using System;
using System.Reflection;
using System.Runtime.InteropServices;
namespace Python.Runtime
{
///
/// Provides the implementation for reflected interface types. Managed
/// interfaces are represented in Python by actual Python type objects.
/// Each of those type objects is associated with an instance of this
/// class, which provides the implementation for the Python type.
///
internal class InterfaceObject : ClassBase
{
internal ConstructorInfo ctor;
internal InterfaceObject(Type tp) : base(tp)
{
CoClassAttribute coclass = (CoClassAttribute)
Attribute.GetCustomAttribute(tp, cc_attr);
if (coclass != null)
{
ctor = coclass.CoClass.GetConstructor(Type.EmptyTypes);
}
}
static Type cc_attr;
static InterfaceObject()
{
cc_attr = typeof(CoClassAttribute);
}
//====================================================================
// Implements __new__ for reflected interface types.
//====================================================================
public static IntPtr tp_new(IntPtr tp, IntPtr args, IntPtr kw)
{
InterfaceObject self = (InterfaceObject)GetManagedObject(tp);
int nargs = Runtime.PyTuple_Size(args);
Type type = self.type;
Object obj;
if (nargs == 1)
{
IntPtr inst = Runtime.PyTuple_GetItem(args, 0);
CLRObject co = GetManagedObject(inst) as CLRObject;
if ((co == null) || (!type.IsInstanceOfType(co.inst)))
{
string msg = "object does not implement " + type.Name;
Exceptions.SetError(Exceptions.TypeError, msg);
return IntPtr.Zero;
}
obj = co.inst;
}
else if ((nargs == 0) && (self.ctor != null))
{
obj = self.ctor.Invoke(null);
if (obj == null || !type.IsInstanceOfType(obj))
{
Exceptions.SetError(Exceptions.TypeError,
"CoClass default constructor failed"
);
return IntPtr.Zero;
}
}
else
{
Exceptions.SetError(Exceptions.TypeError,
"interface takes exactly one argument"
);
return IntPtr.Zero;
}
return CLRObject.GetInstHandle(obj, self.pyHandle);
}
}
}