Android – Advanced Topics Mobile Application Development Selected Topics – CPIT 490 21-Oct-15.
36
Android – Advanced Topics Mobile Application Development Selected Topics – CPIT 490 Mar 19, 2 022
-
Upload
toby-warner -
Category
Documents
-
view
221 -
download
0
Transcript of Android – Advanced Topics Mobile Application Development Selected Topics – CPIT 490 21-Oct-15.
Android – Advanced Topics
Mobile Application Development
Selected Topics – CPIT 490
Apr 20, 2023
2
Objective
Web Browsing Android Animation Android Backup Publishing Your Application
3
Web Browsing – Objectives
Show how to launch the built-in Browser application in three ways. Launch the browser to a specific URL. Create text with links. Launch a Google web search and specify the search criteria.
You will achieve these goals by creating and configuring the appropriate Intents within your application’s Activity class.
4
Launch the Browser Working with URIs:
Use Uri objects to identify the unique location of a piece of data. Create a Uri object from a web URL using the parse()
Uri uriUrl = Uri.parse("http://www.google.com/"); Creating the Intent:
Use android.content.Intent.ACTION_VIEW to view HTML Specify the URI in the intent
Intent launchBrowser = new Intent(Intent.ACTION_VIEW, uriUrl); Launching the Intent:
Call the startActivity() method, passing in your Intent startActivity(launchBrowser);
5
Text with Links Another easy is simply by including links within text on the screen. The TextView object can be configured to find these and turn them into
clickable links No special formatting commands or tags are needed within the string.
Example: <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/contains_links" android:textSize="14dp" android:autoLink="web" />
6
Google Web Search
Enabling Web Searches If content with a Google search, use web search Intent
android.content.Intent.ACTION_WEB_SEARCH Intent search = new Intent(Intent.ACTION_WEB_SEARCH); Supplying Search Criteria
Uses SearchManager.QUERY intent extra field for search criteria
Intent search = new Intent(Intent.ACTION_WEB_SEARCH); search.putExtra(SearchManager.QUERY, "pygmy goats"); startActivity(search);
7
Becoming a Browser
For more fine control over web content, use the WebView control. This special view allows fine control over rendering of web
content. In the following, we describe:
How you can embed an Android WebView in your application with the WebKit engine.
How to both load an external URL and render custom markup that you supply in-app.
8
Becoming a Browser Setting up the WebView Widget
Declare it in a layout file Access it from an Activity and tell it what to do.
<?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" > <WebView android:id="@+id/web_engine" android:layout_width="fill_parent" android:layout_height="fill_parent" /> </LinearLayout>
9
Becoming a Browser
Requesting Internet Permission <uses-permission
android:name="android.permission.INTERNET" />
Load a Web Page In your main activity, add the following code
into the onCreate(): WebView engine = (WebView) findViewById(R.id.web_engine); engine.loadUrl("http://mobile.tutsplus.com");
10
Becoming a Browser
Render Custom Markup Replace the loadUrl() call with loadData(), which takes three
arguments: String htmlData, String mimeType, String encoding
String data = "<html>" + "<body><h1>Yay, Mobiletuts+!</h1></body>" + "</html>";
engine.loadData(data, "text/html", "UTF-8"); Note
JavaScript should be enabled: engine.getSettings().setJavaScriptEnabled( true );
11
Becoming a Browser
Extra features reload() : Refreshes and re-renders the page. goForward() : Goes one step forward in browser history. goBack() : Goes one step back in browser history.
Use WebSettings class to define the features of the browser. WebSettings webSettings = webView.getSettings(); setBlockNetworkImage() : Block network images to reduce
the data loading using the method. setDefaultFontSize() : Set font size of the displayed web
content Other methods: setSaveFormData(), setJavaScriptEnabled(),
setSavePassword(), setSaveFormData(), setJavaScriptEnabled(), setSupportZoom()
12
Android Backup – Overview
Users store a lot of data on different applications like notes, game data, application settings, address book entries, All these data cannot be recovered after they are gone. Backup service hosted by Google was introduced in Android
2.2. All the application data can use the backup service to store
any data to the cloud.
