Success Criterion 2.5.1 Pointer Gestures (Level A): All functionality that uses multipoint or path-based gestures for operation can be operated with a single pointer without a path-based gesture, unless a multipoint or path-based gesture is essential.
This requirement applies to web content that interprets pointer actions (i.e. this does not apply to actions that are required to operate the user agent or assistive technology).
With the advent of smart or touch phones/devices, most of us started using the web on the mobiles. While accessing the web on mobile devices, it is quite common that users need to use certain gestures to complete the task. If those gestures are simpler then all the users including people with disabilities can use those gestures without much difficulties. However, there might be complex gestures as well to do certain tasks on the web. It may be true that people without disabilities would not have any problem in accessing those complex gestures, but 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. The examples of such complex gestures are pinch to zoom, split tap(where we hold one finger and tap with other finger), 2 or 3 finger tap, 2 or 3 finger scroll, and so on.. the examples that I provided as part of complex gestures are called as multipoint gestures. Multipoint gestures are nothing, but it requires more than one touch point to activate the functionality. Since multipoint gesture require more than one touch point to activate the functionality, it is kind of problem for the people who have low dexterity/people who use a specialized or adapted input device such as a head pointer, eye-gaze system, or speech-controlled mouse emulation in accessing the same. In addition, remembering such multipoint gestures increases cognitive load and thereby it creates problem for the people with cognitive disabilities too.
Apart from multipoint gestures, sometimes, users need to follow specific/particular path to complete certain tasks, and these gestures are called as path-based gestures. The example for such path-based gesture is swiping. When user swipes from left to right and vice-versa on the content slider then it displays next/previous slide correspondingly. Since path-based gestures require users to follow particular path, it is kind of problem again for the people who have low dexterity in accessing the same.
WCAG 2.1 introduced the new checkpoint called “2.5.1:pointer gestures” to address the problems with multipoint and path-based gestures for people who have low dexterity. This success Criterion states that functionality that uses multipoint or path-based gestures for operation can be operated with a single pointer without a path-based gesture. To satisfy this success criterion, authors need to provide an alternative mechanism for the people with motor disabilities to access those path-based and multipoint gestures. The alternative is to provide single pointer. Single pointer is nothing, but pointer input that operates with one point of contact with the screen, including single taps and clicks, double-taps and clicks, long presses, and path-based gestures. Let me explain with few examples how the single pointer is an alternative for multipoint and path-based gestures.
- There is map on the web. To zoom the map, user may have to pinch with 2 finger(multipoint gesture). The + and – buttons can be added on the map as alternative for the users who cannot perform such gestures
- There is photo gallery on the web. Users may have to swipe(path-based gesture) to display next/previous photos. The right and left arrow icons can be added on the gallery as an alternative for the users who cannot perform such gestures
Basically, providing single pointer as an alternative for the multipoint and path-based gestures enables all the users including people with disabilities in accessing all the functionalities/features on the web.
- This checkpoint is not applicable If Those multipoint and path-based gestures are essential to the content. For an example, signature requires path-based gesture, and it is sometimes essential
- This checkpoint is applicable for only author supplied gestures but not user agent, operating system, assistive technology gestures
Complimentary info on 2.5.1: pointer gestures
The end points that follow particular path considers to be path-based gesture in this success criterion. However, the end points that do not follow particular path(random path) considers to be free-form gesture and this is not considered as path-based gesture. The example of free-form is drag and drop. Although free-form gestures do need single-pointer gestures as an alternative, this seems to be difficult for the author to implement. Therefore, free-form gestures are not covered as part of this success criterion