Preference dialog code preliminaries for View Settings project

Fix crash initializing GlobalPrefsDialog for special case of undefined temp...
  Future subclasses of PrefsDialog may choose the preferred page by other means.
  PrefsDialog can vary the title prefix string
  Allow tree structuring of the Prefs dialog pages
  Table-driven construction of Prefs dialog.  A factory for each kind of panel...

src/AudacityApp.cpp

@@ -92,6 +92,7 @@ It handles initialization and termination by subclassing wxApp.
 #include "ondemand/ODManager.h"
 #include "commands/Keyboard.h"
 #include "widgets/ErrorDialog.h"
+#include "prefs/DirectoriesPrefs.h"
 
 //temporarilly commented out till it is added to all projects
 //#include "Profiler.h"
@@ -1605,8 +1606,11 @@ bool AudacityApp::InitTempDir()
       // Failed
       wxMessageBox(_("Audacity could not find a place to store temporary files.\nPlease enter an appropriate directory in the preferences dialog."));
 
-      PrefsDialog dialog(NULL);
+      // Only want one page of the preferences
-      dialog.ShowTempDirPage();
+      DirectoriesPrefsFactory directoriesPrefsFactory;
+      PrefsDialog::Factories factories;
+      factories.push_back(&directoriesPrefsFactory);
+      GlobalPrefsDialog dialog(NULL, factories);
       dialog.ShowModal();
 
       wxMessageBox(_("Audacity is now going to exit. Please launch Audacity again to use the new temporary directory."));
@@ -2132,7 +2136,7 @@ void AudacityApp::OnMenuPreferences(wxCommandEvent & event)
    // all platforms.
 
    if(gAudacityProjects.GetCount() == 0) {
-      PrefsDialog dialog(NULL /* parent */ );
+      GlobalPrefsDialog dialog(NULL /* parent */ );
       dialog.ShowModal();
    }
    else

src/DirManager.cpp

@@ -101,7 +101,6 @@
 #include "widgets/Warning.h"
 #include "widgets/MultiDialog.h"
 
-#include "prefs/PrefsDialog.h"
 #include "ondemand/ODManager.h"
 
 #if defined(__WXMAC__)

src/Menus.cpp

@@ -3586,7 +3586,7 @@ void AudacityProject::OnExportMultiple()
 
 void AudacityProject::OnPreferences()
 {
-   PrefsDialog dialog(this /* parent */ );
+   GlobalPrefsDialog dialog(this /* parent */ );
 
    if (!dialog.ShowModal()) {
       // Canceled

src/prefs/BatchPrefs.cpp

@@ -82,3 +82,8 @@ bool BatchPrefs::Apply()
 BatchPrefs::~BatchPrefs()
 {
 }
+
+PrefsPanel *BatchPrefsFactory::Create(wxWindow *parent)
+{
+   return new BatchPrefs(parent);
+}

src/prefs/BatchPrefs.h

@@ -34,4 +34,9 @@ private:
    DECLARE_EVENT_TABLE();
 };
 
+class BatchPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif

src/prefs/DevicePrefs.cpp

@@ -373,3 +373,8 @@ bool DevicePrefs::Apply()
 
    return true;
 }
+
+PrefsPanel *DevicePrefsFactory::Create(wxWindow *parent)
+{
+   return new DevicePrefs(parent);
+}

src/prefs/DevicePrefs.h

@@ -54,4 +54,10 @@ class DevicePrefs :public PrefsPanel
    DECLARE_EVENT_TABLE();
 };
 
+class DevicePrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
+
 #endif

src/prefs/DirectoriesPrefs.cpp

@@ -242,3 +242,8 @@ bool DirectoriesPrefs::Apply()
 
    return true;
 }
+
+PrefsPanel *DirectoriesPrefsFactory::Create(wxWindow *parent)
+{
+   return new DirectoriesPrefs(parent);
+}

src/prefs/DirectoriesPrefs.h

@@ -38,4 +38,9 @@ class DirectoriesPrefs :public PrefsPanel
    DECLARE_EVENT_TABLE();
 };
 
