When designing and implementing Flash Lite applications for the touch UI, consider the following issues:
Touch-enabled vs. touch-optimized
Touch-enabled applications rely on both touch-based and key-based interaction, while touch-optimized applications are designed primarily for the touch UI. When creating your application, consider which interactions benefit the most from the touch UI and whether the application can be optimized for touch. Just because you can use touch interactions, it does not mean that they are appropriate for every situation.
For more information, see section Touch-enabled vs. touch-optimised in the Design and User Experience Library.
Single interaction method per task
The user should be able to perform a task with the same interaction method from start to finish. If the user has to switch interaction methods during a task, for example, from using a finger to using the keypad, this can have a negative impact on the interaction flow. When designing tasks, consider which interaction method to use:
Touch vs. hardware keys
Finger vs. stylus
One hand vs. two hands
For more information, see section Finger vs. stylus in the Design and User Experience Library.
Focus on touch, select on release
Even though the choice of interaction strategy for selecting elements depends on the specific case, prefer focus on touch and select on release as it is the most intuitive strategy. Avoid using select on touch and separate taps for focus and select, since the former is highly prone to mistakes, while the latter requires an extra tap.
Element size and positioning
In order to be finger-usable, the elements on the touch screen must be sufficiently large. S60 UI style defines the minimum sizes as 7 x 7 mm with 1 mm gaps for index finger usage and 8 x 8 mm with 2 mm gaps for thumb usage. When designing for finger use, do not hesitate to make the elements larger, if you can spare the screen space.
For more information, see section Element dimensions.
For more information about designing Flash Lite applications for the touch UI, see the following sections in the Design and User Experience Library: