Category: Android

Android – Audio Manager ”; Previous Next You can easily control your ringer volume and ringer profile i-e:(silent,vibrate,loud e.t.c) in android. Android provides AudioManager class that provides access to these controls. In order to use AndroidManager class, you have to first create an object of AudioManager class by calling the getSystemService() method. Its syntax is given below. private AudioManager myAudioManager; myAudioManager = (AudioManager)getSystemService(Context.AUDIO_SERVICE); Once you instantiate the object of AudioManager class, you can use setRingerMode method to set the audio or ringer profile of your device. Its syntax is given below. myAudioManager.setRingerMode(AudioManager.RINGER_MODE_VIBRATE); The method setRingerMode takes an integer number as a parameter. For each mode , an integer number is assigned that will differentiate between different modes. The possible modes are. Sr.No Mode & Description 1 RINGER_MODE_VIBRATE This Mode sets the device at vibrate mode. 2 RINGER_MODE_NORMAL This Mode sets the device at normal(loud) mode. 3 RINGER_MODE_SILENT This Mode sets the device at silent mode. Once you have set the mode , you can call the getRingerMode() method to get the set state of the system. Its syntax is given below. int mod = myAudioManager.getRingerMode(); Apart from the getRingerMode method, there are other methods available in the AudioManager class to control the volume and other modes. They are listed below. Sr.No Method & description 1 adjustVolume(int direction, int flags) This method adjusts the volume of the most relevant stream 2 getMode() This method returns the current audio mode 3 getStreamMaxVolume(int streamType) This method returns the maximum volume index for a particular stream 4 getStreamVolume(int streamType) This method returns the current volume index for a particular stream 5 isMusicActive() This method checks whether any music is active. 6 startBluetoothSco() This method Start bluetooth SCO audio connection 7 stopBluetoothSco() This method stop bluetooth SCO audio connection. Example The below example demonstrates the use of AudioManager class. It creates a application that allows you to set different ringer modes for your device. To experiment with this example , you need to run this on an actual device. Steps Description 1 You will use Android studio IDE to create an Android application under a package com.example.sairamkrishna.myapplication. 2 Modify src/MainActivity.java file to add AudioManager code 3 Modify layout XML file res/layout/activity_main.xml add any GUI component if required. 4 Modify res/values/string.xml file and add necessary string components. 5 Modify AndroidManifest.xml to add necessary permissions. 6 Run the application and choose a running android device and install the application on it and verify the results. Here is the content of src/MainActivity.java package com.example.sairamkrishna.myapplication; import android.app.Activity; import android.content.Context; import android.media.AudioManager; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.Toast; public class MainActivity extends Activity { Button mode,ring,vibrate,silent; private AudioManager myAudioManager; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); vibrate=(Button)findViewById(R.id.button3); ring=(Button)findViewById(R.id.button2); mode=(Button)findViewById(R.id.button); silent=(Button)findViewById(R.id.button4); myAudioManager = (AudioManager)getSystemService(Context.AUDIO_SERVICE); vibrate.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { myAudioManager.setRingerMode(AudioManager.RINGER_MODE_VIBRATE); Toast.makeText(MainActivity.this,”Now in Vibrate Mode”, Toast.LENGTH_LONG).show(); } }); ring.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { myAudioManager.setRingerMode(AudioManager.RINGER_MODE_NORMAL); Toast.makeText(MainActivity.this,”Now in Ringing Mode”, Toast.LENGTH_LONG).show(); } }); silent.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { myAudioManager.setRingerMode(AudioManager.RINGER_MODE_SILENT); Toast.makeText(MainActivity.this,”Now in silent Mode”, Toast.LENGTH_LONG).show(); } }); mode.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { int mod=myAudioManager.getRingerMode(); if(mod==AudioManager.RINGER_MODE_VIBRATE){ Toast.makeText(MainActivity.this,”Now in Vibrate Mode”, Toast.LENGTH_LONG).show(); } else if(mod==AudioManager.RINGER_MODE_NORMAL){ Toast.makeText(MainActivity.this,”Now in Ringing Mode”, Toast.LENGTH_LONG).show(); } else { Toast.makeText(MainActivity.this,”Now in Vibrate Mode”, Toast.LENGTH_LONG).show(); } } }); } } Here is the content of activity_main.xml Here abc indicates the logo of tutorialspoint <?xml version=”1.0″ encoding=”utf-8″?> <RelativeLayout xmlns:android=”http://schemas.android.com/apk/res/android” xmlns:tools=”http://schemas.android.com/tools” android:layout_width=”match_parent” android:layout_height=”match_parent” android:paddingLeft=”@dimen/activity_horizontal_margin” android:paddingRight=”@dimen/activity_horizontal_margin” android:paddingTop=”@dimen/activity_vertical_margin” android:paddingBottom=”@dimen/activity_vertical_margin” tools:context=”.MainActivity”> <TextView android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:text=”Android Audio Recording” android:id=”@+id/textView” android:textSize=”30dp” android:layout_alignParentTop=”true” android:layout_alignParentRight=”true” android:layout_alignParentEnd=”true” /> <TextView android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:text=”Tutorialspoint” android:id=”@+id/textView2″ android:textColor=”#ff3eff0f” android:textSize=”35dp” android:layout_below=”@+id/textView” android:layout_centerHorizontal=”true” /> <ImageView android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:id=”@+id/imageView” android:src=”@drawable/abc” android:layout_below=”@+id/textView2″ android:layout_alignLeft=”@+id/textView2″ android:layout_alignStart=”@+id/textView2″ android:layout_alignRight=”@+id/textView2″ android:layout_alignEnd=”@+id/textView2″ /> <Button android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:text=”Mode” android:id=”@+id/button” android:layout_below=”@+id/imageView” android:layout_alignParentLeft=”true” android:layout_alignParentStart=”true” android:layout_marginTop=”59dp” /> <Button android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:text=”Ring” android:id=”@+id/button2″ android:layout_alignTop=”@+id/button” android:layout_centerHorizontal=”true” /> <Button android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:text=”vibrate” android:id=”@+id/button3″ android:layout_alignTop=”@+id/button2″ android:layout_alignRight=”@+id/textView” android:layout_alignEnd=”@+id/textView” /> <Button android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:text=”Silent” android:id=”@+id/button4″ android:layout_below=”@+id/button2″ android:layout_alignLeft=”@+id/button2″ android:layout_alignStart=”@+id/button2″ /> </RelativeLayout> Here is the content of Strings.xml <resources> <string name=”app_name”>My Application</string> </resources> Here is the content of AndroidManifest.xml <?xml version=”1.0″ encoding=”utf-8″?> <manifest xmlns:android=”http://schemas.android.com/apk/res/android” package=”com.example.sairamkrishna.myapplication” > <application android:allowBackup=”true” android:icon=”@drawable/ic_launcher” android:label=”@string/app_name” android:theme=”@style/AppTheme” > <activity android:name=”com.example.sairamkrishna.myapplication” 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> Let”s try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from Android Studio, open one of your project”s activity files and click Run icon from the tool bar. Android studio will display Images Now select silent button, you would get silent icon at Notification bar Now just select the ring button and then press the current mode button to see that if its status has been set. Now press the Vibrate button and then press the current mode button to see that if it is set or not.It will display the following screen. Print Page Previous Next Advertisements ”;