+class DirectoriesPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif

src/prefs/EffectsPrefs.cpp

@@ -165,3 +165,8 @@ bool EffectsPrefs::Apply()
 
    return true;
 }
+
+PrefsPanel *EffectsPrefsFactory::Create(wxWindow *parent)
+{
+   return new EffectsPrefs(parent);
+}

src/prefs/EffectsPrefs.h

@@ -34,4 +34,9 @@ class EffectsPrefs :public PrefsPanel
    void PopulateOrExchange(ShuttleGui & S);
 };
 
+class EffectsPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif

src/prefs/ExtImportPrefs.cpp

@@ -780,3 +780,8 @@ void ExtImportPrefsDropTarget::SetDataObject(wxDataObject* data)
 {
    this->m_dataObject = data;
 }
+
+PrefsPanel *ExtImportPrefsFactory::Create(wxWindow *parent)
+{
+   return new ExtImportPrefs(parent);
+}

src/prefs/ExtImportPrefs.h

@@ -107,4 +107,10 @@ class ExtImportPrefs:public PrefsPanel
    DECLARE_EVENT_TABLE()
 };
 
+
+class ExtImportPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif

src/prefs/GUIPrefs.cpp

@@ -158,3 +158,8 @@ bool GUIPrefs::Apply()
 
    return true;
 }
+
+PrefsPanel *GUIPrefsFactory::Create(wxWindow *parent)
+{
+   return new GUIPrefs(parent);
+}

src/prefs/GUIPrefs.h

@@ -43,4 +43,9 @@ class GUIPrefs :public PrefsPanel
    wxArrayString mRangeChoices;
 };
 
+class GUIPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif

src/prefs/ImportExportPrefs.cpp

@@ -109,3 +109,8 @@ bool ImportExportPrefs::Apply()
 
    return true;
 }
+
+PrefsPanel *ImportExportPrefsFactory::Create(wxWindow *parent)
+{
+   return new ImportExportPrefs(parent);
+}

src/prefs/ImportExportPrefs.h

@@ -33,4 +33,9 @@ class ImportExportPrefs :public PrefsPanel
    void PopulateOrExchange(ShuttleGui & S);
 };
 
+class ImportExportPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif

src/prefs/KeyConfigPrefs.cpp

@@ -1211,3 +1211,8 @@ void KeyConfigPrefs::Cancel()
 }
 
 #endif
+
+PrefsPanel *KeyConfigPrefsFactory::Create(wxWindow *parent)
+{
+   return new KeyConfigPrefs(parent);
+}

src/prefs/KeyConfigPrefs.h

@@ -141,6 +141,12 @@ class KeyConfigPrefs:public PrefsPanel
 
    DECLARE_EVENT_TABLE();
 };
-#endif
 
 #endif
+
+class KeyConfigPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
+#endif

src/prefs/LibraryPrefs.cpp

@@ -235,3 +235,8 @@ bool LibraryPrefs::Apply()
 
    return true;
 }
+
+PrefsPanel *LibraryPrefsFactory::Create(wxWindow *parent)
+{
+   return new LibraryPrefs(parent);
+}

src/prefs/LibraryPrefs.h

@@ -46,4 +46,9 @@ class LibraryPrefs :public PrefsPanel
    DECLARE_EVENT_TABLE();
 };
 
+class LibraryPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif

src/prefs/MidiIOPrefs.cpp

@@ -284,4 +284,9 @@ bool MidiIOPrefs::Validate()
    return true;
 }
 
+PrefsPanel *MidiIOPrefsFactory::Create(wxWindow *parent)
+{
+   return new MidiIOPrefs(parent);
+}
+
 #endif

src/prefs/MidiIOPrefs.h

@@ -62,6 +62,11 @@ class MidiIOPrefs:public PrefsPanel
    DECLARE_EVENT_TABLE();
 };
 
