book

Android How to Program, 3/e

by Paul J. Deitel, Harvey M. Deitel

February 2016

Beginner to intermediate

500 pages

187h 36m

English

Pearson

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Android™ HOW TO PROGRAM with an Introduction to Java™
How To Program SeriesDeitel® Developer SeriesSimply SeriesCourseSmart Web BooksLiveLessons Video Learning Products
Android™ HOW TO PROGRAM with and Introduction to Java™
Trademarks
Contents
Preface
Architecture of Android How to Program, 3/eApp-Driven ApproachIntended AudiencesInstructor ResourcesBefore You Begin: Software Used in Android How to Program, 3/eGetting up to Speed in Java and XMLApp-Development CoursesKey TopicsPedagogic FeaturesWorking with Open-Source AppsCopyright Notice and Code LicenseAndroid 6 App-Development Fundamentals LiveLessons Video TrainingJoin the Deitel & Associates, Inc. Social Media CommunitiesContacting the AuthorsAbout the AuthorsAbout Deitel & Associates, Inc
Before You Begin
1 Introduction to Android
ObjectivesOutline
1.1 Introduction
1.2 Android—The World’s Leading Mobile Operating System
1.3 Android Features

1.4 Android Operating System
1.4.1 Android 2.2 (Froyo)1.4.2 Android 2.3 (Gingerbread)1.4.3 Android 3.0 through 3.2 (Honeycomb)1.4.4 Android 4.0 through 4.0.4 (Ice Cream Sandwich)1.4.5 Android 4.1–4.3 (Jelly Bean)1.4.6 Android 4.4 (KitKat)1.4.7 Android 5.0 and 5.1 (Lollipop)1.4.8 Android 6 (Marshmallow)
1.5 Downloading Apps from Google Play
1.6 Packages
1.7 Android Software Development Kit (SDK)
1.8 Object-Oriented Programming: A Quick Refresher
1.8.1 The Automobile as an Object1.8.2 Methods and Classes1.8.3 Instantiation1.8.4 Reuse1.8.5 Messages and Method Calls1.8.6 Attributes and Instance Variables1.8.7 Encapsulation1.8.8 Inheritance1.8.9 Object-Oriented Analysis and Design (OOAD)
1.9 Test-Driving the Tip Calculator App in an Android Virtual Device (AVD)
1.9.1 Opening the Tip Calculator App’s Project in Android Studio1.9.2 Creating Android Virtual Devices (AVDs)1.9.3 Running the Tip Calculator App on the Nexus 6 Smartphone AVDTroubleshooting AVD Startup1.9.4 Running the Tip Calculator App on an Android DeviceTest-Drives for the Book’s AppsPreparing to Distribute Apps
1.10 Building Great Android Apps
1.11 Android Development Resources
1.12 Wrap-Up
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
2 Welcome App
ObjectivesOutline
2.1 Introduction
2.2 Technologies Overview
2.2.1 Android Studio2.2.2 LinearLayout, TextView and ImageView2.2.3 Extensible Markup Language (XML)2.2.4 App Resources2.2.5 Accessibility2.2.6 Internationalization
2.3 Creating an App
2.3.1 Launching Android Studio2.3.2 Creating a New Project2.3.3 Create New Project Dialog2.3.4 Target Android Devices Step2.3.5 Add an Activity to Mobile Step2.3.6 Customize the Activity Step
2.4 Android Studio Window
2.4.1 Project Window2.4.2 Editor Windows2.4.3 Component Tree Window2.4.4 App Resource Files2.4.5 Layout EditorSelecting the Screen Type for GUI Design2.4.6 Default GUI2.4.7 XML for the Default GUI
2.5 Building the App’s GUI with the Layout Editor
2.5.1 Adding an Image to the Projectdrawable FoldersAdding bug.png to the Project2.5.2 Adding an App Icon2.5.3 Changing RelativeLayout to a LinearLayout2.5.4 Changing the LinearLayout’s id and orientationSetting the LinearLayout’s orientation and id PropertiesThe id Property’s XML Representation2.5.5 Configuring the TextView’s id and text PropertiesSetting the TextView’s id PropertyConfiguring the TextView’s text Property Using a String Resource2.5.6 Configuring the TextView’s textSize Property—Scaled Pixels and Density-Independent PixelsCreating a Dimension Resource for the Font Size on a Phone DeviceCreating a Dimension Resource for the Font Size on a Large Tablet Device2.5.7 Setting the TextView’s textColor Property2.5.8 Setting the TextView’s gravity Property2.5.9 Setting the TextView’s layout:gravity Property2.5.10 Setting the TextView’s layout:weight Property2.5.11 Adding an ImageView to Display the Image2.5.12 Previewing the Design
2.6 Running the Welcome App
2.7 Making Your App Accessible
2.8 Internationalizing Your App
2.8.1 Localization2.8.2 Naming the Folders for Localized Resources2.8.3 Adding String Translations to the App’s Project2.8.4 Localizing Strings2.8.5 Testing the App in Spanish on an AVDReturning the AVD to English2.8.6 Testing the App in Spanish on a DeviceReturning Your Device to English2.8.7 TalkBack and Localization2.8.8 Localization Checklist2.8.9 Professional Translation
