WxTrax: Example Android 4.x Application Using Android Studio/Gradle

For your consideration I offer "WxTrax" which is a complete Android 4.x application that collects weather reports from the U.S. National Weather Service.  WxTrax illustrates the following concepts:

• Employs Android 4.x constructs (i.e. loaders, fragments, etc)
• Plays nice w/Android Studio (currently on preview version 0.2.6)
• Builds using Gradle (currently 1.7)
• Is decomposed into an application and a library
• Uses Google Maps V2
• AppWidget example
• Weather stations and observations are stored in SqlLite using a ContentProvider

Complete sources are available on GitHub

The US National Weather Service (NWS) makes weather reports available as a XML based web service.  Hourly weather observations are usually performed by automated stations colocated at airports, so the observations use the IATA location code (i.e. KPDX for Portland, KSEA for Seattle, KSFO for San Francisco, etc).  To obtain the current observation for Los Angeles you would use the URL http://www.weather.gov/xml/current_obs/KLAX.xml

WxTrax will allow you to specify stations of interest and collect these weather reports for you.  WxTrax can also display a Google Map w/the station location.

There is also the concept of a "favorite" station which always displays the most recent report on the "splash" page.  If you display the associated AppWidget, the favorite station temperature is given.

Now on to the sources...

WxTraxLib contains code I wrote in 2010 for the first version of this application.  There is no user interface code here, but it does contain the network support, weather observation collection, XML parser, ContentProvider, etc.  I like to decompose my applications into modular components like this.  The user interface tends to change quite a depending upon the product team while the supporting components tend to be more stable.  Breaking a project into modules allows for reuse across multiple products and makes for easier testing of the "headless" pieces.

WxTrax2 is new, freshly updated to use Android 4.x components.  All the UI components reside in this module, and depends upon WxTraxLib.

MainActivity exists to host fragments and handle the communication logic between them.  Fragment switching is performed within TabHelper.  You can add a station from the menu and a dialog will accept your command.  StationListFragment will display the known stations.  Selecting a station will show the collected observations (via ObservationListFragment).  A long press on a station row will allow you to delete a station or select it as the "favorite" station.  Selecting the "map" fragment allows Google Maps to display station locations.