Starting an Android Service at Boot time

Always a service is started by us manually that means it was not start by default. If we switch off the mobile then all the running services will stop.

For example if we are running a service. If we reboot the mobile then all the running services are stopped. So we have to run the service again.

By default android broadcasts a intent (android.intent.action.BOOT_COMPLETED)at the time of booting. So we have to receive that and in that we again start a service.

This should be accomplished by using Broad Cast Receiver.

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

public class BootBroadcastReceiver extends BroadcastReceiver
{
public void onReceive(Context context, Intent intent)
{
Log.i("Receiver Called.", "start the service.");
}
}
We have to add this receiver in the manifast.xml. The code is as follows.
<!-- Reciver -->
<receiver android:name=".BootBroadcastReceiver">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
<category android:name="android.intent.category.HOME" />
</intent-filter>
</receiver>

Android Service

A Service is a Android Class used to run a process in background to avoid Application Not Responding errors.
Example:
Home.java:
package com.sercivedemo.activities;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class Home extends Activity
{
    Button btnStartService, btnStopservice;
   
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       
        btnStartService = (Button)findViewById(R.id.btnStartService);
        btnStopservice = (Button)findViewById(R.id.btnStopservice);
       
        btnStartService.setOnClickListener(new OnClickListener()
        {          
            @Override
            public void onClick(View arg0)
            {
                startService(new Intent(Home.this, ServiceEx.class));
            }
        });
       
        btnStopservice.setOnClickListener(new OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                stopService(new Intent(Home.this, ServiceEx.class));
            }
        });
    }
}
ServiceEx.java:
package com.sercivedemo.activities;

import java.util.Timer;
import java.util.TimerTask;

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

public class ServiceEx extends Service
{   
    Timer objTimer;
    @Override
    public void onCreate()
    {       
        super.onCreate();
        Log.e("Service :", "onCreate()");
       
        //Do the process here
     }

    @Override
    public void onDestroy()
    {
        super.onDestroy();
        Log.e("Service :", "onDestroy()");
    }

    @Override
    public void onStart(Intent intent, int startId)
    {
        super.onStart(intent, startId);
        Log.e("Service :", "onStart()");
    }

    @Override
    public IBinder onBind(Intent intent)
    {
        return null;
    }
}
main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:gravity="center"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
   
    <Button
        android:layout_width="wrap_content"
        android:id="@+id/btnStartService"
        android:text="StartService"
        android:layout_height="wrap_content">
    </Button>
   
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/btnStopservice"
        android:text="StopService">
    </Button>   
   
</LinearLayout>

Android Launching Camera and attach the image to image view

public void takePhoto()
{
        //Intent to launch camara
        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
       
        //Uri creattion to strore images
        mImageCaptureUri = Uri.fromFile(new File(Environment.getExternalStorageDirectory()+ "/" +   String.valueOf(System.currentTimeMillis())+ ".jpg"));
                   
        intent.putExtra(android.provider.MediaStore.EXTRA_OUTPUT, mImageCaptureUri);

        startActivityForResult(intent, 1);
}


protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent)
{
       super.onActivityResult(requestCode, resultCode, imageReturnedIntent);
      
       if(requestCode == 1)
       {
           if(resultCode == RESULT_OK)
           {
                try
               {
                   ivPhoto.setBackgroundResource(0);
                   ivPhoto.setImageBitmap(BitmapFactory.decodeStream(new FileInputStream(new File(mImageCaptureUri.getPath()))));
               }
               catch (FileNotFoundException e)
               {               
                   e.printStackTrace();
               }
           }
           else if(resultCode == RESULT_CANCELED)
           {
               Log.d("Result: ", "Launch Cancelled.");
           }
     }
}

Call takePhoto() in the button click. 

Note: 

In the manifast.xml we have to add permissions.android.permission.WRITE_EXTERNAL_STORAGE

android.hardware.camera

Output:

Pick Image from Gallery set to Image View

package com.pickimagefromgal.activities;
import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;

public class Home extends Activity
{
    Button btnGal;
    ImageView ivGalImg;
    Bitmap bmp;
   
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       
        btnGal         =     (Button)findViewById(R.id.btnGallary);
        ivGalImg     =     (ImageView)findViewById(R.id.ivImage);
       
        btnGal.setOnClickListener(new OnClickListener()
        {           
            @Override
            public void onClick(View arg0)
            {
                openGallery();               
            }
        });
    }
   
    private void openGallery()
    {
        Intent photoPickerIntent = new Intent(Intent.ACTION_GET_CONTENT);
        photoPickerIntent.setType("image/*");
        startActivityForResult(photoPickerIntent, 1);
    }
   
