This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.
The direction
property of the Web Animations API dictionary AnimationEffectTimingProperties
indicates an animation's playback direction along its timeline, as well as its behavior when it reaches the end of an interation
Element.animate()
, KeyframeEffectReadOnly()
, and KeyframeEffect()
all accept an object of timing properties including direction.
The value of direction
corresponds directly to AnimationEffectTimingReadOnly.direction
in timing
objects returned by AnimationEffectReadOnly
, KeyframeEffectReadOnly
, and KeyframeEffect
.
Syntax
var timingProperties = { direction: "normal" | "reverse" | "alternate" | "alternate-reverse" }; timingProperties.direction = "normal" | "reverse" | "alternate" | "alternate-reverse";
Value
A DOMString
which specifies the direction in which the animation should play as well as what to do when the playback reaches the end of the animation sequence in the current direction. It can take one of the following values, with the default being "normal"
:
"normal"
- The animation runs forwards, from beginning to end, in the way we experience the flow of time.
"reverse
"- The animation runs backwards, or "rewinds."
"alternate"
- The animation switches direction after each iteration, going forward through the animation sequence the first iteration, then backward through the sequence the second iteration, and so forth.
"alternate-reverse"
- Similar to "alternate", except the animation playback starts by going from the end of the animation sequence toward the beginning the first iteration, then goes forward during the second, and so forth.
Examples
In the Forgotten Key example, Alice waves her arm up and down by passing her an alternate
value for her direction
property:
// Get Alice's arm, and wave it up and down document.getElementById("alice_arm").animate([ { transform: 'rotate(10deg)' }, { transform: 'rotate(-40deg)' } ], { easing: 'steps(2, end)', iterations: Infinity, direction: 'alternate', duration: 600 });
Specifications
Specification | Status | Comment |
---|---|---|
Web Animations The definition of 'direction' in that specification. |
Working Draft | Editor's draft. |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | (Yes) | 48 (48)[1] | No support | (Yes) | No support |
Feature | Android | Android Webview | Chrome for Android | Firefox Mobile (Gecko) | Firefox OS | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|---|
Basic support | ? | ? | ? | 48.0 (48)[1] | ? | No support | No support | No support |
[1] The Web Animations API is only enabled by default in Firefox Developer Edition and Nightly builds. You can enable it in beta and release builds by setting the preference dom.animations-api.core.enabled
to true
, and can disable it in any Firefox version by setting this preference to false
.
See also
- Web Animations API
Element.animate()
,KeyframeEffectReadOnly()
, andKeyframeEffect()
all accept an object of timing properties including this one.- The value of this property corresponds to the one in
AnimationEffectTimingReadOnly
(which is thetiming
object forAnimationEffectReadOnly
,KeyframeEffectReadOnly
, andKeyframeEffect
). - CSS's
animation-direction