Palm webOS

Lists

The design for Mojo began with the List. To validate the webOS architecture and the concept of Mojo, the principle webOS architects were challenged to design a list widget that would pull dynamic data from the Contacts database as the user flicked through the list, without any perceptible delay or loss of data (on a low-end CPU, no less). Needless to say, this was not a trivial challenge. However, the challenge was met and the rest of the framework took shape around the resulting design.

The webOS user experience makes extensive use of lists in many applications. Given the form factor and the navigation model, most applications will incorporate a List widget in one way or another. To get the most out of Mojo you need to fully understand the List widget.

The other list widget, the Filter List, is derived from the List widget. It has many of the same features as the List widget, but is designed around a more specialized use case. Our sample application will make use of Filter List in Chapter 5.

List Widgets

Lists are rendered by inserting objects into the DOM using provided HTML templates for both the list container and the individual list rows. Lists can be variable height and include single and multi-line text, images, or other widgets. Some Lists are static, meaning the list items are provided to the widget directly as an array. Other Lists are dynamic, meaning the application provides items as needed for display. Lists can be manipulated in place, with the framework handling ...