protected override void OnAddressChange(CefBrowser browser, CefFrame frame, string url)
 {
     if (frame.IsMain)
     {
         _core.OnAddressChanged(url);
     }
 }

		protected override void OnBeforeClose(CefBrowser browser)
		{
			if (_core.InvokeRequired)
				_core.BeginInvoke((Action)_core.OnBeforeClose);
			else
				_core.OnBeforeClose();
		}

 protected override bool OnJSPrompt(CefBrowser browser, CefFrame frame, string message, string defaultValue, out bool retval, out string result)
 {
     // TODO: CefWebJSDialogHandler.OnJSPrompt
     retval = false;
     result = null;
     return false;
 }

 protected override void OnAddressChange(CefBrowser browser, CefFrame frame, string url)
 {
     if (frame.IsMain)
     {
        _core.InvokeIfRequired(() => _core.OnAddressChanged(new AddressChangedEventArgs(frame, url)));
     }
 }

 protected override void OnNavStateChange(CefBrowser browser, bool canGoBack, bool canGoForward)
 {
     #if DIAGNOSTICS
     Cef.Logger.Trace(LogTarget.CefDisplayHandler, "OnNavStateChange: CanGoBack=[{0}] CanGoForward=[{1}]", canGoBack, canGoForward);
     #endif
     this.context.OnNavStateChanged(canGoBack, canGoForward);
 }

 public ConsoleMessageEventArgs(CefBrowser browser, string message, string source, int line)
 {
     this.CefBrowser = browser;
     this.Message = message;
     this.Source = source;
     this.Line = line;
 }

		protected override bool OnConsoleMessage(CefBrowser browser, string message, string source, int line)
		{
			var e = new ConsoleMessageEventArgs(message, source, line);
			_core.InvokeIfRequired(() => _core.OnConsoleMessage(e));

			return e.Handled;
		}

        protected override void OnAfterCreated(CefBrowser browser)
        {
            #if DIAGNOSTICS
            Cef.Logger.Trace(LogTarget.CefLifeSpanHandler, "OnAfterCreated");
            #endif

            this.context.OnAfterCreated(browser);

            // TODO: check context state, it can be already closed
            this.context.Attach(browser);

            /*
            if (!browser.IsPopup)
            {
                if (this.context.IsDisposed)
                {
                    browser.Close();
                    return;
                }

                this.context.browser = browser;
                this.context.browserWindowHandle = browser.WindowHandle;

                this.context.SetStyle(ControlStyles.Opaque, true);

                this.context.ResizeBrowserWindow();

                // FIXME: this is invalid - can't be accessed from another thread
                //if (this.control.Focused)
                //{
                //    this.control.browser.SetFocus(true);
                //}
            }
            */
        }

 protected unsafe override void OnContextReleased(CefBrowser browser, CefFrame frame, CefV8Context context)
 {
     if (_context.MainFrame != null)
     {
         _context.MainFrame.UnbindV8Context();
     }
 }

        protected override bool OnBeforeBrowse(CefBrowser browser, CefFrame frame, CefRequest request, CefHandlerNavType navType, bool isRedirect)
        {
            #if DIAGNOSTICS
            Cef.Logger.Trace(LogTarget.CefRequestHandler, "OnBeforeBrowse: Method=[{0}] Url=[{1}] NavType=[{2}] IsRedirect=[{3}]", request.GetMethod(), request.GetURL(), navType, isRedirect);
            #endif

            var cancel = this.context.OnNavigating(frame, request, navType, isRedirect);
            if (cancel) return true;

            if (frame.IsMain)
            {
                // browser navigating to a new page
                this.context.ClearFrames();
                this.context.AttachMainFrame(frame);

                this.context.ClearReadyState();
                this.context.SetFrameReadyState(null, FrameReadyState.Navigating);
            }
            else if ((this.context.ReadyOptions & CefReadyOptions.Frames) != 0)
            {
                this.context.SetFrameReadyState(frame.GetName(), FrameReadyState.Navigating);
            }

