question: public void start ( ) { if ( cameras != null ) { CameraDescriptor camera = cameras . get ( currentCamera ) ; CameraView cv = getPreview ( camera ) ; if ( cv . isAvailable ( ) ) { open ( ) ; } } }
target:  Call this from onStart() of an activity or fragment, or from an equivalent point in time. If the CameraView is ready, the preview should begin; otherwise, the preview will begin after the CameraView is ready.