+class MidiIOPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif
 
 #endif

src/prefs/ModulePrefs.cpp

@@ -161,5 +161,9 @@ void ModulePrefs::SetModuleStatus( wxString fname, int iStatus ){
    gPrefs->Flush();
 }
 
+PrefsPanel *ModulePrefsFactory::Create(wxWindow *parent)
+{
+   return new ModulePrefs(parent);
+}
 
 

src/prefs/ModulePrefs.h

@@ -50,4 +50,9 @@ class ModulePrefs:public PrefsPanel
    wxArrayString mPaths;
 };
 
+class ModulePrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif

src/prefs/MousePrefs.cpp

@@ -196,3 +196,8 @@ bool MousePrefs::Apply()
 //   PopulateOrExchange(S);
    return true;
 }
+
+PrefsPanel *MousePrefsFactory::Create(wxWindow *parent)
+{
+   return new MousePrefs(parent);
+}

src/prefs/MousePrefs.h

@@ -38,4 +38,9 @@ class MousePrefs :public PrefsPanel
    wxListCtrl * mList;
 };
 
+class MousePrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif

src/prefs/PlaybackPrefs.cpp

@@ -122,3 +122,8 @@ bool PlaybackPrefs::Apply()
 
    return true;
 }
+
+PrefsPanel *PlaybackPrefsFactory::Create(wxWindow *parent)
+{
+   return new PlaybackPrefs(parent);
+}

src/prefs/PlaybackPrefs.h

@@ -32,4 +32,10 @@ class PlaybackPrefs :public PrefsPanel
    void PopulateOrExchange(ShuttleGui & S);
 };
 
+class PlaybackPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
+
 #endif

src/prefs/PrefsDialog.cpp

@@ -15,6 +15,7 @@
 *//*******************************************************************/
 
 #include "../Audacity.h"
+#include "PrefsDialog.h"
 
 #include <wx/defs.h>
 #include <wx/button.h>
@@ -41,7 +42,6 @@
 #include "../Prefs.h"
 #include "../ShuttleGui.h"
 
-#include "PrefsDialog.h"
 #include "PrefsPanel.h"
 
 #include "BatchPrefs.h"
@@ -81,11 +81,14 @@ class wxTreebookExt : public wxTreebook
 {
 public:
    wxTreebookExt( wxWindow *parent,
-      wxWindowID id) : wxTreebook( parent, id )
+      wxWindowID id, const wxString &titlePrefix)
+      : wxTreebook( parent, id )
+      , mTitlePrefix(titlePrefix)
    {;};
    ~wxTreebookExt(){;};
    virtual int ChangeSelection(size_t n);
    virtual int SetSelection(size_t n);
+   const wxString mTitlePrefix;
 };
 
 
@@ -100,7 +103,7 @@ int wxTreebookExt::ChangeSelection(size_t n) {
 int wxTreebookExt::SetSelection(size_t n)
 {
    int i = wxTreebook::SetSelection(n);
-   wxString Temp = wxString(_("Preferences: ")) + GetPageText( n );
+   wxString Temp = wxString(mTitlePrefix) + GetPageText( n );
    ((wxDialog*)GetParent())->SetTitle( Temp );
    ((wxDialog*)GetParent())->SetName( Temp );
    return i;
@@ -108,11 +111,84 @@ int wxTreebookExt::SetSelection(size_t n)
 
 
 
