![15
www.widbd.com
Getting Started (4)
• Strongly recommend testing with
real Android device
– Android emulator: very slow
– Faster emulator: Genymotion
[14], [15]
– Install USB drivers for your
Android device!
• Bring up the Android SDK
Manager
– Recommended: Install
Android 2.2, 2.3.3 APIs and
4.x API
– Do not worry about Intel x86
Atom, MIPS system images
Settings
Now you’re ready for Android development!
15](https://image.slidesharecdn.com/widtemp-170728010404/85/Mobile-application-and-Game-development-15-320.jpg)
![Activity Lifecycle
• Activity: key building block of
Android apps
• Extend Activity class, override
onCreate(), onPause(),
onResume() methods
• Dalvik VM can stop any Activity
without warning, so saving state is
important!
• Activities need to be “responsive”,
otherwise Android shows user
“App Not Responsive” warning:
– Place lengthy operations in
Runnable Threads,
AsyncTasks
Source: [12]18
www.widbd.com](https://image.slidesharecdn.com/widtemp-170728010404/85/Mobile-application-and-Game-development-18-320.jpg)
![Underlying GUI Code
<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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/hello_world" />
</RelativeLayout>
res/layout/activity_main.xml
– RelativeLayouts are quite complicated. See [13] for details
24
www.widbd.com](https://image.slidesharecdn.com/widtemp-170728010404/85/Mobile-application-and-Game-development-24-320.jpg)
![Android Programming Notes
• Android apps have multiple points of entry: no main() method
– Cannot “sleep” in Android
– During each entrance, certain Objects may be null
– Defensive programming is very useful to avoid crashes, e.g.,
if (!(myObj == null)) { // do something }
• Java concurrency techniques are required
– Don’t block the “main” thread in Activities
– Implement long-running tasks such as network connections
asynchronously, e.g., as AsyncTasks
– Recommendation: read [4]; chapter 20 [10]; [11]
• Logging state via android.util.Log throughout app is essential when
debugging (finding root causes)
• Better to have “too many” permissions than too few
– Otherwise, app crashes due to security exceptions!
– Remove “unnecessary” permissions before releasing app to public
• Event handling in Android GUIs entails many listener Objects
31
www.widbd.com](https://image.slidesharecdn.com/widtemp-170728010404/85/Mobile-application-and-Game-development-31-320.jpg)
Mobile application and Game development
- 1. Women in Digital Empowerment through Technology www.widbd.com Achia Nila Founder, Women in Digital
- 2. www.widbd.com IN THE BEGINNING… MOTOROLA DYNATAC 8000X
- 4. www.widbd.com WHAT IS A “SMARTPHONE” • Semi-Smart: Phone that offers features beyond making calls 1. E-mail 2. Take pictures 3. Plays mp3 • Phone that runs a complete Operating System 1. Offers a standardized platform for development 2. Able to execute arbitrary 3rd party applications
- 5. www.widbd.com • Today 1. Cell phones in use today ~ 1.2 billion 2. Smartphones account for 14% ~ 170 Million QUICK FACTS • Projected 2012 1. Cell phones ~ 1.7 billion 2. Smartphones 29% ~ 500 Million • 300% Smartphone growth in three years
- 6. www.widbd.com Java ME Symbian UIQ S60 Android BlackBerry OVI Windows Mobile iPhone MOBILE DEVELOPMENT SOLUTIONS LiMo Ångström distribution Adobe Flash Light BREW OpenMoko Palm OS (Garnet OS, Cobalt OS) Palm webOS Mojo
- 7. www.widbd.com What is Android • Android is an operating system for mobile devices such as smartphones and tablet computers. It is developed by the Open Handset Alliance led by Google. • Android has beaten Apple iOS, being the leading mobile operating system from first quarter of 2011 • Version: Android 1.0, 1.1 to 1.5 (Cupcake), 1.6 (Donut), 2.0/2.1 (Eclair), 2.2 (Froyo), 2.3 (Gingerbread), to 3.0 (Honeycomb), 4.0 (Ice Cream Sandwich), 5.0 (Lollipop)
- 9. www.widbd.com Outline • Introduction to Android • Getting Started • Android Programming
- 10. www.widbd.com Getting Started (1) • Need to install Java Development Kit (JDK) to write Java (and Android) programs – Do not install Java Runtime Environment (JRE); JDK and JRE are different! • Can download the JDK for your OS at http://java.oracle.com • Alternatively, for OS X, Linux: – OS X: • Open /Applications/Utilities/Terminal.app • Type javac at command line • Install Java when prompt appears – Linux: • Type sudo apt–get install default–jdk at command line (Debian, Ubuntu) • Other distributions: consult distribution’s documentation
- 12. Getting Started (2) • After installing JDK, download Android SDK from http://developer.android.com • Simplest: download and install Android Studio bundle (including Android SDK) for your OS • Alternatives: – Download/install Android Developer Tools from this site (based on Eclipse) – Install Android SDK tools by themselves, then install ADT for Eclipse separately (from this site) • We’ll use Android Studio with SDK included (easy) 12 www.widbd.com
- 14. 14 Getting Started (3) • Install Android Studio directly (Windows, Mac); unzip to directory android-studio, then run ./android-studio/bin/studio.sh (Linux) • You should see this: 14 www.widbd.com