Android – Google Maps ”; Previous Next Android allows us to integrate google maps in our application. You can show any location on the map , or can show different routes on the map e.t.c. You can also customize the map according to your choices. Google Map – Layout file Now you have to add the map fragment into xml layout file. Its syntax is given below − <fragment android:id=”@+id/map” android:name=”com.google.android.gms.maps.MapFragment” android:layout_width=”match_parent” android:layout_height=”match_parent”/> Google Map – AndroidManifest file The next thing you need to do is to add some permissions along with the Google Map API key in the AndroidManifest.XML file. Its syntax is given below − <!–Permissions–> <uses-permission android:name=”android.permission.ACCESS_NETWORK_STATE” /> <uses-permission android:name=”android.permission.INTERNET” /> <uses-permission android:name=”com.google.android.providers.gsf.permission. READ_GSERVICES” /> <uses-permission android:name=”android.permission.WRITE_EXTERNAL_STORAGE” /> <!–Google MAP API key–> <meta-data android:name=”com.google.android.maps.v2.API_KEY” android:value=”AIzaSyDKymeBXNeiFWY5jRUejv6zItpmr2MVyQ0″ /> Customizing Google Map You can easily customize google map from its default view , and change it according to your demand. Adding Marker You can place a maker with some text over it displaying your location on the map. It can be done by via addMarker() method. Its syntax is given below − final LatLng TutorialsPoint = new LatLng(21 , 57); Marker TP = googleMap.addMarker(new MarkerOptions() .position(TutorialsPoint).title(“TutorialsPoint”)); Changing Map Type You can also change the type of the MAP. There are four different types of map and each give a different view of the map. These types are Normal,Hybrid,Satellite and terrain. You can use them as below googleMap.setMapType(GoogleMap.MAP_TYPE_NORMAL); googleMap.setMapType(GoogleMap.MAP_TYPE_HYBRID); googleMap.setMapType(GoogleMap.MAP_TYPE_SATELLITE); googleMap.setMapType(GoogleMap.MAP_TYPE_TERRAIN); Enable/Disable zoom You can also enable or disable the zoom gestures in the map by calling the setZoomControlsEnabled(boolean) method. Its syntax is given below − googleMap.getUiSettings().setZoomGesturesEnabled(true); Apart from these customization, there are other methods available in the GoogleMap class , that helps you more customize the map. They are listed below − Sr.No Method & description 1 addCircle(CircleOptions options) This method add a circle to the map 2 addPolygon(PolygonOptions options) This method add a polygon to the map 3 addTileOverlay(TileOverlayOptions options) This method add tile overlay to the map 4 animateCamera(CameraUpdate update) This method Moves the map according to the update with an animation 5 clear() This method removes everything from the map. 6 getMyLocation() This method returns the currently displayed user location. 7 moveCamera(CameraUpdate update) This method repositions the camera according to the instructions defined in the update 8 setTrafficEnabled(boolean enabled) This method Toggles the traffic layer on or off. 9 snapshot(GoogleMap.SnapshotReadyCallback callback) This method Takes a snapshot of the map 10 stopAnimation() This method stops the camera animation if there is one in progress Example Here is an example demonstrating the use of GoogleMap class. It creates a basic M application that allows you to navigate through the map. To experiment with this example , you can run this on an actual device or in an emulator. Create a project with google maps activity as shown below − It will open the following screen and copy the console url for API Key as shown below − Copy this and paste it to your browser. It will give the following screen − Click on continue and click on Create API Key then it will show the following screen Here is the content of activity_main.xml. <fragment xmlns:android=”http://schemas.android.com/apk/res/android” xmlns:map=”http://schemas.android.com/apk/res-auto” xmlns:tools=”http://schemas.android.com/tools” android:id=”@+id/map” android:name=”com.google.android.gms.maps.SupportMapFragment” android:layout_width=”match_parent” android:layout_height=”match_parent” tools:context=”com.example.tutorialspoint7.myapplication.MapsActivity” /> Here is the content of MapActivity.java. In the below code we have given sample latitude and longitude details package com.example.tutorialspoint7.myapplication; import android.support.v4.app.FragmentActivity; import android.os.Bundle; import com.google.android.gms.maps.CameraUpdateFactory; import com.google.android.gms.maps.GoogleMap; import com.google.android.gms.maps.OnMapReadyCallback; import com.google.android.gms.maps.SupportMapFragment; import com.google.android.gms.maps.model.LatLng; import com.google.android.gms.maps.model.MarkerOptions; public class MapsActivity extends FragmentActivity implements OnMapReadyCallback { private GoogleMap mMap; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_maps); // Obtain the SupportMapFragment and get notified when the map is ready to be used. SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager() .findFragmentById(R.id.map); mapFragment.getMapAsync(this); } /** * Manipulates the map once available. * This callback is triggered when the map is ready to be used. * This is where we can add markers or lines, add listeners or move the camera. * In this case, we just add a marker near Sydney, Australia. * If Google Play services is not installed on the device. * This method will only be triggered once the user has installed Google Play services and returned to the app. */ @Override public void onMapReady(GoogleMap googleMap) { mMap = googleMap; // Add a marker in Sydney and move the camera LatLng TutorialsPoint = new LatLng(21, 57); mMap.addMarker(new MarkerOptions().position(TutorialsPoint).title(“Tutorialspoint.com”)); mMap.moveCamera(CameraUpdateFactory.newLatLng(TutorialsPoint)); } } Following is the content of AndroidManifest.xml file. <?xml version=”1.0″ encoding=”utf-8″?> <manifest xmlns:android=”http://schemas.android.com/apk/res/android” package=”com.example.tutorialspoint7.myapplication”> <!