-PrefsDialog::PrefsDialog(wxWindow * parent)
+PrefsDialog::Factories
+&PrefsDialog::DefaultFactories()
+{
+   // To do, perhaps:  create this table by registration, without including each PrefsPanel
+   // class... and thus allowing a plug-in protocol
+   static DevicePrefsFactory devicePrefsFactory;
+   static PlaybackPrefsFactory playbackPrefsFactory;
+   static RecordingPrefsFactory recordingPrefsFactory;
+#ifdef EXPERIMENTAL_MIDI_OUT
+   static MidiIOPrefsFactory midiIOPrefsFactory;
+#endif
+   static QualityPrefsFactory qualityPrefsFactory;
+   static GUIPrefsFactory guiPrefsFactory;
+   static TracksPrefsFactory tracksPrefsFactory;
+   static ImportExportPrefsFactory importExportPrefsFactory;
+   static ExtImportPrefsFactory extImportPrefsFactory;
+   static ProjectsPrefsFactory projectsPrefsFactory;
+#if !defined(DISABLE_DYNAMIC_LOADING_FFMPEG) || !defined(DISABLE_DYNAMIC_LOADING_LAME)
+   static LibraryPrefsFactory libraryPrefsFactory;
+#endif
+   static SpectrumPrefsFactory spectrumPrefsFactory;
+   static DirectoriesPrefsFactory directoriesPrefsFactory;
+   static WarningsPrefsFactory warningsPrefsFactory;
+   static EffectsPrefsFactory effectsPrefsFactory;
+#ifdef EXPERIMENTAL_THEME_PREFS
+   static ThemePrefsFactory themePrefsFactory;
+#endif
+   // static BatchPrefsFactory batchPrefsFactory;
+   static KeyConfigPrefsFactory keyConfigPrefsFactory;
+   static MousePrefsFactory mousePrefsFactory;
+#ifdef EXPERIMENTAL_MODULE_PREFS
+   static ModulePrefsFactory modulePrefsFactory;
+#endif
+
+   static PrefsNode nodes[] = {
+      &devicePrefsFactory,
+      &playbackPrefsFactory,
+      &recordingPrefsFactory,
+#ifdef EXPERIMENTAL_MIDI_OUT
+      &midiIOPrefsFactory,
+#endif
+      &qualityPrefsFactory,
+      &guiPrefsFactory,
+      &tracksPrefsFactory,
+      &importExportPrefsFactory,
+      &extImportPrefsFactory,
+      &projectsPrefsFactory,
+#if !defined(DISABLE_DYNAMIC_LOADING_FFMPEG) || !defined(DISABLE_DYNAMIC_LOADING_LAME)
+      &libraryPrefsFactory,
+#endif
+      &spectrumPrefsFactory,
+      &directoriesPrefsFactory,
+      &warningsPrefsFactory,
+      &effectsPrefsFactory,
+#ifdef EXPERIMENTAL_THEME_PREFS
+      &themePrefsFactory,
+#endif
+      // &batchPrefsFactory,
+      &keyConfigPrefsFactory,
+      &mousePrefsFactory,
+#ifdef EXPERIMENTAL_MODULE_PREFS
+      &modulePrefsFactory,
+#endif
+   };
+
+   static Factories factories(nodes, nodes + sizeof(nodes) / sizeof(nodes[0]));
+   return factories;
+}
+
+
+PrefsDialog::PrefsDialog
+  (wxWindow * parent, const wxString &titlePrefix, Factories &factories)
 :  wxDialog(parent, wxID_ANY, wxString(_("Audacity Preferences")),
             wxDefaultPosition,
             wxDefaultSize,
             wxDEFAULT_DIALOG_STYLE | wxRESIZE_BORDER)
+, mFactories(factories)
+, mTitlePrefix(titlePrefix)
 {
    ShuttleGui S(this, eIsCreating);
 
@@ -120,42 +196,36 @@ PrefsDialog::PrefsDialog(wxWindow * parent)
    {
       S.StartHorizontalLay(wxALIGN_LEFT | wxEXPAND, true);
       {
-         mCategories = new wxTreebookExt(this, wxID_ANY);
+         mCategories = new wxTreebookExt(this, wxID_ANY, mTitlePrefix);
          S.Prop(1);
          S.AddWindow(mCategories, wxEXPAND);
 
