The intent of this Success Criterion is to ensure that content can be operated using simple inputs on a wide range of pointing devices. This is important for users who cannot perform complex gestures, such as multi-point or path-based gestures, in a precise manner, either because they may lack the accuracy necessary to carry them out or because they use a pointing method that lacks the capability or accuracy.
Examples of path-based gestures include swiping, dragging, or the drawing of a complex path. Such paths may be drawn with a finger or stylus on a touchscreen, on a graphics tablet or trackpad, or with a mouse, joystick, or similar pointer device. A user may find it difficult or impossible to accomplish these if they have impaired fine motor control, or if they use a specialized or adapted input device such as a head pointer, eye-gaze system, or speech-controlled mouse emulation.
Examples of multi-point gestures include a two-finger pinch zoom, a split tap where one finger rests on the screen and a second finger taps, or a two or three finger tap or swipe. A user may find it difficult or impossible to accomplish these if they type and point with a single finger or stick, in addition to any of the causes listed above.
Authors must ensure that their content can be operated without such complex gestures. When they implement multi-point or path-based gestures, they must ensure that the functionality can also be operated via single-point activation. Examples of single-point activation on a touchscreen or touchpad include taps, double taps, and long presses. Examples for a mouse, trackpad, head-pointer, or similar device include single clicks, click-and-hold and double clicks.
The success criterion applies to author-created gestures, as opposed to gestures defined on the level of operating system or user agent. An example for gestures provided on the operating system level would be swiping down to see system notifications, and gestures for built-in assistive technologies (AT) to focus or activate content, or to call up AT menus. An example of user agent-implemented gestures would be horizontal swiping implemented by browsers for navigating within the page history, or vertical dragging to scroll page content.
While some operating systems may provide ways to define "macros" to replace complex gestures, content authors can not rely on such a capability because is not pervasive on all touch-enabled platforms. Moreover, this may work for standard gestures that a user can predefine, but may not work for other author-defined gestures.
This Success Criterion does not require all functionality to be available through pointing devices, but that which is must be available to users who use the pointing device but cannot perform complex gestures. While content authors may provide keyboard commands or other non-pointer mechanisms that perform actions equivalent to complex gestures (see Success Criterion 2.1.1 Keyboard), this is not sufficient to conform to this success criterion. That is because some users rely entirely on pointing devices, or find simple pointer inputs much easier than alternatives. For example, a user relying on a head-pointer would find clicking a control to be much more convenient than activating an on-screen keyboard to emulate a keyboard shortcut, and a person who has difficulty memorizing a series of keys (or gestures) may find it much easier to simply click on a labeled control. Therefore, if one or more pointer-based mechanisms are supported, then their benefits should be afforded to users for users through simple, single-point actions alone.
An exception is made for functionality that is inherently and necessarily based on complex paths or multi-point gestures. For example, entering one's signature may be inherently path-based (although acknowledging something or confirming one's identity need not be).
Users who cannot (accurately) perform complex pointer gestures will have alternative means for operating the content.
The availability of user interface elements provided as a fallback for complex gestures helps users who may often be unaware of the support for complex pointer gestures. This can be beneficial especially for users with cognitive or learning disabilities.
A web site includes a map view that supports the pinch gesture to zoom into the map content, and drag gestures to move the visible area. User interface controls offer the operation via [+] and [-] buttons to zoom in and out, and arrow buttons to pan stepwise in all directions.
A news site has a horizontal content slider with hidden news teasers that can moved into the viewport via horizontal swiping. It also offers forward and backward arrow buttons for single-point activation to navigate to adjacent slider content.
A mortgage lending site has a slider control for setting the amount of credit required. The slider can be operated by dragging the thumb, but also by a single tap or click anywhere on the slider groove in order to set the thumb to the chosen position.
A slider control can be operated by dragging the thumb. Buttons on both sides of the slider increment and decrement the selected value and update the thumb position.
A floor planning web app lets the user place shapes representing pieces of furniture on a map representing a room. The user can drag a shape to reposition it, but they can also accomplish this by clicking on a drag handle in the center of the shape then clicking arrow buttons to move the selected handle. Similarly, they can resize the shape by pinch-and-zoom, but they can also do this by clicking a drag handle on its boundary and then clicking the arrow buttons.
GXXX: Do not rely on path-based gestures
GXXX: Do not rely on multi-point gestures
GXXX: Provide controls that do not require complex gestures and perform the same function as complex gestures
GXXX: Single-point activation for spatial positioning and manipuation
None