Introduction to Android 1
Objectives
In this chapter you’ll be
introduced to:
■ The history of Android and
the Android SDK.
■ The Android Market for apps.
■ A review of basic object-
technology concepts.
■ Key software for Android app
development, including the
Android SDK, the Java SDK
and Eclipse integrated
development environment
(IDE).
■ Important Android
documentation.
■ Test-driving an Android app
that enables you to draw on
the screen.
■ The Deitel online Android
Resource Centers.
,2 Chapter 1 Introduction to Android
Self -Review Exercises
1.1 Fill in the blanks in each of the following statements:
a) In November 2007, the —a 34-company consortium initially and many
more now—was formed to develop Android, driving innovation in mobile technology
and improving the user experience while reducing costs.
ANS: Open Handset Alliance.
b) Using Eclipse with the Plugin, you can create, run, test and debug Android
apps quickly and conveniently, and you can visually design your user interfaces.
ANS: Android Development Tools (ADT).
c) Multitouch screens allow you to control your Android device with involv-
ing one touch or multiple simultaneous touches.
ANS: gestures.
d) You can create , which enable you to rapidly develop apps by combining
the complementary web services of several organizations, possibly with information
feeds of various types (such as RSS, Atom, XML, JSON and others).
ANS: mashups.
e) The Andriod contains APIs for audio focus, auto-scanning files to the me-
dia database (e.g., audio and video files), detecting sound loading completion, auto-
pause and auto-resume of audio playback, and more.
ANS: Media framework.
f) Android uses a collection of , which are named groups of related, pre-
defined classes.
ANS: packages.
g) The package gives access to Android content providers.
ANS: android.provider.
h) The , included in the Android SDK, allows you to run Android apps in a
simulated environment within Windows, Mac OS X or Linux.
ANS: Android emulator.
i) Almost any noun can be reasonably represented as a software object in terms of
(e.g., name, color and size) and behaviors (e.g., calculating, moving and
communicating).
ANS: attributes.
j) A program unit called a houses the methods that perform its tasks.
ANS: class.
k) You send messages to an object. Each message is a that tells a method of
the object to perform its task.
ANS: method call.
1.2 State whether each of the following is true or false. If false, explain why.
a) One benefit of developing Android apps is that the operating system is proprietary to
Google.
ANS: False. The operating system is open source and free.
b) The openness of the Android platform discourages innovation.
ANS: False. The openness of the platform spurs rapid innovation.
c) The Android Development Tools (ADT) Plugin for Eclipse—an extension to the
Eclipse IDE—allows you to create, run and debug Android apps, export them for dis-
tribution (e.g., upload them to Android Market), and more.
ANS: True.
d) You can reuse a class many times to build many objects. Reuse of existing classes when
building new classes and programs saves time and effort.
ANS: True.
, Exercises 3
e) Attributes are specified by the class’s methods.
ANS: False. Attributes are specified by the class’s instance variables.
f) Objects may communicate with one another, but they’re normally not allowed to know
how other objects are implemented—implementation details are hidden within the ob-
jects themselves.
ANS: True.
Exercises
1.3 Fill in the blanks in each of the following statements:
a) Android apps are developed with —the world’s most widely used program-
ming language, a logical choice because it’s powerful, free and open source.
ANS: Java.
b) GUI programming in Java is -driven, you’ll write apps that respond to var-
ious user interactions such as screen touches and keystrokes.
ANS: event.
c) Touching the screen and holding your finger in position is called a .
ANS: long press.
d) Touching and quickly flicking your finger across the screen in the direction you’d like
to move is called a .
ANS: fling.
e) Use the framework to add drag-and-drop capabilities in an app.
ANS: DragEvent.
f)
ANS:
g) As a marketing strategy, many app developers offer basic versions of their apps for free
so users can determine whether they like them, then purchase more feature-rich ver-
sions.This is called the “ ” strategy.
ANS: lite.
h) Before running an app in the emulator, you'll need to create an , which de-
fines the characteristics of the device on which you want to test, including the hardware,
system image, screen size, data storage and more.
ANS: Android Virtual Device.
i) Performing a task in a program requires a which houses the program state-
ments that actually perform its tasks.
ANS: method.
j) You must build an object of a class before a program can perform the tasks that the
class’s methods define. The process of doing this is called .
ANS: instantiation.
k) helps you build more reliable and effective systems, because existing classes
and components often have gone through extensive testing, debugging and perfor-
mance tuning.
ANS: Reuse.
l) Classes (i.e., wrap) attributes and methods into objects—an object’s attri-
butes and methods are intimately related.
ANS: encapsulate.
m) A new class of objects can be created quickly and conveniently by —the
new class absorbs the characteristics of an existing one, possibly customizing them and
adding unique characteristics of its own.
ANS: inheritance.
, 4 Chapter 1 Introduction to Android
n) Unlike actual buttons on a device, buttons appear on the device’s touch
screen.
ANS: soft.
o) Colors are defined using the RGBA color scheme in which the red, green, blue and
components are specified by integers in the range 0–255.
ANS: alpha.
1.4 State whether each of the following is true or false. If false, explain why.
a) The vast majority of Android development is done in C++.
ANS: False. The vast majority of Android development is done in Java.
b) Microsoft Visual Studio is the recommended integrated development environment for
Android development, though developers may also use a text editor and command-line
tools to create Android apps.
ANS: False. Eclipse is the recommended integrated development environment for Android
development, though developers may also use a text editor and command-line tools
to create Android apps.
c) You can reproduce on the emulator most of the Android gestures and controls using
your computer’s keyboard and mouse.
ANS: True.
d) Objects, or more precisely the classes objects come from, are essentially reusable soft-
ware components.
