My program has heavy interaction with the operating system through Win32API functions. now i want to migrate my program to run under Mono under Linux (No wine), and this requires different implementations to the interaction with the operating system.
I started designing a code that can have different implementation for difference
platform and is extensible for new future platforms.
public interface ISomeInterface
{
void SomePlatformSpecificOperation();
}
[PlatformSpecific(PlatformID.Unix)]
public class SomeImplementation : ISomeInterface
{
#region ISomeInterface Members
public void SomePlatformSpecificOperation()
{
Console.WriteLine("From SomeImplementation");
}
#endregion
}
public class PlatformSpecificAttribute : Attribute
{
private PlatformID _platform;
public PlatformSpecificAttribute(PlatformID platform)
{
_platform = platform;
}
public PlatformID
Platform
{
get { return _platform; }
}
}
public static class PlatformSpecificUtils
{
public static IEnumerable<Type> GetImplementationTypes<T>()
{
foreach (Assembly assembly in AppDomain.CurrentDomain.GetAssemblies())
{
foreach (Type type in assembly.GetTypes())
{
if (typeof(T).IsAssignableFrom(type) && type != typeof(T) && IsPlatformMatch(type))
{
yield return type;
}
}
}
}
private static bool IsPlatformMatch(Type type)
{
return GetPlatforms(type).Any(platform =>
platform == Environment.OSVersion.Platform);
}
private static IEnumerable<PlatformID> GetPlatforms(Type type)
{
return type.GetCustomAttributes(typeof(PlatformSpecificAttribute), false)
.Select(obj => ((PlatformSpecificAttribute)obj).Platform);
}
}
class Program
{
static void Main(string[] args)
{
Type first = PlatformSpecificUtils.GetImplementationTypes<ISomeInterface>().FirstOrDefault();
}
}
I see two problems with this design:
I can't force the implementations of ISomeInterface to have a PlatformSpecificAttribute.
Multiple implementations can be marked with the same PlatformID, and i dont know witch to use in the Main. Using the first one is ummm ugly.
How to solve those problems? Can you suggest another design?
