SC 3.2.1 On Focus
Prevent unexpected changes of context when a user component receives focus.
- Requirement: Navigating to an element (via keyboard or mouse) must not automatically trigger a change of context, such as opening a new window, moving focus elsewhere, or significantly rearranging the page.
- Predictability: Users must be able to move through a page and explore components without being forced into an action or having the page content shift unexpectedly.
- Change of Context: Defined as major changes like updates to the viewport, user agent, or page meaning. Note that expanding/collapsing content is not necessarily a change of context unless it moves focus or alters the page significantly.
- Proper Usage: Context-changing actions should only be triggered by deliberate user interaction, such as clicking a button or pressing the Enter/Space keys.
3.2.1 On Focus: When any component receives focus, it does not initiate a change of context.
Users need to interact with and understand page content in predictable ways so that they do not become disoriented. SC 3.2.1 On Focus is intended to ensure that people without vision, with limited vision, with limited manipulation, with limited reach and strength, and with limited language, cognitive and/or learning abilities do not unexpectedly initiate actions. This SC requires that no change of context occurs simply by having a selectable item receive focus by use of the keyboard or mouse. Instead, actions that lead to a change of context must generally only occur when a user initiates a change through clicking the mouse, pressing the ENTER key, pressing the SPACEBAR, or performing another action command.
Key Term: “Changes of context” are major changes in the content of the Web page that, if made without user awareness, can disorient users who are not able to view the entire page simultaneously
Changes in context include changes of:.
- user agent
- viewport
- focus
- content that changes the meaning of the Web page
NOTE:
A change of content is not always a change of context. Changes in content, such as an expanding outline, dynamic menu, or a tab control do not necessarily change the context, unless they also change one of the above (e.g., focus).
Opening a new window, moving focus to a different component, going to a new page (including anything that would look to a user as if they had moved to a new page) or significantly re-arranging the content of a page are examples of changes of context.
SC 3.2.1 On Focus is similar to SC 3.2.2 On Input.
The difference is that:
- SC 3.2.1 On Focus ensures that context does not change when an element receives focus (such as when a user navigates to a form field using the TAB key); while
- SC 3.2.2 On Input ensures that context does not change when an element receives input (such as entering text in to a form field).
Impact of Nonconformance with SC 3.2.1 On Focus
| Type of Disability | Description of Impact |
|---|---|
| 302.1 Without Vision | Users who are blind cannot use a mouse to interact with electronic content and typically use an assistive technology, such as a screen reader, to get audible or other alternative output for the information represented visually. To be able to navigate the content, understand its structure and relationships, and understand the meaning of content represented in graphics and images, the content must provide textual and programmatic cues in addition to the content presented purely visually. |
| 302.2 With Limited Vision | Users with limited vision may have widely different visual perception. Individuals with limited vision may or may not use assistive technologies. Therefore, in addition to textual and programmatic cues necessary for assistive technologies, ICT must also present content consistently and predictably. Users who view content with magnifiers may not pick up alerts, warnings, or other content if such content is presented outside of a consistent and predictable navigation pattern or if the content is not itself viewable at large magnification. Content that becomes distorted when magnified can also prevent some users with limited vision from being able to understand or interact with the content. |
| 302.7 With Limited Manipulation | Some users may not be able to perform actions that require fine motor control (clicking and dragging), path dependent gestures (pattern-based passcodes), or simultaneous actions (Ctrl + Alt + Del). Providing alternative means to perform the same actions, such as entering the size specifications in an input field to resize an object or allowing sequential key entries, can enable users with limited manipulation to interact with the same content. |
| 302.8 With Limited Reach and Strength | Some users may lack sufficient strength to perform actions such as squeezing, grasping, or depressing a hardware control. Some users, including those in wheelchairs or of shorter stature, may not be able to reach controls that are placed too high or too far away from where a user would access the device controls or interface. ICT designers and developers must consider a broad range of statures, strength and dexterity limitations, and the needs of wheelchair users in order to provide interfaces that are operable with limited reach and/or strength. |
| 302.9 With Limited Language, Cognitive, and Learning Abilities | Some users require more time than average to process information while others may find complicated instructions difficult to follow. Furthermore, some ICT content can distract or overwhelm users, preventing them from being able to interact with or understand other ICT content. Designers and developers of ICT must consider a broad range of cognitive abilities in order to provide ICT that is simple and easy to use. |
Applicability of Success Criteria 3.2.1 On Focus
| Technology | Applicability of SC 3.2.1 On Focus |
|---|---|
| Web | Developers can use event listeners to execute functions, including on-focus events for specific elements. When they do so, they must ensure that such events do not change the user’s context when an element receives focus. |
| Software | Developers can use event listeners to execute functions, including on-focus events for specific controls. When they do so, they must ensure that such events do not change the user’s context when an element receives focus. |
| Office documents | Content authors can use macros to create event listeners and execute functions, including on-focus events for specific document objects. When they do so, they must ensure that such events do not change the user’s context when an element receives focus. |
| PDF documents | Content authors can use code scripts to create event listeners and execute functions in PDF documents, including on-focus events for specific document objects. When they do so, they must ensure that such events do not change the user’s context when an element receives focus. |
| Mobile Native | Developers can use event listeners to execute functions, including on-focus events for specific controls. When they do so, they must ensure that such events do not change the user’s context when an element receives focus. |