– The ACCESS_COARSE/FINE_LOCATION permissions are not required to use Google Maps Android API v2, but you must specify either coarse or fine location permissions for the ”MyLocation” functionality. –> <uses-permission android:name=”android.permission.ACCESS_FINE_LOCATION” /> <uses-permission android:name=”android.permission.ACCESS_COARSE_LOCATION” /> <uses-permission android:name=”android.permission.INTERNET” /> <application android:allowBackup=”true” android:icon=”@mipmap/ic_launcher” android:label=”@string/app_name” android:supportsRtl=”true” android:theme=”@style/AppTheme”> <!– The API key for Google Maps-based APIs is defined as a string resource. (See the file “res/values/google_maps_api.xml”). Note that the API key is linked to the encryption key used to sign the APK. You need a different API key for each encryption key, including the release key that is used to sign the APK for publishing. You can define the keys for the debug and release targets in src/debug/ and src/release/. –> <meta-data android:name=”com.google.android.geo.API_KEY” android:value=”AIzaSyAXhBdyKxUo_cb-EkSgWJQTdqR0QjLcqes” /> <activity android:name=”.MapsActivity” android:label=”@string/title_activity_maps”> <intent-filter> <action android:name=”android.intent.action.MAIN” /> <category android:name=”android.intent.category.LAUNCHER” /> </intent-filter> </activity> </application> </manifest> Output should be like this − Print Page Previous Next Advertisements ”;

Android – Auto Complete ”; Previous Next If you want to get suggestions , when you type in an editable text field , you can do this via AutoCompleteTextView. It provides suggestions automatically when the user is typing. The list of suggestions is displayed in a drop down menu from which the user can choose an item to replace the content of the edit box with. In order to use AutoCompleteTextView you have to first create an AutoCompletTextView Field in the xml. Its syntax is given below. <AutoCompleteTextView android:id=”@+id/autoCompleteTextView1″ android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:layout_alignParentTop=”true” android:layout_centerHorizontal=”true” android:layout_marginTop=”65dp” android:ems=”10″ > After that, you have to get a reference of this textview in java. Its syntax is given below. private AutoCompleteTextView actv; actv = (AutoCompleteTextView) findViewById(R.id.autoCompleteTextView1); The the next thing you need to do is to specify the list of suggestions items to be displayed. You can specify the list items as a string array in java or in strings.xml. Its syntax is given below. String[] countries = getResources().getStringArray(R.array.list_of_countries); ArrayAdapter<String> adapter = new ArrayAdapter<String> (this,android.R.layout.simple_list_item_1,countries); actv.setAdapter(adapter); The array adapter class is responsible for displaying the data as list in the suggestion box of the text field. The setAdapter method is used to set the adapter of the autoCompleteTextView. Apart from these methods, the other methods of Auto Complete are listed below. Sr.No Method & description 1 getAdapter() This method returns a filterable list adapter used for auto completion 2 getCompletionHint() This method returns optional hint text displayed at the bottom of the the matching list 3 getDropDownAnchor() This method returns returns the id for the view that the auto-complete drop down list is anchored to. 4 getListSelection() This method returns the position of the dropdown view selection, if there is one 5 isPopupShowing() This method indicates whether the popup menu is showing 6 setText(CharSequence text, boolean filter) This method sets text except that it can disable filtering 7 showDropDown() This method displays the drop down on screen. Example The below example demonstrates the use of AutoCompleteTextView class. It crates a basic application that allows you to type in and it displays suggestions on your device. To experiment with this example , you need to run this on an actual device or in an emulator. Steps Description 1 You will use Android Studio to create an Android application under a package package com.example.sairamkrishna.myapplication. 2 Modify src/MainActivity.java file to add AutoCompleteTextView code 3 Modify layout XML file res/layout/activity_main.xml add any GUI component if required. 4 Run the application and choose a running android device and install the application on it and verify the results. Here is the content of src/MainActivity.java package com.example.sairamkrishna.myapplication; import android.app.Activity; import android.content.Context; import android.media.AudioManager; import android.media.MediaPlayer; import android.media.MediaRecorder; import android.os.Bundle; import android.os.Environment; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.animation.Animation; import android.view.animation.AnimationUtils; import android.widget.ArrayAdapter; import android.widget.AutoCompleteTextView; import android.widget.Button; import android.widget.EditText; import android.widget.ImageView; import android.widget.MultiAutoCompleteTextView; import android.widget.Toast; import java.io.IOException; public class MainActivity extends Activity { AutoCompleteTextView text; MultiAutoCompleteTextView text1; String[] languages={“Android “,”java”,”IOS”,”SQL”,”JDBC”,”Web services”}; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); text=(AutoCompleteTextView)findViewById(R.id.autoCompleteTextView1); text1=(MultiAutoCompleteTextView)findViewById(R.id.multiAutoCompleteTextView1); ArrayAdapter adapter = new ArrayAdapter(this,android.R.layout.simple_list_item_1,languages); text.setAdapter(adapter); text.setThreshold(1); text1.setAdapter(adapter); text1.setTokenizer(new MultiAutoCompleteTextView.CommaTokenizer()); } } Here is the content of activity_main.xml Here abc indicates about logo of tutorialspoint <xml version=”1.0″ encoding=”utf-8″?> <RelativeLayout xmlns:android=”http://schemas.android.com/apk/res/android” xmlns:tools=”http://schemas.android.com/tools” android:layout_width=”match_parent” android:layout_height=”match_parent” android:paddingLeft=”@dimen/activity_horizontal_margin” android:paddingRight=”@dimen/activity_horizontal_margin” android:paddingTop=”@dimen/activity_vertical_margin” android:paddingBottom=”@dimen/activity_vertical_margin” tools:context=”.MainActivity”> <TextView android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:text=”Android Auto Complete” android:id=”@+id/textView” android:textSize=”30dp” android:layout_alignParentTop=”true” android:layout_alignParentRight=”true” android:layout_alignParentEnd=”true” /> <TextView android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:text=”Tutorialspoint” android:id=”@+id/textView2″ android:textColor=”#ff3eff0f” android:textSize=”35dp” android:layout_below=”@+id/textView” android:layout_centerHorizontal=”true” /> <ImageView android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:id=”@+id/imageView” android:src=”@drawable/logo” android:layout_below=”@+id/textView2″ android:layout_alignLeft=”@+id/textView2″ android:layout_alignStart=”@+id/textView2″ android:layout_alignRight=”@+id/textView2″ android:layout_alignEnd=”@+id/textView2″ /> <AutoCompleteTextView android:id=”@+id/autoCompleteTextView1″ android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:ems=”10″ android:layout_below=”@+id/imageView” android:layout_alignLeft=”@+id/imageView” android:layout_alignStart=”@+id/imageView” android:layout_marginTop=”72dp” android:hint=”AutoComplete TextView”> <requestFocus /> </AutoCompleteTextView> <MultiAutoCompleteTextView android:id=”@+id/multiAutoCompleteTextView1″ android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:ems=”10″ android:layout_below=”@+id/autoCompleteTextView1″ android:layout_alignLeft=”@+id/autoCompleteTextView1″ android:layout_alignStart=”@+id/autoCompleteTextView1″ android:hint=”Multi Auto Complete ” /> </RelativeLayout> Here is the content of Strings.xml <resources> <string name=”app_name”>My Application</string> </resources> Here is the content of AndroidManifest.xml <?xml version=”1.0″ encoding=”utf-8″?