Emit an event when the preferences dialog closes

src/Prefs.cpp

@@ -69,6 +69,8 @@ std::unique_ptr<AudacityPrefs> ugPrefs {};
 AudacityPrefs *gPrefs = NULL;
 int gMenusDirty = 0;
 
+wxDEFINE_EVENT(EVT_PREFS_UPDATE, wxCommandEvent);
+
 #if 0
 // Copy one entry from one wxConfig object to another
 static void CopyEntry(wxString path, wxConfigBase *src, wxConfigBase *dst, wxString entry)

src/Prefs.h

@@ -34,6 +34,7 @@
 #include "../include/audacity/ComponentInterface.h"
 
 #include <wx/fileconf.h>  // to inherit wxFileConfig
+#include <wx/event.h> // to declare custom event types
 
 void InitPreferences();
 void FinishPreferences();
@@ -159,4 +160,8 @@ private:
    const wxString mOldKey;
 };
 
+// An event emitted by the application when the Preference dialog commits
+// changes
+wxDECLARE_EVENT(EVT_PREFS_UPDATE, wxCommandEvent);
+
 #endif

src/prefs/PrefsDialog.cpp

@@ -844,6 +844,9 @@ void PrefsDialog::OnOK(wxCommandEvent & WXUNUSED(event))
    }
 #endif
 
+   // PRL:  Is the following concern still valid, now that prefs update is
+   //      handled instead by delayed event processing?
+
    // LL:  wxMac can't handle recreating the menus when this dialog is still active,
    //      so AudacityProject::UpdatePrefs() or any of the routines it calls must
    //      not cause MenuCreator::RebuildMenuBar() to be executed.
@@ -851,6 +854,8 @@ void PrefsDialog::OnOK(wxCommandEvent & WXUNUSED(event))
       gAudacityProjects[i]->UpdatePrefs();
    }
 
+   wxTheApp->AddPendingEvent(wxCommandEvent{ EVT_PREFS_UPDATE });
+
    WaveformSettings::defaults().LoadPrefs();
    SpectrogramSettings::defaults().LoadPrefs();