- 15. 15 www.widbd.com Getting Started (4) • Strongly recommend testing with real Android device – Android emulator: very slow – Faster emulator: Genymotion [14], [15] – Install USB drivers for your Android device! • Bring up the Android SDK Manager – Recommended: Install Android 2.2, 2.3.3 APIs and 4.x API – Do not worry about Intel x86 Atom, MIPS system images Settings Now you’re ready for Android development! 15
- 16. Android Highlights (2) • Android apps written in Java 5 – Actually, a Java dialect (Apache Harmony) – Everything we’ve learned still holds • Apps use four main components: – Activity: A “single screen” that’s visible to user – Service: Long-running background “part” of app (not separate process or thread) – ContentProvider: Manages app data (usually stored in database) and data access for queries – BroadcastReceiver: Component that listens for particular Android system “events”, e.g., “found wireless device”, and responds accordingly 16 www.widbd.com
- 17. App Manifest • Every Android app must include an AndroidManifest.xml file describing functionality • The manifest specifies: – App’s Activities, Services, etc. – Permissions requested by app – Minimum API required – Hardware features required, e.g., camera with autofocus – External libraries to which app is linked, e.g., Google Maps library 17 www.widbd.com
- 18. Activity Lifecycle • Activity: key building block of Android apps • Extend Activity class, override onCreate(), onPause(), onResume() methods • Dalvik VM can stop any Activity without warning, so saving state is important! • Activities need to be “responsive”, otherwise Android shows user “App Not Responsive” warning: – Place lengthy operations in Runnable Threads, AsyncTasks Source: [12]18 www.widbd.com
- 19. App Creation Checklist • If you own an Android device: – Ensure drivers are installed – Enable developer options on device under Settings, specifically USB Debugging • Android 4.2+: Go to Settings→About phone, press Build number 7 times to enable developer options • For Android Studio: – Under File→Settings→Appearance, enable “Show tool window bars”; the Android view shows LogCat, devices – Programs should log states via android.util.Log’s Log.d(APP_TAG_STR, “debug”), where APP_TAG_STR is a final String tag denoting your app – Other commands: Log.e() (error); Log.i() (info); Log.w() (warning); Log.v() (verbose) – same parameters 19 www.widbd.com
- 20. Creating Android App (1) • Creating Android app project in Android Studio: – Go to File→New Project – Enter app, project name – Choose package name using “reverse URL” notation, e.g., edu.osu.myapp – Select APIs for app, then click Next 20 www.widbd.com
- 21. Creating Android App (2) • Determine what kind of Activity to create; then click Next – We’ll choose a Blank Activity for simplicity • Enter information about your Activity, then click Finish • This creates a “Hello World” app 21 www.widbd.com
- 22. Deploying the App • Two choices for deployment: – Real Android device – Android virtual device • Plug in your real device; otherwise, create an Android virtual device • Emulator is slow. Try Intel accelerated version, or perhaps http://www.genymotion.com/ • Run the app: press “Run” button in toolbar 22 www.widbd.com
- 23. Underlying Source Code package edu.osu.helloandroid; import android.os.Bundle; import android.app.Activity; import android.view.Menu; public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; } } src/…/MainActivity.java 23 www.widbd.com
- 24. Underlying GUI Code <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:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context=".MainActivity" > <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/hello_world" /> </RelativeLayout> res/layout/activity_main.xml – RelativeLayouts are quite complicated. See [13] for details 24 www.widbd.com
- 25. The App Manifest <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="edu.osu.helloandroid" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="17" /> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name="edu.osu.helloandroid.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> AndroidManifest.xml 25 www.widbd.com
- 26. A More Interesting App • We’ll now examine an app with more features: WiFi Tester (code on class website) • Press a button, scan for WiFi access points (APs), display them 26 www.widbd.com
- 27. Underlying Source Code (1) @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_wi_fi); // Set up WifiManager. mWifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE); // Create listener object for Button. When Button is pressed, scan for // APs nearby. Button button = (Button) findViewById(R.id.button); button.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { boolean scanStarted = mWifiManager.startScan(); // If the scan failed, log it. if (!scanStarted) Log.e(TAG, "WiFi scan failed..."); } }); // Set up IntentFilter for "WiFi scan results available" Intent. mIntentFilter = new IntentFilter(); mIntentFilter.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION); } 27 www.widbd.com
