Update to CEF 3.3239.1710.g85f637a

Fixed an initialization bug in MDIBrowser, TabBrowser and ToolBoxBrowser
Added several procedures to clear interface and class references before destruction

demos/JavaScript/JSDialog/uJSDialogBrowser.pas

@@ -183,7 +183,6 @@ procedure TJSDialogBrowserFrm.ChromiumBrowser_OnJsdialog(Sender : TObject;
                                                          out   Result            : Boolean);
 begin
   // In this event we must store the dialog information and post a message to the main form to show the dialog
-
   FJSDialogInfoCS.Acquire;
 
   if FPendingDlg then

demos/MDIBrowser/uMainForm.pas

@@ -106,7 +106,8 @@ uses
 
 procedure GlobalCEFApp_OnContextInitialized;
 begin
-  if (MainForm <> nil) then PostMessage(MainForm.Handle, CEFBROWSER_INITIALIZED, 0, 0);
+  if (MainForm <> nil) and MainForm.HandleAllocated then
+    PostMessage(MainForm.Handle, CEFBROWSER_INITIALIZED, 0, 0);
 end;
 
 procedure TMainForm.CreateMDIChild(const Name: string);

demos/TabbedBrowser/uMainForm.pas

@@ -135,7 +135,8 @@ implementation
 
 procedure GlobalCEFApp_OnContextInitialized;
 begin
-  if (MainForm <> nil) then PostMessage(MainForm.Handle, CEFBROWSER_INITIALIZED, 0, 0);
+  if (MainForm <> nil) and MainForm.HandleAllocated then
+    PostMessage(MainForm.Handle, CEFBROWSER_INITIALIZED, 0, 0);
 end;
 
 procedure TMainForm.AddTabBtnClick(Sender: TObject);

demos/ToolBoxBrowser/uMainForm.pas

@@ -104,7 +104,8 @@ uses
 
 procedure GlobalCEFApp_OnContextInitialized;
 begin
-  if (MainForm <> nil) then PostMessage(MainForm.Handle, CEFBROWSER_INITIALIZED, 0, 0);
+  if (MainForm <> nil) and MainForm.HandleAllocated then
+    PostMessage(MainForm.Handle, CEFBROWSER_INITIALIZED, 0, 0);
 end;
 
 procedure TMainForm.CreateToolboxChild(const ChildCaption, URL: string);

source/uBufferPanel.pas

@@ -57,15 +57,20 @@ type
       FBuffer         : TBitmap;
       FScanlineSize   : integer;
 
+      procedure CreateBufferMutex;
+
+      procedure DestroyBufferMutex;
+      procedure DestroyBuffer;
+
       function  GetBufferBits : pointer;
       function  GetBufferWidth : integer;
       function  GetBufferHeight : integer;
 
-      function  CopyBuffer(aDC : HDC; const aRect : TRect) : boolean;
+      function  CopyBuffer : boolean;
       function  SaveBufferToFile(const aFilename : string) : boolean;
-      procedure DestroyBuffer;
 
-      procedure WMPaint(var aMessage: TWMPaint); message WM_PAINT;
+      procedure Paint; override;
+
       procedure WMEraseBkgnd(var aMessage : TWMEraseBkgnd); message WM_ERASEBKGND;
 
     public
@@ -73,7 +78,7 @@ type
       destructor  Destroy; override;
       procedure   AfterConstruction; override;
       function    SaveToFile(const aFilename : string) : boolean;
-      procedure   InvalidatePanel;
+      function    InvalidatePanel : boolean;
       function    BeginBufferDraw : boolean;
       procedure   EndBufferDraw;
       procedure   BufferDraw(x, y : integer; const aBitmap : TBitmap);
@@ -187,12 +192,7 @@ end;
 destructor TBufferPanel.Destroy;
 begin
   DestroyBuffer;
-
+  DestroyBufferMutex;
-  if (FMutex <> 0) then
-    begin
-      CloseHandle(FMutex);
-      FMutex := 0;
-    end;
 
   inherited Destroy;
 end;
@@ -201,9 +201,23 @@ procedure TBufferPanel.AfterConstruction;
 begin
   inherited AfterConstruction;
 
+  CreateBufferMutex;
+end;
+
+procedure TBufferPanel.CreateBufferMutex;
+begin
   FMutex := CreateMutex(nil, False, nil);
 end;
 
+procedure TBufferPanel.DestroyBufferMutex;
+begin
+  if (FMutex <> 0) then
+    begin
+      CloseHandle(FMutex);
+      FMutex := 0;
+    end;
+end;
+
 procedure TBufferPanel.DestroyBuffer;
 begin
   if BeginBufferDraw then
@@ -231,18 +245,18 @@ end;
 
 function TBufferPanel.SaveToFile(const aFilename : string) : boolean;
 begin
+  Result := False;
+
   if BeginBufferDraw then
     begin
       Result := SaveBufferToFile(aFilename);
       EndBufferDraw;
-    end
+    end;
-   else
-    Result := False;
 end;
 
