Added wxVariantData::Clone and wxVariant::Unshare

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@49246 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/variant.h

@@ -81,6 +81,10 @@ public:
     // If it based on wxObject return the ClassInfo.
     virtual wxClassInfo* GetValueClassInfo() { return NULL; }
 
+    // Implement this to make wxVariant::AllocExcusive work. Returns
+    // a copy of the data.
+    virtual wxVariantData* Clone() const { return NULL; }
+
     void IncRef() { m_count++; }
     void DecRef()
     {
@@ -104,7 +108,7 @@ private:
  * wxVariant can store any kind of data, but has some basic types
  * built in.
  */
- 
+
 class WXDLLIMPEXP_FWD_BASE wxVariant;
 
 WX_DECLARE_LIST_WITH_DECL(wxVariant, wxVariantList, class WXDLLIMPEXP_BASE);
@@ -146,6 +150,9 @@ public:
     // destroy a reference
     void UnRef();
 
+    // ensure that the data is exclusive to this variant, and not shared
+    bool Unshare();
+
     // Make NULL (i.e. delete the data)
     void MakeNull();
 
@@ -365,6 +372,8 @@ public:\
 \
     virtual wxString GetType() const; \
     virtual wxClassInfo* GetValueClassInfo(); \
+\
+    virtual wxVariantData* Clone() const { return new classname##VariantData(m_value); } \
 \
 protected:\
     classname m_value; \
@@ -436,6 +445,9 @@ bool classname##VariantData::Eq(wxVariantData& data) const \
     ((classname*)(var.IsValueKindOf(&classname::ms_classInfo) ?\
                   var.GetWxObjectPtr() : NULL));
 
+// Replacement for using wxDynamicCast on a wxVariantData object
+#define wxDynamicCastVariantData(data, classname) dynamic_cast<classname*>(data)
+
 extern wxVariant WXDLLIMPEXP_BASE wxNullVariant;
 
 #endif // wxUSE_VARIANT