The ConstrainDouble type is used to specify a constraint for a property whose value is a double-precision floating-point number. It extends the DoubleRange dictionary (which provides the ability to specify a permitted range of property values) to also support an exact value and/or an ideal value the property should take on. Additionally, you can specify the property's value as a simple floating-point value, in which case the user agent does its best to match the value once all other more stringent constraints are met.
Properties
If the value of a ConstrainDouble is an object rather than a number, it may have the properties below in addition the properties it inherits from DoubleRange.
exact- A double-precision floating-point number specifying a specific, required, value the property must have to be considered acceptable.
ideal- A double-precision floating-point number specifying a value the property would ideally have, but which can be considered optional if necessary to find a match.
Specifications
| Specification | Status | Comment |
| Media Capture and StreamsThe definition of 'ConstrainDouble' in that specification. | Candidate Recommendation | Initial definition |
Technically, ConstrainDouble is actually based on an intermediary dictionary named ConstrainDoubleRange, which adds exact and ideal to DoubleRange, with ConstrainDouble being a type that can be either a long integer or a DoubleRange. However, for the sake of documentation clarity, the intermediate type (present only because of quirks in WebIDL syntax) is ignored here.
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 | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
ConstrainDouble
|
Chrome
Full support Yes |
Edge
Full support ≤79 |
Firefox
Full support 50 |
IE
No support No |
Opera
Full support Yes |
Safari
? |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support 50 |
Opera Android
Full support Yes |
Safari iOS
? |
Samsung Internet Android
Full support Yes |
Legend
- Full support
- Full support
- No support
- No support
- Compatibility unknown
- Compatibility unknown
See also
- Media Capture and Streams API
- Capabilities, constraints, and settings
DoubleRangeMediaTrackConstraintsMediaTrackCapabilitiesMediaTrackSupportedConstraints
ConstrainDouble by Mozilla Contributors is licensed under CC-BY-SA 2.5.
