Forbid creation of wxStandardPaths object directly.

This happens to work under MSW and Unix where there is only one
wxStandardPaths class for both the console and the GUI applications but
doesn't return the correct result under OS X where the Core Foundation
version, returned by wxStandardPaths::Get(), has to be used for the GUI
programs. And historically this confused a lot of people, so just ensure that
they can't accidentally create an object of the wrong type any more.

Closes #13537.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74428 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -408,6 +408,10 @@ Changes in behaviour which may result in compilation errors
   any more. Use wxBookCtrlEvent in your code if you need to forward-declare
   it or just include the appropriate header instead of forward declaration.
 
+- wxStandardPaths class can't be created now. This was never the right thing
+  to do, wxStandardPaths::Get() always had to be used to access the global
+  object of the correct type but now doing it results in a compilation error.
+
 
 Deprecated methods and their replacements
 -----------------------------------------

include/wx/msw/stdpaths.h

@@ -19,10 +19,6 @@
 class WXDLLIMPEXP_BASE wxStandardPaths : public wxStandardPathsBase
 {
 public:
-    // ctor calls IgnoreAppBuildSubDirs() and also sets up the object to use
-    // both vendor and application name by default
-    wxStandardPaths();
-
     // implement base class pure virtuals
     virtual wxString GetExecutablePath() const;
     virtual wxString GetConfigDir() const;
@@ -67,6 +63,13 @@ public:
     static wxString MSWGetShellDir(int csidl);
 
 protected:
+    // Ctor is protected, use wxStandardPaths::Get() instead of instantiating
+    // objects of this class directly.
+    //
+    // It calls IgnoreAppBuildSubDirs() and also sets up the object to use
+    // both vendor and application name by default.
+    wxStandardPaths();
+
     // get the path corresponding to the given standard CSIDL_XXX constant
     static wxString DoGetDirectory(int csidl);
 

include/wx/os2/stdpaths.h

@@ -40,6 +40,11 @@ public:
     virtual wxString GetUserDataDir() const;
     virtual wxString GetPluginsDir() const;
 
+protected:
+    // Ctor is protected, use wxStandardPaths::Get() instead of instantiating
+    // objects of this class directly.
+    wxStandardPaths() { }
+
 private:
     static wxString m_prefix;
 };

include/wx/osx/core/stdpaths.h

@@ -35,7 +35,6 @@ typedef __CFBundle * wxCFBundleRef;
 class WXDLLIMPEXP_BASE wxStandardPathsCF : public wxStandardPathsCFBase
 {
 public:
-    wxStandardPathsCF();
     virtual ~wxStandardPathsCF();
 
     // wxMac specific: allow user to specify a different bundle
@@ -57,6 +56,10 @@ public:
     virtual wxString GetDocumentsDir() const;
 
 protected:
+    // Ctor is protected, use wxStandardPaths::Get() instead of instantiating
+    // objects of this class directly.
+    wxStandardPathsCF();
+
     // this function can be called with any of CFBundleCopyXXXURL function
     // pointer as parameter
     wxString GetFromFunc(wxCFURLRef (*func)(wxCFBundleRef)) const;

include/wx/stdpaths.h

@@ -142,9 +142,6 @@ public:
     virtual wxString GetTempDir() const;
 
 
-    // ctor for the base class
-    wxStandardPathsBase();
-
     // virtual dtor for the base class
     virtual ~wxStandardPathsBase();
 
@@ -158,6 +155,10 @@ public:
 
 
 protected:
+    // Ctor is protected as this is a base class which should never be created
+    // directly.
+    wxStandardPathsBase();
+
     // append the path component, with a leading path separator if a
     // path separator or dot (.) is not already at the end of dir
     static wxString AppendPathComponent(const wxString& dir, const wxString& component);
@@ -210,6 +211,12 @@ public:
     virtual wxString GetPluginsDir() const { return m_prefix; }
     virtual wxString GetDocumentsDir() const { return m_prefix; }
 
+protected:
+    // Ctor is protected because wxStandardPaths::Get() should always be used
+    // to access the global wxStandardPaths object of the correct type instead
+    // of creating one of a possibly wrong type yourself.
+    wxStandardPaths() { }
+
 private:
     wxString m_prefix;
 };

include/wx/unix/stdpaths.h

@@ -51,6 +51,11 @@ public:
     virtual wxString GetDocumentsDir() const;
 #endif
 
+protected:
+    // Ctor is protected, use wxStandardPaths::Get() instead of instantiating
+    // objects of this class directly.
+    wxStandardPaths() { }
+
 private:
     wxString m_prefix;
 };

interface/wx/stdpaths.h

@@ -363,5 +363,15 @@ public:
         @since 2.9.0
     */
     void UseAppInfo(int info);
+
+protected:
+    /**
+        Protected default constructor.
+
+        This constructor is protected in order to prevent creation of objects
+        of this class as Get() should be used instead to access the unique
+        global wxStandardPaths object of the correct type.
+     */
+    wxStandardPaths();
 };
 

src/common/stdpbase.cpp

@@ -36,7 +36,21 @@
 // module globals
 // ----------------------------------------------------------------------------
 
-static wxStandardPaths gs_stdPaths;
+namespace
+{
+
+// Derive a class just to be able to create it: wxStandardPaths ctor is
+// protected to prevent its misuse, but it also means we can't create an object
+// of this class directly.
+class wxStandardPathsDefault : public wxStandardPaths
+{
+public:
+    wxStandardPathsDefault() { }
+};
+
+static wxStandardPathsDefault gs_stdPaths;
+
+} // anonymous namespace
 
 // ============================================================================
 // implementation

src/osx/core/utilsexc_cf.cpp

@@ -156,9 +156,19 @@ wxEventLoopSourcesManagerBase* wxGUIAppTraits::GetEventLoopSourcesManager()
 // NOTE: This doesn't really belong here but this was a handy file to
 // put it in because it's already compiled for wxCocoa and wxMac GUI lib.
 #if wxUSE_STDPATHS
-static wxStandardPathsCF gs_stdPaths;
 wxStandardPaths& wxGUIAppTraits::GetStandardPaths()
 {
+    // Derive a class just to be able to create it: wxStandardPaths ctor is
+    // protected to prevent its misuse, but it also means we can't create an
+    // object of this class directly.
+    class wxStandardPathsDefault : public wxStandardPathsCF
+    {
+    public:
+        wxStandardPathsDefault() { }
+    };
+
+    static wxStandardPathsDefault gs_stdPaths;
+
     return gs_stdPaths;
 }
 #endif