private static FrameMetadata GetFrameMetadata(BitmapDecoder decoder, GifFile gifMetadata, int frameIndex)
{
if (gifMetadata != null && gifMetadata.Frames.Count > frameIndex)
{
return(GetFrameMetadata(gifMetadata.Frames[frameIndex]));
}
return(GetFrameMetadata(decoder.Frames[frameIndex]));
}
private static Int32Size GetFullSize(BitmapDecoder decoder, GifFile gifMetadata)
{
if (gifMetadata != null)
{
var lsd = gifMetadata.Header.LogicalScreenDescriptor;
return(new Int32Size(lsd.Width, lsd.Height));
}
int width = decoder.Metadata.GetQueryOrDefault("/logscrdesc/Width", 0);
int height = decoder.Metadata.GetQueryOrDefault("/logscrdesc/Height", 0);
return(new Int32Size(width, height));
}
private static RepeatBehavior GetActualRepeatBehavior(System.Windows.Controls.Image imageControl, BitmapDecoder decoder, GifFile gifMetadata)
{
// If specified explicitly, use this value
var repeatBehavior = GetRepeatBehavior(imageControl);
if (repeatBehavior != default(RepeatBehavior))
{
return(repeatBehavior);
}
int repeatCount;
if (gifMetadata != null)
{
repeatCount = gifMetadata.RepeatCount;
}
else
{
repeatCount = GetRepeatCount(decoder);
}
if (repeatCount == 0)
{
return(RepeatBehavior.Forever);
}
return(new RepeatBehavior(repeatCount));
}
private static BitmapDecoder GetDecoder(BitmapSource image, out GifFile gifFile)
{
gifFile = null;
BitmapDecoder decoder = null;
Stream stream = null;
Uri uri = null;
BitmapCreateOptions createOptions = BitmapCreateOptions.None;
if (image is BitmapImage bmp)
{
createOptions = bmp.CreateOptions;
if (bmp.StreamSource != null)
{
stream = bmp.StreamSource;
}
else if (bmp.UriSource != null)
{
uri = bmp.UriSource;
if (bmp.BaseUri != null && !uri.IsAbsoluteUri)
{
uri = new Uri(bmp.BaseUri, uri);
}
}
}
else
{
if (image is BitmapFrame frame)
{
decoder = frame.Decoder;
Uri.TryCreate(frame.BaseUri, frame.ToString(), out uri);
}
}
if (decoder == null)
{
if (stream != null)
{
stream.Position = 0;
decoder = BitmapDecoder.Create(stream, createOptions, BitmapCacheOption.OnLoad);
}
else if (uri != null && uri.IsAbsoluteUri)
{
decoder = BitmapDecoder.Create(uri, createOptions, BitmapCacheOption.OnLoad);
}
}
if (decoder is GifBitmapDecoder && !CanReadNativeMetadata(decoder))
{
if (stream != null)
{
stream.Position = 0;
gifFile = GifFile.ReadGifFile(stream, true);
}
else if (uri != null)
{
gifFile = DecodeGifFile(uri);
}
else
{
throw new InvalidOperationException("Can't get URI or Stream from the source. AnimatedSource should be either a BitmapImage, or a BitmapFrame constructed from a URI.");
}
}
if (decoder == null)
{
throw new InvalidOperationException("Can't get a decoder from the source. AnimatedSource should be either a BitmapImage or a BitmapFrame.");
}
return(decoder);
}