- 28. Underlying Source Code (2) • Code much more complex • First get system WifiManager • Create listener Object for button that performs scans • We register Broadcast Receiver, mReceiver, to listen for WifiManager’s “finished scan” system event (expressed as Intent WifiManager.SCAN_RESULTS_ AVAILABLE_ACTION) • Unregister Broadcast Receiver when leaving Activity @Override protected void onResume() { super.onResume(); registerReceiver(mRecei ver, mIntentFilter); } @Override protected void onPause() { super.onPause(); unregisterReceiver(mReceiver); } 28 www.widbd.com
- 29. The Broadcast Receiver private final BroadcastReceiver mReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { String action = intent.getAction(); if (WifiManager.SCAN_RESULTS_AVAILABLE_ACTION.equals(action)) { Log.e(TAG, "Scan results available"); List<ScanResult> scanResults = mWifiManager.getScanResults(); mApStr = ""; for (ScanResult result : scanResults) { mApStr = mApStr + result.SSID + "; "; mApStr = mApStr + result.BSSID + "; "; mApStr = mApStr + result.capabilities + "; "; mApStr = mApStr + result.frequency + " MHz;"; mApStr = mApStr + result.level + " dBmnn"; } // Update UI to show all this information. setTextView(mApStr); } } }; 29 www.widbd.com
- 30. User Interface Updating UI in code private void setTextView(String str) { TextView tv = (TextView) findViewById(R.id.textview); tv.setMovementMethod(new ScrollingMovementMethod()); tv.setText(str); } •This code simply has the UI display all collected WiFi APs, makes the text information scrollable UI Layout (XML) <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical"> <Button android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@+id/button" android:text="@string/button_text"/> <TextView android:id="@+id/header" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/ap_list" tools:context=".WiFiActivity" android:textStyle="bold" android:gravity="center"> </TextView> <TextView android:layout_width="fill_parent" android:layout_height="fill_parent" tools:context=".WiFiActivity" android:id="@+id/textview" android:scrollbars="vertical"> </TextView> </LinearLayout> 30 www.widbd.com
- 31. Android Programming Notes • Android apps have multiple points of entry: no main() method – Cannot “sleep” in Android – During each entrance, certain Objects may be null – Defensive programming is very useful to avoid crashes, e.g., if (!(myObj == null)) { // do something } • Java concurrency techniques are required – Don’t block the “main” thread in Activities – Implement long-running tasks such as network connections asynchronously, e.g., as AsyncTasks – Recommendation: read [4]; chapter 20 [10]; [11] • Logging state via android.util.Log throughout app is essential when debugging (finding root causes) • Better to have “too many” permissions than too few – Otherwise, app crashes due to security exceptions! – Remove “unnecessary” permissions before releasing app to public • Event handling in Android GUIs entails many listener Objects 31 www.widbd.com
- 32. www.widbd.com References (1) 1. C. Horstmann, Big Java Late Objects, Wiley, 2012. Online: http://proquest.safaribooksonline. com.proxy.lib.ohio–state.edu/book/–/9781118087886 2. J. Bloch, Effective Java, 2nd ed., Addison–Wesley, 2008. Online: http://proquest. safaribooksonline.com.proxy.lib.ohio– state.edu/book/programming/java/9780137150021 3. S.B. Zakhour, S. Kannan, and R. Gallardo, The Java® Tutorial: A Short Course on the Basics, 5th ed., Addison–Wesley, 2013. Online: http://proquest.safaribooksonline.com.proxy.lib. ohio–state.edu/book/programming/java/9780132761987 4. C. Collins, M. Galpin, and M. Kaeppler, Android in Practice, Manning, 2011. Online: http://proquest.safaribooksonline.com.proxy.lib.ohio– state.edu/book/programming/android/9781935182924 5. M.L. Sichitiu, 2011, http://www.ece.ncsu.edu/wireless/MadeInWALAN/AndroidTutorial/PPTs/ javaReview.ppt 6. Oracle, http://docs.oracle.com/javase/1.5.0/docs/api/index.html 7. Wikipedia, https://en.wikipedia.org/wiki/Vehicle_Identification_Number 8. Nielsen Co., “Smartphone Milestone: Half of Mobile Subscribers Ages 55+ Own Smartphones”, 22 Apr. 2014, http://www.nielsen.com/us/en/insights/news/2014/ smartphone-milestone-half-of-americans-ages-55-own-smartphones.html 32
- 36. www.widbd.com Game Here's a rundown of some of the best game creators for making PC, Android and iOS games. 1. GameSalad. ... 2. Stencyl. ... 3. GameMaker: Studio. ... 4. FlowLab. ... 5. Sploder. ... 6. ClickTeam Fusion 2.5. ... 7. Construct 2. 8. GameFroot.
- 38. www.widbd.com Women in Digital Achievement (5 award) Spark International Award BRAC Manthan Award
- 39. www.widbd.com Women in Digital Achievement Bangladesh Brand forum Award
- 40. www.widbd.com Contact Women In Digital House 79, Road 3, Mohammadia Housing Limited ,Dhaka, Bangladesh Phone: +880-163-549-7868 Email: info@widbd.com , womenindigitalbd@gmail.com /WomeninDigital.net /wid_bd /widbd.Widbd.com womenindigital womenindigital womenindigital womenindigital