// Run the precapture sequence for capturing a still image. This method should be called when
// we get a response in {@link #mCaptureCallback} from {@link #lockFocus()}.
public void RunPrecaptureSequence()
{
try
{
// This is how to tell the camera to trigger.
mPreviewRequestBuilder.Set(CaptureRequest.ControlAePrecaptureTrigger, (int)ControlAEPrecaptureTrigger.Start);
// Tell #mCaptureCallback to wait for the precapture sequence to be set.
mState = CameraConstants.CameraStates.STATE_WAITING_PRECAPTURE;
mCaptureSession.Capture(mPreviewRequestBuilder.Build(), mCaptureCallback, mBackgroundHandler);
}
catch (CameraAccessException e)
{
e.PrintStackTrace();
}
}
// Lock the focus as the first step for a still image capture.
private void LockFocus()
{
try
{
mPreviewRequestBuilder.Set(CaptureRequest.ControlAfTrigger, (int)ControlAFTrigger.Start);
// Tell #mCaptureCallback to wait for the lock.
mState = CameraConstants.CameraStates.STATE_WAITING_LOCK;
mCaptureSession.Capture(mPreviewRequestBuilder.Build(), mCaptureCallback,
mBackgroundHandler);
}
catch (CameraAccessException e)
{
e.PrintStackTrace();
}
}
// Unlock the focus. This method should be called when still image capture sequence is
// finished.
public void UnlockFocus()
{
try
{
if (mCaptureSession != null)
{
// Reset the auto-focus trigger
mPreviewRequestBuilder.Set(CaptureRequest.ControlAfTrigger, (int)ControlAFTrigger.Cancel);
SetAutoFlash(mPreviewRequestBuilder);
mCaptureSession.Capture(mPreviewRequestBuilder.Build(), mCaptureCallback,
mBackgroundHandler);
// After this, the camera will go back to the normal state of preview.
mState = CameraConstants.CameraStates.STATE_PREVIEW;
mCaptureSession.SetRepeatingRequest(mPreviewRequest, mCaptureCallback,
mBackgroundHandler);
}
}
catch (CameraAccessException e)
{
e.PrintStackTrace();
}
}