ANS: True.
Objectives
In this chapter you’ll be
introduced to:
■ The history of Android and
the Android SDK.
■ The Android Market for apps.
■ A review of basic object-
technology concepts.
■ Key software for Android app
development, including the
Android SDK, the Java SDK
and Eclipse integrated
development environment
(IDE).
■ Important Android
documentation.
■ Test-driving an Android app
that enables you to draw on
the screen.
■ The Deitel online Android
Resource Centers.
,2 Chapter 1 Introduction to Android
Self -Review Exercises
1.1 Fill in the blanks in each of the following statements:
a) In November 2007, the —a 34-company consortium initially and many
more now—was formed to develop Android, driving innovation in mobile technology
and improving the user experience while reducing costs.
ANS: Open Handset Alliance.
b) Using Eclipse with the Plugin, you can create, run, test and debug Android
apps quickly and conveniently, and you can visually design your user interfaces.
ANS: Android Development Tools (ADT).
c) Multitouch screens allow you to control your Android device with involv-
ing one touch or multiple simultaneous touches.
ANS: gestures.
d) You can create , which enable you to rapidly develop apps by combining
the complementary web services of several organizations, possibly with information
feeds of various types (such as RSS, Atom, XML, JSON and others).
ANS: mashups.
e) The Andriod contains APIs for audio focus, auto-scanning files to the me-
dia database (e.g., audio and video files), detecting sound loading completion, auto-
pause and auto-resume of audio playback, and more.
ANS: Media framework.
f) Android uses a collection of , which are named groups of related, pre-
defined classes.
ANS: packages.
g) The package gives access to Android content providers.
ANS: android.provider.
h) The , included in the Android SDK, allows you to run Android apps in a
simulated environment within Windows, Mac OS X or Linux.
ANS: Android emulator.
i) Almost any noun can be reasonably represented as a software object in terms of
(e.g., name, color and size) and behaviors (e.g., calculating, moving and
communicating).
ANS: attributes.
j) A program unit called a houses the methods that perform its tasks.
ANS: class.
k) You send messages to an object. Each message is a that tells a method of
the object to perform its task.
ANS: method call.
1.2 State whether each of the following is true or false. If false, explain why.
a) One benefit of developing Android apps is that the operating system is proprietary to
Google.
ANS: False. The operating system is open source and free.
b) The openness of the Android platform discourages innovation.
ANS: False. The openness of the platform spurs rapid innovation.
c) The Android Development Tools (ADT) Plugin for Eclipse—an extension to the
Eclipse IDE—allows you to create, run and debug Android apps, export them for dis-
tribution (e.g., upload them to Android Market), and more.
ANS: True.
d) You can reuse a class many times to build many objects. Reuse of existing classes when
building new classes and programs saves time and effort.
ANS: True.
, Exercises 3
e) Attributes are specified by the class’s methods.
ANS: False. Attributes are specified by the class’s instance variables.
f) Objects may communicate with one another, but they’re normally not allowed to know
how other objects are implemented—implementation details are hidden within the ob-
jects themselves.
ANS: True.
Exercises
1.3 Fill in the blanks in each of the following statements:
a) Android apps are developed with —the world’s most widely used program-
ming language, a logical choice because it’s powerful, free and open source.
ANS: Java.
b) GUI programming in Java is -driven, you’ll write apps that respond to var-
ious user interactions such as screen touches and keystrokes.
ANS: event.
c) Touching the screen and holding your finger in position is called a .
ANS: long press.
d) Touching and quickly flicking your finger across the screen in the direction you’d like
to move is called a .
ANS: fling.
e) Use the framework to add drag-and-drop capabilities in an app.
ANS: DragEvent.
f)
ANS:
g) As a marketing strategy, many app developers offer basic versions of their apps for free
so users can determine whether they like them, then purchase more feature-rich ver-
sions.This is called the “ ” strategy.
ANS: lite.
h) Before running an app in the emulator, you'll need to create an , which de-
fines the characteristics of the device on which you want to test, including the hardware,
system image, screen size, data storage and more.
ANS: Android Virtual Device.
i) Performing a task in a program requires a which houses the program state-
ments that actually perform its tasks.
ANS: method.
j) You must build an object of a class before a program can perform the tasks that the
class’s methods define. The process of doing this is called .
ANS: instantiation.
k) helps you build more reliable and effective systems, because existing classes
and components often have gone through extensive testing, debugging and perfor-
mance tuning.
ANS: Reuse.
l) Classes (i.e., wrap) attributes and methods into objects—an object’s attri-
butes and methods are intimately related.
ANS: encapsulate.
m) A new class of objects can be created quickly and conveniently by —the
new class absorbs the characteristics of an existing one, possibly customizing them and
adding unique characteristics of its own.
ANS: inheritance.
, 4 Chapter 1 Introduction to Android
n) Unlike actual buttons on a device, buttons appear on the device’s touch
screen.
ANS: soft.
o) Colors are defined using the RGBA color scheme in which the red, green, blue and
components are specified by integers in the range 0–255.
ANS: alpha.
1.4 State whether each of the following is true or false. If false, explain why.
a) The vast majority of Android development is done in C++.
ANS: False. The vast majority of Android development is done in Java.
b) Microsoft Visual Studio is the recommended integrated development environment for
Android development, though developers may also use a text editor and command-line
tools to create Android apps.
ANS: False. Eclipse is the recommended integrated development environment for Android
development, though developers may also use a text editor and command-line tools
to create Android apps.
c) You can reproduce on the emulator most of the Android gestures and controls using
your computer’s keyboard and mouse.
ANS: True.
d) Objects, or more precisely the classes objects come from, are essentially reusable soft-
ware components.
ANS: True.
