Form Factor

Laptops, notebooks , and Tablet PCs present challenges to application developers not encountered on desktop PCs. These challenges include grab-and-go docking and readability.

Grab-and-Go Docking

One feature of Longhorn laptops and Tablet PCs is the ability to remove the computer from a docking station or port at any time, without prior warning. Grab-and-go docking presents a challenge for the software designer, who must consider computer connectivity to mass storage devices (hard disks in docking stations , CD-R drives , 1394 hard disks, and others). Any device to which the user is currently writing data or from which the user is reading data can suddenly be disconnected. Software developers should design fallbacks for all these actions ”preferably fallbacks that do not require user interaction and are self-healing when device connectivity is restored.

Many Longhorn mobile PC form factors will include two display adapters: one for the built-in screen and one for an external monitor that is used while the device is docked . Consider how your application works when a user interacts with it by using a pen on a Tablet PC or runs another application on an external monitor. You can take advantage of both displays simultaneously . While docked, the built-in display becomes a private display that interacts with the pen, while the external screen is the public interface.

Data such as files, contacts, and devices should be synchronized using the Longhorn Synchronization Manager. The Synchronization Manager will provide users with a single place to synchronize all data.

Designing for Readability

Reading is a common and frequent task for mobile PC users. You can take advantage of mobile PCs as a reading tool by ensuring that your application provides the following capabilities:

• Responds to page-up and page-down events.

• Uses smooth scrolling (real time, no flashing) to allow a user s eye to track the movement of a document as the user scrolls .

• Provides a riffle control that uses a half-second transition per move and per repeat. A riffle control enables users to flip through pages or screens of content quickly.

• Provides a rich contrast between the background and the content of the document so that it is readable even when viewed from an angle or when some glare exists.

• Uses colors with a rich contrast for better readability. Do not use yellows, oranges, or other light colors for important items on the screen. Dark colors are easier to distinguish on backlit screens.