The Media Session API's MediaSessionActionDetails
dictionary is the type used by the sole input parameter into the callback which is executed when a media session action occurs. It specifies the type of action which needs to be performed as well as the data needed to perform the action.
Properties
action
- A Media Session action type string taken from the
MediaSessionAction
enumerated type, indicating which type of action needs to be performed. See Media action types below for possible values. fastSeek
Optional- An
seekto
action may optionally include this property, which is a Boolean value indicating whether or not to perform a "fast" seek. A "fast" seek is a seek being performed in a rapid sequence, such as when fast-forwarding or reversing through the media, rapidly skipping through it. This property can be used to indicate that you should use the shortest possible method to seek the media.fastSeek
is not included on the final action in the seek sequence in this situation. seekOffset
Optional- If the
action
is eitherseekforward
orseekbackward
and this property is present, it is a floating point value which indicates the number of seconds to move the play position forward or backward. If this property isn't present, those actions should choose a reasonable default distance to skip forward or backward (such as 7 or 10 seconds). seekTime
Optional- If the
action
isseekto
, this property must be present and must be a floating-point value indicating the absolute time within the media to move the playback position to, where 0 indicates the beginning of the media. This property is not present for other action types.
Media action types
A media session action's type is specified using a string from the MediaSessionAction
enumerated type.
Values
Each of the actions is a common media session control request. Implement support for each of these in order to allow that type of action to be performed. The following strings identify the currently available types of media session action:
nexttrack
- Advances playback to the next track.
pause
- Pauses playback of the media.
play
- Begins (or resumes) playback of the media.
previoustrack
- Moves back to the previous track.
seekbackward
- Seeks backward through the media from the current position. The
MediaSessionActionDetails
propertyseekOffset
specifies the amount of time to seek backward. seekforward
- Seeks forward from the current position through the media. The
MediaSessionActionDetails
propertyseekOffset
specifies the amount of time to seek forward. seekto
- Moves the playback position to the specified time within the media. The time to which to seek is specified in the
MediaSessionActionDetails
propertyseekTime
. If you intend to perform multipleseekto
operations in rapid succession, you can also specify theMediaSessionActionDetails
propertyfastSeek
property with a value oftrue
. This lets the browser know it can take steps to optimize repeated operations, and is likely to result in improved performance. skipad
- Skips past the currently playing advertisement or commercial. This action may or may not be available, depending on the platform and user agent, or may be disabled due to subscription level or other circumstances.
stop
- Halts playback entirely.
Examples
Adding action handlers
This example implements seek forward and backward actions for an audio player by setting up the seekforward
and seekbackward
action handlers.
let skipTime = 10; // Time to skip in seconds
navigator.mediaSession.setActionHandler('seekforward', details => {
// User clicked "Seek Forward" media notification icon.
audio.currentTime = Math.min(audio.currentTime + skipTime,
audio.duration);
});
navigator.mediaSession.setActionHandler('seekbackward', details => {
// User clicked "Seek Backward" media notification icon.
audio.currentTime = Math.max(audio.currentTime - skipTime, 0);
});
In this case, both the seekforward
and seekbackward
handlers are using a fixed distance, ignoring the time specified by the MediaSessionActionDetails
passed into the handler.
Supporting multiple actions in one handler function
You can also, if you prefer, use a single function to handle multiple action types, by checking the value of the MediaSessionActionDetails
object's action
property:
let skipTime = 7;
navigator.mediaSession.setActionHandler("seekforward", handleSeek);
navigator.mediaSession.setActionHandler("seekbackward", handleSeek);
function handleSeek(details) {
switch(details.action) {
case "seekforward":
audio.currentTime = Math.min(audio.currentTime + skipTime,
audio.duration);
break;
case "seekbackward":
audio.currentTime = Math.max(audio.currentTime - skipTime, 0);
break;
}
}
Here, the handleSeek()
function handles both seekbackward
and seekforward
actions.
Using data provided by MediaSessionActionDetails
In this example, instead of seeking a specified distance, the seekforward
and seekbackward
handlers use the time specified in the MediaSessionActionDetails
object's seekOffset
property.
navigator.mediaSession.setActionHandler("seekforward", handleSeek);
navigator.mediaSession.setActionHandler("seekbackward", handleSeek);
function handleSeek(details) {
switch(details.action) {
case "seekforward":
audio.currentTime = Math.min(audio.currentTime + details.seekOffset,
audio.duration);
break;
case "seekbackward":
audio.currentTime = Math.max(audio.currentTime - details.seekOffset, 0);
break;
}
});
Specifications
Specification | Status | Comment |
Media Session StandardThe definition of 'MediaSessionActionDetails' in that specification. | Draft | Initial definition. |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Update compatibility data on GitHub
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Chrome
Full support 73 |
Edge
Full support ≤79 |
Firefox Full support 71 Full support 71 Disabled' From version 71: this feature is behind the |
IE
? |
Opera
No support No |
Safari
? |
WebView Android
No support No |
Chrome Android
Full support 57 |
Firefox Android
No support No |
Opera Android
No support No |
Safari iOS
? |
Samsung Internet Android
Full support 7.0 |
Chrome
Full support 73 |
Edge
Full support ≤79 |
Firefox Full support 71 Full support 71 Disabled' From version 71: this feature is behind the |
IE
? |
Opera
No support No |
Safari
? |
WebView Android
No support No |
Chrome Android
Full support 57 |
Firefox Android
No support No |
Opera Android
No support No |
Safari iOS
? |
Samsung Internet Android
Full support 7.0 | |
Chrome
Full support 73 |
Edge
Full support ≤79 |
Firefox
No support No |
IE
? |
Opera
No support No |
Safari
? |
WebView Android
No support No |
Chrome Android
Full support 57 |
Firefox Android
No support No |
Opera Android
No support No |
Safari iOS
? |
Samsung Internet Android
Full support 7.0 | |
Chrome
Full support 73 |
Edge
Full support ≤79 |
Firefox Full support 76 Full support 76 Disabled' From version 76: this feature is behind the |
IE
? |
Opera
No support No |
Safari
? |
WebView Android
No support No |
Chrome Android
Full support 57 |
Firefox Android
No support No |
Opera Android
No support No |
Safari iOS
? |
Samsung Internet Android
Full support 7.0 | |
Chrome
Full support 73 |
Edge
Full support ≤79 |
Firefox
No support No |
IE
? |
Opera
No support No |
Safari
? |
WebView Android
No support No |
Chrome Android
Full support 57 |
Firefox Android
No support No |
Opera Android
No support No |
Safari iOS
? |
Samsung Internet Android
Full support 7.0 |
Legend
- Full support
- Full support
- No support
- No support
- Compatibility unknown
- Compatibility unknown
- Experimental. Expect behavior to change in the future.'
- Experimental. Expect behavior to change in the future.
- User must explicitly enable this feature.'
- User must explicitly enable this feature.
MediaSessionActionDetails by Mozilla Contributors is licensed under CC-BY-SA 2.5.