// ==========================================================================

// This software is subject to the provisions of the Zope Public License,

// Version 2.0 (ZPL). A copy of the ZPL should accompany this distribution.

// THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED

// WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

// WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS

// FOR A PARTICULAR PURPOSE.

// ==========================================================================

using System;

using System.Reflection;

using System.Runtime.InteropServices;

namespace Python.Runtime {

/// <summary>

/// 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.

/// </summary>

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);

}

}

}