-         wxWindow *w;
+         {
+            typedef std::pair<int, int> IntPair;
+            std::vector<IntPair> stack;
+            int iPage = 0;
+            for (Factories::const_iterator it = factories.begin(), end = factories.end();
+               it != end; ++it, ++iPage)
+            {
+               const PrefsNode &node = *it;
+               PrefsPanelFactory &factory = *node.pFactory;
+               wxWindow *const w = factory.Create(mCategories);
+               if (stack.empty())
                   // Parameters are: AddPage(page, name, IsSelected, imageId).
-         w = new DevicePrefs(mCategories);      mCategories->AddPage(w, w->GetName(), false, 0);
+                  mCategories->AddPage(w, w->GetName(), false, 0);
-         w = new PlaybackPrefs(mCategories);    mCategories->AddPage(w, w->GetName(), false, 0);
+               else {
-         w = new RecordingPrefs(mCategories);   mCategories->AddPage(w, w->GetName(), false, 0);
+                  IntPair &top = *stack.rbegin();
-#ifdef EXPERIMENTAL_MIDI_OUT
+                  mCategories->InsertSubPage(top.first, w, w->GetName(), false, 0);
-         w = new MidiIOPrefs(mCategories);      mCategories->AddPage(w, w->GetName(), false, 0);
+                  if (--top.second == 0) {
-#endif
+                     // Expand all nodes before the layout calculation
-         w = new QualityPrefs(mCategories);     mCategories->AddPage(w, w->GetName(), false, 0);
+                     mCategories->ExpandNode(top.first, true);
-         w = new GUIPrefs(mCategories);         mCategories->AddPage(w, w->GetName(), false, 0);
+                     stack.pop_back();
-         w = new TracksPrefs(mCategories);      mCategories->AddPage(w, w->GetName(), false, 0);
+                  }
-         w = new ImportExportPrefs(mCategories);mCategories->AddPage(w, w->GetName(), false, 0);
+               }
-         w = new ExtImportPrefs(mCategories);   mCategories->AddPage(w, w->GetName(), false, 0);
+               if (node.nChildren > 0)
-         w = new ProjectsPrefs(mCategories);    mCategories->AddPage(w, w->GetName(), false, 0);
+                  stack.push_back(IntPair(iPage, node.nChildren));
-#if !defined(DISABLE_DYNAMIC_LOADING_FFMPEG) || !defined(DISABLE_DYNAMIC_LOADING_LAME)
+            }
-         w = new LibraryPrefs(mCategories);     mCategories->AddPage(w, w->GetName(), false, 0);
+         }
-#endif
-         w = new SpectrumPrefs(mCategories);    mCategories->AddPage(w, w->GetName(), false, 0);
-         w = new DirectoriesPrefs(mCategories); mCategories->AddPage(w, w->GetName(), false, 0);
-         w = new WarningsPrefs(mCategories);    mCategories->AddPage(w, w->GetName(), false, 0);
-         w = new EffectsPrefs(mCategories);     mCategories->AddPage(w, w->GetName(), false, 0);
-
-#ifdef EXPERIMENTAL_THEME_PREFS
-         w = new ThemePrefs(mCategories);       mCategories->AddPage(w, w->GetName(), false, 0);
-#endif
-
-//       w = new BatchPrefs(mCategories);       mCategories->AddPage(w, w->GetName(), false, 0);
-         w = new KeyConfigPrefs(mCategories);   mCategories->AddPage(w, w->GetName(), false, 0);
-         w = new MousePrefs(mCategories);       mCategories->AddPage(w, w->GetName(), false, 0);
-#ifdef EXPERIMENTAL_MODULE_PREFS
-         w = new ModulePrefs(mCategories);      mCategories->AddPage(w, w->GetName(), false, 0);
-#endif
       }
       S.EndHorizontalLay();
    }
@@ -163,23 +233,6 @@ PrefsDialog::PrefsDialog(wxWindow * parent)
 
    S.AddStandardButtons(eOkButton | eCancelButton);
 
