Windows Phone Chassis Design

So far you know that hardware manufacturers can optionally include a keyboard, but what else can they modify? In the past this was quite an open - ended discussion as manufacturers could build a device to meet a certain price point. For example, for high - end devices, they could include GPS, an accelerometer, and a high - resolution camera; a low - end device may only have a T9 keypad and no camera at all. Even the number and layout of physical hardware buttons could change between devices. Of course, all these options come at a cost, and the first place this took hold was with developers. When building applications, developers were seldom able to rely on a particular hardware feature being present. Instead, you would typically either query an API to determine if hardware existed, or simply attempt to address the hardware. Failure or an exception would indicate the lack of supported hardware.

After the application had been developed, the problem was transposed to the end users. They would see a product advertised as being compatible with Windows Mobile and purchase it, only to discover that it required hardware that they didn�t have. No two Windows Mobile devices were alike. When it came to Marketplace for Windows Mobile, Microsoft acknowledged this issue, and as part of application submission, developers had to indicate what device capabilities their application required. The Marketplace client running on the device would then restrict the list of applications to only those that matched the device capabilities.

For Windows Phone, Microsoft has taken the proactive position of enforcing a set of requirements around device capabilities. This has been achieved by taking the traditional minimum hardware specifications and turning them into what Microsoft calls a chassis design . This specifies the external buttons, and in some cases their location, and the inclusion of particular hardware features such as Wi-Fi, GPS, accelerometer, compass, camera, light and proximity sensors, and the ability to vibrate. A device that doesn � t include all of the features dictated by a chassis design cannot be called a Windows Phone.

On the front- facing side of a Windows Phone there will be three buttons: Back, Start, and Search. There will also be dedicated camera, power, and volume controls.

It� s important to note that these hardware buttons have a dedicated purpose. Unlike in Windows Mobile, where the buttons could be assigned by the user to different functions, and then applications could elect to override all or some of the buttons, on a Windows Phone the buttons have a sole purpose. This reinforces the overall user experience through a consistent interface. The one exception to this rule is the Back button. Within your application you are able to control the navigation sequence. This means that you are able to intercept and handle the Back button. However, it is important to remember that the purpose of this button is to navigate back to whence the user came. For example, if they click to delete an item from a list and the application displays a confirmation prompt, the Back button should dismiss this prompt without deleting the item. Similarly, if the user has clicked an item in a list and gone through to a Details view, the Back button should navigate the user back to the list of items.

If you ensure that you correctly handle the Back button, there should be little need for your application to include navigation controls within the context of your application. Forward navigation is typically done through interaction with content; Back navigation is instigated from the Back button, and exiting your application is little more than pressing the Back button when on the first page of the application.

You can think of every application you open as being placed on a stack. When you hit the Back button and have not purposely handled it within your application, the application is popped off the stack and the previous one is displayed. This analogy works well as Windows Phone will automatically close your application when it goes out of focus by being popped off the application stack.

Similar to other mobile platforms, Windows Phone has a dedicated� I �m lost, take me to a known location � button. As it � s a Microsoft platform, this button is logically called the Start button and takes the user back to the Start experience. As you will learn, the Start is an area on the device that contains a personalized set of tiles that reflect what�s important to the user. It also acts as a launching point for accessing areas of the device and applications that the user may have installed. The last of the buttons on the front of the device is the Search button, also known as the Bing button . Pressing the Search button launches a context- sensitive search. For example, if you are looking through your contacts, pressing the Search button will filter your contacts based on the search criteria. If there is no appropriate search context, pressing the Search button will launch Bing Search, allowing you to search over Web content, images, and maps. At this stage it is not possible to integrate the Search button into your application, so tapping it within any third � party application will launch Bing Search.

The inclusion of Wi-Fi seems like an obvious requirement, but with the advent of 3G+ networks that are continuing to get cheaper, it would have been an easy cost saving for manufacturers to omit the Wi-Fi stack. In the early days of Windows Mobile, before Microsoft tightened security, it used to be possible to synchronize your contracts, calendar, and e - mail with Outlook by connecting to ActiveSync through a Wi-Fi network. This capability is returning with the ability to synchronize across your home Wi-Fi network to your Zune desktop experience.

Location is definitely one of the hip new fads being talked about across the software development community. Software that is aware of the user�s location means that it can locate information and people nearby. Of course, there are all manner of privacy issues to navigate, but it is important that Windows Phone can provide location information. This topic will be covered in detail in the context of the location services offered by the platform, but it � s enough to say that having a GPS is essential in order to accurately geolocate the user.

One thing that you will notice about Windows Phone is that it is the first mobile offering from Microsoft that has been designed with a consumer rather than enterprise or business user focus.
Previously, Windows Mobile was more tailored for the mobile worker, with support for enterprise features such as device deployment and management at the expense of a consistent set of hardware capabilities. As a consumer device Windows Phone will offer a minimum of a 5 - megapixel camera with integrated fl ash. Windows Phones will also include light and proximity sensors that will be used to enhance the user experience.

In building your application, you need to be very aware of the experience you are constructing for the user. Where you would have once provided simple on - screen feedback, you can now use more complex animation and sounds and even have the device vibrate. You should use all visual and hardware effects sparingly as it is easy to overwhelm the user and drain the phone�s battery in the process.

Source of Information : Wiley-Professiona Windows Phone 7 Application Development 2010