Data entry on a small screen is fascinating, but customer inputs must be combined together in forms to ultimately enable interaction. Luke Wroblewski made an eloquent statement about filling out forms in Web Form Design: Filling in the Blanks (2008, Rosenfeld Media): “Forms suck.” That’s the reality. This chapter is mostly about how to make them suck less on Android devices—and in some cases, even make filling out Android forms downright fun.
Whenever an error occurs when you fill out a form, the Inline Error Message pattern provides the standard way to help the customer out of it.
When an input error occurs, the system notifies the customer which fields need to be corrected. Generally you can recognize two components of the Inline Error Message: a field-level error indicator and a general error message (usually on top of the screen).
Visual error indicators differ greatly between apps. My favorites are positive visual indicators such as icons combined with the traditional red color, such as the reference implementation from the registration flow of the Calendar app (see Figure 11-1), which adds a red round (!) icon on the right side of the textbox if the person attempts to move past the e-mail field.
The Calendar ...