-   /* long is signed, size_t is unsigned. On some platforms they are different
-    * lengths as well. So we must check that the stored category is both > 0
-    * and within the possible range of categories, making the first check on the
-    * _signed_ value to avoid issues when converting an unsigned one.
-    */
-   size_t selected;
-   long prefscat = gPrefs->Read(wxT("/Prefs/PrefsCategory"), 0L);
-   if (prefscat > 0L )
-      selected = prefscat; // only assign if number will fit
-   else
-      selected = 0;  // use 0 if value can't be assigned
-
-   if (selected >= mCategories->GetPageCount())
-      selected = 0;  // clamp to available range of tabs
-
-   mCategories->SetSelection(selected);
-
 #if defined(__WXGTK__)
    mCategories->GetTreeCtrl()->EnsureVisible(mCategories->GetTreeCtrl()->GetRootItem());
 #endif
@@ -189,6 +242,14 @@ PrefsDialog::PrefsDialog(wxWindow * parent)
    Fit();
    wxSize sz = GetSize();
 
+   // Collapse nodes only after layout so the tree is wide enough
+   {
+      int iPage = 0;
+      for (Factories::const_iterator it = factories.begin(), end = factories.end();
+         it != end; ++it, ++iPage)
+         mCategories->ExpandNode(iPage, it->expanded);
+   }
+
    // This ASSERT used to limit us to 800 x 600.
    // However, we think screens have got bigger now, and that was a bit too restrictive.
    // The impetus for increasing the limit (before we ASSERT) was that this ASSERT
@@ -219,8 +280,25 @@ PrefsDialog::~PrefsDialog()
 {
 }
 
+int PrefsDialog::ShowModal()
+{
+   /* long is signed, size_t is unsigned. On some platforms they are different
+    * lengths as well. So we must check that the stored category is both > 0
+    * and within the possible range of categories, making the first check on the
+    * _signed_ value to avoid issues when converting an unsigned one.
+    */
+   long selected = GetPreferredPage();
+   if (selected < 0 || size_t(selected) >= mCategories->GetPageCount())
+      selected = 0;  // clamp to available range of tabs
+   mCategories->SetSelection(selected);
+
+   return wxDialog::ShowModal();
+}
+
 void PrefsDialog::OnCancel(wxCommandEvent & WXUNUSED(event))
 {
+   RecordExpansionState();
+
    for (size_t i = 0; i < mCategories->GetPageCount(); i++) {
       ((PrefsPanel *) mCategories->GetPage(i))->Cancel();
    }
@@ -238,6 +316,8 @@ void PrefsDialog::OnTreeKeyDown(wxTreeEvent & event)
 
 void PrefsDialog::OnOK(wxCommandEvent & WXUNUSED(event))
 {
+   RecordExpansionState();
+
    // Validate all pages first
    for (size_t i = 0; i < mCategories->GetPageCount(); i++) {
       PrefsPanel *panel = (PrefsPanel *) mCategories->GetPage(i);
@@ -256,8 +336,7 @@ void PrefsDialog::OnOK(wxCommandEvent & WXUNUSED(event))
       panel->Apply();
    }
 
-   gPrefs->Write(wxT("/Prefs/PrefsCategory"), (long)mCategories->GetSelection());
+   SavePreferredPage();
-   gPrefs->Flush();
 
 #if USE_PORTMIXER
    if (gAudioIO) {
@@ -307,7 +386,39 @@ void PrefsDialog::SelectPageByName(wxString pageName)
    }
 }
 
