Well-deployed technologies
An increasing share of mobile devices relies on touch-based interactions. While the traditional interactions recognized in the Web platform (keyboard, mouse input) can still be applied in this context, a more specific handling of touch-based input is a critical aspect of creating well-adapted user experiences, which Touch Events in the DOM (Document Object Model) enable.
The Vibration API lets mobile developers take advantage of haptic feedback to create new form of interactions (e.g. in games).
Mobile devices follow their users everywhere, and many mobile users rely on them to remind them or notify them of events, such as messages: the Web Notifications specification enables that feature in the Web environment.
The hardware constraints of mobile devices, and their different usage context can make mobile users experience similar barriers to people with disabilities. These similarities in barriers mean that similar solutions can be used to cater for them, making a Web site accessible both for people with disabilities and mobile devices a natural goal (as detailed in Relationship between Mobile Web Best Practices and WCAG).
The WCAG and UAWG Working Group provide guidance on mobile accessibility in how Web Content Accessibility Guidelines (WCAG) and other WAI guidelines apply to mobile — that is, making websites and applications more accessible to people with disabilities when they are using mobile phones and a broad range of other devices.
WAI-ARIA provides semantic information on widgets, structures and behaviors hooks to make Web applications more accessible, including on mobile devices.
| Feature | Specification | Maturity | Current implementations |
|---|---|---|---|
| Touch-based interactions | Touch Events |  | Shipped |
| Vibration | Vibration API | | Shipped |
| Notification | Web Notifications | | Shipped |
| Accessibility | Relationship between Mobile Web Best Practices (MWBP) and Web Content Accessibility Guidelines (WCAG) |  | N/A |
| Mobile Accessibility: How WCAG 2.0 and Other W3C/WAI Guidelines Apply to Mobile |  | N/A | |
| Accessible Rich Internet Applications (WAI-ARIA) 1.0 | | Shipped |
Technologies in progress
The Pointer Events Working Group has made good progress on an alternative approach to handle user input, Pointer Events, that allows to handle mouse, touch and pen events under a single model. It provides a complementary and more unified approach to the currently more widely deployed Touch Events.
In particular, the CSS property touch-action that lets filter gesture events on elements is gaining traction beyond implementations of Pointer Events.
The early proposal for an Input Device capabilities API would provide information about a given “mouse” event comes from a touch-capable device.
As more and more content gets rendered as long scrollable lists, more and more logic is attached to scrolling events, and the quality of the user experience of these actions is highly dependent on their performances. The CSSOM View Module determines when scrolling events get fired, and let developers specify the type of scrolling behavior they want.
The proposed work on CSS Scroll Snap Points adds greater ability to control the behavior of panning and scrolling by defining points to which an app view would snap when the user moves through the page.
The CSS will-change property is also available to indicate to browsers that a given part of the page will be soon scrolled to and should be pre-rendered.
The Push API makes it possible for server-side notifications to alert the user, even if the browser is not running.
Whether users are speaking commands to their apps or working with them through non-haptic interactions, they risk seeing the screens turned off automatically by their devices screensaver. An early proposal for a Wake Lock API would let developers signal the needs to keep the screen up in these circumstances.
| Feature | Specification | Maturity | Current implementations |
|---|---|---|---|
| Touch-based interactions | Pointer Events - Level 2 |  | In development Shipped |
| touch-action in Pointer Events - Level 2 | | Shipped | |
| Input Device Capabilities | | N/A | |
| Smooth scrolling | CSSOM View Module | | N/A |
| CSS Scroll Snap Module Level 1 |  | Shipped | |
| CSS Will Change Module Level 1 | | Under consideration Shipped | |
| Notification | Push API | | In development Shipped |
| Screen wake | Wake Lock API | | N/A |
Exploratory work
Mobile devices, and mobile phones in particular, are also in many cases well-suited to be used through voice-interactions; the Speech API Community Group developed a JavaScript API to enable interactions with a Web page through spoken commands. Speech synthesis is well supported across browsers. Support for speech recognition is still underway.
The Input Method Editor (IME) API provides Web applications with scripted access to an IME (input-method editor) associated with a hosting user agent. Editorial support is required for this specification to move forward.
| Feature | Specification | Group | Implementation intents |
|---|---|---|---|
| Speech-based interactions | Speech synthesis in Web Speech API | Speech API Community Group | Shipped |
| Speech recognition in Web Speech API | Speech API Community Group | Under consideration Experimental Shipped | |
| Input method | Input Method Editor API | Web Platform Working Group | Shipped |
Discontinued features
- Intent-based events
- As the Web reaches new devices, and as devices gain new user interactions mechanisms, it seems useful to allow Web developers to react to a more abstract set of user interactions: instead of having to work in terms of “click”, “key press”, or “touch event”, being able to react to an “undo” command, or a “next page” command independently of how the user instructed it to the device. The IndieUI Events specification was an attempt to address this need. The work has been discontinued for now, due to lack of support from would-be implementers.