-procedure TBufferPanel.InvalidatePanel;
+function TBufferPanel.InvalidatePanel : boolean;
 begin
-  PostMessage(Handle, CM_INVALIDATE, 0, 0);
+  Result := HandleAllocated and PostMessage(Handle, CM_INVALIDATE, 0, 0);
 end;
 
 function TBufferPanel.BeginBufferDraw : boolean;
@@ -255,50 +269,39 @@ begin
   if (FMutex <> 0) then ReleaseMutex(FMutex);
 end;
 
-function TBufferPanel.CopyBuffer(aDC : HDC; const aRect : TRect) : boolean;
+function TBufferPanel.CopyBuffer : boolean;
 begin
   Result := False;
 
   if BeginBufferDraw then
     begin
       Result := (FBuffer <> nil) and
-                (aDC     <> 0)   and
+                BitBlt(Canvas.Handle, 0, 0, Width, Height,
-                BitBlt(aDC, aRect.Left, aRect.Top, aRect.Right - aRect.Left, aRect.Bottom - aRect.Top,
+                       FBuffer.Canvas.Handle, 0, 0,
-                       FBuffer.Canvas.Handle, aRect.Left, aRect.Top,
                        SrcCopy);
 
       EndBufferDraw;
     end;
 end;
 
-procedure TBufferPanel.WMPaint(var aMessage: TWMPaint);
+procedure TBufferPanel.Paint;
-var
-  TempPaintStruct : TPaintStruct;
-  TempDC          : HDC;
 begin
-  try
+  if csDesigning in ComponentState then
-    TempDC := BeginPaint(Handle, TempPaintStruct);
+    begin
+      Canvas.Font.Assign(Font);
+      Canvas.Brush.Color := Color;
+      Canvas.Brush.Style := bsSolid;
+      Canvas.Pen.Style   := psDash;
 
-    if csDesigning in ComponentState then
+      Canvas.Rectangle(0, 0, Width, Height);
+    end
+   else
+    if not(CopyBuffer) then
       begin
-        Canvas.Font.Assign(Font);
         Canvas.Brush.Color := Color;
         Canvas.Brush.Style := bsSolid;
-        Canvas.Pen.Style   := psDash;
+        Canvas.FillRect(rect(0, 0, Width, Height));
-
+      end;
-        Canvas.Rectangle(0, 0, Width, Height);
-      end
-     else
-      if not(CopyBuffer(TempDC, TempPaintStruct.rcPaint)) then
-        begin
-          Canvas.Brush.Color := Color;
-          Canvas.Brush.Style := bsSolid;
-          Canvas.FillRect(rect(0, 0, Width, Height));
-        end;
-  finally
-    EndPaint(Handle, TempPaintStruct);
-    aMessage.Result := 1;
-  end;
 end;
 
 procedure TBufferPanel.WMEraseBkgnd(var aMessage : TWMEraseBkgnd);
@@ -337,6 +340,8 @@ end;
 
 function TBufferPanel.UpdateBufferDimensions(aWidth, aHeight : integer) : boolean;
 begin
+  Result := False;
+
   if ((FBuffer        =  nil)      or
       (FBuffer.Width  <> aWidth)   or
       (FBuffer.Height <> aHeight)) then
@@ -350,9 +355,7 @@ begin
       FBuffer.Height      := aHeight;
       FScanlineSize       := FBuffer.Width * SizeOf(TRGBQuad);
       Result              := True;
-    end
+    end;
-   else
-    Result := False;
 end;
 
 function TBufferPanel.BufferIsResized(aUseMutex : boolean) : boolean;

source/uCEFApplication.pas

@@ -57,7 +57,7 @@ uses
 const
   CEF_SUPPORTED_VERSION_MAJOR   = 3;
   CEF_SUPPORTED_VERSION_MINOR   = 3239;
-  CEF_SUPPORTED_VERSION_RELEASE = 1709;
+  CEF_SUPPORTED_VERSION_RELEASE = 1710;
   CEF_SUPPORTED_VERSION_BUILD   = 0;
 
   CEF_CHROMEELF_VERSION_MAJOR   = 63;
@@ -230,6 +230,7 @@ type
       function  FindFlashDLL(var aFileName : string) : boolean;
       procedure ShowErrorMessageDlg(const aError : string); virtual;
       function  ParseProcessType : TCefProcessType;
+      procedure RemoveAppReferences;
       procedure CreateAppHandlers;
 
     public
@@ -496,6 +497,8 @@ destructor TCefApplication.Destroy;
 begin
   if FMustShutDown then ShutDown;
 