> <manifest xmlns:android=”http://schemas.android.com/apk/res/android” package=”com.example.sairamkrishna.myapplication” > <application android:allowBackup=”true” android:icon=”@drawable/ic_launcher” android:label=”@string/app_name” android:theme=”@style/AppTheme” > <activity android:name=”com.example.sairamkrishna.myapplication.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> Let”s try to run your application. I assume you have connected your AVD while doing environment setup. To run the app from Android Studio, open one of your project”s activity files and click Run icon from the toolbar. Android studio will install this application in your AVD and your AVD will display following screen. Now just type in the text view to see suggestions of the Languages. As i just type one letter which are asa, and it shows me suggestion of language. The multiAutoCompleteTextView demonstrates suggestions for not only a word but for whole text. As after writing first word , when i start writing the second word , it displays me the suggestions. This can be shown in the picture below. Print Page Previous Next Advertisements ”;

Android – Fragments ”; Previous Next A Fragment is a piece of an activity which enable more modular activity design. It will not be wrong if we say, a fragment is a kind of sub-activity. Following are important points about fragment − A fragment has its own layout and its own behaviour with its own life cycle callbacks. You can add or remove fragments in an activity while the activity is running. You can combine multiple fragments in a single activity to build a multi-pane UI. A fragment can be used in multiple activities. Fragment life cycle is closely related to the life cycle of its host activity which means when the activity is paused, all the fragments available in the activity will also be stopped. A fragment can implement a behaviour that has no user interface component. Fragments were added to the Android API in Honeycomb version of Android which API version 11. You create fragments by extending Fragment class and You can insert a fragment into your activity layout by declaring the fragment in the activity”s layout file, as a <fragment> element. Prior to fragment introduction, we had a limitation because we can show only a single activity on the screen at one given point in time. So we were not able to divide device screen and control different parts separately. But with the introduction of fragment we got more flexibility and removed the limitation of having a single activity on the screen at a time. Now we can have a single activity but each activity can comprise of multiple fragments which will have their own layout, events and complete life cycle. Following is a typical example of how two UI modules defined by fragments can be combined into one activity for a tablet design, but separated for a handset design. The application can embed two fragments in Activity A, when running on a tablet-sized device. However, on a handset-sized screen, there”s not enough room for both fragments, so Activity A includes only the fragment for the list of articles, and when the user selects an article, it starts Activity B, which includes the second fragment to read the article. Fragment Life Cycle Android fragments have their own life cycle very similar to an android activity. This section briefs different stages of its life cycle. Fragment lifecycle Here is the list of methods which you can to override in your fragment class − onAttach()The fragment instance is associated with an activity instance.The fragment and the activity is not fully initialized. Typically you get in this method a reference to the activity which uses the fragment for further initialization work. onCreate() The system calls this method when creating the fragment. You should initialize essential components of the fragment that you want to retain when the fragment is paused or stopped, then resumed. onCreateView() The system calls this callback when it”s time for the fragment to draw its user interface for the first time. To draw a UI for your fragment, you must return a View component from this method that is the root of your fragment”s layout. You can return null if the fragment does not provide a UI. onActivityCreated()The onActivityCreated() is called after the onCreateView() method when the host activity is created. Activity and fragment instance have been created as well as the view hierarchy of the activity. At this point, view can be accessed with the findViewById() method. example. In this method you can instantiate objects which require a Context object onStart()The onStart() method is called once the fragment gets visible. onResume()Fragment becomes active. onPause() The system calls this method as the first indication that the user is leaving the fragment. This is usually where you should commit any changes that should be persisted beyond the current user session. onStop()Fragment going to be stopped by calling onStop() onDestroyView()Fragment view will destroy after call this method onDestroy()onDestroy() called to do final clean up of the fragment”s state but Not guaranteed to be called by the Android platform. How to use Fragments? This involves number of simple steps to create Fragments. First of all decide how many fragments you want to use in an activity. For example let”s we want to use two fragments to handle landscape and portrait modes of the device. Next based on number of fragments, create classes which will extend the Fragment class. The Fragment class has above mentioned callback functions. You can override any of the functions based on your requirements. Corresponding to each fragment, you will need to create layout files in XML file. These files will have layout for the defined fragments. Finally modify activity file to define the actual logic of replacing fragments based on your requirement. Types of Fragments Basically fragments are divided as three stages as shown below. Single frame fragments − Single frame fragments are using for hand hold devices like mobiles, here we can show only one fragment as a view. List fragments − fragments having special list view is called as list fragment Fragments transaction − Using with fragment transaction. we can move one fragment to another fragment. Print Page Previous Next Advertisements ”;