2.9 Wrap-Up
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
3 Tip Calculator App
ObjectivesOutline
3.1 Introduction
3.2 Test-Driving the Tip Calculator App
3.3 Technologies Overview
3.3.1 Class Activity3.3.2 Activity Lifecycle Methods3.3.3 AppCompat Library and Class AppCompatActivity3.3.4 Arranging Views with a GridLayout3.3.5 Creating and Customizing the GUI with the Layout Editor and the Component Tree and Properties Windows3.3.6 Formatting Numbers as Locale-Specific Currency and Percentage Strings3.3.7 Implementing Interface TextWatcher for Handling EditText Text Changes3.3.8 Implementing Interface OnSeekBarChangeListener for Handling SeekBar Thumb Position Changes3.3.9 Material Themes3.3.10 Material Design: Elevation and Shadows3.3.11 Material Design: Colors3.3.12 AndroidManifest.xml3.3.13 Searching in the Properties Window
3.4 Building the GUI
3.4.1 GridLayout Introductionid Property Values for This App’s Views3.4.2 Creating the TipCalculator Project3.4.3 Changing to a GridLayoutSpecifying Two Columns and Default Margins for the GridLayout3.4.4 Adding the TextViews, EditText and SeekBarStep 1: Adding Views to the First RowStep 2: Adding Views to the Second RowStep 3: Adding Views to the Third RowStep 4: Adding Views to the Fourth RowReviewing the Layout So FarA Note Regarding the EditText’s Virtual Keyboard3.4.5 Customizing the ViewsStep 5: Specifying Literal TextStep 6: Right Aligning the TextViews in the Left ColumnStep 7: Configuring the amountEditTextStep 8: Configuring the amountTextViewStep 9: Configuring the percentTextViewStep 10: Configuring the percentSeekBarStep 11: Configuring the tipTextView and totalTextView
3.5 Default Theme and Customizing Theme Colors
3.5.1 parent Themes3.5.2 Customizing Theme ColorsModifying the Theme’s Primary, Dark Primary and Accent Colors3.5.3 Common View Property Values as Styles
3.6 Adding the App’s Logic
3.6.1 package and import Statements3.6.2 MainActivity Subclass of AppCompatActivity3.6.3 Class Variables and Instance Variables3.6.4 Overriding Activity Method onCreateonCreate’s Bundle ParameterGenerated R Class Contains Resource IDsInflating the GUIGetting References to the WidgetsDisplaying Initial Values in the TextViewsRegistering the Event ListenersNote Regarding Android 6 Data Binding3.6.5 MainActivity Method calculate3.6.6 Anonymous Inner Class That Implements Interface OnSeekBarChangeListenerOverriding Method onProgressChanged of Interface OnSeekBarChangeListenerOverriding Methods onStartTrackingTouch and onStopTrackingTouch of Interface OnSeekBarChangeListenerAndroid Studio Tools for Overriding Methods3.6.7 Anonymous Inner Class That Implements Interface TextWatcherOverriding Method onTextChanged of Interface TextWatcherOther Methods of the amountEditTextWatcher TextWatcher
3.7 AndroidManifest.xml
3.7.1 manifest Element3.7.2 application Element3.7.3 activity Element3.7.4 intent-filter ElementInter-App CommunicationExecuting AppsDetermining Which Activity to Execute
3.8 Wrap-Up
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
4 Flag Quiz App
ObjectivesOutline
4.1 Introduction
4.2 Test-Driving the Flag Quiz App
4.2.1 Configuring the Quiz’s Settings4.2.2 Taking the QuizMaking a Correct SelectionMaking an Incorrect SelectionCompleting the Quiz
4.3 Technologies Overview
4.3.1 Menus4.3.2 Fragments4.3.3 Fragment Lifecycle Methods4.3.4 Managing Fragments4.3.5 Preferences4.3.6 assets Folder4.3.7 Resource Folders4.3.8 Supporting Different Screen Sizes and Resolutions4.3.9 Determining the Device Orientation4.3.10 Toasts for Displaying Messages4.3.11 Using a Handler to Execute a Runnable in the Future4.3.12 Applying an Animation to a View4.3.13 Using ViewAnimationUtils to Create a Circular Reveal Animator4.3.14 Specifying Colors Based on a View’s State Via a Color State List4.3.15 AlertDialog4.3.16 Logging Exception Messages4.3.17 Launching Another Activity Via an Explicit IntentImplicit and Explicit Intents4.3.18 Java Data Structures4.3.19 Java SE 7 Features4.3.20 AndroidManifest.xml
4.4 Creating the Project, Resource Files and Additional Classes
4.4.1 Creating the Project4.4.2 Blank Activity Template Layoutsactivity_main.xmlcontent_main.xmlfragment_main.xmlPreparing to Design the GUI4.4.3 Configuring Java SE 7 Support4.4.4 Adding the Flag Images to the Project4.4.5 strings.xml and Formatted String ResourcesFormat Strings as String Resources4.4.6 arrays.xml4.4.7 colors.xml4.4.8 button_text_color.xml4.4.9 Editing menu_main.xml4.4.10 Creating the Flag Shake Animation4.4.11 preferences.xml for Specifying the App’s Settings4.4.12 Adding Classes SettingsActivity and SettingsActivityFragment to the Project