+  RemoveAppReferences;
+
   if (FLibHandle <> 0) then
     begin
       FreeLibrary(FLibHandle);
@@ -511,6 +514,18 @@ begin
   inherited Destroy;
 end;
 
+procedure TCefApplication.RemoveAppReferences;
+begin
+  try
+    if (FResourceBundleHandler <> nil) then FResourceBundleHandler.InitializeVars;
+    if (FBrowserProcessHandler <> nil) then FBrowserProcessHandler.InitializeVars;
+    if (FRenderProcessHandler  <> nil) then FRenderProcessHandler.InitializeVars;
+  except
+    on e : exception do
+      if CustomExceptionHandler('TCefApplication.RemoveAppReferences', e) then raise;
+  end;
+end;
+
 procedure TCefApplication.AfterConstruction;
 begin
   inherited AfterConstruction;

source/uCEFBrowserProcessHandler.pas

@@ -58,23 +58,26 @@ type
       function  GetPrintHandler : ICefPrintHandler; virtual;
       procedure OnScheduleMessagePumpWork(const delayMs: Int64); virtual; abstract;
 
+      procedure InitializeVars; virtual; abstract;
+
     public
       constructor Create; virtual;
   end;
 
   TCefCustomBrowserProcessHandler = class(TCefBrowserProcessHandlerOwn)
-    protected
+    protected
-      FCefApp : TCefApplication;
+      FCefApp : TCefApplication;
-
+
-      procedure OnContextInitialized; override;
+      procedure OnContextInitialized; override;
-      procedure OnBeforeChildProcessLaunch(const commandLine: ICefCommandLine); override;
+      procedure OnBeforeChildProcessLaunch(const commandLine: ICefCommandLine); override;
-      procedure OnRenderProcessThreadCreated(const extraInfo: ICefListValue); override;
+      procedure OnRenderProcessThreadCreated(const extraInfo: ICefListValue); override;
-      procedure OnScheduleMessagePumpWork(const delayMs: Int64); override;
+      procedure OnScheduleMessagePumpWork(const delayMs: Int64); override;
-
+
-    public
+    public
-      constructor Create(const aCefApp : TCefApplication); reintroduce;
+      constructor Create(const aCefApp : TCefApplication); reintroduce;
-      destructor  Destroy; override;
+      destructor  Destroy; override;
-  end;
+      procedure   InitializeVars; override;
+  end;
 
 implementation
 
@@ -85,8 +88,8 @@ procedure cef_browser_process_handler_on_context_initialized(self: PCefBrowserPr
 var
   TempObject : TObject;
 begin
-  TempObject := CefGetObject(self);
+  TempObject := CefGetObject(self);
-
+
   if (TempObject <> nil) and (TempObject is TCefBrowserProcessHandlerOwn) then
     TCefBrowserProcessHandlerOwn(TempObject).OnContextInitialized;
 end;
@@ -96,8 +99,8 @@ procedure cef_browser_process_handler_on_before_child_process_launch(self
 var
   TempObject : TObject;
 begin
-  TempObject := CefGetObject(self);
+  TempObject := CefGetObject(self);
-
+
   if (TempObject <> nil) and (TempObject is TCefBrowserProcessHandlerOwn) then
     TCefBrowserProcessHandlerOwn(TempObject).OnBeforeChildProcessLaunch(TCefCommandLineRef.UnWrap(command_line));
 end;
@@ -107,8 +110,8 @@ procedure cef_browser_process_handler_on_render_process_thread_created(self
 var
   TempObject : TObject;
 begin
-  TempObject := CefGetObject(self);
+  TempObject := CefGetObject(self);
-
+
   if (TempObject <> nil) and (TempObject is TCefBrowserProcessHandlerOwn) then
     TCefBrowserProcessHandlerOwn(TempObject).OnRenderProcessThreadCreated(TCefListValueRef.UnWrap(extra_info));
 end;
@@ -117,12 +120,12 @@ function cef_browser_process_handler_get_print_handler(self: PCefBrowserProcessH
 var
   TempObject : TObject;
 begin
-  TempObject := CefGetObject(self);
+  TempObject := CefGetObject(self);
-
+
   if (TempObject <> nil) and (TempObject is TCefBrowserProcessHandlerOwn) then
-    Result := CefGetData(TCefBrowserProcessHandlerOwn(TempObject).GetPrintHandler)
+    Result := CefGetData(TCefBrowserProcessHandlerOwn(TempObject).GetPrintHandler)
-   else
+   else
-    Result := nil;
+    Result := nil;
 end;
 
 procedure cef_browser_process_handler_on_schedule_message_pump_work(self     : PCefBrowserProcessHandler;
@@ -130,8 +133,8 @@ procedure cef_browser_process_handler_on_schedule_message_pump_work(self     : P
 var
   TempObject : TObject;
 begin
-  TempObject := CefGetObject(self);
+  TempObject := CefGetObject(self);
-
+
   if (TempObject <> nil) and (TempObject is TCefBrowserProcessHandlerOwn) then
     TCefBrowserProcessHandlerOwn(TempObject).OnScheduleMessagePumpWork(delay_ms);
 end;
@@ -152,45 +155,50 @@ end;
 
 function TCefBrowserProcessHandlerOwn.GetPrintHandler : ICefPrintHandler;
 begin
-  Result := nil; // only linux
+  Result := nil; // only linux
 end;
 
