }
  
 };

}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:orientation="vertical" >

   <TextView
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"
       android:text="@string/hello" />
   <Button
       android:id="@+id/download"
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"
       android:text="Start Download" />

</LinearLayout>

remark: "android.permission.INTERNET" is needed in AndroidManifest.xml.

Interactive between Activity and Service

Modify from last post Pass data from Activity to Service via Intent in startService(); a BroadcastReceiver is added in MyService, such that our main activity (AndroidServiceTestActivity) can send data (CMD) to service via another intent(MY_ACTION_FROMACTIVITY).



MyService.java

package com.AndroidServiceTest;

import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.IBinder;
import android.widget.Toast;

public class MyService extends Service {
 
 MyServiceReceiver myServiceReceiver;

 final static String MY_ACTION = "MY_ACTION";
 final static String MY_ACTION_FROMACTIVITY = "MY_ACTION_FROMACTIVITY";
 
 public static final String CMD = "CMD";
 public static final int CMD_STOP = 1;
 boolean running;
 
 String initData;

 @Override
 public void onCreate() {
  // TODO Auto-generated method stub
  myServiceReceiver = new MyServiceReceiver();
  super.onCreate();
 }

 @Override
 public IBinder onBind(Intent arg0) {
  // TODO Auto-generated method stub
  return null;
 }

 @Override
 public int onStartCommand(Intent intent, int flags, int startId) {
  // TODO Auto-generated method stub
  
  IntentFilter intentFilter = new IntentFilter();
  intentFilter.addAction(MY_ACTION_FROMACTIVITY);
  registerReceiver(myServiceReceiver, intentFilter);
  running = true;
  
  initData = intent.getStringExtra("INIT_DATA");
  
  MyThread myThread = new MyThread();
  myThread.start();
  
  return super.onStartCommand(intent, flags, startId);
 }
 
 @Override
 public void onDestroy() {
  // TODO Auto-generated method stub
  this.unregisterReceiver(myServiceReceiver);
  super.onDestroy();
 }

 public class MyThread extends Thread{

  @Override
  public void run() {
   // TODO Auto-generated method stub
   int i = 0;
   while(running){
    try {
     Thread.sleep(5000);
     Intent intent = new Intent();
        intent.setAction(MY_ACTION);
       
        intent.putExtra("DATAPASSED", i);
        intent.putExtra("DATA_BACK", initData);
       
        sendBroadcast(intent);
       
        i++;
    } catch (InterruptedException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
   }
   stopSelf();
  }

 }
 
 public class MyServiceReceiver extends BroadcastReceiver {

  @Override
  public void onReceive(Context arg0, Intent arg1) {
   // TODO Auto-generated method stub
   int hostCmd = arg1.getIntExtra(CMD, 0);
   if(hostCmd == CMD_STOP){
    running = false;
       stopSelf();
      
       Toast.makeText(MyService.this,
         "Service stopped by main Activity!",
         Toast.LENGTH_LONG).show();
   }
  }

 }

}

Modify main activity (AndroidServiceTestActivity.java) to send command to stop our service, by pressing of the Stop button.

package com.AndroidServiceTest;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class AndroidServiceTestActivity extends Activity {
 
 MyReceiver myReceiver;
 
 Button btnStop;
 
   /** Called when the activity is first created. */
   @Override
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.main);
       btnStop = (Button)findViewById(R.id.stop);
       btnStop.setOnClickListener(new Button.OnClickListener(){

   @Override
   public void onClick(View arg0) {
    // TODO Auto-generated method stub
    Intent intent = new Intent();
    intent.setAction(MyService.MY_ACTION_FROMACTIVITY);
    intent.putExtra(MyService.CMD, MyService.CMD_STOP);
    sendBroadcast(intent);
   }});

   }

 @Override
 protected void onStart() {
  // TODO Auto-generated method stub
  
       //Register BroadcastReceiver
       //to receive event from our service
       myReceiver = new MyReceiver();
       IntentFilter intentFilter = new IntentFilter();
       intentFilter.addAction(MyService.MY_ACTION);
       registerReceiver(myReceiver, intentFilter);
      
       //Start our own service
       Intent intent = new Intent(AndroidServiceTestActivity.this,
         com.AndroidServiceTest.MyService.class);
       intent.putExtra("INIT_DATA", "Data passed from Activity to Service in startService");
       startService(intent);
  
  super.onStart();
 }

 @Override
 protected void onStop() {
  // TODO Auto-generated method stub
  unregisterReceiver(myReceiver);
  super.onStop();
 }
 
 private class MyReceiver extends BroadcastReceiver{

  @Override
  public void onReceive(Context arg0, Intent arg1) {
   // TODO Auto-generated method stub
   
   int datapassed = arg1.getIntExtra("DATAPASSED", 0);
   String orgData = arg1.getStringExtra("DATA_BACK");
   