4.5 Building the App’s GUI
4.5.1 activity_main.xml Layout for Devices in Portrait Orientation4.5.2 Designing fragment_main.xml LayoutStep 1: Changing from a RelativeLayout to a LinearLayoutStep 2: Adding the questionNumberTextView to the LinearLayoutStep 3: Adding the flagImageView to the LinearLayoutStep 4: Adding the guessCountryTextView to the LinearLayoutStep 5: Adding the Buttons to the LinearLayoutStep 6: Adding the answerTextView to the LinearLayoutStep 7: Setting the Properties of the Buttons4.5.3 Graphical Layout Editor Toolbar4.5.4 content_main.xml Layout for Tablet Landscape OrientationCreating content_main.xml for Tablets in Landscape OrientationCreating the Tablet Layout’s GUISelecting a Fragment to Preview in the Layout Editor’s Design View
4.6 MainActivity Class
4.6.1 package Statement and import Statements4.6.2 Fields4.6.3 Overridden Activity Method onCreateSetting the Default Preference Values and Registering a Change ListenerConfiguring a Phone Device for Portrait Orientation4.6.4 Overridden Activity Method onStart4.6.5 Overridden Activity Method onCreateOptionsMenu4.6.6 Overridden Activity Method onOptionsItemSelected4.6.7 Anonymous Inner Class That Implements OnSharedPreferenceChangeListener
4.7 MainActivityFragment Class
4.7.1 package and import Statements4.7.2 Fields4.7.3 Overridden Fragment Method onCreateView4.7.4 Method updateGuessRows4.7.5 Method updateRegions4.7.6 Method resetQuiz4.7.7 Method loadNextFlag4.7.8 Method getCountryName4.7.9 Method animate4.7.10 Anonymous Inner Class That Implements OnClickListenerCreating and Configuring the AlertDialog4.7.11 Method disableButtons
4.8 SettingsActivity Class
4.9 SettingsActivityFragment Class
4.10 AndroidManifest.xml
Launch Mode
4.11 Wrap-Up
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
Project Exercises
5 Doodlz App
ObjectivesOutline
5.1 Introduction
5.2 Test-Driving the Doodlz App in an Android Virtual Device (AVD)
5.3 Technologies Overview
5.3.1 Activity and Fragment Lifecycle Methods5.3.2 Custom Views5.3.3 Using SensorManager to Listen for Accelerometer Events5.3.4 Custom DialogFragmentsPreventing Multiple Dialogs from Appearing at the Same Time5.3.5 Drawing with Canvas, Paint and Bitmap5.3.6 Processing Multiple Touch Events and Storing Lines in Paths5.3.7 Saving to the Device5.3.8 Printing and the Android Support Library’s PrintHelper Class5.3.9 New Android 6.0 (Marshmallow) Permissions Model5.3.10 Adding Dependencies Using the Gradle Build System
5.4 Creating the Project and Resources
5.4.1 Creating the Project5.4.2 Gradle: Adding a Support Library to the Project5.4.3 strings.xml5.4.4 Importing the Material Design Icons for the App’s Menu Items5.4.5 MainActivityFragment MenuMenus for Different Android VersionsCreating the Menu5.4.6 Adding a Permission to AndroidManifest.xml
5.5 Building the App’s GUI
5.5.1 content_main.xml Layout for MainActivity5.5.2 fragment_main.xml Layout for MainActivityFragment5.5.3 fragment_color.xml Layout for ColorDialogFragmentAdding the colorView to the LayoutAdding Class ColorDialogFragment to the Project5.5.4 fragment_line_width.xml Layout for LineWidthDialogFragmentAdding Class LineWidthDialogFragment to the Project5.5.5 Adding Class EraseImageDialogFragment
5.6 MainActivity Class
5.7 MainActivityFragment Class
5.7.1 package Statement, import Statements and Fields5.7.2 Overridden Fragment Method onCreateView5.7.3 Methods onResume and enableAccelerometerListening5.7.4 Methods onPause and disableAccelerometerListening5.7.5 Anonymous Inner Class for Processing Accelerometer Events5.7.6 Method confirmErase5.7.7 Overridden Fragment Methods onCreateOptionsMenu and onOptionsItemSelected5.7.8 Method saveImage5.7.9 Overridden Method onRequestPermissionsResult5.7.10 Methods getDoodleView and setDialogOnScreen
5.8 DoodleView Class
5.8.1 package Statement and import Statements5.8.2 static and Instance Variables5.8.3 Constructor5.8.4 Overridden View Method onSizeChanged5.8.5 Methods clear, setDrawingColor, getDrawingColor, setLineWidth and getLineWidth5.8.6 Overridden View Method onDraw5.8.7 Overridden View Method onTouchEvent5.8.8 touchStarted Method5.8.9 touchMoved Method5.8.10 touchEnded Method5.8.11 Method saveImage5.8.12 Method printImage