 
 // TCefCustomBrowserProcessHandler
-
+
-
+
-constructor TCefCustomBrowserProcessHandler.Create(const aCefApp : TCefApplication);
+constructor TCefCustomBrowserProcessHandler.Create(const aCefApp : TCefApplication);
-begin
+begin
-  inherited Create;
+  inherited Create;
-
+
-  FCefApp := aCefApp;
+  FCefApp := aCefApp;
+end;
+
+destructor TCefCustomBrowserProcessHandler.Destroy;
+begin
+  InitializeVars;
+
+  inherited Destroy;
 end;
-
+
-destructor TCefCustomBrowserProcessHandler.Destroy;
+procedure TCefCustomBrowserProcessHandler.InitializeVars;
-begin
+begin
-  FCefApp := nil;
+  FCefApp := nil;
-
-  inherited Destroy;
 end;
-
+
-procedure TCefCustomBrowserProcessHandler.OnContextInitialized;
+procedure TCefCustomBrowserProcessHandler.OnContextInitialized;
-begin
+begin
-  if (FCefApp <> nil) then FCefApp.Internal_OnContextInitialized;
+  if (FCefApp <> nil) then FCefApp.Internal_OnContextInitialized;
-end;
+end;
-
+
-procedure TCefCustomBrowserProcessHandler.OnBeforeChildProcessLaunch(const commandLine: ICefCommandLine);
+procedure TCefCustomBrowserProcessHandler.OnBeforeChildProcessLaunch(const commandLine: ICefCommandLine);
-begin
+begin
-  if (FCefApp <> nil) then FCefApp.Internal_OnBeforeChildProcessLaunch(commandLine);
+  if (FCefApp <> nil) then FCefApp.Internal_OnBeforeChildProcessLaunch(commandLine);
-end;
+end;
-
+
-procedure TCefCustomBrowserProcessHandler.OnRenderProcessThreadCreated(const extraInfo: ICefListValue);
+procedure TCefCustomBrowserProcessHandler.OnRenderProcessThreadCreated(const extraInfo: ICefListValue);
-begin
+begin
-  if (FCefApp <> nil) then FCefApp.Internal_OnRenderProcessThreadCreated(extraInfo);
+  if (FCefApp <> nil) then FCefApp.Internal_OnRenderProcessThreadCreated(extraInfo);
-end;
+end;
-
+
-procedure TCefCustomBrowserProcessHandler.OnScheduleMessagePumpWork(const delayMs: Int64);
+procedure TCefCustomBrowserProcessHandler.OnScheduleMessagePumpWork(const delayMs: Int64);
-begin
+begin
-  if (FCefApp <> nil) then FCefApp.Internal_OnScheduleMessagePumpWork(delayMs);
+  if (FCefApp <> nil) then FCefApp.Internal_OnScheduleMessagePumpWork(delayMs);
 end;
 
 end.

source/uCEFChromium.pas

@@ -261,6 +261,14 @@ type
       function  CreateBrowserHost(aWindowInfo : PCefWindowInfo; const aURL : ustring; const aSettings : PCefBrowserSettings; const aContext : ICefRequestContext): Boolean;
       function  CreateBrowserHostSync(aWindowInfo : PCefWindowInfo; const aURL : ustring; const aSettings : PCefBrowserSettings; const aContext : ICefRequestContext): ICefBrowser;
 
+      procedure DestroyClientHandler;
+      procedure DestroyVisitor;
+      procedure DestroyPDFPrintcb;
+      procedure DestroyResolveHostcb;
+      procedure DestroyCookiDeletercb;
+
+      procedure ClearBrowserReference;
+
       procedure InitializeEvents;
       procedure InitializeSettings(var aSettings : TCefBrowserSettings);
 
@@ -758,13 +766,13 @@ begin
           FCompHandle := 0;
         end;
 