Android – Architecture ”; Previous Next Android operating system is a stack of software components which is roughly divided into five sections and four main layers as shown below in the architecture diagram. Linux kernel At the bottom of the layers is Linux – Linux 3.6 with approximately 115 patches. This provides a level of abstraction between the device hardware and it contains all the essential hardware drivers like camera, keypad, display etc. Also, the kernel handles all the things that Linux is really good at such as networking and a vast array of device drivers, which take the pain out of interfacing to peripheral hardware. Libraries On top of Linux kernel there is a set of libraries including open-source Web browser engine WebKit, well known library libc, SQLite database which is a useful repository for storage and sharing of application data, libraries to play and record audio and video, SSL libraries responsible for Internet security etc. Android Libraries This category encompasses those Java-based libraries that are specific to Android development. Examples of libraries in this category include the application framework libraries in addition to those that facilitate user interface building, graphics drawing and database access. A summary of some key core Android libraries available to the Android developer is as follows − android.app − Provides access to the application model and is the cornerstone of all Android applications. android.content − Facilitates content access, publishing and messaging between applications and application components. android.database − Used to access data published by content providers and includes SQLite database management classes. android.opengl − A Java interface to the OpenGL ES 3D graphics rendering API. android.os − Provides applications with access to standard operating system services including messages, system services and inter-process communication. android.text − Used to render and manipulate text on a device display. android.view − The fundamental building blocks of application user interfaces. android.widget − A rich collection of pre-built user interface components such as buttons, labels, list views, layout managers, radio buttons etc. android.webkit − A set of classes intended to allow web-browsing capabilities to be built into applications. Having covered the Java-based core libraries in the Android runtime, it is now time to turn our attention to the C/C++ based libraries contained in this layer of the Android software stack. Android Runtime This is the third section of the architecture and available on the second layer from the bottom. This section provides a key component called Dalvik Virtual Machine which is a kind of Java Virtual Machine specially designed and optimized for Android. The Dalvik VM makes use of Linux core features like memory management and multi-threading, which is intrinsic in the Java language. The Dalvik VM enables every Android application to run in its own process, with its own instance of the Dalvik virtual machine. The Android runtime also provides a set of core libraries which enable Android application developers to write Android applications using standard Java programming language. Application Framework The Application Framework layer provides many higher-level services to applications in the form of Java classes. Application developers are allowed to make use of these services in their applications. The Android framework includes the following key services − Activity Manager − Controls all aspects of the application lifecycle and activity stack. Content Providers − Allows applications to publish and share data with other applications. Resource Manager − Provides access to non-code embedded resources such as strings, color settings and user interface layouts. Notifications Manager − Allows applications to display alerts and notifications to the user. View System − An extensible set of views used to create application user interfaces. Applications You will find all the Android application at the top layer. You will write your application to be installed on this layer only. Examples of such applications are Contacts Books, Browser, Games etc. Print Page Previous Next Advertisements ”;

Android – Hello World Example ”; Previous Next Let us start actual programming with Android Framework. Before you start writing your first example using Android SDK, you have to make sure that you have set-up your Android development environment properly as explained in Android – Environment Set-up tutorial. I also assume that you have a little bit working knowledge with Android studio. So let us proceed to write a simple Android Application which will print “Hello World!”. Create Android Application The first step is to create a simple Android Application using Android studio. When you click on Android studio icon, it will show screen as shown below You can start your application development by calling start a new android studio project. in a new installation frame should ask Application name, package information and location of the project.− After entered application name, it going to be called select the form factors your application runs on, here need to specify Minimum SDK, in our tutorial, I have declared as API23: Android 6.0(Mashmallow) − The next level of installation should contain selecting the activity to mobile, it specifies the default layout for Applications. At the final stage it going to be open development tool to write the application code. Anatomy of Android Application Before you run your app, you should be aware of a few directories and files in the Android project − Sr.No. Folder, File & Description 1 Java This contains the .java source files for your project. By default, it includes an MainActivity.java source file having an activity class that runs when your app is launched using the app icon. 2 res/drawable-hdpi This is a directory for drawable objects that are designed for high-density screens. 3 res/layout This is a directory for files that define your app”s user interface. 4 res/values This is a directory for other various XML files that contain a collection of resources, such as strings and colours definitions. 5 AndroidManifest.xml This is the manifest file which describes the fundamental characteristics of the app and defines each of its components. 6 Build.gradle This is an auto generated file which contains compileSdkVersion, buildToolsVersion, applicationId, minSdkVersion, targetSdkVersion, versionCode and versionName Following section will give a brief overview of the important application files. The Main Activity File The main activity code is a Java file MainActivity.java. This is the actual application file which ultimately gets converted to a Dalvik executable and runs your application. Following is the default code generated by the application wizard for Hello World! application − package com.example.helloworld; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } } Here, R.layout.activity_main refers to the activity_main.xml file located in the res/layout folder. The onCreate() method is one of many methods that are figured when an activity is loaded. The Manifest File Whatever component you develop as a part of your application, you must declare all its components in a manifest.xml which resides at the root of the application project directory. This file works as an interface between Android OS and your application, so if you do not declare your component in this file, then it will not be considered by the OS. For example, a default manifest file will look like as following file − <?xml version=”1.0″ encoding=”utf-8″?