5.9 ColorDialogFragment Class
5.9.1 Overridden DialogFragment Method onCreateDialog5.9.2 Method getDoodleFragment5.9.3 Overridden Fragment Lifecycle Methods onAttach and onDetach5.9.4 Anonymous Inner Class That Responds to the Events of the Alpha, Red, Green and Blue SeekBars
5.10 LineWidthDialogFragment Class
5.10.1 Method onCreateDialog5.10.2 Anonymous Inner Class That Responds to the Events of the widthSeekBar
5.11 EraseImageDialogFragment Class
5.12 Wrap-Up
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
6 Cannon Game App
ObjectivesOutline
6.1 Introduction
6.2 Test-Driving the Cannon Game App
Opening and Running the AppPlaying the Game
6.3 Technologies Overview
6.3.1 Using the Resource Folder res/raw6.3.2 Activity and Fragment Lifecycle Methods6.3.3 Overriding View Method onTouchEvent6.3.4 Adding Sound with SoundPool and AudioManager6.3.5 Frame-by-Frame Animation with Threads, SurfaceView and SurfaceHolder6.3.6 Simple Collision Detection6.3.7 Immersive Mode
6.4 Building the GUI and Resource Files
6.4.1 Creating the ProjectConfigure the App for Landscape Orientation6.4.2 Adjusting the Theme to Remove the App Title and App Bar6.4.3 strings.xml6.4.4 Colors6.4.5 Adding the Sounds to the App6.4.6 Adding Class MainActivityFragment6.4.7 Editing activity_main.xml6.4.8 Adding the CannonView to fragment_main.xml
6.5 Overview of This App’s Classes
6.6 MainActivity Subclass of Activity
6.7 MainActivityFragment Subclass of Fragment
6.8 Class GameElement
6.8.1 Instance Variables and Constructor6.8.2 Methods update, draw, and playSound
6.9 Blocker Subclass of GameElement
6.10 Target Subclass of GameElement
6.11 Cannon Class
6.11.1 Instance Variables and Constructor6.11.2 Method align6.11.3 Method fireCannonball6.11.4 Method drawDrawing the Cannon Barrel with Canvas Method drawLineDrawing the Cannon Base with Canvas Method drawCircle6.11.5 Methods getCannonball and removeCannonball
6.12 Cannonball Subclass of GameElement
6.12.1 Instance Variables and Constructor6.12.2 Methods getRadius, collidesWith, isOnScreen, and reverseVelocityXChecking for Collisions with Another GameElement with the collidesWith MethodReversing the Cannonball’s Horizontal Velocity with reverseVelocityX6.12.3 Method update6.12.4 Method draw
6.13 CannonView Subclass of SurfaceView
6.13.1 package and import Statements6.13.2 Instance Variables and Constants6.13.3 ConstructorRegistering the SurfaceHolder.Callback ListenerConfiguring the SoundPool and Loading the SoundsCreating the Paint Objects Used to Draw the Background and Timer Text6.13.4 Overriding View Method onSizeChanged6.13.5 Methods getScreenWidth, getScreenHeight, and playSound6.13.6 Method newGame6.13.7 Method updatePositionsElapsed Time Since the Last Animation FrameUpdating the Cannonball, Blocker and Target PositionsUpdating the Time Left and Determining Whether Time Ran Out6.13.8 Method alignAndFireCannonball6.13.9 Method showGameOverDialog6.13.10 Method drawGameElementsClearing the Canvas with Method drawRectDisplaying the Time Remaining with Canvas Method drawTextDrawing the Cannon, Cannonball, Blocker and Targets with the draw Method6.13.11 Method testForCollisions6.13.12 Methods stopGame and releaseResources6.13.13 Implementing the SurfaceHolder.Callback Methods6.13.14 Overriding View Method onTouchEvent6.13.15 CannonThread: Using a Thread to Create a Game Loop6.13.16 Methods hideSystemBars and showSystemBars
6.14 Wrap-Up
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
7 WeatherViewer App
ObjectivesOutline
7.1 Introduction
7.2 Test-Driving the WeatherViewer App
7.3 Technologies Overview
7.3.1 Web ServicesREST Web ServicesWeb Services Often Require an API KeyOpenWeatherMap.org Web ServicesOpenWeatherMap.org Web Service LicenseObtaining an OpenWeatherMap.org API Key7.3.2 JavaScript Object Notation (JSON) and the org.json Packageorg.json Package7.3.3 HttpUrlConnection Invoking a REST Web Service7.3.4 Using AsyncTask to Perform Network Requests Outside the GUI Thread7.3.5 ListView, ArrayAdapter and the View-Holder PatternView-Holder Pattern7.3.6 FloatingActionButton7.3.7 TextInputLayout7.3.8 Snackbar
7.4 Building the App’s GUI and Resource Files
7.4.1 Creating the Project7.4.2 AndroidManifest.xmlPermissions That Are Automatically Granted in Android 6.07.4.3 strings.xml7.4.4 colors.xml7.4.5 activity_main.xml7.4.6 content_main.xml7.4.7 list_item.xmlStep 1: Creating the Layout File and Customizing the LinearLayout’s OrientationStep 2: Adding the ImageView for Displaying a Weather-Condition IconStep 3: Adding the GridLayout for Displaying the TextViewsStep 4: Adding the TextViews
