Touch targets

Since users touch the screen with their fingertips, touch targets (hit areas) for UI components need to be large enough for users to initiate actions without frustration. If you use BlackBerry UI components, you don’t need to worry about the size of the touch target for each UI component. The sizes are designed to be large enough for users to touch with a finger. The design also allows users to be a bit "sloppy" when touching the screen. This means that the touch area is forgiving and allows users to be less precise but still carry out the action that they want.

If you create custom UI components, be aware that the size of the touch target depends on the pixels per inch (PPI) for the screen. If you are designing your application for different BlackBerry devices, create touch targets to accommodate the pixel densities for each screen size.

Best practices for custom UI components

• Create touch targets. For BlackBerry smartphones, create touch targets that are a minimum of 101 x 101 pixels (7.2 mm).
• Make the size of the touch target larger than the visible UI component. Provide enough space around each component so that users can initiate a specific action easily. This extra space provides leniency for users whose attention is divided or who are on the go.
• For check boxes and radio buttons, create a touch target area for the entire row and associated label. These UI components have notoriously small visible areas. 
• Make the size of the release area larger than the visible UI component. This extra space allows for imprecise interactions, such as when a finger moves after initially touching the screen.
• Test the size of each touch target with users.