From 762cf327beee6226fce3761dbc99e4f16ce04618 Mon Sep 17 00:00:00 2001
From: ed <eddavies95@gmail.com>
Date: Thu, 25 Mar 2021 10:02:48 +0000
Subject: [PATCH] macOS:  Removed static display change callback

---
 .../native/juce_mac_Windowing.mm              | 22 +++++++++----------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/modules/juce_gui_basics/native/juce_mac_Windowing.mm b/modules/juce_gui_basics/native/juce_mac_Windowing.mm
index 918f0b4a68a6..269c7daa38b9 100644
--- a/modules/juce_gui_basics/native/juce_mac_Windowing.mm
+++ b/modules/juce_gui_basics/native/juce_mac_Windowing.mm
@@ -441,30 +441,30 @@ void timerCallback() override
 {
     DisplaySettingsChangeCallback()
     {
-        CGDisplayRegisterReconfigurationCallback (displayReconfigurationCallback, nullptr);
+        CGDisplayRegisterReconfigurationCallback (displayReconfigurationCallback, this);
     }
 
     ~DisplaySettingsChangeCallback()
     {
-        CGDisplayRemoveReconfigurationCallback (displayReconfigurationCallback, nullptr);
+        CGDisplayRemoveReconfigurationCallback (displayReconfigurationCallback, this);
         clearSingletonInstance();
     }
 
-    static void displayReconfigurationCallback (CGDirectDisplayID, CGDisplayChangeSummaryFlags, void*)
+    static void displayReconfigurationCallback (CGDirectDisplayID, CGDisplayChangeSummaryFlags, void* userInfo)
     {
-        if (forceDisplayUpdate != nullptr)
-            forceDisplayUpdate();
+        if (auto* thisPtr = static_cast<DisplaySettingsChangeCallback*> (userInfo))
+            if (thisPtr->forceDisplayUpdate != nullptr)
+                thisPtr->forceDisplayUpdate();
     }
 
-    static std::function<void()> forceDisplayUpdate;
+    std::function<void()> forceDisplayUpdate;
 
-    JUCE_DECLARE_SINGLETON_SINGLETHREADED_MINIMAL (DisplaySettingsChangeCallback)
+    JUCE_DECLARE_SINGLETON (DisplaySettingsChangeCallback, false)
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (DisplaySettingsChangeCallback)
 };
 
 JUCE_IMPLEMENT_SINGLETON (DisplaySettingsChangeCallback)
 
-std::function<void()> DisplaySettingsChangeCallback::forceDisplayUpdate = nullptr;
 
 static Rectangle<int> convertDisplayRect (NSRect r, CGFloat mainScreenBottom)
 {
@@ -498,10 +498,8 @@ static void displayReconfigurationCallback (CGDirectDisplayID, CGDisplayChangeSu
 {
     JUCE_AUTORELEASEPOOL
     {
-        auto& settingsChangeCallback = *DisplaySettingsChangeCallback::getInstance();
-
-        if (settingsChangeCallback.forceDisplayUpdate == nullptr)
-            settingsChangeCallback.forceDisplayUpdate = [this] { refresh(); };
+        if (DisplaySettingsChangeCallback::getInstanceWithoutCreating() == nullptr)
+            DisplaySettingsChangeCallback::getInstance()->forceDisplayUpdate = [this] { refresh(); };
 
         CGFloat mainScreenBottom = 0;