-      FBrowser        := nil;
+      ClearBrowserReference;
-      FBrowserId      := 0;
+
-      FHandler        := nil;
+      DestroyClientHandler;
-      FVisitor        := nil;
+      DestroyVisitor;
-      FPDFPrintcb     := nil;
+      DestroyPDFPrintcb;
-      FResolveHostcb  := nil;
+      DestroyResolveHostcb;
-      FCookiDeletercb := nil;
+      DestroyCookiDeletercb;
 
       if (FFontOptions     <> nil) then FreeAndNil(FFontOptions);
       if (FOptions         <> nil) then FreeAndNil(FOptions);
@@ -778,6 +786,57 @@ begin
   end;
 end;
 
+procedure TChromium.ClearBrowserReference;
+begin
+  FBrowser   := nil;
+  FBrowserId := 0;
+end;
+
+procedure TChromium.DestroyClientHandler;
+begin
+  if (FHandler <> nil) then
+    begin
+      FHandler.InitializeVars;
+      FHandler := nil;
+    end;
+end;
+
+procedure TChromium.DestroyVisitor;
+begin
+  if (FVisitor <> nil) then
+    begin
+      FVisitor.InitializeVars;
+      FVisitor := nil;
+    end;
+end;
+
+procedure TChromium.DestroyPDFPrintcb;
+begin
+  if (FPDFPrintcb <> nil) then
+    begin
+      FPDFPrintcb.InitializeVars;
+      FPDFPrintcb := nil;
+    end;
+end;
+
+procedure TChromium.DestroyResolveHostcb;
+begin
+  if (FResolveHostcb <> nil) then
+    begin
+      FResolveHostcb.InitializeVars;
+      FResolveHostcb := nil;
+    end;
+end;
+
+procedure TChromium.DestroyCookiDeletercb;
+begin
+  if (FCookiDeletercb <> nil) then
+    begin
+      FCookiDeletercb.InitializeVars;
+      FCookiDeletercb := nil;
+    end;
+end;
+
 procedure TChromium.AfterConstruction;
 begin
   inherited AfterConstruction;
@@ -2770,9 +2829,8 @@ begin
   if (browser <> nil) and (FBrowserId = browser.Identifier) then
     begin
       FInitialized := False;
-      FBrowser     := nil;
+      ClearBrowserReference;
-      FBrowserId   := 0;
+      DestroyClientHandler;
-      FHandler     := nil;
     end;
 
   if Assigned(FOnBeforeClose) then FOnBeforeClose(Self, browser);

source/uCEFClient.pas

@@ -73,6 +73,8 @@ type
       function GetRequestHandler: ICefRequestHandler; virtual;
       function OnProcessMessageReceived(const browser: ICefBrowser; sourceProcess: TCefProcessId; const message: ICefProcessMessage): Boolean; virtual;
 
+      procedure InitializeVars; virtual;
+
     public
       class function UnWrap(data: Pointer): ICefClient;
   end;
@@ -95,6 +97,8 @@ type
       function GetRequestHandler: ICefRequestHandler; virtual;
       function OnProcessMessageReceived(const browser: ICefBrowser; sourceProcess: TCefProcessId; const message: ICefProcessMessage): Boolean; virtual;
 
+      procedure InitializeVars; virtual;
+
     public
       constructor Create; virtual;
   end;
@@ -133,8 +137,6 @@ type
       function  GetRequestHandler: ICefRequestHandler; override;
       function  OnProcessMessageReceived(const browser: ICefBrowser; sourceProcess: TCefProcessId; const message: ICefProcessMessage): Boolean; override;
 
-      procedure InitializeInterfaces;
-
     public
       constructor Create(const events: IChromiumEvents;
                          aCreateLoadHandler, aCreateFocusHandler, aCreateContextMenuHandler, aCreateDialogHandler,
@@ -142,6 +144,7 @@ type
                          aCreateJsDialogHandler, aCreateLifeSpanHandler, aCreateRenderHandler, aCreateRequestHandler,
                          aCreateDragHandler, aCreateFindHandler : boolean); reintroduce; virtual;
       destructor  Destroy; override;
+      procedure   InitializeVars; override;
   end;
 
 implementation
@@ -246,6 +249,11 @@ begin
   Result := False;
 end;
 
+procedure TCefClientRef.InitializeVars;
+begin
+  //
+end;
+
 
 // ******************************************************
 // ****************** TCefClientOwn *********************
@@ -442,6 +450,11 @@ begin
   Result := False;
 end;
 
+procedure TCefClientOwn.InitializeVars;
+begin
+  //
+end;
+
 
 // ******************************************************
 // *************** TCustomClientHandler *****************
@@ -466,7 +479,7 @@ constructor TCustomClientHandler.Create(const events                     : IChro
 begin
   inherited Create;
 
-  InitializeInterfaces;
+  InitializeVars;
 
   FEvents := events;
 
@@ -491,12 +504,12 @@ end;
 
 destructor TCustomClientHandler.Destroy;
 begin
-  InitializeInterfaces;
+  InitializeVars;
 
   inherited Destroy;
 end;
 