> <manifest xmlns:android=”http://schemas.android.com/apk/res/android” package=”com.example.tutorialspoint7.myapplication”> <application android:allowBackup=”true” android:icon=”@mipmap/ic_launcher” android:label=”@string/app_name” android:supportsRtl=”true” android:theme=”@style/AppTheme”> <activity android:name=”.MainActivity”> <intent-filter> <action android:name=”android.intent.action.MAIN” /> <category android:name=”android.intent.category.LAUNCHER” /> </intent-filter> </activity> </application> </manifest> Here <application>…</application> tags enclosed the components related to the application. Attribute android:icon will point to the application icon available under res/drawable-hdpi. The application uses the image named ic_launcher.png located in the drawable folders The <activity> tag is used to specify an activity and android:name attribute specifies the fully qualified class name of the Activity subclass and the android:label attributes specifies a string to use as the label for the activity. You can specify multiple activities using <activity> tags. The action for the intent filter is named android.intent.action.MAIN to indicate that this activity serves as the entry point for the application. The category for the intent-filter is named android.intent.category.LAUNCHER to indicate that the application can be launched from the device”s launcher icon. The @string refers to the strings.xml file explained below. Hence, @string/app_name refers to the app_name string defined in the strings.xml file, which is “HelloWorld”. Similar way, other strings get populated in the application. Following is the list of tags which you will use in your manifest file to specify different Android application components − <activity>elements for activities <service> elements for services <receiver> elements for broadcast receivers <provider> elements for content providers The Strings File The strings.xml file is located in the res/values folder and it contains all the text that your application uses. For example, the names of buttons, labels, default text, and similar types of strings go into this file. This file is responsible for their textual content. For example, a default strings file will look like as following file − <resources> <string name=”app_name”>HelloWorld</string> <string name=”hello_world”>Hello world!</string> <string name=”menu_settings”>Settings</string> <string name=”title_activity_main”>MainActivity</string> </resources> The Layout File The activity_main.xml is a layout file available in res/layout directory, that is referenced by your application when building its interface. You will modify this file very frequently to change the layout of your application. For your “Hello World!” application, this file will have following content related to default layout − <RelativeLayout xmlns:android=”http://schemas.android.com/apk/res/android” xmlns:tools=”http://schemas.android.com/tools” android:layout_width=”match_parent” android:layout_height=”match_parent” > <TextView android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:layout_centerHorizontal=”true” android:layout_centerVertical=”true” android:padding=”@dimen/padding_medium” android:text=”@string/hello_world” tools:context=”.MainActivity” /> </RelativeLayout> This is an example of simple RelativeLayout which we will study in a separate chapter. The TextView is an Android control used to build the GUI and it have various attributes like android:layout_width, android:layout_height etc which are being used to set its width and height etc.. The @string refers to the strings.xml file located in the res/values folder. Hence, @string/hello_world refers to the hello string defined in the strings.xml file, which is “Hello World!”. Running the Application Let”s try to run our Hello World! application we just created. I assume you had created

Android – Services ”; Previous Next A service is a component that runs in the background to perform long-running operations without needing to interact with the user and it works even if application is destroyed. A service can essentially take two states − Sr.No. State & Description 1 Started A service is started when an application component, such as an activity, starts it by calling startService(). Once started, a service can run in the background indefinitely, even if the component that started it is destroyed. 2 Bound A service is bound when an application component binds to it by calling bindService(). A bound service offers a client-server interface that allows components to interact with the service, send requests, get results, and even do so across processes with interprocess communication (IPC). A service has life cycle callback methods that you can implement to monitor changes in the service”s state and you can perform work at the appropriate stage. The following diagram on the left shows the life cycle when the service is created with startService() and the diagram on the right shows the life cycle when the service is created with bindService(): (image courtesy : android.com ) To create an service, you create a Java class that extends the Service base class or one of its existing subclasses. The Service base class defines various callback methods and the most important are given below. You don”t need to implement all the callbacks methods. However, it”s important that you understand each one and implement those that ensure your app behaves the way users expect. Sr.No. Callback & Description 1 onStartCommand() The system calls this method when another component, such as an activity, requests that the service be started, by calling startService(). If you implement this method, it is your responsibility to stop the service when its work is done, by calling stopSelf() or stopService() methods. 2 onBind() The system calls this method when another component wants to bind with the service by calling bindService(). If you implement this method, you must provide an interface that clients use to communicate with the service, by returning an IBinder object. You must always implement this method, but if you don”t want to allow binding, then you should return null. 3 onUnbind() The system calls this method when all clients have disconnected from a particular interface published by the service. 4 onRebind() The system calls this method when new clients have connected to the service, after it had previously been notified that all had disconnected in its onUnbind(Intent). 