   Toast.makeText(AndroidServiceTestActivity.this,
     "Triggered by Service!\n"
     + "Data passed: " + String.valueOf(datapassed) + "\n"
     + "original Data: " + orgData,
     Toast.LENGTH_LONG).show();
   
  }
  
 }
}

Modify layout to add the Stop button.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:orientation="vertical"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   >
<TextView 
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:text="@string/hello"
   />
<Button
   android:id="@+id/stop"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:text="Stop"
   />
</LinearLayout>

Pass data from Activity to Service via Intent in startService()

In this example, modify from last post Pass data from Service to Activity, Extra is pass from Activity to Service in startService(). It will be retrieved in onStartCommand() of Service.



AndroidServiceTestActivity.java

package com.AndroidServiceTest;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.widget.Toast;

public class AndroidServiceTestActivity extends Activity {

MyReceiver myReceiver;

  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);

  }

@Override
protected void onStart() {
 // TODO Auto-generated method stub

      //Register BroadcastReceiver
      //to receive event from our service
      myReceiver = new MyReceiver();
      IntentFilter intentFilter = new IntentFilter();
      intentFilter.addAction(MyService.MY_ACTION);
      registerReceiver(myReceiver, intentFilter);
    
      //Start our own service
      Intent intent = new Intent(AndroidServiceTestActivity.this,
        com.AndroidServiceTest.MyService.class);
      intent.putExtra("INIT_DATA", "Data passed from Activity to Service in startService");
      startService(intent);

 super.onStart();
}

@Override
protected void onStop() {
 // TODO Auto-generated method stub
 unregisterReceiver(myReceiver);
 super.onStop();
}

private class MyReceiver extends BroadcastReceiver{

 @Override
 public void onReceive(Context arg0, Intent arg1) {
  // TODO Auto-generated method stub
 
  int datapassed = arg1.getIntExtra("DATAPASSED", 0);
  String orgData = arg1.getStringExtra("DATA_BACK");
 
  Toast.makeText(AndroidServiceTestActivity.this,
    "Triggered by Service!\n"
    + "Data passed: " + String.valueOf(datapassed) + "\n"
    + "original Data: " + orgData,
    Toast.LENGTH_LONG).show();
 
 }

}
}

package com.AndroidServiceTest;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;

public class MyService extends Service {

final static String MY_ACTION = "MY_ACTION";
String initData;

@Override
public IBinder onBind(Intent arg0) {
 // TODO Auto-generated method stub
 return null;
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
 // TODO Auto-generated method stub

 initData = intent.getStringExtra("INIT_DATA");

 MyThread myThread = new MyThread();
 myThread.start();

 return super.onStartCommand(intent, flags, startId);
}

public class MyThread extends Thread{

 @Override
 public void run() {
  // TODO Auto-generated method stub
  for(int i=0; i<10; i++){
   try {
    Thread.sleep(5000);
    Intent intent = new Intent();
       intent.setAction(MY_ACTION);
     
       intent.putExtra("DATAPASSED", i);
       intent.putExtra("DATA_BACK", initData);
     
       sendBroadcast(intent);
   } catch (InterruptedException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
  }
  stopSelf();
 }

}

}

Note: Modify AndroidManifest.xml to add service ".MyService", refer to the post Create our own Service and BroadcastReceiver.

Next post:
- Interactive between Activity and Service

Pass data from Service to Activity

Refer to the last post Create our own Service and BroadcastReceiver, data can be passed from Service using intent.putExtra(); on the other hand, the data passed can be retrieved using getIntExtra() in BroadcastReceiver.