7.5 Class Weather
7.5.1 package Statement, import Statements and Instance Variables7.5.2 Constructor7.5.3 Method convertTimeStampToDay
7.6 Class WeatherArrayAdapter
7.6.1 package Statement and import Statements7.6.2 Nested Class ViewHolder7.6.3 Instance Variable and Constructor7.6.4 Overridden ArrayAdapter Method getView7.6.5 AsyncTask Subclass for Downloading Images in a Separate ThreadDownloading the Weather-Condition Image
7.7 Class MainActivity
7.7.1 package Statement and import Statements7.7.2 Instance Variables7.7.3 Overridden Activity Method onCreate7.7.4 Methods dismissKeyboard and createURL7.7.5 AsyncTask Subclass for Invoking a Web Service7.7.6 Method convertJSONtoArrayList
7.8 Wrap-Up
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
Web Services and Mashups
8 Twitter® Searches App
ObjectivesOutline
8.1 Introduction
8.2 Test-Driving the App
8.2.1 Adding a Favorite Search8.2.2 Viewing Twitter Search Results8.2.3 Editing a Search8.2.4 Sharing a Search8.2.5 Deleting a Search8.2.6 Scrolling Through Saved Searches
8.3 Technologies Overview
8.3.1 Storing Key–Value Data in a SharedPreferences File8.3.2 Implicit Intents and Intent Choosers8.3.3 RecyclerViewRecyclerView vs. ListViewRecyclerView Layout Managers8.3.4 RecyclerView.Adapter and RecyclerView.ViewHolder8.3.5 RecyclerView.ItemDecoration8.3.6 Displaying a List of Options in an AlertDialog
8.4 Building the App’s GUI and Resource Files
8.4.1 Creating the Project8.4.2 AndroidManifest.xml8.4.3 Adding the RecyclerView Library8.4.4 colors.xml8.4.5 strings.xml8.4.6 arrays.xml8.4.7 dimens.xml8.4.8 Adding the Save Button Icon8.4.9 activity_main.xml8.4.10 content_main.xmlStep 1: Adding the queryTextInputLayout and Its Nested EditTextStep 2: Adding the tagTextInputLayout and Its Nested EditTextStep 3: Adding the LinearLayoutStep 3: Adding the LinearLayout’s Nested TextView and RecyclerView8.4.11 RecyclerView Item’s Layout: list_item.xmlOther Predefined Android Resources
8.5 MainActivity Class
8.5.1 package and import Statements8.5.2 MainActivity Fields8.5.3 Overriden Activity Method onCreateGetting a SharedPreferences ObjectGetting the Keys Stored in the SharedPreferences ObjectSorting the ArrayList of TagsConfiguring the RecyclerViewRegistering a Listener for the FloatingActionButton8.5.4 TextWatcher Event Handler and Method updateSaveFAB8.5.5 saveButton’s OnClickListener8.5.6 addTaggedSearch MethodEditing a SharedPreferences Object’s ContentsNotifying the RecyclerView.Adapter That Its Data Has Changed8.5.7 Anonymous Inner Class That Implements View.OnClickListener to Display Search ResultsGetting String ResourcesGetting Strings from a SharedPreferences ObjectCreating an Intent to Launch the Device’s Web BrowserStarting an Activity for an Intent8.5.8 Anonymous Inner Class That Implements View.OnLongClickListener to Share, Edit or Delete a Searchfinal Local Variables for Use in Anonymous Inner ClassesAlertDialog That Displays a List of ItemsEvent Handler for the Dialog’s List of ItemsConfiguring the Negative Button and Displaying the Dialog8.5.9 shareSearch MethodAdding Extras to an IntentDisplaying an Intent Chooser8.5.10 deleteSearch Method
8.6 SearchesAdapter Subclass of RecyclerView.Adapter
8.6.1 package Statement, import statements, Instance Variables and Constructor8.6.2 Nested ViewHolder Subclass of RecyclerView.ViewHolder8.6.3 Overridden RecyclerView.Adapter MethodsOverriding the onCreateViewHolder MethodOverriding the onBindViewHolder MethodOverriding the getItemCount Method
8.7 ItemDivider Subclass of RecyclerView.ItemDecoration
8.8 A Note on Fabric: Twitter’s New Mobile Development Platform
8.9 Wrap-Up
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
Project ExercisesAdvanced Project Exercises
9 Address Book App
ObjectivesOutline
9.1 Introduction
9.2 Test-Driving the Address Book App
9.2.1 Adding a Contact9.2.2 Viewing a Contact9.2.3 Editing a Contact9.2.4 Deleting a Contact
9.3 Technologies Overview
9.3.1 Displaying Fragments with FragmentTransactions9.3.2 Communicating Data Between a Fragment and a Host Activity9.3.3 Manipulating a SQLite Database9.3.4 ContentProviders and ContentResolversUrisContentResolver9.3.5 Loader and LoaderManager—Asynchronous Database AccessLoadersLoaderManager and LoaderManager.LoaderCallbacks9.3.6 Defining Styles and Applying Them to GUI Components9.3.7 Specifying a TextView Background
