public abstract bool MatchesCriteria(Dimensions dimensions);
public Dimensions ReadDimensions(Stream byteStream)
{
byteStream.Seek(0, SeekOrigin.Begin);
List <HashNode <FileType> > relevantHashNodes = new List <HashNode <FileType> >();
while (InternalFileType == FileType.UNKNOWN)
{
int readByte = byteStream.ReadByte();
if (readByte == -1)
{
throw new HeaderNotFoundException("Header not found in stream.");
}
HashNode <FileType> hashNode;
for (int i = 0; i < relevantHashNodes.Count; i++)
{
hashNode = relevantHashNodes[i].GetFirstKey((byte)readByte);
if (hashNode != null)
{
if (hashNode.HasValue)
{
InternalFileType = hashNode.Value;
break;
}
else
{
relevantHashNodes[i] = hashNode;
}
}
else
{
relevantHashNodes.RemoveAt(i);
i--;
}
}
hashNode = HeaderMap.GetFirstKey((byte)readByte);
if (hashNode != null)
{
relevantHashNodes.Add(hashNode);
}
}
Dimensions dimensions = Dimensions.None;
switch (InternalFileType)
{
case FileType.PNG:
dimensions = ReadPngDimensions(byteStream);
break;
case FileType.JPG:
dimensions = ReadJpgDimensions(byteStream);
break;
default:
Console.WriteLine("Found currently unsupported filetype");
break;
}
EndOfMetadataIndex = byteStream.Position;
if (byteStream.ReadByte() == -1)
{
throw new HeaderNotFoundException("Header only partially present in stream.");
}
if (dimensions.Width < 0 || dimensions.Height < 0)
{
Console.WriteLine("Bad negative value found - Width: " + dimensions.Width + " Height: " + dimensions.Height);
}
return(dimensions);
}