private void _AddWeakCacheCallback(object sender, GetImageSourceCompletedEventArgs e)
{
if (e.Error != null || e.Cancelled)
{
return;
}
var bs = (BitmapSource)e.ImageSource;
if (_isSquarish)
{
if (e.ImageSource.Height == 0)
{
return;
}
double aspectRatio = e.ImageSource.Width / e.ImageSource.Height;
// Allow for some flexibility. This is really a special case for newsfeed filter icons and I can't really predict how Facebook is going to break things in the future.
if (aspectRatio > 1.8 && aspectRatio < 2.5)
{
// Take the right half of the image.
bs = new CroppedBitmap(bs, new Int32Rect((int)(.5 * bs.Width), 0, (int)(bs.Width * .5), (int)bs.Height));
}
else
{
// If we didn't need to do cropping then we won't in the future, so just short circuit this next time.
_isSquarish = false;
}
}
var userState = (_ImageCallbackState)e.UserState;
switch (userState.RequestedSize)
{
case FacebookImageDimensions.Big:
_bigWR = new WeakReference(bs);
break;
case FacebookImageDimensions.Normal:
_normalWR = new WeakReference(bs);
break;
case FacebookImageDimensions.Small:
_smallWR = new WeakReference(bs);
break;
case FacebookImageDimensions.Square:
_squareWR = new WeakReference(bs);
break;
}
if (userState.Callback != null)
{
userState.Callback(this, new GetImageSourceCompletedEventArgs(bs, this));
}
}
private void _ProcessNextLocalRequest(object unused)
{
while (_asyncPhotoPool != null)
{
// Retrieve the next data request for processing.
GetImageSourceAsyncCallback callback = null;
object userState = null;
object sender = null;
SmallUri ssUri = default(SmallUri);
lock (_localLock)
{
while (_activePhotoRequests.Count > 0)
{
_DataRequest nextDataRequest = _activePhotoRequests.Pop();
Assert.IsTrue(nextDataRequest.Callback is GetImageSourceAsyncCallback);
if (!nextDataRequest.Canceled)
{
sender = nextDataRequest.Sender;
callback = (GetImageSourceAsyncCallback)nextDataRequest.Callback;
userState = nextDataRequest.UserState;
ssUri = nextDataRequest.SmallUri;
break;
}
}
if (ssUri == default(SmallUri))
{
Assert.AreEqual(0, _activePhotoRequests.Count);
return;
}
}
Assert.IsNotNull(callback);
GetImageSourceCompletedEventArgs callbackArgs = null;
string localCachePath = null;
try
{
localCachePath = _GetCacheLocation(ssUri);
if (localCachePath == null)
{
callbackArgs = new GetImageSourceCompletedEventArgs(new FileNotFoundException(), false, userState);
}
else
{
using (Stream imageStream = File.Open(localCachePath, FileMode.Open, FileAccess.Read, FileShare.Read))
{
callbackArgs = new GetImageSourceCompletedEventArgs(_GetBitmapSourceFromStream(imageStream), userState);
}
}
}
catch (Exception e)
{
if (!string.IsNullOrEmpty(localCachePath))
{
// If the cache is bad try removing the file so we can fetch it correctly next time.
try
{
File.Delete(localCachePath);
}
catch { }
}
callbackArgs = new GetImageSourceCompletedEventArgs(e, false, userState);
}
_callbackDispatcher.BeginInvoke(callback, sender, callbackArgs);
}
}
