ECE 455/555 Embedded System Design. Android Programming. Wei Gao. Fall

Transcription

1 ECE 455/555 Embedded System Design Android Programming Wei Gao Fall

2 Fundamentals of Android Application Java programming language Code along with any required data and resource files are compiled into an Android package,.apk file. Android applications don't have a single entry point for everything in the application No main() function Default entry when you click the application icon Components can also be started by other applications ntals.html ECE 455/555 Embedded System Design 2

3 Activating Components Application components Activities, services, broadcast receivers Activated by an asynchronous message called intent Bind components at runtime You can start an activity by passing an intent to startactivity() Specify the main entry of your program in this way! You can start a service by passing an intent to startservice() ECE 455/555 Embedded System Design 3

4 Analyzing HelloWorld Application One of the standard entry function: crate an activity instance Create an user interface and set the text Default function to setup the user menu specified in class R ECE 455/555 Embedded System Design 4

5 Manifest XML file Applications must declare their components in a manifest file Before Android can start an application component, it must learn that the component exists. AndroidManifest.xml for each application Declares the application's components Names any libraries the application needs to be linked against Identifies any permissions the application expects to be granted ECE 455/555 Embedded System Design 5

6 The Manifest XML File of HelloWorld The only component <manifest xmlns:android=" package="com.example.helloandroid" android:versioncode="1" android:versionname="1.0" > <uses-sdk android:minsdkversion="10" android:targetsdkversion="15" /> <application > <activity android:name=".mainactivity" > <intent-filter> </activity> </application> </manifest> <action android:name="android.intent.action.main" /> <category android:name="android.intent.category.launcher" /> </intent-filter> Similarly you can claim <service>, <receiver> and <provider> within the <application> tag ECE 455/555 Embedded System Design 6

7 The Manifest XML File of HelloWorld <manifest xmlns:android=" package="com.example.helloandroid" android:versioncode="1" android:versionname="1.0" > <uses-sdk android:minsdkversion="10" android:targetsdkversion="15" /> The platform version used Type of action <application > <activity android:name=".mainactivity" > <intent-filter> <action android:name="android.intent.action.main" /> </intent-filter> </activity> </application> </manifest> Being indicated as application entry <category android:name="android.intent.category.launcher" /> Other action types: CALL, SYNC, BATTERY_LOW,etc /intents-filters.html ECE 455/555 Embedded System Design 7

8 More in the Manifest XML file Application requirements Using external sensor/devices <uses-feature android:name="android.hardware.bluetooth" /> <uses-feature android:name="android.hardware.camera" /> Using Android library <uses-library android:name="android.view.animation" /> Request permission <uses-permission android:name="android.permission.camera" /> More details at: t-intro.html ECE 455/555 Embedded System Design 8

9 API Demos Demonstrating how the system API work Import demo projects into Eclipse -> Android project from existing code \...\Android\android- sdk\samples\android- 10\ApiDemos ECE 455/555 Embedded System Design 9

10 API Demos Run the program as a Java application It will automatically compile and upload the.apk file to the phone There will be an application named API Demos on your phone You will see something looks like: ECE 455/555 Embedded System Design 10

11 Sensing API Demo In the API Demo menu, choose OS->Sensors Application that displays the values of 3-axis acceleration sensors graphically Frequently used in games for gravity detection! implementation com.example.android.apis.os /Sensors.java ECE 455/555 Embedded System Design 11

12 Sensing API Demo Access sensor readings through SensorManager class Get an instance of SensorManager Listen sensor readings when the application is active at foreground Release listening ECE 455/555 Embedded System Design 12

13 Sensing API Demo Read and convert sensor readings Implemented as an event handler Readings of 3D orientation sensors Otherwise, use accelerator data Reading conversions ECE 455/555 Embedded System Design 13

14 Sensing Related Packages Media ackage-summary.html Location package-summary.html Hardware e/sensor.html ECE 455/555 Embedded System Design 14

15 Thoughts Can you realize fancier functionalities based on the sensing capabilities provided by Android? All the codes you need are included in the samples! Check \...\Android\android-sdk\samples\android-10\ Integrating sensing capabilities with other applications SMS, GPS, camera, etc ECE 455/555 Embedded System Design 15

16 Summary Android: an open-source operating system for smartphones Micro-kernel, middleware-based OS implementation Each application runs in Java virtual machine Expensive but reliable and secure Application Java programming enabled Components: activity, service, content provider, broadcast receiver Configured by Manifest XML file Sensing capabilities of smartphones Enable more flexible software design ECE 455/555 Embedded System Design 16

17 Other Smartphone Platforms Doing your project on your own smartphones or tablets iphone, BlackBerry, ipad, etc. A tutorial of iphone programming can be found here. Development.zip ECE 455/555 Embedded System Design 17