13
Creating a Backup of Runtime Data Use BackupManager class to notify the Backup service to do backup and
restore operations. After the notification is received, the backup manager requests backup
data from the application and delivers it to a cloud storage server during backup.
It also retrieves backup data from the backup transport and returns it to applications during a restore process.
A backup agent is the interface where the BackupManager communicates with the applications.
Extend the BackupAgent in their class. Two methods need to be overridden: onBackup() : triggered whenever there is a dataChanged() method call. onRestore(): triggered whenever there is a requestRestore()
14
Creating a Backup of Runtime Data
onBackup() has three parameters: oldState—Return the state from the last backup. data—The data that is backed up newState—Write the current state of the backup, which
becomes the oldState for the next backup onRestore() has three parameters:
data—The data from the last backup. appVersionCode—The application’s version code during the
backup operation. The version code is defined as the attribute android:versionCode in the Android-Manifest XML file.
newState—Write the current state as the restore point.
15
Creating a Backup of Runtime Data public class MyBackupAgent extends BackupAgent { @Override public void onCreate() { ... } @Override public void onBackup(ParcelFileDescriptor oldState, BackupDataOutput
data, ParcelFileDescriptor newState){ ... } @Override public void onRestore(BackupDataInput data, int appVersionCode,
ParcelFileDescriptor newState){ ... } }
16
Backing Up Files to the Cloud
BackupAgent is intended to save application run-time data. BackupAgentHelper is intended to save files
Wrapper class for the backup agent class. Supports two different kinds of backup helpers
SharedPreferencesBackupHelper to backup SharedPreferences files
FileBackupHelper to backup file
17
Triggering Backup and Restore To define Backup agent, add android:backupAgent attribute inside the application
manifest file <application android:label="Backup/Restore"
android:backupAgent="myBackupAgent"> Anytime the application triggers a backup or restore to the BackupManager, it initiates
with the identified backup agent. public class MyBandRActivity extends Activity { BackupManager mBackupManager; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); ... mBackupManager = new BackupManager(this); } void dataUpdate() { ... // We also need to perform an initial backup; ask for one mBackupManager.dataChanged(); //use BackupAgent defined in manifest file } }
18
Triggering Backup and Restore
Use requestRestore() of the BackupManager to trigger restore. triggers a call to the backup agent’s onRestore() method
Also, a factory data reset or when the application is reinstalled trigger restore for the application.
Android provides a command-line script bmgr that can trigger backup/restore Back trigger: “ > adb shell bmgr backup <package> ” Restore trigger: “ > adb shell bmgr restore <package> ” To force the BackupManager to do the backup right away:
“ > adb shell bmgr run ”
19
Android Animation Two types of animation: frame-by-frame and Tween animation. Frame-by-frame animation needs an animation-list element in the layout file
Containing a list of item elements specifying an ordered list of the different pictures to display.
oneshot attribute specifies whether the animation is played only once or repeatedly
Example: res/anim/animated.xml <?xml version="1.0" encoding="utf-8"?> <animation-list xmlns:android="http://schemas.android.com/apk/res/android"
android:oneshot="false"> <item android:drawable="@drawable/anddev1" android:duration="200" /> <item android:drawable="@drawable/anddev2" android:duration="200" /> <item android:drawable="@drawable/anddev3" android:duration="200" /> </animation-list>
20
Android Animation
To display the frame-by-frame animation, set the animation to a view’s background a drawable can be retrieved by calling getBackground() and
casting it to AnimationDrawable calling the start() method starts the animation.
ImageView im = (ImageView) this.findViewById(R.id.myanimated);
im.setBackgroundResource(R.anim.animated); AnimationDrawable ad =
(AnimationDrawable)im.getBackground(); ad.start();
21
Android Animation
Tween animation uses a different approach that creates an animation by performing a series of transformations on a single image.
