CameraControl.focusAreas

This API is available on Firefox OS for privileged or certified applications only.

Summary

The focusAreas property is an Array of one or more Area objects that define where the camera will perform auto-focusing.

When set, if the array contains more objects than the number defined in CameraCapabilities.maxFocusAreas, extra objects will be ignored.

If set to null, the camera will determine the auto-focus areas by itself.

Area

Area objects are arbitrary JavaScript objects which describe an area of the sensor field. They are used in the Array presented by the focusAreas property. Each object must have the following properties:

top
A number ranging from -1000 at the topmost of the sensor to 1000 at the bottommost of the sensor.
left
A number ranging from -1000 at the leftmost of the sensor to 1000 at the rightmost of the sensor.
bottom
A number ranging from -1000 at the topmost of the sensor to 1000 at the bottommost of the sensor.
right
A number ranging from -1000 at the leftmost of the sensor to 1000 at the rightmost of the sensor.
weight
A number defining the relative importance of the area against other areas, range from 0 to 1000.

Note: Objects missing one or more of these properties will be ignored.

Syntax

JavaScript
var focus = instanceOfCameraControl.focusAreas

Value

Return an Array of one or more objects that define where the camera will perform auto-focusing.

Example

JavaScript
var options = {
  camera: navigator.mozCameras.getListOfCameras()[0]
};
 
function onSuccess( camera ) {
  var max = camera.capabilities.maxFocusAreas;

  if (max > 0) {
    camera.focusAreas = [
      {top: -500, bottom: 500, left: -500, right: 500, weight: 1000}
    ];
  }
};

navigator.mozCameras.getCamera(options, onSuccess)

Specification

Not part of any specification; however, this API should be removed when the WebRTC Capture and Stream API has been implemented.

See also

License

© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/cameracontrol/focusareas

API B2G Camera camera Firefox OS Graphics JavaScript Property Reference Référence WebAPI