Chapter 1: Voilà! Meet the Android

Transcription

1 Chapter 1: Voilà! Meet the Android

2 Meet the Android Smartphones Can browse the Web Allow you to play games Use business applications Check Play music Record video Map locations with GPS Oh yes, make phone calls and send text messages 2

3 Meet the Android (continued) Android phone platform runs a free, open-source operating system from Google Open Handset Alliance 80 companies that develop standards for mobile devices Android Phone Device Most popular are EVO, Droid, Galaxy, Echo, etc. OS also powers tablets, netbooks, e-readers, MP4 players and Internet TVs 3

4 Meet the Android (continued) Features of the Android Flash support - Flash video plays within the Android Web browser. (The iphone does not support Flash capabilities.) Power management - Android identifies programs running in the background using memory and processor resources. Optimized gaming - Android supports the use of gyroscope, gravity, barometric sensors, linear acceleration, and rotation vector. 4

5 Meet the Android (continued) Features of the Android (continued) Onscreen keyboard - Spell-check, predictive text, voice-input mode. Wi-Fi Internet tethering - Allows a phone to be used as a wireless or wired hot spot. Multiple language support - Android supports multiple human languages. Front- and rear-facing cameras Voice-based recognition for calling, texting, and navigating with the phone. 5

6 Meet the Android (continued) Features of the Android (continued) 3D graphics - The interface can support 3D graphics for a 3D interactive game experience or 3D image rendering. Facial recognition - Android provides this high-level feature for automatically identifying or verifying a person s face from a digital image or a video frame. 6

7 Meet the Android (continued) Writing Android Apps Java is the language of choice for Android Apps Object-oriented programming languages allow for good software engineering practices Eclipse The most popular tool (IDE) for writing Java programs Can also be used to develop applications in other languages XML is used to assist in the layout of the Android emulator 7

8 Meet the Android (continued) Android Emulator Design, develop, prototype, and test Android apps without using a physical device Mimics almost every feature of a real Android handset, except placing phone calls Current version is Ice Cream Sandwich all versions named after dessert items (in alphabetical order) Previous versions include Cupcake, Donut, Éclair, Froyo (frozen yogurt), Gingerbread, and Honeycomb 8

9 Meet the Android (continued) Getting Oriented with Market Deployment Platform consists of the Android OS, application development tools, and a marketplace Apps are compiled into package files with an.apk extension Android Market ( sells and deploys all apps Programs must meet minimum standards Apps are free or paid (70/30 split between developer and wireless carrier) Also sold through Amazon (amazon.com/appstore) and itunes (both charge a $99 registration fee) 9

10 First Venture into the Android World (cont d) Building the User Interface Must be intuitive Interface must not distract from functionality Java code or XML layout files are needed XML method is preferred Can design interface without writing large amounts of code 10

11 First Venture into the Android World (cont d) Taking a Tour of the Package Explorer Src folder contains Java source code Gen folder contains automatically generated Java files Android 4.0 library contains all class libraries Assets folder contains asset files Res folder contains images, music, and video Android Manifest.xml contains information about the application that Android needs to run 11

12 First Venture into the Android World (cont d) Designing the user Interface Layout Layout a container that holds as many widgets as needed Widget a single element on the screen (Button, Text Box, etc.) Also called an object 12

13 First Venture into the Android World (cont d) Figure 1-10 Layout Displayed in Eclipse Window 13

14 First Venture into the Android World (cont d) Adding a Form Widget to the User Interface Layout Figure 1-12 TextView form widget in the emulator 14

15 First Venture into the Android World (cont d) Adding a Form Widget to the User Interface Layout Figure 1-14 Changing the TextView control text Figure 1-15 Displaying the revised text in the emulator 15

16 First Venture into the Android World (cont d) Testing the Application in the Emulator Figure 1-16 Run As Dialog Box 16

17 First Venture into the Android World (cont d) Testing the Application in the Emulator Figure 1-17 Android main screen and lock icon Figure 1-18 Message in the Android Emulator 17

18 First Venture into the Android World (cont d) Opening a Saved App in Eclipse Figure 1-19 Import dialog box Figure 1-20 Project and directory selected 18

19 Summary Android OS is released under Apache license allowing anyone to get the full open-source for free Android OS powers all types of mobile devices To write apps, you can use Eclipse, an IDE used for building applications The Android emulator lets you design, develop prototype, and test Android applications The Android platform consists of the Android OS, the Android application development platform, and the Android marketplace 19

20 Summary (continued) Android supports both Java code and XML layout files, although XML is preferred The Package Explorer contains folders for an Android project To design a user interface for an Android app, you can create a layout containing widgets (objects) The Android emulator allows you to test an application and make sure it runs correctly 20