re-organise the Help System functions into a class as static methods for future utility

src/widgets/ErrorDialog.cpp

@@ -147,7 +147,7 @@ void ErrorDialog::OnHelp(wxCommandEvent & WXUNUSED(event))
 {
    if( dhelpURL.StartsWith(wxT("innerlink:")) )
    {
-      ShowHtmlText(
+      HelpSystem::ShowHtmlText(
          this,
          TitleText(dhelpURL.Mid( 10 ) ),
          HelpText( dhelpURL.Mid( 10 )),

src/widgets/HelpSystem.cpp

@@ -37,7 +37,7 @@
 /// Mostly we use this so that we have the code for resizability
 /// in one place.  Other considerations like screen readers are also
 /// handled by having the code in one place.
-void ShowInfoDialog( wxWindow *parent,
+void HelpSystem::ShowInfoDialog( wxWindow *parent,
                      const wxString &dlogTitle,
                      const wxString &shortMsg,
                      const wxString &message,
@@ -77,7 +77,7 @@ void ShowInfoDialog( wxWindow *parent,
    dlog.ShowModal();
 }
 
-void ShowHtmlText(wxWindow *pParent,
+void HelpSystem::ShowHtmlText(wxWindow *pParent,
                   const wxString &Title,
                   const wxString &HtmlText,
                   bool bIsFile = false, bool bModal = false)
@@ -164,7 +164,7 @@ void ShowHtmlText(wxWindow *pParent,
    return;
 }
 
-void ShowHelpDialog(wxWindow *parent,
+void HelpSystem::ShowHelpDialog(wxWindow *parent,
                     const wxString &localFileName,
                     const wxString &remoteURL)
 {

src/widgets/HelpSystem.h

@@ -18,25 +18,34 @@
 
 class AudacityProject;
 
-/// Displays cutable information in a text ctrl, with an OK button.
-void ShowInfoDialog( wxWindow *parent,
+/** @brief Class which contains static methods and data needed for implementing
+ * help buttons
+ *
+ * This class should be the only place in the codebase where the location of
+ * the online copy of the Audacity manual is stored, so that it can be 
+ * changed if required
+ */
+class HelpSystem
+{
+public:
+   /// Displays cutable information in a text ctrl, with an OK button.
+   static void ShowInfoDialog( wxWindow *parent,
                      const wxString &dlogTitle,
                      const wxString &shortMsg,
                      const wxString &message, 
                      const int xSize, const int ySize);
 
-/// Displays a new window with wxHTML help.
-void ShowHtmlText( wxWindow * pParent, 
+   /// Displays a new window with wxHTML help.
+   static void ShowHtmlText( wxWindow * pParent, 
                    const wxString &Title,
                    const wxString &HtmlText,
                    bool bIsFile, bool bModal);
 
-/// Displays a file in your browser, if it's available locally,
-/// OR else links to the internet.
-void ShowHelpDialog(wxWindow *parent,
+   /// Displays a file in your browser, if it's available locally,
+   /// OR else links to the internet.
+   static void ShowHelpDialog(wxWindow *parent,
                      const wxString &localFileName,
                      const wxString &remoteURL);
-
-
+};
 
 #endif // __AUDACITY_HELPSYSTEM__

src/widgets/LinkingHtmlWindow.cpp

@@ -99,7 +99,7 @@ void LinkingHtmlWindow::OnLinkClicked(const wxHtmlLinkInfo& link)
          wxFileName( FileNames::HtmlHelpDir(), href.Mid( 10 ) + wxT(".htm") ).GetFullPath();
       if( wxFileExists( FileName ) )
       {
-         ShowHelpDialog(NULL, FileName, wxT(""));
+         HelpSystem::ShowHelpDialog(NULL, FileName, wxT(""));
          return;
       }
       else