Page 122 - GIGW2

CH 11 Mobile App Guidelines

11.4.13 Resizable Content

Users with low vision may need to increase the size of the UI elements to be able
to see well. The app MUST resize its UI elements in accordance with device
settings for text size.

11.4.14 Color contrast
Users with low vision or users in poor lighting condition would find it difficult
to see the UI elements on the screen if the foreground elements cannot be
differentiated from the background. Therefore, color contrast ratio between
foreground text for up to 18 point font and background MUST be at least
4.5:1.

11.4.15 Color or shapes MUST not be used to communicate important information

Relying only on color or shape to communicate important information can be
problematic for certain persons with disabilities such as users with color blindness
or users with blindness. The following considerations are critical:

a. Text equivalence for color coded or shape dependent information must
be added. For example, if an app has a required field, then it could
provide the word (Required) if the space permits or use placeholders.

b. The app must disable the button used to move the menu forward until
the field is filled-out. Just relying on the shape of a button to indicate the
disabled state does not work for many users with disabilities.

c. Apps must not use color-based references such as Click on Red or Square
button; instead have text references such as Click on Next button.

11.4.16 Onscreen keyboard and hardware keyboard

Mobile platforms provide support for both onscreen keyboard and hardware
keyboard. App designers must ensure that both are accessible with assistive
technology such as magnifier or a screen reader. Note the following points while
developing and testing the input interface:

a. Do not automatically change focus: If a user is entering data and the
focus shifts automatically, the user would find it difficult to enter data.
Focus MUST be changed only when the user activates a UI element
that is designated for confirming an action such as the Submit button.
b. Select the correct onscreen keyboard: It MUST be Ensured that the
appropriate keyboard is invoked by the app depending on the type
of field or the data that needs to be provided by the user. For example,
the appropriate on-screen keyboard must be invoked for normal text,
numerical data, email address or web address. This recommendation is

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