public override void ViewDidLoad()
{
base.ViewDidLoad();
// Disable UI. The UI is enabled if and only if the session starts running.
MetadataObjectTypesButton.Enabled = false;
SessionPresetsButton.Enabled = false;
CameraButton.Enabled = false;
ZoomSlider.Enabled = false;
// Add the open barcode gesture recognizer to the region of interest view.
PreviewView.AddGestureRecognizer(OpenBarcodeURLGestureRecognizer);
// Set up the video preview view.
PreviewView.Session = session;
// Check video authorization status. Video access is required and audio
// access is optional. If audio access is denied, audio is not recorded
// during movie recording.
switch (AVCaptureDevice.GetAuthorizationStatus(AVMediaType.Video))
{
case AVAuthorizationStatus.Authorized:
// The user has previously granted access to the camera.
break;
case AVAuthorizationStatus.NotDetermined:
// The user has not yet been presented with the option to grant
// video access. We suspend the session queue to delay session
// setup until the access request has completed.
sessionQueue.Suspend();
AVCaptureDevice.RequestAccessForMediaType(AVMediaType.Video, granted => {
if (!granted)
{
setupResult = SessionSetupResult.NotAuthorized;
}
sessionQueue.Resume();
});
break;
default:
// The user has previously denied access.
setupResult = SessionSetupResult.NotAuthorized;
break;
}
// Setup the capture session.
// In general it is not safe to mutate an AVCaptureSession or any of its
// inputs, outputs, or connections from multiple threads at the same time.
// Why not do all of this on the main queue?
// Because AVCaptureSession.StartRunning() is a blocking call which can
// take a long time. We dispatch session setup to the sessionQueue so
// that the main queue isn't blocked, which keeps the UI responsive.
sessionQueue.DispatchAsync(ConfigureSession);
}
void ReleaseDesignerOutlets()
{
if (CameraButton != null)
{
CameraButton.Dispose();
CameraButton = null;
}
if (CameraUnavailableLabel != null)
{
CameraUnavailableLabel.Dispose();
CameraUnavailableLabel = null;
}
if (MetadataObjectTypesButton != null)
{
MetadataObjectTypesButton.Dispose();
MetadataObjectTypesButton = null;
}
if (PreviewView != null)
{
PreviewView.Dispose();
PreviewView = null;
}
if (SessionPresetsButton != null)
{
SessionPresetsButton.Dispose();
SessionPresetsButton = null;
}
if (ZoomSlider != null)
{
ZoomSlider.Dispose();
ZoomSlider = null;
}
}
public override void ViewWillTransitionToSize(CGSize toSize, IUIViewControllerTransitionCoordinator coordinator)
{
base.ViewWillTransitionToSize(toSize, coordinator);
var videoPreviewLayerConnection = PreviewView.VideoPreviewLayer.Connection;
if (videoPreviewLayerConnection != null)
{
var deviceOrientation = UIDevice.CurrentDevice.Orientation;
if (!deviceOrientation.IsPortrait() && !deviceOrientation.IsLandscape())
{
return;
}
var newVideoOrientation = VideoOrientationFor(deviceOrientation);
var oldSize = View.Frame.Size;
var oldVideoOrientation = videoPreviewLayerConnection.VideoOrientation;
videoPreviewLayerConnection.VideoOrientation = newVideoOrientation;
// When we transition to the new size, we need to adjust the region
// of interest's origin and size so that it stays anchored relative
// to the camera.
coordinator.AnimateAlongsideTransition(context => {
var oldRegion = PreviewView.RegionOfInterest;
var newRegion = new CGRect();
if (oldVideoOrientation == LandscapeRight && newVideoOrientation == LandscapeLeft)
{
newRegion = oldRegion.WithX(oldSize.Width - oldRegion.X - oldRegion.Width);
}
else if (oldVideoOrientation == LandscapeRight && newVideoOrientation == Portrait)
{
newRegion.X = toSize.Width - oldRegion.Y - oldRegion.Height;
newRegion.Y = oldRegion.X;
newRegion.Width = oldRegion.Height;
newRegion.Height = oldRegion.Width;
}
else if (oldVideoOrientation == LandscapeLeft && newVideoOrientation == LandscapeRight)
{
newRegion = oldRegion.WithX(oldSize.Width - oldRegion.X - oldRegion.Width);
}
else if (oldVideoOrientation == LandscapeLeft && newVideoOrientation == Portrait)
{
newRegion.X = oldRegion.Y;
newRegion.Y = oldSize.Width - oldRegion.X - oldRegion.Width;
newRegion.Width = oldRegion.Height;
newRegion.Height = oldRegion.Width;
}
else if (oldVideoOrientation == Portrait && newVideoOrientation == LandscapeRight)
{
newRegion.X = oldRegion.Y;
newRegion.Y = toSize.Height - oldRegion.X - oldRegion.Width;
newRegion.Width = oldRegion.Height;
newRegion.Height = oldRegion.Width;
}
else if (oldVideoOrientation == Portrait && newVideoOrientation == LandscapeLeft)
{
newRegion.X = oldSize.Height - oldRegion.Y - oldRegion.Height;
newRegion.Y = oldRegion.X;
newRegion.Width = oldRegion.Height;
newRegion.Height = oldRegion.Width;
}
PreviewView.SetRegionOfInterestWithProposedRegionOfInterest(newRegion);
}, context => {
sessionQueue.DispatchAsync(() => {
metadataOutput.RectOfInterest = PreviewView.VideoPreviewLayer.MapToLayerCoordinates(PreviewView.RegionOfInterest);
});
// Remove the old metadata object overlays.
RemoveMetadataObjectOverlayLayers();
});
}
}