9.4 Building the GUI and Resource Files
9.4.1 Creating the Project9.4.2 Creating the App’s ClassesPackage com.deitel.addressbookPackage com.deitel.addressbook.data9.4.3 Add the App’s Icons9.4.4 strings.xml9.4.5 styles.xml9.4.6 textview_border.xml9.4.7 MainActivity’s LayoutPhone Layout: content_main.xmlTablet Layout: content_main.xml for Large Devices9.4.8 ContactsFragment’s Layout9.4.9 DetailFragment’s LayoutGridLayout SettingsLeft Column TextView SettingsRight Column TextView Settings9.4.10 AddEditFragment’s LayoutScrollView SettingsLinearLayout SettingsEditText Settings9.4.11 DetailFragment’s Menu
9.5 Overview of This Chapter’s Classes
9.6 DatabaseDescription Class
9.6.1 static Fields9.6.2 Nested Class Contact
9.7 AddressBookDatabaseHelper Class
9.8 AddressBookContentProvider Class
9.8.1 AddressBookContentProvider Fields9.8.2 Overridden Methods onCreate and getType9.8.3 Overridden Method querySQLiteQueryBuilderUsing the UriMatcher to Determine the Operation to PerformQuerying the DatabaseRegistering the Cursor to Watch for Content Changes9.8.4 Overridden Method insert9.8.5 Overridden Method update9.8.6 Overridden Method delete
9.9 MainActivity Class
9.9.1 Superclass, Implemented Interfaces and Fields9.9.2 Overridden Method onCreate9.9.3 ContactsFragment.ContactsFragmentListener Methods9.9.4 Method displayContact9.9.5 Method displayAddEditFragment9.9.6 DetailFragment.DetailFragmentListener Methods9.9.7 AddEditFragment.AddEditFragmentListener Method
9.10 ContactsFragment Class
9.10.1 Superclass and Implemented Interface9.10.2 ContactsFragmentListener9.10.3 Fields9.10.4 Overridden Fragment Method onCreateView9.10.5 Overridden Fragment Methods onAttach and onDetach9.10.6 Overridden Fragment Method onActivityCreated9.10.7 Method updateContactList9.10.8 LoaderManager.LoaderCallbacks<Cursor> MethodsMethod onCreateLoaderMethod onLoadFinishedMethod onLoaderReset
9.11 ContactsAdapter Class
9.12 AddEditFragment Class
9.12.1 Superclass and Implemented Interface9.12.2 AddEditFragmentListener9.12.3 Fields9.12.4 Overridden Fragment Methods onAttach, onDetach and onCreateView9.12.5 TextWatcher nameChangedListener and Method updateSaveButtonFAB9.12.6 View.OnClickListener saveContactButtonClicked and Method saveContact9.12.7 LoaderManager.LoaderCallbacks<Cursor> Methods
9.13 DetailFragment Class
9.13.1 Superclass and Implemented Interface9.13.2 DetailFragmentListener9.13.3 Fields9.13.4 Overridden Methods onAttach, onDetach and onCreateView9.13.5 Overridden Methods onCreateOptionsMenu and onOptionsItemSelected9.13.6 Method deleteContact and DialogFragment confirmDelete9.13.7 LoaderManager.LoaderCallback<Cursor> Methods
9.14 Wrap-Up
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
10 Google Play and App Business Issues
ObjectivesOutline
10.1 Introduction
10.2 Preparing Your Apps for Publication
10.2.1 Testing Your App10.2.2 End User License Agreement10.2.3 Icons and Labels10.2.4 Versioning Your App10.2.5 Licensing to Control Access to Paid Apps10.2.6 Obfuscating Your Code10.2.7 Getting a Private Key for Digitally Signing Your App10.2.8 Featured Image and ScreenshotsFeatured ImageScreenshots and Using the Android Device Manager’s Screen Capture Tool10.2.9 Promotional App Video
10.3 Pricing Your App: Free or Fee
10.3.1 Paid Apps10.3.2 Free Apps
10.4 Monetizing Apps with In-App Advertising
10.5 Monetizing Apps: Using In-App Billing to Sell Virtual Goods
10.6 Registering at Google Play
10.7 Setting Up a Google Payments Merchant Account
10.8 Uploading Your Apps to Google Play
10.9 Launching Play Store from Within Your App
10.10 Managing Your Apps in Google Play
10.11 Other Android App Marketplaces
10.12 Other Mobile App Platforms and Porting Your Apps
10.13 Marketing Your Apps
10.14 Wrap-Up
Staying in Contact with the Authors and Deitel & Associates, Inc
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
A Introduction to Java Applications
ObjectivesOutline
A.1 Introduction
A.2 Your First Program in Java: Printing a Line of Text
A.3 Modifying Your First Java Program
A.4 Displaying Text with printf
A.5 Another Application: Adding Integers
A.6 Memory Concepts
A.7 Arithmetic
A.8 Decision Making: Equality and Relational Operators
A.9 Wrap-Up
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
B Introduction to Classes, Objects, Methods and Strings