-procedure TCustomClientHandler.InitializeInterfaces;
+procedure TCustomClientHandler.InitializeVars;
 begin
   FLoadHandler        := nil;
   FFocusHandler       := nil;

source/uCEFDeleteCookiesCallback.pas

@@ -53,6 +53,7 @@ type
   TCefDeleteCookiesCallbackOwn = class(TCefBaseRefCountedOwn, ICefDeleteCookiesCallback)
     protected
       procedure OnComplete(numDeleted: Integer); virtual; abstract;
+      procedure InitializeVars; virtual; abstract;
 
     public
       constructor Create; virtual;
@@ -66,6 +67,8 @@ type
 
     public
       constructor Create(const callback: TCefDeleteCookiesCallbackProc); reintroduce;
+      destructor  Destroy; override;
+      procedure   InitializeVars; override;
   end;
 
   TCefCustomDeleteCookiesCallback = class(TCefDeleteCookiesCallbackOwn)
@@ -76,6 +79,8 @@ type
 
     public
       constructor Create(const aChromiumBrowser : TObject); reintroduce;
+      destructor  Destroy; override;
+      procedure   InitializeVars; override;
   end;
 
 implementation
@@ -108,7 +113,19 @@ end;
 
 procedure TCefFastDeleteCookiesCallback.OnComplete(numDeleted: Integer);
 begin
-  FCallback(numDeleted)
+  if assigned(FCallback) then FCallback(numDeleted)
+end;
+
+destructor TCefFastDeleteCookiesCallback.Destroy;
+begin
+  InitializeVars;
+
+  inherited Destroy;
+end;
+
+procedure TCefFastDeleteCookiesCallback.InitializeVars;
+begin
+  FCallback := nil;
 end;
 
 // TCefCustomDeleteCookiesCallback
@@ -120,6 +137,18 @@ begin
   FChromiumBrowser := aChromiumBrowser;
 end;
 
+destructor TCefCustomDeleteCookiesCallback.Destroy;
+begin
+  InitializeVars;
+
+  inherited Destroy;
+end;
+
+procedure TCefCustomDeleteCookiesCallback.InitializeVars;
+begin
+  FChromiumBrowser := nil;
+end;
+
 procedure TCefCustomDeleteCookiesCallback.OnComplete(numDeleted: Integer);
 begin
   if (FChromiumBrowser <> nil) and (FChromiumBrowser is TChromium) then

source/uCEFInterfaces.pas

@@ -166,6 +166,7 @@ type
   ICefPdfPrintCallback = interface(ICefBaseRefCounted)
   ['{F1CC58E9-2C30-4932-91AE-467C8D8EFB8E}']
     procedure OnPdfPrintFinished(const path: ustring; ok: Boolean);
+    procedure InitializeVars; // custom procedure to clear all references
   end;
 
   TOnDownloadImageFinishedProc = {$IFDEF DELPHI12_UP}reference to{$ENDIF}
@@ -383,6 +384,7 @@ type
   ICefStringVisitor = interface(ICefBaseRefCounted)
     ['{63ED4D6C-2FC8-4537-964B-B84C008F6158}']
     procedure Visit(const str: ustring);
+    procedure InitializeVars; // custom procedure to clear all references
   end;
 
   ICefFrame = interface(ICefBaseRefCounted)
@@ -859,6 +861,8 @@ type
     function GetLocalizedString(stringId: Integer; var stringVal: ustring): Boolean;
     function GetDataResource(resourceId: Integer; var data: Pointer; var dataSize: NativeUInt): Boolean;
     function GetDataResourceForScale(resourceId: Integer; scaleFactor: TCefScaleFactor; var data: Pointer; var dataSize: NativeUInt): Boolean;
+
+    procedure InitializeVars; // custom procedure to clear all references
   end;
 
   ICefBrowserProcessHandler = interface(ICefBaseRefCounted)
@@ -868,6 +872,8 @@ type
     procedure OnRenderProcessThreadCreated(const extraInfo: ICefListValue);
     function  GetPrintHandler : ICefPrintHandler;
     procedure OnScheduleMessagePumpWork(const delayMs: Int64);
+
+    procedure InitializeVars; // custom procedure to clear all references
   end;
 
   ICefRenderProcessHandler = interface(ICefBaseRefCounted)
@@ -883,6 +889,8 @@ type
     procedure OnUncaughtException(const browser: ICefBrowser; const frame: ICefFrame; const context: ICefv8Context; const exception: ICefV8Exception; const stackTrace: ICefV8StackTrace);
     procedure OnFocusedNodeChanged(const browser: ICefBrowser; const frame: ICefFrame; const node: ICefDomNode);
     function  OnProcessMessageReceived(const browser: ICefBrowser; sourceProcess: TCefProcessId; const aMessage: ICefProcessMessage): Boolean;
+
+    procedure InitializeVars; // custom procedure to clear all references
   end;
 
