[glibmm] Simplify VariantBase .hg code and use it in Settings.

[Murray Cumming <murrayc src gnome org>]

commit 9dfa656d7d0aff2ad7590bc74bbf9111a510adb6
Author: Murray Cumming <murrayc murrayc com>
Date:   Thu Jun 24 14:53:53 2010 +0200

    Simplify VariantBase .hg code and use it in Settings.
    
    * glib/src/variant.[hg|ccg]: Use CLASS_OPAQUE_COPYABLE() instead of
        _CLASS_GENERIC() to avoid writing some stuff manually. This seems to be OK.
        Do not include the C header in our .h file.
    * tools/m4/convert_gio.m4: Added GVariantBase conversions.
    * gio/src/settings.hg: Added get_value() and set_value().

 ChangeLog               |   10 +++++++++
 gio/src/settings.hg     |    4 +++
 glib/src/variant.ccg    |   50 ++--------------------------------------------
 glib/src/variant.hg     |   42 +++-----------------------------------
 tools/m4/convert_gio.m4 |    4 +++
 5 files changed, 25 insertions(+), 85 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 8e448b1..4df16f4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2010-06-24  Murray Cumming  <murrayc murrayc com>
+
+	Simplify VariantBase .hg code and use it in Settings.
+
+	* glib/src/variant.[hg|ccg]: Use CLASS_OPAQUE_COPYABLE() instead of
+    _CLASS_GENERIC() to avoid writing some stuff manually. This seems to be OK.
+    Do not include the C header in our .h file.
+	* tools/m4/convert_gio.m4: Added GVariantBase conversions.
+	* gio/src/settings.hg: Added get_value() and set_value().
+
 2010-06-22  Murray Cumming  <murrayc murrayc com>
 
     Clean up glib_functions.defs.
diff --git a/gio/src/settings.hg b/gio/src/settings.hg
index 1a84a84..6388338 100644
--- a/gio/src/settings.hg
+++ b/gio/src/settings.hg
@@ -16,6 +16,7 @@
  */
 
 #include <glibmm/object.h>
+#include <glibmm/variant.h>
 #include <giomm/settingsbackend.h>
 
 _DEFS(giomm,gio)
@@ -51,6 +52,9 @@ public:
 
   // FIXME: implement the GVariant stuff
 
+  _WRAP_METHOD(bool set_value(const Glib::ustring& key, const Glib::VariantBase& value),  g_settings_set_value)
+  _WRAP_METHOD(Glib::VariantBase get_value(const Glib::ustring& key), g_settings_get_value)
+
   _WRAP_METHOD(int get_int(const Glib::ustring& key) const, g_settings_get_int)
   _WRAP_METHOD(void set_int(const Glib::ustring& key, int value), g_settings_set_int)
   _WRAP_METHOD(bool get_boolean(const Glib::ustring& key) const, g_settings_get_boolean)
diff --git a/glib/src/variant.ccg b/glib/src/variant.ccg
index a6a2d8d..1d16e4c 100644
--- a/glib/src/variant.ccg
+++ b/glib/src/variant.ccg
@@ -16,55 +16,11 @@
  */
 
 #include <glibmm/variant.h>
+#include <glib/gvariant.h>
 
 namespace Glib
 {
 
-/**** Glib::VariantBase ****************************************************/
-
-VariantBase::VariantBase()
-  : gobject_(0)
-{
-}
-
-VariantBase::VariantBase(GVariant *castitem)
-  : gobject_(castitem)
-{
-  //TODO: It would be nice to remove a possible floating reference but the C
-  //API makes it difficult.
-  if(castitem)
-    g_variant_ref(castitem);
-}
-
-VariantBase::VariantBase(const VariantBase& other)
-{
-  // The copy constructor simply copies the underlying GVariant* and increases
-  // its reference.  The reference is decreased upon destruction.
-  gobject_ = other.gobject_;
-
-  if(gobject_)
-    g_variant_ref(gobject_);
-}
-
-VariantBase& VariantBase::operator=(const VariantBase& other)
-{
-  // Check against self-assignment and simply copy the underlying GVariant*,
-  // increasing its reference.
-  if( this != &other)
-  {
-    gobject_ = other.gobject_;
-
-    if(gobject_)
-      g_variant_ref(gobject_);
-  }
-  return *this;
-}
-
-VariantBase::~VariantBase()
-{
-  if(gobject_)
-    g_variant_unref(gobject_);
-}
 
 /****************** Specializations ***********************************/
 
@@ -74,9 +30,9 @@ const GVariantType* Variant<VariantBase>::variant_type()
   return G_VARIANT_TYPE_VARIANT;
 }
 
