Parameters-Focus

Focus

The focus modes can be controlled using this extension.

The available focus modes are defined in the CameraParameters class:

  • CameraParameters.FOCUS_MODE_LOCKED: The focal length is fixed
  • CameraParameters.FOCUS_MODE_AUTO: The camera does a single scan focus then reverts to locked
  • CameraParameters.FOCUS_MODE_CONTINUOUS: The camera continuously auto-focuses as needed

Availability

Focus modes aren't available on all devices so it's important that you check whether the device supports the mode before attempting to set it.

if (device.isFocusSupported( CameraParameters.FOCUS_MODE_CONTINUOUS ))
{
// Continuous focus mode is supported
}

Changing Modes

To set the focus simply call setFocusMode with the required mode

if (device.isFocusSupported( CameraParameters.FOCUS_MODE_CONTINUOUS ))
{
device.setFocusMode( CameraParameters.FOCUS_MODE_CONTINUOUS );
}

Point of Interest

You can control the point of interest for the camera to focus on.

This property represents a point where {0,0} corresponds to the top left of the picture area, and {1,1} corresponds to the bottom right in landscape mode with the home button on the right—this applies even if the device is in portrait mode.

To set this point call the setFocusPointOfInterest() function with the point of interest required. For example to set the middle of the capture area:

device.setFocusPointOfInterest( new Point( 0.5, 0.5 ) );