:touch CSS 伪类或类似的东西？

Question

I am trying to make a button, such that when the user clicks on it, it changes its style while the mouse button is being held down. I also want it to change its style in a similar way if it is touched in a mobile browser. The seemingly-obvious thing to me was to use the CSS :active pseudo-class, but that didn't work. I tried :focus, and it didn't work too. I tried :hover, and it seemed to work, but it kept the style after I took my finger off the button. All of these observations were on an iPhone 4 and a Droid 2.

Is there any way to replicate the effect on mobile browsers (iPhone, iPad, Android, and hopefully others)? For now, I am doing something like this:

<style type="text/css">
    #testButton {
        background: #dddddd;
    }
    #testButton:active, #testButton.active {
        background: #aaaaaa;
    }
</style>

...

<button type="button" id="testButton">test</button>

...

<script type='text/javascript' src='http://code.jquery.com/jquery-1.6.1.min.js'></script>
<script type='text/javascript'>
    $("*").live("touchstart", function() {
      $(this).addClass("active");
    }).live("touchend", function() {
      $(this).removeClass("active");
    });
</script>

The :active pseudo-class is for desktop browsers, and the active class is for touch browsers.

I am wondering if there is a simpler way to do it, without involving Javascript.

Answer 1

There is no such thing as :touch in the W3C specifications, http://www.w3.org/TR/CSS2/selector.html#pseudo-class-selectors

:active should work, I would think.

Order on the :active / :hover pseudo class is important for it to function correctly.

Here is a quote from that above link

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 (eg, 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.
• The :focus pseudo-class applies while an element has the focus (accepts keyboard events or other forms of text input).

Answer 2

Since mobile doesn't give hover feedback, I want, as a user, to see instant feedback when a link is tapped. I noticed that -webkit-tap-highlight-color is the fastest to respond (subjective).

Add the following to your body and your links will have a tap effect.

body {
    -webkit-tap-highlight-color: #ccc;
}

Answer 3

I was having trouble with mobile touchscreen button styling. This will fix your hover-stick / active button problems.

 body, html { width: 600px; } p { font-size: 20px; } button { border: none; width: 200px; height: 60px; border-radius: 30px; background: #00aeff; font-size: 20px; } button:active { background: black; color: white; } .delayed { transition: all 0.2s; transition-delay: 300ms; } .delayed:active { transition: none; }

 <h1>Sticky styles for better touch screen buttons!</h1> <button>Normal button</button> <button class="delayed"><a href="https://www.google.com"/>Delayed style</a></button> <p>The CSS :active psuedo style is displayed between the time when a user touches down (when finger contacts screen) on a element to the time when the touch up (when finger leaves the screen) occures. With a typical touch-screen tap interaction, the time of which the :active psuedo style is displayed can be very small resulting in the :active state not showing or being missed by the user entirely. This can cause issues with users not undertanding if their button presses have actually reigstered or not.</p> <p>Having the the :active styling stick around for a few hundred more milliseconds after touch up would would improve user understanding when they have interacted with a button.</p>

Answer 4

The much upvoted comment by @gion_13 solved the issue for me:

Add ontouchstart="" to your page's body element and the :active selector will work more as expected on touch screens. Still not perfect in Chrome.