+ + If you've completed the Hello World and RSS Reader tutorials and feel that you + understand them well but still want to learn more, then this tutorial is for you! + The Travel Companion widget that we will create in this tutorial is something that + would be very useful for anyone who travels a lot. It's a widget that offers many + helpful features for travellers: a world clock that allows the user to simultaneously + follow the time at home and at the destination, a 5-day weather forecast for the + destination city and the current weather for both the home and destination cities, + a currency converter, and a summary of the current news headlines. +
+ ++ + But because this tutorial is about using the WRTKit for developing widget user interfaces + we will not implement all the code that is required to actually carry out all the + functionality that was described above. Instead we will have a Travel Companion "engine" + that will provide all these services for us so that we can focus on the user interface. + The engine that we will use (that has been created for this example) is a mock engine, + meaning that it mimics what the real Travel Companion engine would do, but actually it + just returns hard coded weather forecasts and exchange rates. That's all we need for this + tutorial, but after you've created the widget you can modify the engine so that it + actually fetches news headlines, currency exchange rates and weather forecasts from + various data sources online. There are plenty of free services that you can integrate to. + And here's the best part: because we will implement the user interface so that it's + cleanly separated from the engine, you won't have to change a single line of the user + interface code after you change the engine to use real world data! +
+ ++ + Our widget will have no less than five views: one main view, three functional views and + a settings view. The main view exists purely for navigational purposes. Because the widget + is so complex we want to give the user an overview of what's available and an easy way of + getting to everything. The three functional views include an information view that gives + the user the most important information in a single glance, a currency converter view, + and a five day weather forecast view. And finally the settings view lets the user configure + the home and local cities, daylight saving time and temperature unit (Celsius or + Fahrenheit) to use in the weather forecast. +
+ ++ + The tutorial will teach several important things. First of all, we'll learn how to + create widgets that have multiple views. Second, we'll learn how to separate the code + in the widget so that the user interface doesn't need to know anything about how the + business logic works, and vice versa. Third, we'll create a navigational view using + the NavigationButton control. Fourth, we'll customize the look of the widget to include + a logo for our application in the list view caption area. And finally, we'll learn how + to update the content in the user interface using a timer. We'll use the timer to keep + the world clock, weather forecast and news headlines up to date. This is very important + because widgets are often used so that the user starts them and then just keeps them + running for days on end. If we didn't refresh the user interface then the information + would quickly get old and the user would be forced to do manual refreshes. +
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