ObjectivesOutline
B.1 Introduction
B.2 Declaring a Class with a Method and Instantiating an Object of a Class
B.3 Declaring a Method with a Parameter
B.4 Instance Variables, set Methods and get Methods
B.5 Primitive Types vs. Reference Types
B.6 Initializing Objects with Constructors
B.7 Floating-Point Numbers and Type double
B.8 Wrap-Up
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
C Control Statements
ObjectivesOutline
C.1 Introduction
C.2 Algorithms
C.3 Pseudocode
C.4 Control Structures
C.5 if Single-Selection Statement
C.6 if…else Double-Selection Statement
C.7 while Repetition Statement
C.8 Case Study: Counter-Controlled Repetition
C.9 Case Study: Sentinel-Controlled Repetition
C.10 Case Study: Nested Control Statements
C.11 Compound Assignment Operators
C.12 Increment and Decrement Operators
C.13 Primitive Types
C.14 Essentials of Counter-Controlled Repetition
C.15 for Repetition Statement
C.16 Examples Using the for Statement
C.17 do…while Repetition Statement
C.18 switch Multiple-Selection Statement
C.19 break and continue Statements
C.20 Logical Operators
C.21 Wrap-Up
Self-Review Exercises (Sections C.1–C.13)
Self-Review Exercises (Sections C.14–C.20)
Answers to Self-Review Exercises (Sections C.1–C.13)
Answers to Self-Review Exercises (Sections C.14–C.20)
Exercises (Sections C.1–C.13)
Exercises (Sections C.14–C.20)
D Methods: A Deeper Look
ObjectivesOutline
D.1 Introduction
D.2 Program Modules in Java
D.3 static Methods, static Fields and Class Math
D.4 Declaring Methods with Multiple Parameters
D.5 Notes on Declaring and Using Methods
D.6 Method-Call Stack and Activation Records
D.7 Argument Promotion and Casting
D.8 Java API Packages
D.9 Introduction to Random-Number Generation
D.9.1 Scaling and Shifting of Random NumbersGeneralizing the Random Number CalculationsD.9.2 Random-Number Repeatability for Testing and Debugging
D.10 Case Study: A Game of Chance; Introducing Enumerations
D.11 Scope of Declarations
D.12 Method Overloading
D.13 Wrap-Up
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
E Arrays and ArrayLists
ObjectivesOutline
E.1 Introduction
E.2 Arrays
E.3 Declaring and Creating Arrays
E.4 Examples Using Arrays
E.5 Case Study: Card Shuffling and Dealing Simulation
E.6 Enhanced for Statement
E.7 Passing Arrays to Methods
E.8 Case Study: Class GradeBook Using an Array to Store Grades
E.9 Multidimensional Arrays
E.10 Case Study: Class GradeBook Using a Two-Dimensional Array
E.11 Class Arrays
E.12 Introduction to Collections and Class ArrayList
E.13 Wrap-Up
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
F Classes and Objects: A Deeper Look
ObjectivesOutline
F.1 Introduction
F.2 Time Class Case Study
F.3 Controlling Access to Members
F.4 Referring to the Current Object’s Members with the this Reference
F.5 Time Class Case Study: Overloaded Constructors
Class Time2 with Overloaded Constructors
F.6 Default and No-Argument Constructors
F.7 Composition
F.8 Enumerations
F.9 Garbage Collection
F.10 static Class Members
F.11 final Instance Variables
F.12 Packages
F.13 Package Access
F.14 Wrap-Up
Self-Review Exercise
Answers to Self-Review Exercise
Exercises
G Object-Oriented Programming: Inheritance and Polymorphism
ObjectivesOutline
G.1 Introduction to Inheritance
G.2 Superclasses and Subclasses
G.3 protected Members
G.4 Relationship between Superclasses and Subclasses
G.4.1 Creating and Using a CommissionEmployee ClassOverview of Class CommissionEmployee’s Methods and Instance VariablesClass CommissionEmployee’s ConstructorClass CommissionEmployee’s earnings MethodClass CommissionEmployee’s toString Method and the @Override AnnotationClass CommissionEmployeeTestG.4.2 Creating and Using a BasePlusCommissionEmployee ClassTesting Class BasePlusCommissionEmployeeNotes on Class BasePlusCommissionEmployeeG.4.3 Creating a CommissionEmployee–BasePlusCommissionEmployee Inheritance HierarchyA Subclass’s Constructor Must Call Its Superclass’s ConstructorBasePlusCommissionEmployee Method EarningsG.4.4 CommissionEmployee–BasePlusCommissionEmployee Inheritance Hierarchy Using protected Instance VariablesClass BasePlusCommissionEmployeeTesting Class BasePlusCommissionEmployeeNotes on Using protected Instance VariablesG.4.5 CommissionEmployee–BasePlusCommissionEmployee Inheritance Hierarchy Using private Instance VariablesClass BasePlusCommissionEmployee’s earnings MethodClass BasePlusCommissionEmployee’s toString MethodTesting Class BasePlusCommissionEmployee
