[glibmm] Gio::TlsClientConnection: Make the class work correctly.

[José Alburquerque <jaalburqu src gnome org>]

commit ed95a3b5ddfb036e91be5d868e74f23ba304f37b
Author: José Alburquerque <jaalburqu svn gnome org>
Date:   Sun Apr 7 16:40:12 2013 -0400

    Gio::TlsClientConnection: Make the class work correctly.
    
        * tools/m4/class_interface.m4 (_CUSTOM_CTOR_CAST): Add a new macro so
        that classes wrapped by the _CLASS_INTERFACE() macro can implement a
        custom cast constructor.  This is so that classes like
        Tls[Client|Server]Connection, that derive from Glib::Interface but
        should also derive from a Glib::Object derived type, though they do
        not do so in the C API, don't produce warnings from an attempt to set
        the non-existent properties of the GObject derived type when an
        attempt to construct the C object is made in the default Glib::Object
        constructor.  Glib::wrap_auto_interface<>(), which is called by
        Glib::wrap() for interfaces, uses the cast constructor to create the
        wrapper which calls the cast constructor of Glib::Interface.  If the
        Glib::Object derived base class of the wrapper has a default
        constructor, that constructor is then called which leads to the
        Glib::Object default constructor being called, which tries to
        construct the C object and set its properties thus producing the
        property setting warnings.  A custom cast constructor can chain up to
        the cast constructor of the Glib::Object derived type thus avoiding
        the call to the Glib::Object default constructor and the non-existent
        property setting warnings.
        * glib/glibmm/interface.cc:
        * glib/glibmm/interface.h (Interface): Add a default constructor so
        that in the cases above (when the cast constructor of the
        Glib::Object's derived type is used), the compiler can find a
        Glib::Interface default constructor to use.  Using the Glib::Interface
        cast constructor as well as the cast constructor of the Glib::Object
        derived type would cause "ObjectBase::initialize() called twice
        for the same GObject" errors.

 ChangeLog                       |   32 ++++++++++++++++++++++++++++++++
 gio/src/tlsclientconnection.ccg |    9 +++++++++
 gio/src/tlsclientconnection.hg  |    1 +
 glib/glibmm/interface.cc        |    4 ++++
 glib/glibmm/interface.h         |    4 ++++
 tools/m4/class_interface.m4     |   11 +++++++++++
 6 files changed, 61 insertions(+), 0 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index ce0349d..c0d14e6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,35 @@
+2013-04-07  José Alburquerque  <jaalburquerque gmail com>
+
+       Gio::TlsClientConnection: Make the class work correctly.
+
+       * tools/m4/class_interface.m4 (_CUSTOM_CTOR_CAST): Add a new macro so
+       that classes wrapped by the _CLASS_INTERFACE() macro can implement a
+       custom cast constructor.  This is so that classes like
+       Tls[Client|Server]Connection, that derive from Glib::Interface but
+       should also derive from a Glib::Object derived type, though they do
+       not do so in the C API, don't produce warnings from an attempt to set
+       the non-existent properties of the GObject derived type when an
+       attempt to construct the C object is made in the default Glib::Object
+       constructor.  Glib::wrap_auto_interface<>(), which is called by
+       Glib::wrap() for interfaces, uses the cast constructor to create the
+       wrapper which calls the cast constructor of Glib::Interface.  If the
+       Glib::Object derived base class of the wrapper has a default
+       constructor, that constructor is then called which leads to the
+       Glib::Object default constructor being called, which tries to
+       construct the C object and set its properties thus producing the
+       property setting warnings.  A custom cast constructor can chain up to
+       the cast constructor of the Glib::Object derived type thus avoiding
+       the call to the Glib::Object default constructor and the non-existent
+       property setting warnings.
+       * glib/glibmm/interface.cc:
+       * glib/glibmm/interface.h (Interface): Add a default constructor so
+       that in the cases above (when the cast constructor of the
+       Glib::Object's derived type is used), the compiler can find a
+       Glib::Interface default constructor to use.  Using the Glib::Interface
+       cast constructor as well as the cast constructor of the Glib::Object
+       derived type would cause "ObjectBase::initialize() called twice
+       for the same GObject" errors.
+
 2013-04-06  Murray Cumming  <murrayc murrayc com>
 