Modify from the last post Create our own Service and BroadcastReceiver.
AndroidServiceTestActivity.java

package com.AndroidServiceTest;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.widget.Toast;

public class AndroidServiceTestActivity extends Activity {

MyReceiver myReceiver;

  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);

  }

@Override
protected void onStart() {
 // TODO Auto-generated method stub

      //Register BroadcastReceiver
      //to receive event from our service
      myReceiver = new MyReceiver();
      IntentFilter intentFilter = new IntentFilter();
      intentFilter.addAction(MyService.MY_ACTION);
      registerReceiver(myReceiver, intentFilter);
    
      //Start our own service
      Intent intent = new Intent(AndroidServiceTestActivity.this,
        com.AndroidServiceTest.MyService.class);
      startService(intent);

 super.onStart();
}

@Override
protected void onStop() {
 // TODO Auto-generated method stub
 unregisterReceiver(myReceiver);
 super.onStop();
}

private class MyReceiver extends BroadcastReceiver{

 @Override
 public void onReceive(Context arg0, Intent arg1) {
  // TODO Auto-generated method stub
 
  int datapassed = arg1.getIntExtra("DATAPASSED", 0);
 
  Toast.makeText(AndroidServiceTestActivity.this,
    "Triggered by Service!\n"
    + "Data passed: " + String.valueOf(datapassed),
    Toast.LENGTH_LONG).show();
 
 }

}
}

MyService.java

package com.AndroidServiceTest;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;

public class MyService extends Service {

final static String MY_ACTION = "MY_ACTION";

@Override
public IBinder onBind(Intent arg0) {
 // TODO Auto-generated method stub
 return null;
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
 // TODO Auto-generated method stub

 MyThread myThread = new MyThread();
 myThread.start();

 return super.onStartCommand(intent, flags, startId);
}

public class MyThread extends Thread{

 @Override
 public void run() {
  // TODO Auto-generated method stub
  for(int i=0; i<10; i++){
   try {
    Thread.sleep(5000);
    Intent intent = new Intent();
       intent.setAction(MY_ACTION);
     
       intent.putExtra("DATAPASSED", i);
     
       sendBroadcast(intent);
   } catch (InterruptedException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
  }
  stopSelf();
 }

}

}

Note: Modify AndroidManifest.xml to add service ".MyService", refer to the post Create our own Service and BroadcastReceiver.

Next:
- Pass data from Activity to Service via Intent in startService()

Create our own Service and BroadcastReceiver

In this onStart() of the main activity(AndroidServiceTestActivity.java), we instance and register our own BroadcastReceiver(myReceiver), and also start our service(MyService.java). In MyService.java, It will send 10 actions with MY_ACTION. It will trigger the myReceiver in AndroidServiceTestActivity.java.



Main activity AndroidServiceTestActivity.java

package com.AndroidServiceTest;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.widget.Toast;

public class AndroidServiceTestActivity extends Activity {

MyReceiver myReceiver;

   /** Called when the activity is first created. */
   @Override
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.main);

   }

@Override
protected void onStart() {
 // TODO Auto-generated method stub

       //Register BroadcastReceiver
       //to receive event from our service
       myReceiver = new MyReceiver();
       IntentFilter intentFilter = new IntentFilter();
       intentFilter.addAction(MyService.MY_ACTION);
       registerReceiver(myReceiver, intentFilter);
      
       //Start our own service
       Intent intent = new Intent(AndroidServiceTestActivity.this,
         com.AndroidServiceTest.MyService.class);
       startService(intent);

 super.onStart();
}

@Override
protected void onStop() {
 // TODO Auto-generated method stub
 unregisterReceiver(myReceiver);
 super.onStop();
}

private class MyReceiver extends BroadcastReceiver{

 @Override
 public void onReceive(Context arg0, Intent arg1) {
  // TODO Auto-generated method stub
  Toast.makeText(AndroidServiceTestActivity.this,
    "Triggered by Service!",
    Toast.LENGTH_LONG).show();
 
 }

}
}

MyService.java

package com.AndroidServiceTest;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;

public class MyService extends Service {

final static String MY_ACTION = "MY_ACTION";

@Override
public IBinder onBind(Intent arg0) {
 // TODO Auto-generated method stub
 return null;
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
 // TODO Auto-generated method stub

 MyThread myThread = new MyThread();
 myThread.start();

 return super.onStartCommand(intent, flags, startId);
}

public class MyThread extends Thread{

 @Override
 public void run() {
  // TODO Auto-generated method stub
  for(int i=0; i<10; i++){
   try {
    Thread.sleep(5000);
    Intent intent = new Intent();
       intent.setAction(MY_ACTION);
       sendBroadcast(intent);
   } catch (InterruptedException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
  }
  stopSelf();
 }

}

}

Modify AndroidManifest.xml to add service ".MyService"

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.AndroidServiceTest"
     android:versionCode="1"
     android:versionName="1.0">
   <uses-sdk android:minSdkVersion="7" />

   <application android:icon="@drawable/icon" android:label="@string/app_name">
       <activity android:name=".AndroidServiceTestActivity"
                 android:label="@string/app_name">
           <intent-filter>
               <action android:name="android.intent.action.MAIN" />
               <category android:name="android.intent.category.LAUNCHER" />
           </intent-filter>
       </activity>
 <service android:name=".MyService"/>
   </application>
</manifest>

next:
- Pass data from Service to Activity

Read raw resource of text

Create a raw resource of text, /res/raw/mytext.txt.

