CSS :hover on mobile or other device as toggle

Question

I am doing a simple :hover slide-in cover as shown in picture, it's supposed to slide in a "favorite article" control, which user can then click to favorite this item.

While it work well on desktop with mouse hover and click, I am not sure if it can be used as an effective control on mobile or other device (ie. click to toggle, then click again to favorite item) .

If I understand correctly, at least on iOS (Safari) and Android (Chrome), the default browser behaviour is to emulate touch as both hover and click. But is it a standard? eg.

• Will Windows Phone or maybe a Wii U does the same?
• Will click be fired about 300ms after hover, so there can be ghost click issue?

I can certainly bind a click/touch event on this element, just wondering if css :hover is sufficient nowadays.

To clarify: I am not asking about :hover support, which only make senses in a pointer driven environment. I am asking if devices can and should handle hover-able element as users click/tap (as iOS/Android do)

Answer 1

Your question isn't totally clear and I cannot understand whether you're asking "Can I use :hover across all the devices?" or "Will :hover behave the same across all the devices?" or "Is :hover a standard element on the web?"

Also it greatly depends of your concept of "all devices", if you have in mind the currently most used devices or you are taking in account also the less-known and used devices.

I will quote you the following, but I am pretty sure you have already read that:

Interactive user agents sometimes change the rendering in response to user actions. CSS provides three pseudo-classes for common cases:

The :hover pseudo-class applies while the user designates an element (with some pointing device), but does not activate it. For example, a visual user agent could apply this pseudo-class when the cursor (mouse pointer) hovers over a box generated by the element. User agents not supporting interactive media do not have to support this pseudo-class. Some conforming user agents supporting interactive media may not be able to support this pseudo-class (e.g., a pen device). The :active pseudo-class applies while an element is being activated by the user. For example, between the times the user presses the mouse button and releases it.

CSS does not define which elements may be in the above states, or how the states are entered and left. Scripting may change whether elements react to user events or not, and different devices and UAs may have different ways of pointing to, or activating elements.

5.11.3 The dynamic pseudo-classes: :hover, :active, and :focus http://www.w3.org/TR/CSS2/selector.html#dynamic-pseudo-classes

As you can see on the W3C specification it claims that the :hover pseudo-class is not required to a non-interactive media user agents as well as some interactive media user agents. Therefore is safe to assume :hover is not always supported.

To dig deep on the matter, take a read at the following specification for Safari Mobile:

Additionally, Safari on iOS users interact with your web content directly with their fingers, rather than using a mouse. This creates new opportunities for touch-enabled interfaces, but does not work well with hover states. For example, a mouse pointer can hover over a webpage element and trigger an event; a finger on a Multi-Touch screen cannot. For this reason, mouse events are emulated in Safari on iOS. As a result, elements that rely only on mousemove, mouseover, mouseout or the CSS pseudo-class :hover may not always behave as expected on a touch-screen device such as iPad or iPhone.

You can handle touches directly or even detect advanced gestures in Safari on iOS, using the DOM Touch events touchstart, touchmove, touchend, and touchcancel. Unlike mouse events which are emulated, DOM Touch events are specifically designed to work with touch interfaces, so their behavior is reliable and expected.

5. Prepare for a touch interface https://developer.apple.com/library/content/technotes/tn2010/tn2262/_index.html

Apple clearly states here that they tend to emulate the pointer with the touch gestures, however they clearly suggest to avoid using the :hover pseudo-class as won't behave the same on their touch device.

We could dig deeper and fetch every documentation for each user-agent existing on earth but the previous two are enough to assume the following:

• Non interactive devices do not have to support :hover
• Interactive devices can support the pseudo-class (but it's not mandatory and they can ignore it, for example screen-readers or braille screens)
• Apple touch devices in absence of a pointer emulates :hover
• It is safe to assume current touch devices also emulates :hover
• It is safe to assume any other browser/device don't necessarily have to support :hover depending on their interface.
• Very likely the recent browsers will all support :hover because is a visual aid for the user.

So to answer to all the question(s) I have assumed above:

"Is :hover a standard element on the web?"

