Refactor wxXRC to allow defining handlers outside of xrc library.

Split wxXmlResourceHandler into an ABC and the real implementation to allow
referencing the ABC in the core library itself but without pulling in all of
the XRC into it. This also allows defining XRC handlers, which only depend on
this ABC and not the xrc library, in other libraries, such as richtext, as
demonstrated by the now enabled wxRichTextXMLHandler.

Closes #10996.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72727 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/xrc/xmlres.h

@@ -31,6 +31,8 @@
 
 #include "wx/xml/xml.h"
 
+#include "wx/xrc/xmlreshandler.h"
+
 class WXDLLIMPEXP_FWD_BASE wxFileName;
 
 class WXDLLIMPEXP_FWD_CORE wxIconBundle;
@@ -43,7 +45,6 @@ class WXDLLIMPEXP_FWD_CORE wxWindow;
 class WXDLLIMPEXP_FWD_CORE wxFrame;
 class WXDLLIMPEXP_FWD_CORE wxToolBar;
 
-class WXDLLIMPEXP_FWD_XRC wxXmlResourceHandler;
 class WXDLLIMPEXP_FWD_XRC wxXmlSubclassFactory;
 class wxXmlSubclassFactories;
 class wxXmlResourceModule;
@@ -393,7 +394,7 @@ private:
     // domain to pass to translation functions, if any.
     wxString m_domain;
 
-    friend class wxXmlResourceHandler;
+    friend class wxXmlResourceHandlerImpl;
     friend class wxXmlResourceModule;
     friend class wxIdRangeManager;
     friend class wxIdRange;
@@ -443,18 +444,20 @@ private:
 #define XRCSIZERITEM(window, id) \
     ((window).GetSizer() ? (window).GetSizer()->GetItemById(XRCID(id)) : NULL)
 
-// wxXmlResourceHandler is an abstract base class for resource handlers
-// capable of creating a control from an XML node.
 
-class WXDLLIMPEXP_XRC wxXmlResourceHandler : public wxObject
+// wxXmlResourceHandlerImpl is the back-end of the wxXmlResourceHander class to
+// really implementing all its functionality. It is defined in the "xrc"
+// library unlike wxXmlResourceHandler itself which is defined in "core" to
+// allow inheriting from it in the code from the other libraries too.
+
+class WXDLLIMPEXP_XRC wxXmlResourceHandlerImpl : public wxXmlResourceHandlerImplBase
 {
-DECLARE_ABSTRACT_CLASS(wxXmlResourceHandler)
 public:
     // Constructor.
-    wxXmlResourceHandler();
+    wxXmlResourceHandlerImpl(wxXmlResourceHandler *handler);
 
     // Destructor.
-    virtual ~wxXmlResourceHandler() {}
+    virtual ~wxXmlResourceHandlerImpl() {}
 
     // Creates an object (menu, dialog, control, ...) from an XML node.
     // Should check for validity.
@@ -465,33 +468,12 @@ public:
     wxObject *CreateResource(wxXmlNode *node, wxObject *parent,
                              wxObject *instance);
 
-    // This one is called from CreateResource after variables
-    // were filled.
-    virtual wxObject *DoCreateResource() = 0;
-
-    // Returns true if it understands this node and can create
-    // a resource from it, false otherwise.
-    virtual bool CanHandle(wxXmlNode *node) = 0;
-
-    // Sets the parent resource.
-    void SetParentResource(wxXmlResource *res) { m_resource = res; }
-
-protected:
-    wxXmlResource *m_resource;
-    wxArrayString m_styleNames;
-    wxArrayInt m_styleValues;
-
-    // Variables (filled by CreateResource)
-    wxXmlNode *m_node;
-    wxString m_class;
-    wxObject *m_parent, *m_instance;
-    wxWindow *m_parentAsWindow;
 
     // --- Handy methods:
 
     // Returns true if the node has a property class equal to classname,
     // e.g. <object class="wxDialog">.
-    static bool IsOfClass(wxXmlNode *node, const wxString& classname);
+    bool IsOfClass(wxXmlNode *node, const wxString& classname) const;
 
     // Gets node content from wxXML_ENTITY_NODE
     // The problem is, <tag>content<tag> is represented as
@@ -512,13 +494,6 @@ protected:
     // Returns the parameter value from given node.
     wxString GetParamValue(const wxXmlNode* node);
 
-    // Add a style flag (e.g. wxMB_DOCKABLE) to the list of flags
-    // understood by this handler.
-    void AddStyle(const wxString& name, int value);
-
-    // Add styles common to all wxWindow-derived classes.
-    void AddWindowStyles();
-
     // Gets style flags from text in form "flag | flag2| flag3 |..."
     // Only understands flags added with AddStyle
     int GetStyle(const wxString& param = wxT("style"), int defaults = 0);
@@ -611,12 +586,11 @@ protected:
 
     // Creates a resource from a node.
     wxObject *CreateResFromNode(wxXmlNode *node,
-                                wxObject *parent, wxObject *instance = NULL)
-        { return m_resource->CreateResFromNode(node, parent, instance); }
+                                wxObject *parent, wxObject *instance = NULL);
 
     // helper
 #if wxUSE_FILESYSTEM
-    wxFileSystem& GetCurFileSystem() { return m_resource->GetCurFileSystem(); }
+    wxFileSystem& GetCurFileSystem();
 #endif
 
     // reports input error at position 'context'
@@ -630,8 +604,6 @@ protected:
 
 // Programmer-friendly macros for writing XRC handlers:
 
-#define XRC_ADD_STYLE(style) AddStyle(wxT(#style), style)
-
 #define XRC_MAKE_INSTANCE(variable, classname) \
    classname *variable = NULL; \
    if (m_instance) \