5 onCreate() The system calls this method when the service is first created using onStartCommand() or onBind(). This call is required to perform one-time set-up. 6 onDestroy() The system calls this method when the service is no longer used and is being destroyed. Your service should implement this to clean up any resources such as threads, registered listeners, receivers, etc. The following skeleton service demonstrates each of the life cycle methods − package com.tutorialspoint; import android.app.Service; import android.os.IBinder; import android.content.Intent; import android.os.Bundle; public class HelloService extends Service { /** indicates how to behave if the service is killed */ int mStartMode; /** interface for clients that bind */ IBinder mBinder; /** indicates whether onRebind should be used */ boolean mAllowRebind; /** Called when the service is being created. */ @Override public void onCreate() { } /** The service is starting, due to a call to startService() */ @Override public int onStartCommand(Intent intent, int flags, int startId) { return mStartMode; } /** A client is binding to the service with bindService() */ @Override public IBinder onBind(Intent intent) { return mBinder; } /** Called when all clients have unbound with unbindService() */ @Override public boolean onUnbind(Intent intent) { return mAllowRebind; } /** Called when a client is binding to the service with bindService()*/ @Override public void onRebind(Intent intent) { } /** Called when The service is no longer used and is being destroyed */ @Override public void onDestroy() { } } Example This example will take you through simple steps to show how to create your own Android Service. Follow the following steps to modify the Android application we created in Hello World Example chapter − Step Description 1 You will use Android StudioIDE to create an Android application and name it as My Application under a package com.example.tutorialspoint7.myapplication as explained in the Hello World Example chapter. 2 Modify main activity file MainActivity.java to add startService() and stopService() methods. 3 Create a new java file MyService.java under the package com.example.My Application. This file will have implementation of Android service related methods. 4 Define your service in AndroidManifest.xml file using <service…/> tag. An application can have one or more services without any restrictions. 5 Modify the default content of res/layout/activity_main.xml file to include two buttons in linear layout. 6 No need to change any constants in res/values/strings.xml file. Android studio take care of string values 7 Run the application to launch Android emulator and verify the result of the changes done in the application. Following is the content of the modified main activity file MainActivity.java. This file can include each of the fundamental life cycle methods. We have added startService() and stopService() methods to start and stop the service. package com.example.tutorialspoint7.myapplication; import android.content.Intent; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.os.Bundle; import android.app.Activity; import android.util.Log; import android.view.View; public class MainActivity extends Activity { String msg = “Android : “; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Log.d(msg, “The onCreate() event”); } public void startService(View view) { startService(new Intent(getBaseContext(), MyService.class)); } // Method to stop the service public void stopService(View view) { stopService(new Intent(getBaseContext(), MyService.class)); } } Following is the content of MyService.java. This file can have implementation of one or more methods associated with Service based on requirements. For now we are going to implement only two methods onStartCommand() and onDestroy() − package com.example.tutorialspoint7.myapplication; import android.app.Service; import android.content.Intent; import android.os.IBinder; import android.support.annotation.Nullable; import android.widget.Toast; /** * Created by TutorialsPoint7 on

Android – Overview ”; Previous Next What is Android? Android is an open source and Linux-based Operating System for mobile devices such as smartphones and tablet computers. Android was developed by the Open Handset Alliance, led by Google, and other companies. Android offers a unified approach to application development for mobile devices which means developers need only develop for Android, and their applications should be able to run on different devices powered by Android. The first beta version of the Android Software Development Kit (SDK) was released by Google in 2007 where as the first commercial version, Android 1.0, was released in September 2008. On June 27, 2012, at the Google I/O conference, Google announced the next Android version, 4.1 Jelly Bean. Jelly Bean is an incremental update, with the primary aim of improving the user interface, both in terms of functionality and performance. The source code for Android is available under free and open source software licenses. Google publishes most of the code under the Apache License version 2.0 and the rest, Linux kernel changes, under the GNU General Public License version 2. Why Android ? Features of Android Android is a powerful operating system competing with Apple 4GS and supports great features. Few of them are listed below − Sr.No. Feature & Description 1 Beautiful UI Android OS basic screen provides a beautiful and intuitive user interface. 2 Connectivity GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth, Wi-Fi, LTE, NFC and WiMAX. 3 Storage SQLite, a lightweight relational database, is used for data storage purposes. 4 Media support H.263, H.264, MPEG-4 SP, AMR, AMR-WB, AAC, HE-AAC, AAC 5.1, MP3, MIDI, Ogg Vorbis, WAV, JPEG, PNG, GIF, and BMP. 5 Messaging SMS and MMS 6 Web browser Based on the open-source WebKit layout engine, coupled with Chrome”s V8 JavaScript engine supporting HTML5 and CSS3. 7 Multi-touch Android has native support for multi-touch which was initially made available in handsets such as the HTC Hero. 8 Multi-tasking User can jump from one task to another and same time various application can run simultaneously. 9 Resizable widgets Widgets are resizable, so users can expand them to show more content or shrink them to save space. 10 Multi-Language Supports single direction and bi-directional text. 11 GCM Google Cloud Messaging (GCM) is a service that lets developers send short message data to their users on Android devices, without needing a proprietary sync solution. 12 Wi-Fi Direct A technology that lets apps discover and pair directly, over a high-bandwidth peer-to-peer connection. 