-Variant<VariantBase> Variant<VariantBase>::create(VariantBase& data)
+Variant<VariantBase> Variant<VariantBase>::create(const VariantBase& data)
 {
-  return Variant<VariantBase>(g_variant_new_variant(data.gobj()));
+  return Variant<VariantBase>(g_variant_new_variant(const_cast<GVariant*>(data.gobj())));
 }
 
 VariantBase Variant<VariantBase>::get() const
diff --git a/glib/src/variant.hg b/glib/src/variant.hg
index b1da904..eba1763 100644
--- a/glib/src/variant.hg
+++ b/glib/src/variant.hg
@@ -18,7 +18,6 @@
 _DEFS(glibmm,glib)
 
 #include <glibmmconfig.h>
-#include <glib/gvariant.h>
 #include <glibmm/ustring.h>
 
 namespace Glib
@@ -40,47 +39,13 @@ namespace Glib
  */
 class VariantBase
 {
-  _CLASS_GENERIC(VariantBase, GVariant)
+  _CLASS_OPAQUE_COPYABLE(VariantBase, GVariant, NONE, g_variant_ref_sink, g_variant_unref)
   _IGNORE(g_variant_ref, g_variant_ref_sink, g_variant_unref,
     g_variant_get, g_variant_get_va)
 public:
-  /** Default constructor.
-   */
-  VariantBase();
-
-  /** Constructs a VariantBase from a GVariant.
-   * @param casitem The GVariant.
-   */
-  explicit VariantBase(GVariant* castitem);
-
-  /** Copy constructor.  Since GVariant is reference counted, the copy
-   * constructor simply copies the underlying GVariant* and increases its
-   * reference count.
-   */
-  VariantBase(const VariantBase& other);
-
-  /** Assignment operator.  Since GVariant is reference counted, assignment
-   * simply copies the underlying GVariant* and increases its reference count.
-   */
-  VariantBase& operator=(const VariantBase& other);
-
-  /** Get the underlying GVariant.
-   * @return The underlying GVariant.
-   */
-  GVariant*       gobj()       { return gobject_; }
-
-  /** Get the underlying GVariant.
-   * @return The underlying GVariant.
-   */
-  const GVariant* gobj() const { return gobject_; }
 
   _WRAP_METHOD(bool is_container() const, g_variant_is_container)
   _WRAP_METHOD(GVariantClass classify() const, g_variant_classify)
-
-  virtual ~VariantBase();
-
-protected:
-  GVariant* gobject_;
 };
 
 /** Template class from which other Glib::Variant<> specializations derive.
@@ -96,7 +61,7 @@ public:
 
 
 // Each specialization has (or should have) a variant_type() method that gets
-// the type so the C function can be ignored.
+// the type. So the C g_variant_get_type() function can be ignored.
 _IGNORE(g_variant_get_type)
 
 /****************** Specializations ***********************************/
@@ -114,7 +79,8 @@ class Variant<VariantBase> : public VariantBase
   Variant<VariantBase>(GVariant* castitem) : VariantBase(castitem) { }
   static const GVariantType* variant_type() G_GNUC_CONST;
 
-  static Variant<VariantBase> create(Glib::VariantBase& data);
+  //This must have a create() method because otherwise it would be a copy constructor.
+  static Variant<VariantBase> create(const Glib::VariantBase& data);
   _IGNORE(g_variant_new_variant)
 
   VariantBase get() const;
diff --git a/tools/m4/convert_gio.m4 b/tools/m4/convert_gio.m4
index 4a6263c..0daacf3 100644
--- a/tools/m4/convert_gio.m4
+++ b/tools/m4/convert_gio.m4
@@ -130,6 +130,10 @@ _CONVERSION(`GSettings*',`Glib::RefPtr<Settings>',`Glib::wrap($3)')
 _CONVERSION(`const Glib::StringArrayHandle&',`const gchar*-const*',`($3).data()')
 _CONVERSION(`const Glib::RefPtr<SettingsBackend>&',`GSettingsBackend*',__CONVERT_REFPTR_TO_P)
 
+
+_CONVERSION(`GVariant*',`Glib::VariantBase',`Glib::wrap($3, true)')
+_CONVERSION(`const Glib::VariantBase&',`GVariant*',`const_cast<GVariant*>(($3).gobj())')
+
 #Socket
 _CONVERSION(`const Glib::RefPtr<Socket>&',`GSocket*',__CONVERT_CONST_REFPTR_TO_P)
 _CONVERSION(`GSocket*',`Glib::RefPtr<Socket>',`Glib::wrap($3)')