Core - Change Cef.IsInitialized from bool to bool? (#4869)

Resolves #4867

Author: amaitland

CefSharp.Core.Runtime/Cef.h

@@ -46,7 +46,7 @@ namespace CefSharp
         private:
             static Object^ _sync;
 
-            static bool _initialized = false;
+            static Nullable<bool> _initialized;
             static bool _hasShutdown = false;
             static HashSet<IDisposable^>^ _disposables;
             static int _initializedThreadId;
@@ -86,9 +86,9 @@ namespace CefSharp
 
             /// <summary>Gets a value that indicates whether CefSharp is initialized.</summary>
             /// <value>true if CefSharp is initialized; otherwise, false.</value>
-            static property bool IsInitialized
+            static property Nullable<bool> IsInitialized
             {
-                bool get()
+                Nullable<bool> get()
                 {
                     return _initialized;
                 }
@@ -255,7 +255,7 @@ namespace CefSharp
             /// <returns>true if successful; otherwise, false.</returns>
             static bool Initialize(CefSettingsBase^ cefSettings, bool performDependencyCheck, IApp^ cefApp)
             {
-                if (_initialized)
+                if (_initialized.HasValue)
                 {
                     // NOTE: Can only initialize Cef once, to make this explicitly clear throw exception on subsiquent attempts
                     throw gcnew Exception("Cef.Initialize can only be called once per process. This is a limitation of the underlying " +
@@ -555,11 +555,11 @@ namespace CefSharp
             /// </summary>
             static void Shutdown()
             {
-                if (_initialized)
+                if (_initialized.GetValueOrDefault())
                 {
                     msclr::lock l(_sync);
 
-                    if (_initialized)
+                    if (_initialized.GetValueOrDefault())
                     {
                         if (_initializedThreadId != Thread::CurrentThread->ManagedThreadId)
                         {
@@ -615,11 +615,11 @@ namespace CefSharp
             /// </summary>
             static void ShutdownWithoutChecks()
             {
-                if (_initialized)
+                if (_initialized.GetValueOrDefault())
                 {
                     msclr::lock l(_sync);
 
-                    if (_initialized)
+                    if (_initialized.GetValueOrDefault())
                     {
                         CefShutdown();
                         _initialized = false;
@@ -821,7 +821,7 @@ namespace CefSharp
                     return;
                 }
 
-                if (_initialized)
+                if (_initialized.HasValue)
                 {
                     throw gcnew Exception("Must be enabled before Cef.Initialize is called. ");
                 }

CefSharp.Core/Cef.cs

@@ -50,8 +50,11 @@ public static void RemoveDisposable(IDisposable item)
         }
 
         /// <summary>Gets a value that indicates whether CefSharp is initialized.</summary>
-        /// <value>true if CefSharp is initialized; otherwise, false.</value>
-        public static bool IsInitialized
+        /// <value>
+        /// true if CefSharp is initialized; returns false if initialize failed.
+        /// null if initialize not yet called.
+        /// </value>
+        public static bool? IsInitialized
         {
             get { return Core.Cef.IsInitialized; }
         }

CefSharp.OffScreen/ChromiumWebBrowser.cs

@@ -224,15 +224,7 @@ public ChromiumWebBrowser(string address = "", IBrowserSettings browserSettings
             IRequestContext requestContext = null, bool automaticallyCreateBrowser = true,
             Action<IBrowser> onAfterBrowserCreated = null, bool useLegacyRenderHandler = true)
         {
-            if (!Cef.IsInitialized)
-            {
-                var settings = new CefSettings();
-
-                if (!Cef.Initialize(settings))
-                {
-                    throw new InvalidOperationException(CefInitializeFailedErrorMessage);
-                }
-            }
+            InitializeCefInternal();
 
             RequestContext = requestContext;
 

CefSharp.Test/CefSharpFixture.cs

@@ -31,7 +31,7 @@ public CefSharpFixture(IMessageSink messageSink)
 
         private void CefInitialize()
         {
-            if (!Cef.IsInitialized)
+            if (Cef.IsInitialized == null)
             {
                 var isDefault = AppDomain.CurrentDomain.IsDefaultAppDomain();
                 if (!isDefault)
@@ -63,11 +63,16 @@ private void CefInitialize()
 
                 diagnosticMessageSink.OnMessage(new DiagnosticMessage("Cef Initialized:" + success));
             }
+
+            if (Cef.IsInitialized == false)
+            {
+                throw new InvalidOperationException("Cef.Initialize failed.");
+            }
         }
 
         private void CefShutdown()
         {
-            if (Cef.IsInitialized)
+            if (Cef.IsInitialized == true)
             {
                 diagnosticMessageSink.OnMessage(new DiagnosticMessage("Before Cef Shutdown"));
 

CefSharp.WinForms/ChromiumWebBrowser.cs

@@ -333,10 +333,7 @@ private void InitializeFieldsAndCefIfRequired()
         {
             if (!initialized)
             {
-                if (!Cef.IsInitialized && !Cef.Initialize(new CefSettings()))
-                {
-                    throw new InvalidOperationException(CefInitializeFailedErrorMessage);
-                }
+                InitializeCefInternal();
 
                 Cef.AddDisposable(this);
 

CefSharp.Wpf/ChromiumWebBrowser.cs

@@ -552,16 +552,7 @@ public ChromiumWebBrowser(string initialAddress)
         [MethodImpl(MethodImplOptions.NoInlining)]
         private void NoInliningConstructor()
         {
-            //Initialize CEF if it hasn't already been initialized
-            if (!Cef.IsInitialized)
-            {
-                var settings = new CefSettings();
-
-                if (!Cef.Initialize(settings))
-                {
-                    throw new InvalidOperationException(CefInitializeFailedErrorMessage);
-                }
-            }
+            InitializeCefInternal();
 
             //Add this ChromiumWebBrowser instance to a list of IDisposable objects
             // that if still alive at the time Cef.Shutdown is called will be disposed of

CefSharp/Internals/Partial/ChromiumWebBrowser.Partial.cs

@@ -27,6 +27,7 @@ public partial class ChromiumWebBrowser
             "the IsBrowserInitialized property to determine when the browser has been initialized.";
 
         private const string CefInitializeFailedErrorMessage = "Cef.Initialize() failed.Check the log file see https://github.com/cefsharp/CefSharp/wiki/Trouble-Shooting#log-file for details.";
+        private const string CefIsInitializedFalseErrorMessage = "Cef.IsInitialized was false!.Check the log file for errors!. See https://github.com/cefsharp/CefSharp/wiki/Trouble-Shooting#log-file for details.";
 
         /// <summary>
         /// Used as workaround for issue https://github.com/cefsharp/CefSharp/issues/3021
@@ -506,6 +507,22 @@ private void FreeHandlersExceptLifeSpanAndFocus()
             this.FreeDevToolsContext();
         }
 
+        private static void InitializeCefInternal()
+        {
+            if (Cef.IsInitialized == null)
+            {
+                if (!Cef.Initialize(new CefSettings()))
+                {
+                    throw new InvalidOperationException(CefInitializeFailedErrorMessage);
+                }
+            }
+
+            if (Cef.IsInitialized == false)
+            {
+                throw new InvalidOperationException(CefIsInitializedFalseErrorMessage);
+            }
+        }
+
         /// <summary>
         /// Check is browser is initialized
         /// </summary>