using System;
namespace Python.Runtime
{
///
/// Managed class that provides the implementation for reflected delegate
/// types. Delegates are represented in Python by generated type objects.
/// Each of those type objects is associated an instance of this class,
/// which provides its implementation.
///
[Serializable]
internal class DelegateObject : ClassBase
{
private MethodBinder binder;
internal DelegateObject(Type tp) : base(tp)
{
binder = new MethodBinder(tp.GetMethod("Invoke"));
}
///
/// Given a PyObject pointer to an instance of a delegate type, return
/// the true managed delegate the Python object represents (or null).
///
private static Delegate GetTrueDelegate(IntPtr op)
{
var o = GetManagedObject(op) as CLRObject;
if (o != null)
{
var d = o.inst as Delegate;
return d;
}
return null;
}
internal override bool CanSubclass()
{
return false;
}
///
/// DelegateObject __new__ implementation. The result of this is a new
/// PyObject whose type is DelegateObject and whose ob_data is a handle
/// to an actual delegate instance. The method wrapped by the actual
/// delegate instance belongs to an object generated to relay the call
/// to the Python callable passed in.
///
public static IntPtr tp_new(IntPtr tp, IntPtr args, IntPtr kw)
{
var self = (DelegateObject)GetManagedObject(tp);
if (!self.type.Valid)
{
return Exceptions.RaiseTypeError(self.type.DeletedMessage);
}
Type type = self.type.Value;
if (Runtime.PyTuple_Size(args) != 1)
{
return Exceptions.RaiseTypeError("class takes exactly one argument");
}
IntPtr method = Runtime.PyTuple_GetItem(args, 0);
if (Runtime.PyCallable_Check(method) != 1)
{
return Exceptions.RaiseTypeError("argument must be callable");
}
Delegate d = PythonEngine.DelegateManager.GetDelegate(type, method);
return CLRObject.GetInstHandle(d, self.pyHandle);
}
///
/// Implements __call__ for reflected delegate types.
///
public static IntPtr tp_call(IntPtr ob, IntPtr args, IntPtr kw)
{
// TODO: add fast type check!
IntPtr pytype = Runtime.PyObject_TYPE(ob);
var self = (DelegateObject)GetManagedObject(pytype);
var o = GetManagedObject(ob) as CLRObject;
if (o == null)
{
return Exceptions.RaiseTypeError("invalid argument");
}
var d = o.inst as Delegate;
if (d == null)
{
return Exceptions.RaiseTypeError("invalid argument");
}
return self.binder.Invoke(ob, args, kw);
}
///
/// Implements __cmp__ for reflected delegate types.
///
public new static IntPtr tp_richcompare(IntPtr ob, IntPtr other, int op)
{
if (op != Runtime.Py_EQ && op != Runtime.Py_NE)
{
Runtime.XIncref(Runtime.PyNotImplemented);
return Runtime.PyNotImplemented;
}
IntPtr pytrue = Runtime.PyTrue;
IntPtr pyfalse = Runtime.PyFalse;
// swap true and false for NE
if (op != Runtime.Py_EQ)
{
pytrue = Runtime.PyFalse;
pyfalse = Runtime.PyTrue;
}
Delegate d1 = GetTrueDelegate(ob);
Delegate d2 = GetTrueDelegate(other);
if (d1 == d2)
{
Runtime.XIncref(pytrue);
return pytrue;
}
Runtime.XIncref(pyfalse);
return pyfalse;
}
}
}