13 Android Beam A popular NFC-based technology that lets users instantly share, just by touching two NFC-enabled phones together. Android Applications Android applications are usually developed in the Java language using the Android Software Development Kit. Once developed, Android applications can be packaged easily and sold out either through a store such as Google Play, SlideME, Opera Mobile Store, Mobango, F-droid and the Amazon Appstore. Android powers hundreds of millions of mobile devices in more than 190 countries around the world. It”s the largest installed base of any mobile platform and growing fast. Every day more than 1 million new Android devices are activated worldwide. This tutorial has been written with an aim to teach you how to develop and package Android application. We will start from environment setup for Android application programming and then drill down to look into various aspects of Android applications. Categories of Android applications There are many android applications in the market. The top categories are − History of Android The code names of android ranges from A to N currently, such as Aestro, Blender, Cupcake, Donut, Eclair, Froyo, Gingerbread, Honeycomb, Ice Cream Sandwitch, Jelly Bean, KitKat, Lollipop and Marshmallow. Let”s understand the android history in a sequence. What is API level? API Level is an integer value that uniquely identifies the framework API revision offered by a version of the Android platform. Platform Version API Level VERSION_CODE Android 6.0 23 MARSHMALLOW Android 5.1 22 LOLLIPOP_MR1 Android 5.0 21 LOLLIPOP Android 4.4W 20 KITKAT_WATCH KitKat for Wearables Only Android 4.4 19 KITKAT Android 4.3 18 JELLY_BEAN_MR2 Android 4.2, 4.2.2 17 JELLY_BEAN_MR1 Android 4.1, 4.1.1 16 JELLY_BEAN Android 4.0.3, 4.0.4 15 ICE_CREAM_SANDWICH_MR1 Android 4.0, 4.0.1, 4.0.2 14 ICE_CREAM_SANDWICH Android 3.2 13 HONEYCOMB_MR2 Android 3.1.x 12 HONEYCOMB_MR1 Android 3.0.x 11 HONEYCOMB Android 2.3.4 Android 2.3.3 10 GINGERBREAD_MR1 Android 2.3.2 Android 2.3.1 Android 2.3 9 GINGERBREAD Android 2.2.x 8 FROYO Android 2.1.x 7 ECLAIR_MR1 Android 2.0.1 6 ECLAIR_0_1 Android 2.0 5 ECLAIR Android 1.6 4 DONUT Android 1.5 3 CUPCAKE Android 1.1 2 BASE_1_1 Android 1.0 1 BASE Print Page Previous Next Advertisements ”;

Android – Application Components ”; Previous Next Application components are the essential building blocks of an Android application. These components are loosely coupled by the application manifest file AndroidManifest.xml that describes each component of the application and how they interact. There are following four main components that can be used within an Android application − Sr.No Components & Description 1 Activities They dictate the UI and handle the user interaction to the smart phone screen. 2 Services They handle background processing associated with an application. 3 Broadcast Receivers They handle communication between Android OS and applications. 4 Content Providers They handle data and database management issues. Activities An activity represents a single screen with a user interface,in-short Activity performs actions on the screen. For example, an email application might have one activity that shows a list of new emails, another activity to compose an email, and another activity for reading emails. If an application has more than one activity, then one of them should be marked as the activity that is presented when the application is launched. An activity is implemented as a subclass of Activity class as follows − public class MainActivity extends Activity { } Services A service is a component that runs in the background to perform long-running operations. For example, a service might play music in the background while the user is in a different application, or it might fetch data over the network without blocking user interaction with an activity. A service is implemented as a subclass of Service class as follows − public class MyService extends Service { } Broadcast Receivers Broadcast Receivers simply respond to broadcast messages from other applications or from the system. For example, applications can also initiate broadcasts to let other applications know that some data has been downloaded to the device and is available for them to use, so this is broadcast receiver who will intercept this communication and will initiate appropriate action. A broadcast receiver is implemented as a subclass of BroadcastReceiver class and each message is broadcaster as an Intent object. public class MyReceiver extends BroadcastReceiver { public void onReceive(context,intent){} } Content Providers A content provider component supplies data from one application to others on request. Such requests are handled by the methods of the ContentResolver class. The data may be stored in the file system, the database or somewhere else entirely. A content provider is implemented as a subclass of ContentProvider class and must implement a standard set of APIs that enable other applications to perform transactions. public class MyContentProvider extends ContentProvider { public void onCreate(){} } We will go through these tags in detail while covering application components in individual chapters. Additional Components There are additional components which will be used in the construction of above mentioned entities, their logic, and wiring between them. These components are − S.No Components & Description 1 Fragments Represents a portion of user interface in an Activity. 2 Views UI elements that are drawn on-screen including buttons, lists forms etc. 3 Layouts View hierarchies that control screen format and appearance of the views. 4 Intents Messages wiring components together. 5 Resources External elements, such as strings, constants and drawable pictures. 6 Manifest Configuration file for the application. Print Page Previous Next Advertisements ”;

Android – Environment Setup ”; Previous Next You will be glad to know that you can start your Android application development on either of the following operating systems − Microsoft Windows XP or later version. Mac OS X 10.5.8 or later version with Intel chip. Linux including GNU C Library 2.7 or later. Second point is that all the required tools to develop Android applications are freely available and can be downloaded from the Web. Following is the list of software”s you will need before you start your Android application programming. Java JDK5 or later version Android Studio Here last two components are optional and if you are working on Windows machine then these components make your life easy while doing Java based application development. So let us have a look how to proceed to set required environment. Set-up Java Development Kit (JDK) You can download the latest version of Java JDK from Oracle”s Java site − Java SE Downloads. You will find instructions for installing JDK in downloaded files, follow the given instructions to install and configure the setup. Finally set PATH and JAVA_HOME environment variables to refer to the directory that contains java and javac, typically java_install_dir/bin and java_install_dir respectively. If you are running Windows and installed the JDK in C:jdk1.8.0_102, you would have to put the following line in your C:autoexec.bat file. set PATH=C:jdk1.8.0_102bin;%PATH% set JAVA_HOME=C:jdk1.8.0_102 Alternatively, you could also right-click on My Computer, select Properties, then Advanced, then Environment Variables. Then, you would update the PATH value and press the OK button. On Linux, if the SDK is installed in /usr/local/jdk1.8.0_102 and you use the C shell, you would put the following code into your .cshrc file. setenv PATH /usr/local/jdk1.8.0_102/bin:$PATH setenv JAVA_HOME /usr/local/jdk1.8.0_102 Alternatively, if you use Android studio, then it will know automatically where you have installed your Java. Android IDEs There are so many sophisticated Technologies are available to develop android applications, the familiar technologies, which are predominantly using tools as follows Android Studio Eclipse IDE(Deprecated) Print Page Previous Next Advertisements ”;