-void PrefsDialog::ShowTempDirPage()
+int PrefsDialog::GetSelectedPage() const
 {
-   SelectPageByName(_("Directories"));
+   return mCategories->GetSelection();
+}
+
+GlobalPrefsDialog::GlobalPrefsDialog(wxWindow * parent, Factories &factories)
+   : PrefsDialog(parent, _("Preferences: "), factories)
+{
+}
+
+GlobalPrefsDialog::~GlobalPrefsDialog()
+{
+}
+
+long GlobalPrefsDialog::GetPreferredPage()
+{
+   long prefscat = gPrefs->Read(wxT("/Prefs/PrefsCategory"), 0L);
+   return prefscat;
+}
+
+void GlobalPrefsDialog::SavePreferredPage()
+{
+   gPrefs->Write(wxT("/Prefs/PrefsCategory"), (long)GetSelectedPage());
+   gPrefs->Flush();
+}
+
+void PrefsDialog::RecordExpansionState()
+{
+   // Remember expansion state of the tree control
+   {
+      int iPage = 0;
+      for (Factories::iterator it = mFactories.begin(), end = mFactories.end();
+         it != end; ++it, ++iPage)
+         it->expanded = mCategories->IsNodeExpanded(iPage);
+   }
 }

src/prefs/PrefsDialog.h

@@ -12,6 +12,7 @@
 #ifndef __AUDACITY_PREFS_DIALOG__
 #define __AUDACITY_PREFS_DIALOG__
 
+#include <vector>
 #include <wx/button.h>
 #include <wx/event.h>
 #include <wx/dialog.h>
@@ -19,24 +20,74 @@
 #include <wx/treebook.h>
 #include <wx/window.h>
 
+class PrefsPanelFactory;
+
+#ifdef __GNUC__
+#define CONST
+#else
+#define CONST const
+#endif
+
 class PrefsDialog:public wxDialog
 {
  public:
-   PrefsDialog(wxWindow * parent);
+    // An array of PrefsNode specifies the tree of pages in pre-order traversal.
+    struct PrefsNode {
+       PrefsPanelFactory * CONST pFactory;
+       CONST int nChildren;
+       bool expanded;
+
+       PrefsNode(PrefsPanelFactory *pFactory_, int nChildren_ = 0)
+          : pFactory(pFactory_), nChildren(nChildren_), expanded(false)
+       {}
+    };
+   typedef std::vector<PrefsNode> Factories;
+   static Factories &DefaultFactories();
+
+   PrefsDialog(wxWindow * parent,
+      const wxString &titlePrefix = _("Preferences: "),
+      Factories &factories = DefaultFactories());
    virtual ~PrefsDialog();
 
+   // Defined this so a protected virtual can be invoked after the constructor
+   virtual int ShowModal();
+
    void OnCategoryChange(wxCommandEvent & e);
    void OnOK(wxCommandEvent & e);
    void OnCancel(wxCommandEvent & e);
    void OnTreeKeyDown(wxTreeEvent & e); // Used to dismiss the dialog when enter is pressed with focus on tree
 
    void SelectPageByName(wxString pageName);
-   void ShowTempDirPage();
+
+   // Accessor to help implementations of SavePreferredPage(),
+   // such as by saving a preference after DoModal() returns
+   int GetSelectedPage() const;
+
+ protected:
+    // Decide which page to open first; return -1 for undecided
+    virtual long GetPreferredPage() = 0;
+
+    // Called after OK is clicked and all pages validate
+    virtual void SavePreferredPage() = 0;
 
 private:
+   void RecordExpansionState();
    wxTreebook *mCategories;
+   Factories &mFactories;
+   const wxString mTitlePrefix;
 
    DECLARE_EVENT_TABLE()
 };
 
+// This adds code appropriate only to the original use of PrefsDialog for
+// global settings -- not its reuses elsewhere as in View Settings
+class GlobalPrefsDialog : public PrefsDialog
+{
+public:
+   GlobalPrefsDialog(wxWindow * parent, Factories &factories = DefaultFactories());
+   virtual ~GlobalPrefsDialog();
+   virtual long GetPreferredPage();
+   virtual void SavePreferredPage();
+};
+
 #endif

src/prefs/PrefsPanel.h

@@ -61,4 +61,10 @@ class PrefsPanel:public wxPanel
    }
 };
 
