public async void SurfaceChanged(ISurfaceHolder holder, global::Android.Graphics.Format format, int width, int height)
{
if (!HasValidSurface)
{
return;
}
// portrait mode
if (height > width)
{
CameraService.SetViewSize(height, width);
}
else
{
CameraService.SetViewSize(width, height);
}
if (!Element.IsEnabled)
{
return;
}
CameraService.HaltPreview();
await Task.Run(() => {
CameraService.StartPreview(holder);
});
}
protected async override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
if (e.PropertyName == Xamarin.Forms.VisualElement.IsEnabledProperty.PropertyName)
{
if (Element.IsEnabled)
{
InitializeView();
}
if (!Element.IsEnabled)
{
ReleaseCamera();
}
}
if (e.PropertyName == BarcodeScanner.PreviewActiveProperty.PropertyName)
{
if (Element.PreviewActive)
{
await Task.Run(() => CameraService.StartPreview(Control.Holder));
}
if (!Element.PreviewActive)
{
CameraService.HaltPreview();
}
}
if (e.PropertyName == BarcodeScanner.TorchProperty.PropertyName)
{
if (!Platform.HasFlashPermission)
{
return;
}
if (!Platform.HasFlash)
{
return;
}
CameraService.ToggleTorch(Element.Torch);
}
if (e.PropertyName == BarcodeScanner.BarcodeDecoderProperty.PropertyName)
{
if (Element.BarcodeDecoder)
{
CameraService.StartDecoder();
}
if (!Element.BarcodeDecoder)
{
CameraService.StopDecoder();
}
}
}
protected async override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
this.Debug("OnElementPropertyChanged");
if (!HasValidSurface)
{
return;
}
if (e.PropertyName == BarcodeScanner.IsEnabledProperty.PropertyName)
{
this.Debug("Enabled [{0}]", Element.IsEnabled);
if (Element.IsEnabled && HasValidSurface)
{
await Task.Run(() => CameraService.OpenCamera());
}
if (!Element.IsEnabled)
{
ReleaseCamera();
}
}
if (e.PropertyName == BarcodeScanner.PreviewActiveProperty.PropertyName)
{
this.Debug("ScannerActive [{0}]", Element.PreviewActive);
if (Element.PreviewActive)
{
await Task.Run(() => CameraService.StartPreview(Control.Holder));
}
if (!Element.PreviewActive)
{
CameraService.HaltPreview();
}
}
if (e.PropertyName == BarcodeScanner.TorchProperty.PropertyName)
{
if (!Platform.HasFlashPermission)
{
this.Debug("Unable to use flashlight: Android Manifest '{0}' permission not granted.", Android.Manifest.Permission.Flashlight);
return;
}
if (!Platform.HasFlash)
{
this.Debug("Unable to use flashlight: Device's camera does not support flash.");
return;
}
this.Debug("Torch [{0}]", Element.Torch);
CameraService.ToggleTorch(Element.Torch);
}
if (e.PropertyName == BarcodeScanner.BarcodeDecoderProperty.PropertyName)
{
this.Debug("Decoder state [{0}]", Element.BarcodeDecoder);
if (Element.BarcodeDecoder)
{
CameraService.StartDecoder();
}
if (!Element.BarcodeDecoder)
{
CameraService.StopDecoder();
}
}
}