Hello!

It's a example of raw text in 
/res/raw/mytext.txt

Some text here:
Android is an operating system for mobile devices such as smartphones and tablet computers. It is developed by the Open Handset Alliance led by Google.

Java main code:

package com.AndroidTextResource;

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

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class AndroidTextResourceActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //setContentView(R.layout.main);
        
        TextView myTextView = new TextView(this);
        setContentView(myTextView);
        

        InputStream inputStream = getResources().openRawResource(R.raw.mytext);
        
        ByteArrayOutputStream byteArrayOutputStream 
         = new ByteArrayOutputStream();
        
        String myText = "";
        int in;
  try {
   in = inputStream.read();
   while (in != -1)
         {
    byteArrayOutputStream.write(in);
          in = inputStream.read();
         }
   inputStream.close();
   myText = byteArrayOutputStream.toString();
  }catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }

        myTextView.setText(myText);
    }
}

- Read raw text file, and display in ScrollView.

Using shape to define round drawable

To define our shape as a drawable, create XML(s) under /res/drawable/ folder.

/res/drawable/redroundrect.xml

<shape xmlns:android="http://schemas.android.com/apk/res/android">
 <solid 
  android:color="#FFFF0000"/>
 <corners 
  android:radius="15dp" />
 <padding 
  android:left="20dp" 
  android:top="20dp" 
  android:right="20dp" 
  android:bottom="2dp" />
</shape>

/res/drawable/greenroundrect.xml

<shape xmlns:android="http://schemas.android.com/apk/res/android">
 <solid 
  android:color="#FF00FF00"/>
 <corners 
  android:radius="15dp" />
 <padding 
  android:left="20dp" 
  android:top="20dp" 
  android:right="20dp" 
  android:bottom="2dp" />
</shape>

/res/drawable/blueroundrect.xml

<shape xmlns:android="http://schemas.android.com/apk/res/android">
 <solid 
  android:color="#FF0000FF"/>
 <corners 
  android:radius="15dp" />
 <padding 
  android:left="20dp" 
  android:top="20dp" 
  android:right="20dp" 
  android:bottom="2dp" />
</shape>

Using it inside main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="RED in XML"
    android:background="@drawable/redroundrect" />
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="GREEN in XML"
    android:background="@drawable/greenroundrect" />
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="BLUE in XML"
    android:background="@drawable/blueroundrect" />
<TextView  
    android:id="@+id/javared"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="RED using Java"/>
<TextView  
    android:id="@+id/javagreen"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="GREEN using Java"/>
<TextView  
    android:id="@+id/javablue"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="BLUE using Java"/>
</LinearLayout>

In Java code

package com.AndroidTestResources;

import android.app.Activity;
import android.graphics.drawable.ColorDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.GradientDrawable;
import android.os.Bundle;
import android.widget.TextView;

public class AndroidTestResourcesActivity extends Activity {
 
 TextView javaRed, javaGreen, javaBlue;
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        javaRed = (TextView)findViewById(R.id.javared);
        javaGreen = (TextView)findViewById(R.id.javagreen);
        javaBlue = (TextView)findViewById(R.id.javablue);
        
        Drawable redRoundRect 
        = getResources().getDrawable(R.drawable.redroundrect);
        Drawable greenRoundRect 
        = getResources().getDrawable(R.drawable.greenroundrect);
        Drawable blueRoundRect 
        = getResources().getDrawable(R.drawable.blueroundrect);
        
        javaRed.setBackgroundDrawable(redRoundRect);
        javaGreen.setBackgroundDrawable(greenRoundRect);
        javaBlue.setBackgroundDrawable(blueRoundRect);
    }
}

Related: Define color drawable in XML

Define color drawable in XML

We can define our custom color in XML under /res/values/ folder.

example: /res/values/myresources.xml

<resources>
 <drawable name="red_color">#ff0000</drawable>
 <drawable name="blue_color">#0000ff</drawable>
 <drawable name="green_color">#00ff00</drawable>
</resources>