Android provides access to the following classes that are the basis for all the animations AlphaAnimation—Controls transparency changes RotateAnimation—Controls rotations ScaleAnimation—Controls growing or shrinking TranslateAnimation—Controls position changes
Used for transitions between activities, layouts, views, etc. Defined in the layout XML file as <alpha>, <rotate>, <scale>,
and <translate>.
22
Example Creates a new mail animation that can be used when mail is received. Layout file: res/layout/main.xml <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" android:gravity="center" > <ImageView android:id="@+id/myanimated" android:layout_width="wrap_content" android:layout_height="wrap_content“ android:src="@drawable/mail" /> <Button android:id="@+id/startAnimated" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="you’ve got mail" /> </LinearLayout>
23
Example Animation file: res/anim/animated.xml <?xml version="1.0" encoding="utf-8"?> <set xmlns:android="http://schemas.android.com/apk/res/android" android:interpolator="@android:anim/accelerate_interpolator"> <translate android:fromXDelta="100%p" android:toXDelta="0“
android:duration="5000" /> <alpha android:fromAlpha="0.0" android:toAlpha="1.0"
android:duration="3000" /> <rotate android:fromDegrees="0“ android:toDegrees="-45" android:toYScale="0.0“ android:pivotX="50%" android:pivotY="50%“ android:startOffset="700" android:duration="3000" /> <scale android:fromXScale="0.0“ android:toXScale="1.4" android:fromYScale="0.0“ android:toYScale="1.0" android:pivotX="50%“ android:pivotY="50%" android:startOffset="700“ android:duration="3000" android:fillBefore="false" /> </set>
24
Example Main Activitiy package edu.odu.cs.cs495.animation; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.view.animation.Animation; import android.view.animation.AnimationUtils; import android.widget.Button; import android.widget.ImageView; public class myanimation extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); final ImageView im = (ImageView) this.findViewById(R.id.myanimated); final Animation an = AnimationUtils.loadAnimation(this, R.anim.animated); im.setVisibility(View.INVISIBLE); Button bt = (Button) this.findViewById(R.id.startAnimated); bt.setOnClickListener(new OnClickListener(){ public void onClick(View view){ im.setVisibility(View.VISIBLE); im.startAnimation(an); } }); } }
25
Publish to Android Market
The Checklist Have I tested my application
extensively? Emulator + Physical device Multiple hardware devices
running different Android versions.
Does my application perform well? Performance is really important
especially in games Have I decided on SDK
compatibility? Android 2.2 & 2.3 dominate?
26
Publish to Android Market
Publishing an application requires these: Export your application as an APK (Android Package) file. Generate your own self-signed certificate and digitally sign
your application with it. Deploy the signed application. Use the Android Market for hosting and selling your
application.
27
Getting your application ready Step 1: Request necessary Android permissions
Make sure that you’re requesting all necessary permissions, otherwise your application won’t work.
<uses-permission android:name="android.permission.VIBRATE" /> <uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.REBOOT" />
Step 2: Specify a name (label) and icon Name your application and give it an icon using the android:label and
android:icon attribute in the application tag <application android:label="@string/app_name"
android:icon="@drawable/myIcon" > This name is displayed in the Settings Apps section of your Android ➪
device
28
Getting your application ready Step 3: Configure version manifest data
Pick a version your application using android:versionCode and android:versionName.
versionCode is an integer that must increment for every update. Not used by android system but used by developer’s to obtain the application’s version number. Used by android market to find whether a new version exist or not. versionCode can be retrieved programmatically using getPackageInfo() method from the PackageManager class
PackageManager pm = getPackageManager(); PackageInfo pi = pm.getPackageInfo(“net.learn2develop.LBS”, 0); Toast.makeText(getBaseContext(), “VersionCode: ” +
Integer.toString(pi.versionCode), Toast.LENGTH_SHORT).show(); versionName is a user-friendly value (e.g., 0.1 or 1.0b or 2.4.1). It is
visible to the users <manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example" android:versionCode="1" android:versionName="1.0.0" >
29
Getting your application ready
Step 4: Set compatibility options If you’re utilizing Android features that aren’t available in
older versions specify a set of version requirements within uses-sdk.
android:minSdkVersion The minimum Android platform API level on which your application will be able to run.
android:targetSdkVersion The API level that your application was designed to run on.
android:maxSdkVersion An upper limit for compatibility. Don’t set this unless you have a very good reason to.
