private void startIfReady()
{
try
{
if (mStartRequested && mSurfaceAvailable)
{
mCameraSource.Start(mSurfaceView.Holder);
if (mOverlay != null)
{
Android.Gms.Common.Images.Size size = mCameraSource.PreviewSize;
int min = Math.Min(size.Width, size.Height);
int max = Math.Max(size.Width, size.Height);
if (IsPortraitMode())
{
// Swap width and height sizes when in portrait, since it will be rotated by
// 90 degrees
mOverlay.SetCameraInfo(min, max, mCameraSource.CameraFacing);
}
else
{
mOverlay.SetCameraInfo(max, min, mCameraSource.CameraFacing);
}
mOverlay.Clear();
}
mStartRequested = false;
}
}
catch (IOException ex)
{
}
}
protected override void OnLayout(bool changed, int left, int top, int right, int bottom)
{
int previewWidth = 320;
int previewHeight = 240;
if (mCameraSource != null)
{
Android.Gms.Common.Images.Size size = mCameraSource.PreviewSize;
if (size != null)
{
previewWidth = size.Width;
previewHeight = size.Height;
}
}
// Swap width and height sizes when in portrait, since it will be rotated 90 degrees
if (IsPortraitMode())
{
int tmp = previewWidth;
previewWidth = previewHeight;
previewHeight = tmp;
}
int viewWidth = right - left;
int viewHeight = bottom - top;
int childWidth;
int childHeight;
int childXOffset = 0;
int childYOffset = 0;
float widthRatio = (float)viewWidth / (float)previewWidth;
float heightRatio = (float)viewHeight / (float)previewHeight;
// To fill the view with the camera preview, while also preserving the correct aspect ratio,
// it is usually necessary to slightly oversize the child and to crop off portions along one
// of the dimensions. We scale up based on the dimension requiring the most correction, and
// compute a crop offset for the other dimension.
if (widthRatio > heightRatio)
{
childWidth = viewWidth;
childHeight = (int)((float)previewHeight * widthRatio);
childYOffset = (childHeight - viewHeight) / 2;
}
else
{
childWidth = (int)((float)previewWidth * heightRatio);
childHeight = viewHeight;
childXOffset = (childWidth - viewWidth) / 2;
}
for (int i = 0; i < ChildCount; ++i)
{
// One dimension will be cropped. We shift child over or up by this offset and adjust
// the size to maintain the proper aspect ratio.
GetChildAt(i).Layout(
-1 * childXOffset, -1 * childYOffset,
childWidth - childXOffset, childHeight - childYOffset);
}
try
{
startIfReady();
}
catch (IOException e)
{
Log.Error(TAG, "Could not start camera source.", e);
}
}