G.5 Class Object
G.6 Introduction to Polymorphism
G.7 Polymorphism: An Example
G.8 Demonstrating Polymorphic Behavior
G.9 Abstract Classes and Methods
G.10 Case Study: Payroll System Using Polymorphism
G.10.1 Abstract Superclass EmployeeG.10.2 Concrete Subclass SalariedEmployeeG.10.3 Concrete Subclass HourlyEmployeeG.10.4 Concrete Subclass CommissionEmployeeG.10.5 Indirect Concrete Subclass BasePlusCommissionEmployeeG.10.6 Polymorphic Processing, Operator instanceof and DowncastingCreating the Array of EmployeesPolymorphically Processing EmployeesPerforming Type-Specific Operations on BasePlusCommissionEmployeesCalling earnings PolymorphicallyUsing Reflection to Get Each Employee’s Class NameAvoiding Compilation Errors with DowncastingG.10.7 Summary of the Allowed Assignments Between Superclass and Subclass Variables
G.11 final Methods and Classes
G.12 Case Study: Creating and Using Interfaces
G.12.1 Developing a Payable HierarchyG.12.2 Interface PayableG.12.3 Class InvoiceG.12.4 Modifying Class Employee to Implement Interface PayableG.12.5 Modifying Class SalariedEmployee for Use in the Payable HierarchyG.12.6 Using Interface Payable to Process Invoices and Employees Polymorphically
G.13 Common Interfaces of the Java API
G.14 Wrap-Up
Self-Review Exercises (Sections G.1G.5)
Self-Review Exercises (Sections G.6G.13)
Answers to Self-Review Exercises (Sections G.1G.5)
Answers to Self-Review Exercises (Sections G.6G.13)
Exercises (Sections G.1G.5)
Exercises (Sections G.6G.13)
H Exception Handling: A Deeper Look
ObjectivesOutline
H.1 Introduction
H.2 Example: Divide by Zero without Exception Handling
H.3 Example: Handling ArithmeticExceptions and InputMismatchExceptions
H.4 When to Use Exception Handling
H.5 Java Exception Hierarchy
H.6 finally Block
H.7 Stack Unwinding and Obtaining Information from an Exception Object
H.8 Wrap-Up
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
I GUI Components and Event Handling
ObjectivesOutline
I.1 Introduction
I.2 Nimbus Look-and-Feel
I.3 Text Fields and an Introduction to Event Handling with Nested Classes
I.4 Common GUI Event Types and Listener Interfaces
I.5 How Event Handling Works
I.6 JButton
I.7 JComboBox; Using an Anonymous Inner Class for Event Handling
I.8 Adapter Classes
I.9 Wrap-Up
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
J Other Java Topics
ObjectivesOutline
J.1 Introduction
J.2 Collections Overview
J.3 Type-Wrapper Classes for Primitive Types
J.4 Interface Collection and Class Collections
J.5 Lists
J.5.1 ArrayList and IteratorJ.5.2 LinkedListMethod convertToUppercaseStringsMethod removeItemsMethod printReversedListJ.5.3 Views into Collections and Arrays Method asListViewing Arrays as Lists and Converting Lists to Arrays
J.6 Collections Methods
J.6.1 Method sortSorting in Ascending or Descending OrderSorting with a ComparatorJ.6.2 Method shuffle
J.7 Interface Queue
J.8 Sets
J.9 Maps
J.10 Introduction to Files and Streams
J.11 Class File
J.12 Introduction to Object Serialization
J.13 Introduction to Multithreading
J.14 Creating and Executing Threads with the Executor Framework
J.15 Overview of Thread Synchronization
J.16 Concurrent Collections Overview
J.17 Multithreading with GUI
J.18 Wrap-Up
Self-Review Exercises
Answers to Self-Review Exercises
Exercises
K Operator Precedence Chart
L Primitive Types
Index
Symbols
Numerics
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z

Content preview from Android How to Program, 3/e

8.5 `MainActivity` Class

This app consists of three classes:

Class MainActivity—which we discuss in this section—configures the app’s GUI and defines the app’s logic.
Class SearchesAdapter (Section 8.6) is a subclass of RecyclerView.Adapter that defines how to bind the tag names for the user’s searches to the RecyclerView’s items. Class MainActivity’s onCreate method creates an object of class SearchesAdapter as the RecyclerView’s adapter.
Class ItemDivider (Section 8.7) is a subclass of RecyclerView.ItemDecoration that the RecyclerView uses to draw a horizontal line between items.

Sections 8.5.1–8.5.10 discuss class MainActivity in detail. This app does not need a menu, so we removed the MainActivity methods onCreateOptionsMenu and onOptionsItemSelected ...

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Android How to Program, 3/e

by Paul J. Deitel, Harvey M. Deitel

8.5 `MainActivity` Class

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