Step 5: Cleanup files and remove logging
30
Getting your application ready Step 6: Sign and ZIP-align your application
Android applications must be digitally signed with a certificate that the developer holds to ensure the authenticity.
Pick a strong password for your private key and ensure to keep it safe
Eclipse by default signs compiled apps with debug key.
Use Export Wizard: 1.Select the project and select File > Export. 2.Open the Android drop-down and select
Export Android Application 3.Follow the wizard’s steps to compile, sign
and ZIP-align your application. Create a new one for the first time or
use an existing one
Your validity period must extend 2033 orelse the Android Market will reject your app!
31
Getting your application ready In Eclipse, pressing F11 will automatically deploy the application in the
Emulator. You can verify this by going to Windows Preferences in Eclipse, ➪expanding the Android item, and selecting Build. Eclipse uses a default debug keystore (appropriately named “debug.keystore”) to sign your application. A keystore is commonly known as a digital certificate
Debug certificate cannot be used to publish your application. Manually you could generate your certificate using keytool. Eclipse has a wizard to make this process easier
Select the project, File Export. . . . In the Export dialog, expand the Android ➪item and select Export Android Application. Click Next. The project should now be displayed. Click Next. Select the “Create new keystore” option to create a new certificate (keystore) for signing your application. Enter a path to save your new keystore and then enter a password to protect the keystore. Click Next. Provide an alias for the private key and enter a password to protect the private key. You also need to enter a validity period for the key. Finally, enter your name in the field labeled First and Last Name. Click Next. Enter a path to store the destination APK file.Click Finish. The APK file will now be generated
32
Getting your application ready If your application uses Google Maps API:
As your MD5 certificate is new now, you need to get Google Maps API key with this MD5 certificate, if your code uses Google API
C:\Program Files\Java\jre6\bin>keytool.exe -list -v -alias DistributionKeyStoreAlias -keystore “C:\Users\username\Desktop\MyNewCert.keystore” -storepass keystorepassword -keypass keypassword –v
Add the Google Maps API key in main.xml <com.google.android.maps.MapView …
android:apiKey=”your_key_here” /> Export the application again as mentioned in previous slide using the
existing key For applications that use the Maps API key, note that the Maps API key
must be associated with the new keystore that you use to sign your APK file
33
Getting your application ready Install using adb (Android Debug Bridge)
adb.exe is located at platform-tools folder of the Android SDK adb install “C:\Users\username\Desktop\LBS.apk”
List the devices connected: adb devices To install on a specific device: adb –s emulator-5556 install LBS.apk
emulator-5556 was retrieved as a result of the command adb devices You could also deploy an application using DDMS by choosing /data/app
folder and use the “Push a file onto the device” button Uninstall an application: adb uninstall packagename.applicationname
34
Becoming a Market Publisher Requirements:
APK should be the file format available Two screenshots (DDMS can be used to get picture of running application on a
device or emulator) You need to provide a high-resolution application icon. This size of this image
must be 512x512 pixels. Registration 1. Register as a publisher and setup your profile.
http://market.android.com/publish/Home and sign in with your Google account Fill out all the required information along with your real phone number Note: you can always change “developer name” later via your profile page
2. Read and agree to the Android Market Developer Distribution Agreement. http://www.android.com/us/developer-distribution-agreement.html http://www.android.com/market/terms/developer-content-policy.html
3. Pay a registration fee of $25 USD via Google Checkout. Click the Google Checkout button and pay the one-time registration fee
35
Becoming a Market Publisher
Uploading an application Login to your publisher account and click “Upload an
Application”. Fill in all of the form data and include screenshots if you can
and provide a precise, short and well-formatted description. You can also choose whether or not you want to release it as a
free or paid app. Click “Publish.”
Congratulations, you’ve just successfully published an application to the Android Market!
36
References
App Development for Smart Devices http://www.cs.odu.edu/~cs495/