Hover is a standard W3C in fact it claims it must be triggered by a pointer event, but isn't required for some interfaces.

"Can I use :hover across all the devices?"

Yes you probably can. The devices which won't support :hover very likely are devices/users that probably aren't your main target. Better ask yourself "Who will be the end-user of my product?" if they are only mobile users or only blind people or only people who like to browse using the Nintendo DS then don't use :hover events, otherwise do.

"Will :hover behave the same across all the devices?"

No, as Apple stated on their devices will not behave the same as a desktop would, and that probably reflects the same behaviour on all devices without a pointer.

If you plan to have an user action via a hover state don't do it. This is generally bad practice and it should avoided in any case, including desktop devices. Hover is not an call to action, click is. Hover should not be treated as a "toggle" but more like a visual helper for the user making him/her understand that element, if clicked, triggers an action.

If I understood your application then hover isn't reliable and in your specific case you should rethink on how it should work. Use a more reliable method (and expected from your user)

Answer 2

Hovering your cursor over a webpage element is a common action when browsing with a mouse and keyboard, but there is no equivalent when it comes to touch-based browsing. This topic demonstrates how to use the aria-haspopup Document Object Model (DOM) property to simulate hover on touch-enabled devices with Internet Explorer 10 on Windows 8.

This behavior is not applicable to Internet Explorer 10 on Windows 7 (which does not support hover simulation with aria-haspopup) or Internet Explorer 11 on Windows 8.1 (which has built-in touch hover support).

In touch scenarios, hover is applied to an element while it is being touched. However, tapping an element can also activate an element, such as navigating a link. Effectively, a tap is both hover and activation in one action. This makes interactive content hidden behind hover inaccessible for touch users. The interaction model is completely different, and there is no touch analog to hovering the cursor over a page element.

The best practice is to not use hover to hide content that a user can interact with. Instead, consider using the onclick event to toggle the visibility.

Answer 3

It seems to me that part of this question hasn't yet been answered, namely what is the actual behaviour of Windows phones in relation to 'hover'. To clarify:

Consider a web page written for desktop/mouse use in which there is css markup so that 'hover' changes a style applied to an object. If one views that page on iPhone or Android and taps on the object the style change occurs. (i.e. it is behaving as if the object had an onClick() event handler to change the style). Does the same thing happen on a Windows Phone?

I can answer that question, at least for the Nokia Lumia 630 running Win 8.1:

No. As you press down with your finger in the initial part of a tap the style change does occur, but when you release your finger at the end of the tap the style reverts to the original. (This is arguably a more valid interpretation of 'hover' for touch, although whether it is of any practical use is another matter.)

I would add that the iPhone/Safari interpretation of hover also has an 'off' state. This is triggered when you tap on another object.

To show this and allow testing on different devices/browsers I have set up a demo page at www.davidleader.net/mobiledemo.html. This implements onClick(), onMouseover() and :hover to change the opacity of an image, revealing a different one underneath. (It therefore depends on support for opacity, but this has been around for a while.) There is also a 'dumb graphic' to click on to demonstrate the end of hover on the iPhone.

To summarize, as well as there being no de jure standards for interpretation of hover on mobile devices there are no de facto ones either. Therefore if you are targetting mobiles, avoid 'hover'.

Answer 4

Theres none at the moment that has a good support for :hover state in mobile

See related question about this

I havent use Modernzr.js for mobile , but it says it can detect if the browser supports touch events , so basically it adds ".touch" class in the html tag if the user uses mobile device.

so you'll use it like this, for e.g

.touch a:active{ /*css code here */ }

hopefully this would help somehow

Answer 5

When it comes to mobile phones, I doubt there is any standard. Yes it is very common for a touch device to apply a hover state while is is being touched, but you can never tell if a user could be using any number of browsers that may interpret a hover state differently.

I would say your best bet would be to shoot for the lowest common denominator and just assume that every touch device can only respond to touch actions.

The answer to that, of course, is to write media queries and/or javascript to force the browsers to act the way you want it to.

That's just my personal philosophy, for what it is worth.