EDWARD'S LECTURE NOTES:
More notes at http://tanguay.info/learntracker
C O U R S E
Programming Mobile Applications for Android
Adam Porter, University of Maryland
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C O U R S E L E C T U R E Developing an Android App Notes taken on June 17, 2014 by Edward Tanguay |
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four kinds of application components
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1. Activity
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users see these
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enables users to give and receive
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2. Service
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supports long-running background operations
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3. Broadcastreceiver
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listens for and responds to device events
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4. Contentprovider
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stores and shares data between multiple applications
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applications have any number of the above kinds of components
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implemented as Java classes
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Activity class
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primary class for user interaction
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an activity should provide a single, focused thing for a user to do
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e.g. phone dialer
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DialtactsActivity.java
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a sub-class of Activity
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Service class
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run in the background
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run away from UI thread
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e.g. music application
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allows music to continue playing even when you move to another app
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users a service to play the music file
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BroadcastReceiver
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listens for and responds to events
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events are represented by the intent class
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use e.g. sendBroadcast
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e.g. the messaging application
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someone wants to send me an SMS message
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arrives at my phone
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Android sits and waits for SMS messages to arrive and when one arrived, publishes an SMSmessageReceived intent
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Content Providers
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stores and shares data across applications
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use database-style interface
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handle interprocess communication
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e.g. browser application
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browser opens bookmarks in a Content
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BrowserProvider extends ContentProvider
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more complex application with two activities
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MapLocation
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user enters address
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presses button
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building an application
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you get an apk file
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apk is signed to identify the developer
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steps
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1. define resources
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apps are more than source code
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layout files
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strings
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animations
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images
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you can easily alter these resources
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e.g. strings
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individual strings
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arrays of strings
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plurals
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e.g. book/books
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in java, you refer to them as R.string.string_name
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implement applicatoin classes
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package application
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install and run application
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you can add another language of strings by adding a directory, e.g.
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videos-fr