   ICefApp = interface(ICefBaseRefCounted)
@@ -912,6 +920,7 @@ type
   ICefDeleteCookiesCallback = interface(ICefBaseRefCounted)
     ['{758B79A1-B9E8-4F0D-94A0-DCE5AFADE33D}']
     procedure OnComplete(numDeleted: Integer);
+    procedure InitializeVars; // custom procedure to clear all references
   end;
 
   ICefCookieManager = Interface(ICefBaseRefCounted)
@@ -1377,8 +1386,9 @@ type
     function GetLoadHandler: ICefLoadHandler;
     function GetRenderHandler: ICefRenderHandler;
     function GetRequestHandler: ICefRequestHandler;
-    function OnProcessMessageReceived(const browser: ICefBrowser;
+    function OnProcessMessageReceived(const browser: ICefBrowser; sourceProcess: TCefProcessId; const message: ICefProcessMessage): Boolean;
-      sourceProcess: TCefProcessId; const message: ICefProcessMessage): Boolean;
+
+    procedure InitializeVars; // custom procedure to clear all references
   end;
 
   ICefUrlRequest = interface(ICefBaseRefCounted)
@@ -1482,6 +1492,7 @@ type
   ICefResolveCallback = interface(ICefBaseRefCounted)
     ['{0C0EA252-7968-4163-A1BE-A1453576DD06}']
     procedure OnResolveCompleted(result: TCefErrorCode; const resolvedIps: TStrings);
+    procedure InitializeVars; // custom procedure to clear all references
   end;
 
   ICefRequestContext = interface(ICefBaseRefCounted)

source/uCEFPDFPrintCallback.pas

@@ -54,6 +54,8 @@ type
     protected
       procedure OnPdfPrintFinished(const path: ustring; ok: Boolean); virtual; abstract;
 
+      procedure InitializeVars; virtual; abstract;
+
     public
       constructor Create; virtual;
   end;
@@ -66,6 +68,8 @@ type
 
     public
       constructor Create(const proc: TOnPdfPrintFinishedProc); reintroduce;
+      destructor  Destroy; override;
+      procedure   InitializeVars; override;
   end;
 
   TCefCustomPDFPrintCallBack = class(TCefPdfPrintCallbackOwn)
@@ -76,6 +80,8 @@ type
 
     public
       constructor Create(const aChromiumBrowser : TObject); reintroduce;
+      destructor  Destroy; override;
+      procedure   InitializeVars; override;
   end;
 
 implementation
@@ -105,7 +111,19 @@ end;
 
 procedure TCefFastPdfPrintCallback.OnPdfPrintFinished(const path: ustring; ok: Boolean);
 begin
-  FProc(path, ok);
+  if assigned(FProc) then FProc(path, ok);
+end;
+
+destructor TCefFastPdfPrintCallback.Destroy;
+begin
+  InitializeVars;
+
+  inherited Destroy;
+end;
+
+procedure TCefFastPdfPrintCallback.InitializeVars;
+begin
+  FProc := nil;
 end;
 
 // TCefCustomPDFPrintCallBack
@@ -117,6 +135,18 @@ begin
   FChromiumBrowser := aChromiumBrowser;
 end;
 
+destructor TCefCustomPDFPrintCallBack.Destroy;
+begin
+  InitializeVars;
+
+  inherited Destroy;
+end;
+
+procedure TCefCustomPDFPrintCallBack.InitializeVars;
+begin
+  FChromiumBrowser := nil;
+end;
+
 procedure TCefCustomPDFPrintCallBack.OnPdfPrintFinished(const path: ustring; aResultOK : Boolean);
 begin
   if (FChromiumBrowser <> nil) and (FChromiumBrowser is TChromium) then

source/uCEFRenderProcessHandler.pas

@@ -69,6 +69,9 @@ type
       procedure OnUncaughtException(const browser: ICefBrowser; const frame: ICefFrame; const context: ICefv8Context; const exception: ICefV8Exception; const stackTrace: ICefV8StackTrace); virtual; abstract;
       procedure OnFocusedNodeChanged(const browser: ICefBrowser; const frame: ICefFrame; const node: ICefDomNode); virtual; abstract;
       function  OnProcessMessageReceived(const browser: ICefBrowser; sourceProcess: TCefProcessId; const aMessage: ICefProcessMessage): Boolean; virtual;
+
+      procedure InitializeVars; virtual; abstract;
+
     public
       constructor Create; virtual;
   end;
@@ -91,6 +94,7 @@ type
     public
       constructor Create(const aCefApp : TCefApplication); reintroduce;
       destructor  Destroy; override;
+      procedure   InitializeVars; override;
   end;
 
 implementation
@@ -313,11 +317,16 @@ end;
 
 destructor TCefCustomRenderProcessHandler.Destroy;
 begin
-  FCefApp := nil;
+  InitializeVars;
 
   inherited Destroy;
 end;
 