  @Override
  protected void onActivityResult(int requestCode, int resultcode, Intent intent)
  {
      super.onActivityResult(requestCode, resultcode, intent);
     
      if (requestCode == 1)
      {
          if (intent != null && resultcode == RESULT_OK)
          {             
             
                Uri selectedImage = intent.getData();
               
                String[] filePathColumn = {MediaStore.Images.Media.DATA};
                Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
                cursor.moveToFirst();
                int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
                String filePath = cursor.getString(columnIndex);
                cursor.close();
             
                if(bmp != null && !bmp.isRecycled())
                {
                    bmp = null;               
                }
                               
                bmp = BitmapFactory.decodeFile(filePath);
                ivGalImg.setBackgroundResource(0);
                ivGalImg.setImageBitmap(bmp);             
          }
          else
          {
              Log.d("Status:", "Photopicker canceled");           
          }
      }
  }
}

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">
   
    <ImageView
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:id="@+id/ivImage"
        android:background="@drawable/icon"   
        >
    </ImageView>
   
    <Button
        android:layout_width="wrap_content"
        android:text="Click To Open Gallary"
        android:id="@+id/btnGallary"
        android:layout_height="wrap_content">
    </Button>
   
</LinearLayout>

Manifast: 

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.pickimagefromgal.activities"
      android:versionCode="1"
      android:versionName="1.0">
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>


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

Out Put:

Dom Parsing Example

 parse.xml :

<Books>
    <Book>
        <Name>Cryptography</Name>
        <Author>Harish</Author>
        <Price>$200</Price>
    </Book>
    <Book>
        <Name>Android</Name>
        <Author>Harish</Author>
        <Price>$250</Price>
    </Book>
</Books>
Method to parse xml  using dom :
public HashMap doDomParsing(String strUrl, String strParent, String[] child)
{
       HashMap hmap, hmapchild = null;
       URL url;
       hmap = new HashMap();
       
       try
       {
           //url = new URL(strUrl);
           
           DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
           DocumentBuilder db = dbf.newDocumentBuilder();

          Document doc = db.parse(new InputSource(getClass().getResourceAsStream("/res/raw/parse.xml")));

           
           NodeList nodeList = doc.getElementsByTagName("item");
           for (int i = 0; i < nodeList.getLength(); i++)
           {
               
               Node node = nodeList.item(i);
               NodeList properties = node.getChildNodes();
               
               hmapchild = new HashMap();
               
               for(int j=0 ; j < properties.getLength() ; j++)
               {
                   Node property = properties.item(j);
                   String nodename = property.getNodeName();
                   Log.e("Node NAME", nodename);
                   
                   for(int inew =0 ;inew < child.length ; inew++)
                   {
                       if(nodename.equalsIgnoreCase(child[inew]))
                       {
                           hmapchild.put(nodename, property.getFirstChild().getNodeValue());
                       }
                   }
               }
               hmap.put(i, hmapchild);
           }
       }
       catch (Exception e)
       {
           // TODO Auto-generated catch block
           e.printStackTrace();
       }
       
       return  hmap;
}

For this method we have to pass three parameters.
URL
PARENT NODE
CHILDREN

For the above xml we are parsing local file presented at raw folder. so url is empty. 
Parent is Book
child array is {Name, Author, Price}


That's it. It will parse the data store the values in Hash Map and returns that Hash Map.

Passing Intent to Browser

Intent intent = new Intent("android.intent.action.VIEW", Uri.parse(stringurl));
startActivity(intent);

SUPPORTING FULL SCREEN IN ANROID

In order to run the application in full screen mode you should add the following code to your activity.
getWindow().setFlags(WindowManager.LayoutParams.NO_STATUS_BAR_FLAG,
                   WindowManager.LayoutParams.NO_STATUS_BAR_FLAG); 

ANDROID MENUS

Android supports 3 types of Application Menus. Those are
1. Options Menu
2. Context Menu
3. Sub Menu
Options Menu :
      It is a collection of Menu items which will appear when the user invokes "Menu" button on the Android device.

 

                                                           Example for Options Menu
If the item count is <= 6 then all those are displayed properly.

If the item count is >6 then more button will appear default. If we press on the more button then remaining items will appear as shown below.

  

Context Menu :

    Context Menu is the menu which is similar to right click on your desktop computer. It means it will raise when the user tap or click on a list item it will display a menu.