+class PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent) = 0;
+};
+
 #endif

src/prefs/ProjectsPrefs.cpp

@@ -79,3 +79,8 @@ bool ProjectsPrefs::Apply()
 
    return true;
 }
+
+PrefsPanel *ProjectsPrefsFactory::Create(wxWindow *parent)
+{
+   return new ProjectsPrefs(parent);
+}

src/prefs/ProjectsPrefs.h

@@ -33,4 +33,9 @@ class ProjectsPrefs :public PrefsPanel
    void PopulateOrExchange(ShuttleGui & S);
 };
 
+class ProjectsPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif

src/prefs/QualityPrefs.cpp

@@ -228,3 +228,8 @@ bool QualityPrefs::Apply()
 
    return true;
 }
+
+PrefsPanel *QualityPrefsFactory::Create(wxWindow *parent)
+{
+   return new QualityPrefs(parent);
+}

src/prefs/QualityPrefs.h

@@ -53,4 +53,9 @@ class QualityPrefs :public PrefsPanel
    DECLARE_EVENT_TABLE();
 };
 
+class QualityPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif

src/prefs/RecordingPrefs.cpp

@@ -202,3 +202,8 @@ bool RecordingPrefs::Apply()
    #endif
    return gPrefs->Flush();
 }
+
+PrefsPanel *RecordingPrefsFactory::Create(wxWindow *parent)
+{
+   return new RecordingPrefs(parent);
+}

src/prefs/RecordingPrefs.h

@@ -32,4 +32,9 @@ class RecordingPrefs :public PrefsPanel
    void PopulateOrExchange(ShuttleGui & S);
 };
 
+class RecordingPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif

src/prefs/SpectrumPrefs.cpp

@@ -342,6 +342,11 @@ BEGIN_EVENT_TABLE(SpectrumPrefs, PrefsPanel)
    EVT_CHOICE(ID_WINDOW_SIZE, SpectrumPrefs::OnWindowSize)
 END_EVENT_TABLE()
 
+PrefsPanel *SpectrumPrefsFactory::Create(wxWindow *parent)
+{
+   return new SpectrumPrefs(parent);
+}
+
 SpectrogramSettings::SpectrogramSettings()
 : hFFT(0)
 , window(0)

src/prefs/SpectrumPrefs.h

@@ -124,4 +124,10 @@ public:
 #endif
 };
 
+class SpectrumPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
+
 #endif

src/prefs/ThemePrefs.cpp

@@ -205,3 +205,8 @@ bool ThemePrefs::Apply()
 
    return true;
 }
+
+PrefsPanel *ThemePrefsFactory::Create(wxWindow *parent)
+{
+   return new ThemePrefs(parent);
+}

src/prefs/ThemePrefs.h

@@ -41,4 +41,9 @@ class ThemePrefs :public PrefsPanel
    DECLARE_EVENT_TABLE();
 };
 
+class ThemePrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif

src/prefs/TracksPrefs.cpp

@@ -165,3 +165,8 @@ bool TracksPrefs::Apply()
 
    return true;
 }
+
+PrefsPanel *TracksPrefsFactory::Create(wxWindow *parent)
+{
+   return new TracksPrefs(parent);
+}

src/prefs/TracksPrefs.h

@@ -39,4 +39,9 @@ class TracksPrefs :public PrefsPanel
    wxArrayString mViewChoices;
 };
 
+class TracksPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif

src/prefs/WarningsPrefs.cpp

@@ -83,3 +83,8 @@ bool WarningsPrefs::Apply()
 
    return true;
 }
+
+PrefsPanel *WarningsPrefsFactory::Create(wxWindow *parent)
+{
+   return new WarningsPrefs(parent);
+}

src/prefs/WarningsPrefs.h

@@ -33,4 +33,9 @@ class WarningsPrefs :public PrefsPanel
    void PopulateOrExchange(ShuttleGui & S);
 };
 
+class WarningsPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif