From 5d28a05702dd1683081164cab167a36af0c34833 Mon Sep 17 00:00:00 2001
From: Paul Licameli <paul.licameli@audacityteam.org>
Date: Tue, 12 Apr 2016 16:16:32 -0400
Subject: [PATCH] RAII object for pausing and unpausing OD manager

---
 src/Menus.cpp              |  3 +--
 src/Project.cpp            |  9 ++-------
 src/ondemand/ODManager.cpp |  4 ++--
 src/ondemand/ODManager.h   | 15 ++++++++++++---
 4 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/src/Menus.cpp b/src/Menus.cpp
index 6368c8de1..5adffbe12 100644
--- a/src/Menus.cpp
+++ b/src/Menus.cpp
@@ -5450,7 +5450,7 @@ void AudacityProject::OnImport()
    //sort selected files by OD status.  Load non OD first so user can edit asap.
    //first sort selectedFiles.
    selectedFiles.Sort(CompareNoCaseFileName);
-   ODManager::Pause();
+   ODManager::Pauser pauser;
 
    for (size_t ff = 0; ff < selectedFiles.GetCount(); ff++) {
       wxString fileName = selectedFiles[ff];
@@ -5466,7 +5466,6 @@ void AudacityProject::OnImport()
    gPrefs->Flush();
 
    HandleResize(); // Adjust scrollers for NEW track sizes.
-   ODManager::Resume();
 }
 
 void AudacityProject::OnImportLabels()
diff --git a/src/Project.cpp b/src/Project.cpp
index dc4391c87..4891e4ce4 100644
--- a/src/Project.cpp
+++ b/src/Project.cpp
@@ -412,7 +412,7 @@ public:
       //sort by OD non OD.  load Non OD first so user can start editing asap.
       wxArrayString sortednames(filenames);
 
-      ODManager::Pause();
+      ODManager::Pauser pauser;
 
       sortednames.Sort(CompareNoCaseFileName);
       for (unsigned int i = 0; i < sortednames.GetCount(); i++) {
@@ -421,8 +421,6 @@ public:
       }
       mProject->HandleResize(); // Adjust scrollers for NEW track sizes.
 
-      ODManager::Resume();
-
       return true;
    }
 
@@ -2500,7 +2498,7 @@ void AudacityProject::OpenFiles(AudacityProject *proj)
    //For the open menu we load OD first so user can edit asap.
    //first sort selectedFiles.
    selectedFiles.Sort(CompareNoCaseFileName);
-   ODManager::Pause();
+   ODManager::Pauser pauser;
 
    for (size_t ff = 0; ff < selectedFiles.GetCount(); ff++) {
       const wxString &fileName = selectedFiles[ff];
@@ -2534,9 +2532,6 @@ void AudacityProject::OpenFiles(AudacityProject *proj)
 
    gPrefs->Write(wxT("/LastOpenType"),wxT(""));
    gPrefs->Flush();
-
-   ODManager::Resume();
-
 }
 
 // Most of this string was duplicated 3 places. Made the warning consistent in this global.
diff --git a/src/ondemand/ODManager.cpp b/src/ondemand/ODManager.cpp
index 3099b3962..4d498f30e 100644
--- a/src/ondemand/ODManager.cpp
+++ b/src/ondemand/ODManager.cpp
@@ -330,7 +330,7 @@ void ODManager::Start()
 //static function that prevents ODTasks from being scheduled
 //does not stop currently running tasks from completing their immediate subtask,
 //but presumably they will finish within a second
-void ODManager::Pause(bool pause)
+void ODManager::Pauser::Pause(bool pause)
 {
    if(IsInstanceCreated())
    {
@@ -349,7 +349,7 @@ void ODManager::Pause(bool pause)
    }
 }
 
-void ODManager::Resume()
+void ODManager::Pauser::Resume()
 {
    Pause(false);
 }
diff --git a/src/ondemand/ODManager.h b/src/ondemand/ODManager.h
index 872f48364..0423246ed 100644
--- a/src/ondemand/ODManager.h
+++ b/src/ondemand/ODManager.h
@@ -106,9 +106,18 @@ class ODManager final
    ///Get Total Number of Tasks.
    int GetTotalNumTasks();
 
-   //Pause/unpause all OD Tasks.  Does not occur immediately.
-   static void Pause(bool pause = true);
-   static void Resume();
+   // RAII object for pausing and resuming..
+   class Pauser
+   {
+      //Pause/unpause all OD Tasks.  Does not occur immediately.
+      static void Pause(bool pause = true);
+      static void Resume();
+   public:
+      Pauser() { Pause(); }
+      ~Pauser() { Resume(); }
+      Pauser(const Pauser&) PROHIBITED;
+      Pauser &operator= (const Pauser&) PROHIBITED;
+   };
 
    static void LockLibSndFileMutex();
    static void UnlockLibSndFileMutex();