detect disconnect webcam

[neda]

hi
how to detect disconnect webcam?
i use many event for detect change state of webcam but does not work.
and after disconnect camera i does not see any log.
please guide me
thanks

Camera {
                                id: camera
                                captureMode: Camera.CaptureStillImage


                                onErrorChanged: {
                                    console.log("neda");
                                }

                                onError: {
                                    console.log("neda");
                                }

                                onCameraStateChanged: {
                                    console.log("Camera State = " + camera.cameraState);
                                    if (camera.cameraState === Camera.LoadedState) {
onsole.log("neda");
                                    }

                                    if (camera.cameraState === Camera.ActiveState) {
onsole.log("neda");
                                    }
                                }

                                videoRecorder {
                                    id:vr
                                    
                                }
                           onAvailabilityChanged: {
                                    console.log("Availability: ")
                                    if (availability == camera.ResourceMissing) {
                                        console.debug("neda: " + status);
                                    }

                                }

                                onCameraStatusChanged: {
                                    console.debug("Camera status changed: " + cameraState);

                                    if (cameraStatus == camera.UnavailableStatus) {
                                        console.debug("neda: " + status);
                                    }

                                    if (cameraStatus == Camera.ActiveStatus) {

                                        var fr = camera.supportedViewfinderFrameRateRanges();
                                        fpsList.model = fr;

                                        var res = camera.supportedViewfinderResolutions(15);
                                        resolutionList.model = res;
                                    }
                                }                                


                                flash.mode: Camera.FlashRedEyeReduction
                                imageCapture {
                                    onImageCaptured: {
                                        photoPreview.source = preview
                                        stillControls.previewAvailable = true
                                        cameraUI.state = "PhotoPreview"
                                    }
                                }



                            }