After color defined, it can be acccessed as drawable in XML or using Java code.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="RED in XML"
    android:background="@drawable/red_color" />
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="GREEN in XML"
    android:background="@drawable/green_color" />
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="BLUE in XML"
    android:background="@drawable/blue_color" />
<TextView  
    android:id="@+id/javared"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="RED using Java"/>
<TextView  
    android:id="@+id/javagreen"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="GREEN using Java"/>
<TextView  
    android:id="@+id/javablue"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="BLUE using Java"/>
</LinearLayout>

package com.AndroidTestResources;

import android.app.Activity;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.widget.TextView;

public class AndroidTestResourcesActivity extends Activity {
 
 TextView javaRed, javaGreen, javaBlue;
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        javaRed = (TextView)findViewById(R.id.javared);
        javaGreen = (TextView)findViewById(R.id.javagreen);
        javaBlue = (TextView)findViewById(R.id.javablue);
        
        ColorDrawable red = (ColorDrawable)getResources().getDrawable(R.drawable.red_color);
        ColorDrawable green = (ColorDrawable)getResources().getDrawable(R.drawable.green_color);
        ColorDrawable blue = (ColorDrawable)getResources().getDrawable(R.drawable.blue_color);
        
        javaRed.setBackgroundDrawable(red);
        javaGreen.setBackgroundDrawable(green);
        javaBlue.setBackgroundDrawable(blue);
    }
}

Related: Using shape to define round drawable

Using Android device build-in light sensor

It's a simple light meter Using Android device build-in light sensor. A ProgressBar is defined in main.xml as a indicator of the light sensor. The default value of 100 defined in android:max is a dummy value, it will be updated after lightSensor.getMaximumRange(). The updated reading will be be read in lightSensorEventListener, and update the ProgressBar accordingly.

package com.AndroidLightSensor;

import android.app.Activity;
import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

public class AndroidLightSensorActivity extends Activity {
 
 ProgressBar lightMeter;
 TextView textMax, textReading;
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        lightMeter = (ProgressBar)findViewById(R.id.lightmeter);
        textMax = (TextView)findViewById(R.id.max);
        textReading = (TextView)findViewById(R.id.reading);
        
        SensorManager sensorManager 
        = (SensorManager)getSystemService(Context.SENSOR_SERVICE);
        Sensor lightSensor 
        = sensorManager.getDefaultSensor(Sensor.TYPE_LIGHT);
     
        if (lightSensor == null){
         Toast.makeText(AndroidLightSensorActivity.this, 
           "No Light Sensor! quit-", 
           Toast.LENGTH_LONG).show();
        }else{
         float max =  lightSensor.getMaximumRange();
         lightMeter.setMax((int)max);
         textMax.setText("Max Reading: " + String.valueOf(max));
         
         sensorManager.registerListener(lightSensorEventListener, 
           lightSensor, 
           SensorManager.SENSOR_DELAY_NORMAL);
         
        }
    }
    
    SensorEventListener lightSensorEventListener
    = new SensorEventListener(){

  @Override
  public void onAccuracyChanged(Sensor sensor, int accuracy) {
   // TODO Auto-generated method stub
   
  }

  @Override
  public void onSensorChanged(SensorEvent event) {
   // TODO Auto-generated method stub
   if(event.sensor.getType()==Sensor.TYPE_LIGHT){
    float currentReading = event.values[0];
    lightMeter.setProgress((int)currentReading);
    textReading.setText("Current Reading: " + String.valueOf(currentReading));
   }
  }
     
    };
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
<ProgressBar
    android:id="@+id/lightmeter"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:padding="20dp"
    style="?android:attr/progressBarStyleHorizontal"
    android:max="100"
    android:progress="0"
    />
<TextView  
    android:id="@+id/max"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    />
<TextView  
    android:id="@+id/reading"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    />
</LinearLayout>

Start Battery use checking using Intent.ACTION_POWER_USAGE_SUMMARY

package com.AndroidBatteryUsage;

import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.os.Bundle;
import android.widget.Toast;

public class AndroidBatteryUsageActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        PackageManager packageManager = getPackageManager();
        Intent intent = new Intent(Intent.ACTION_POWER_USAGE_SUMMARY);
        ResolveInfo resolveInfo = packageManager.resolveActivity(intent, 0);
        
        if(resolveInfo == null){
         Toast.makeText(AndroidBatteryUsageActivity.this, 
           "No suitable Activity found!", 
           Toast.LENGTH_LONG).show(); 
        }else{
         startActivity(intent);
        }
    }
}