+procedure TCefCustomRenderProcessHandler.InitializeVars;
+begin
+  FCefApp := nil;
+end;
+
 procedure TCefCustomRenderProcessHandler.OnRenderThreadCreated(const extraInfo: ICefListValue);
 begin
   if (FCefApp <> nil) then FCefApp.Internal_OnRenderThreadCreated(extraInfo);

source/uCEFResolveCallback.pas

@@ -58,6 +58,8 @@ type
   TCefResolveCallbackOwn = class(TCefBaseRefCountedOwn, ICefResolveCallback)
     protected
       procedure OnResolveCompleted(result: TCefErrorCode; const resolvedIps: TStrings); virtual; abstract;
+      procedure InitializeVars; virtual; abstract;
+
     public
       constructor Create; virtual;
   end;
@@ -69,6 +71,8 @@ type
 
     public
       constructor Create(const aChromiumBrowser : TObject); reintroduce;
+      destructor  Destroy; override;
+      procedure   InitializeVars; override;
   end;
 
 implementation
@@ -129,6 +133,18 @@ begin
   FChromiumBrowser := aChromiumBrowser;
 end;
 
+destructor TCefCustomResolveCallback.Destroy;
+begin
+  InitializeVars;
+
+  inherited Destroy;
+end;
+
+procedure TCefCustomResolveCallback.InitializeVars;
+begin
+  FChromiumBrowser := nil;
+end;
+
 procedure TCefCustomResolveCallback.OnResolveCompleted(result: TCefErrorCode; const resolvedIps: TStrings);
 begin
   if (FChromiumBrowser <> nil) and (FChromiumBrowser is TChromium) then

source/uCEFResourceBundleHandler.pas

@@ -56,6 +56,8 @@ type
       function GetDataResource(resourceId: Integer; var data: Pointer; var dataSize: NativeUInt): Boolean; virtual; abstract;
       function GetDataResourceForScale(resourceId: Integer; scaleFactor: TCefScaleFactor; var data: Pointer; var dataSize: NativeUInt): Boolean; virtual; abstract;
 
+      procedure InitializeVars; virtual; abstract;
+
     public
       constructor Create; virtual;
   end;
@@ -71,6 +73,7 @@ type
     public
       constructor Create(const aCefApp : TCefApplication); reintroduce;
       destructor  Destroy; override;
+      procedure   InitializeVars; override;
   end;
 
 implementation
@@ -154,11 +157,16 @@ end;
 
 destructor TCefCustomResourceBundleHandler.Destroy;
 begin
-  FCefApp := nil;
+  InitializeVars;
 
   inherited Destroy;
 end;
 
+procedure TCefCustomResourceBundleHandler.InitializeVars;
+begin
+  FCefApp := nil;
+end;
+
 function TCefCustomResourceBundleHandler.GetLocalizedString(stringid : Integer;
                                                             var stringVal : ustring): Boolean;
 begin

source/uCEFStringVisitor.pas

@@ -53,12 +53,13 @@ type
   TCefStringVisitorOwn = class(TCefBaseRefCountedOwn, ICefStringVisitor)
     protected
       procedure Visit(const str: ustring); virtual;
+      procedure InitializeVars; virtual;
 
     public
       constructor Create; virtual;
   end;
 
-  TCefFastStringVisitor = class(TCefStringVisitorOwn, ICefStringVisitor)
+  TCefFastStringVisitor = class(TCefStringVisitorOwn)
     protected
       FVisit: TCefStringVisitorProc;
 
@@ -76,6 +77,8 @@ type
 
     public
       constructor Create(const aChromiumBrowser : TObject); reintroduce;
+      destructor  Destroy; override;
+      procedure   InitializeVars; override;
   end;
 
 implementation
@@ -102,6 +105,11 @@ begin
   //
 end;
 
+procedure TCefStringVisitorOwn.InitializeVars;
+begin
+  //
+end;
+
 // TCefFastStringVisitor
 
 constructor TCefFastStringVisitor.Create(const callback: TCefStringVisitorProc);
@@ -125,6 +133,18 @@ begin
   FChromiumBrowser := aChromiumBrowser;
 end;
 
+destructor TCustomCefStringVisitor.Destroy;
+begin
+  InitializeVars;
+
+  inherited Destroy;
+end;
+
+procedure TCustomCefStringVisitor.InitializeVars;
+begin
+  FChromiumBrowser := nil;
+end;
+
 procedure TCustomCefStringVisitor.Visit(const str: ustring);
 begin
   if (FChromiumBrowser <> nil) and (FChromiumBrowser is TChromium) then