Sub Menu :

    It is also a list of menu item that will appear if the user selects item in the menu item contains a nested list of menu.

   For example item 3 is having a Sub Menu.

 

Sub Menu

If you want more detail about Menus go through the following link

http://developer.android.com/guide/topics/ui/menus.html

DIALOG IN ANDROID / CUSTOM DIALOG

cdialog.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="200dip"
  android:orientation="vertical"
  android:padding="5dip"
  android:layout_height="fill_parent">
 
  <TextView
      android:layout_width="fill_parent"
      android:text="Dialog Title"
      android:gravity="center_vertical"
      android:layout_height="20dip">
  </TextView>
 
  <TextView
      android:layout_width="fill_parent"
      android:layout_marginTop="5dip"
      android:background="#FFFFFF"
      android:layout_height="0.5sp">
  </TextView>
 
  <TextView
      android:layout_width="fill_parent"
      android:text="Dialog Message"
      android:gravity="center_vertical"
      android:layout_height="50dip">
  </TextView>
 
  <Button
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="OK"
      android:id="@+id/btnOk"
      android:layout_gravity="center">
  </Button>
 
</LinearLayout>
 
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">
  
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/btnDialog"
        android:text="ShowDialog">
    </Button>

</LinearLayout>


CustomDialog.java:
package com.customdialog.home;

import android.app.Dialog;
import android.content.Context;
import android.os.Bundle;
import android.view.Window;

public class CustomDialog extends Dialog
{

    public CustomDialog(Context context)
    {
        super(context);
    }
   
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.cdialog);
    }
}
Home.java:
package com.customdialog.home;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class Home extends Activity
{
    /** Called when the activity is first created. */
    Button btnClick;
    CustomDialog cd;
    @Override   
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       
        btnClick = (Button)findViewById(R.id.btnDialog);
        btnClick.setOnClickListener(new OnClickListener()
        {           
            @Override
            public void onClick(View arg0)
            {
                cd = new CustomDialog(Home.this);
                cd.show();
               
                Button btnDimiss = (Button)cd.findViewById(R.id.btnOk);
                btnDimiss.setOnClickListener(new OnClickListener()
                {                   
                    @Override
                    public void onClick(View arg0)
                    {
                        cd.dismiss();   
                    }
                });

            }
        });
    }
}

TABS IN ANDROID

In order to create the tabs we have to use the following
TabHost
TabWidget
The TabHost is the root node for the layout contain TabWidget and Frame Layout.
The TabWidget is to maintain the tabs.
The Frame Layout contains the visible view for that Tab.

tabs.xml

<?xml version="1.0" encoding="utf-8"?>
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/tabhost"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
   
    <LinearLayout
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">
       
        <!-- Contain Tabs -->
        <TabWidget
            android:id="@android:id/tabs"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" />
       
        <!-- Contain Content of the Tab -->
        <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"/>
           
    </LinearLayout>
</TabHost>

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"
    />
</LinearLayout>




Home.java
package com.tabsdemo.activities;
import android.app.TabActivity;
import android.content.ComponentName;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TabHost;


public class Home extends TabActivity
{
    /** Called when the activity is first created. */
    TabHost objTabHost;
    public String TAB_NAMES[] = {"tab1","tab2","tab3"};
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.tabs);
       
        //Getting the TabHost Object to add TabSpec
        objTabHost = getTabHost();
       
        for(int i=0 ; i
        {
            //Creation of a Tab
            TabHost.TabSpec tab = objTabHost.newTabSpec(TAB_NAMES[i]);
           
            //Associating Intent to Tab
            ComponentName oneActivity = new ComponentName("com.tabsdemo.activities", "com.tabsdemo.activities." + TAB_NAMES[i]);
            Intent intent = new Intent().setComponent(oneActivity);                       
            tab.setContent(intent);
           
            //Adding Name and Drawable to Tab
            tab.setIndicator(TAB_NAMES[i], getResources().getDrawable(R.drawable.more_tab));//("TAB"+i, R.drawable.more_tab);
           
            objTabHost.addTab(tab);
        }
       
        objTabHost.setCurrentTab(0);
    }
}

tab1.iava:

 package com.tabsdemo.activities;

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

public class tab1 extends Activity
{
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        //Content of the Tab1
    }
}

tab2.java:

 package com.tabsdemo.activities;

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

public class tab2 extends Activity
{
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
}

tab3.java:

package com.tabsdemo.activities;

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


public class tab3 extends Activity
{
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
}

If you want  more detail go to the following link:
http://developer.android.com/resources/tutorials/views/hello-tabwidget.html