        Add a test of implementing an interface.
diff --git a/gio/src/tlsclientconnection.ccg b/gio/src/tlsclientconnection.ccg
index 0ea183e..3033364 100644
--- a/gio/src/tlsclientconnection.ccg
+++ b/gio/src/tlsclientconnection.ccg
@@ -17,3 +17,12 @@
 
 #include <gio/gio.h>
 #include <giomm/socketconnectable.h>
+
+namespace Gio
+{
+
+TlsClientConnection::TlsClientConnection(GTlsClientConnection* castitem)
+: TlsConnection(G_TLS_CONNECTION(castitem))
+{}
+
+} // namespace Gio
diff --git a/gio/src/tlsclientconnection.hg b/gio/src/tlsclientconnection.hg
index 20c8a50..e493f56 100644
--- a/gio/src/tlsclientconnection.hg
+++ b/gio/src/tlsclientconnection.hg
@@ -42,6 +42,7 @@ class TlsClientConnection
   public TlsConnection
 {
   _CLASS_INTERFACE(TlsClientConnection, GTlsClientConnection, G_TLS_CLIENT_CONNECTION, 
GTlsClientConnectionInterface)
+  _CUSTOM_CTOR_CAST
 
 public:
   //TODO: It's not possible to use _WRAP_CTOR/_WRAP_CREATE to wrap the new
diff --git a/glib/glibmm/interface.cc b/glib/glibmm/interface.cc
index c8fde23..d8d055f 100644
--- a/glib/glibmm/interface.cc
+++ b/glib/glibmm/interface.cc
@@ -73,6 +73,10 @@ Interface::Interface(GObject* castitem)
   ObjectBase::initialize(castitem);
 }
 
+Interface::Interface()
+{
+}
+
 Interface::~Interface()
 {}
 
diff --git a/glib/glibmm/interface.h b/glib/glibmm/interface.h
index 0ff2216..0639044 100644
--- a/glib/glibmm/interface.h
+++ b/glib/glibmm/interface.h
@@ -41,6 +41,10 @@ public:
   typedef GTypeInterface  BaseClassType;
 #endif /* DOXYGEN_SHOULD_SKIP_THIS */
 
+  /** A Default constructor.
+   */
+  Interface();
+
   /** Called by constructors of derived classes. Provide the result of
    * the Class object's init() function to ensure that it is properly
    * initialized.
diff --git a/tools/m4/class_interface.m4 b/tools/m4/class_interface.m4
index 99d1d75..a2ab274 100644
--- a/tools/m4/class_interface.m4
+++ b/tools/m4/class_interface.m4
@@ -16,6 +16,14 @@ define(`__PCAST__',`(__CPARENT__`'*)')
 define(`__BOOL_IS_INTERFACE__',`1')
 
 
+dnl For classes that need custom code in their cast constructor.
+define(`_CUSTOM_CTOR_CAST',`dnl
+_PUSH()
+dnl Define this macro to be tested for later.
+define(`__BOOL_CUSTOM_CTOR_CAST__',`$1')
+_POP()
+')
+
 _POP()
 _SECTION(SECTION_CLASS2)
 ') dnl end of _CLASS_INTERFACE
@@ -178,10 +186,13 @@ __CPPNAME__::__CPPNAME__`'()
   __CPPPARENT__`'(__BASE__`'_class_.init())
 {}
 
+ifdef(`__BOOL_CUSTOM_CTOR_CAST__',`dnl
+',`dnl
 __CPPNAME__::__CPPNAME__`'(__CNAME__* castitem)
 :
   __CPPPARENT__`'(__PCAST__`'(castitem))
 {}
+')dnl
 
 __CPPNAME__::__CPPNAME__`'(const Glib::Interface_Class& interface_class)
 : __CPPPARENT__`'(interface_class)