            return false;
        }

        protected override void OnTitleChange(CefBrowser browser, string title)
        {
            #if DIAGNOSTICS
            Cef.Logger.Trace(LogTarget.CefDisplayHandler, "OnTitleChange: Title=[{0}]", title);
            #endif

            this.context.OnTitleChanged(title);
        }

 protected override void OnCursorChange(CefBrowser browser, IntPtr cursorHandle)
 {
     _uiHelper.PerformInUiThread(() =>
         {
             Cursor cursor = CursorInteropHelper.Create(new SafeFileHandle(cursorHandle, false));
             _owner.Cursor = cursor;
         });
 }

 public CefUncaughtExceptionEventArgs(CefBrowser browser, CefFrame frame, CefV8Context context, CefV8Exception exception, CefV8StackTrace stackTrace)
 {
     this.browser = browser;
     this.frame = frame;
     this.context = context;
     this.exception = exception;
     this.stackTrace = stackTrace;
 }

        protected override bool DoClose(CefBrowser browser)
        {
            #if DIAGNOSTICS
            Cef.Logger.Trace(LogTarget.CefLifeSpanHandler, "DoClose");
            #endif

            return false;
        }

 public CefBeforePopupEventArgs(CefBrowser parentBrowser, CefPopupFeatures popupFeatures, CefWindowInfo windowInfo, string url, ref CefClient client, CefBrowserSettings settings)
 {
     this.parentBrowser = parentBrowser;
     this.popupFeatures = popupFeatures;
     this.windowInfo = windowInfo;
     this.url = url;
     this.client = client;
     this.settings = settings;
 }

        protected override bool OnKeyEvent(CefBrowser browser, CefHandlerKeyEventType type, int code, CefHandlerKeyEventModifiers modifiers, bool isSystemKey, bool isAfterJavaScript)
        {
            #if DIAGNOSTICS
            Cef.Logger.Trace(LogTarget.CefKeyboardHandler, "OnKeyEvent: type=[{0}] code=[{1}] modifiers=[{2}] isSystemKey=[{3}] isAfterJavaScript=[{4}]", type, code, modifiers, isSystemKey, isAfterJavaScript);
            #endif

            // TODO: CefWebKeyboardHandler.OnKeyEvent: return this.context.PostKeyEvent(type, code, modifiers, isSystemKey);
            return false;
        }

 protected override void OnAddressChange(CefBrowser browser, CefFrame frame, string url)
 {
     #if DIAGNOSTICS
     Cef.Logger.Trace(LogTarget.CefDisplayHandler, "OnAddressChange: URL=[{0}] Frame.IsMain=[{1}]", url, frame.IsMain);
     #endif
     if (frame.IsMain)
     {
         this.context.OnAddressChanged(url);
     }
 }

        protected override bool OnConsoleMessage(CefBrowser browser, string message, string source, int line)
        {
            #if DIAGNOSTICS
            Cef.Logger.Trace(LogTarget.CefDisplayHandler, "OnConsoleMessage: Message=[{0}] Source=[{1}] Line=[{2}]", message, source, line);
            #endif
            // FIXME: check context state? if (this.context.IsDisposed) return false;

            this.context.OnConsoleMessage(new ConsoleMessageEventArgs(message, source, line));

            return true;
        }

        // TODO: use OnBeforeResourceLoad to OnResourceResponse to detect resource loading, and waiting when all resources will be loaded
        protected override bool OnBeforeResourceLoad(CefBrowser browser, CefRequest request, out string redirectUrl, out CefStreamReader resourceStream, CefResponse response, int loadFlags)
        {
            var prevColor = Console.ForegroundColor;
            Console.ForegroundColor = ConsoleColor.DarkMagenta;
            Console.WriteLine("OnBeforeResourceLoad: {0}", request.GetURL());
            Console.ForegroundColor = prevColor;

            redirectUrl = null;
            resourceStream = null;
            return false;
        }

        internal void OnCreated(CefBrowser browser)
        {
            //if (_created) throw new InvalidOperationException("Browser already created.");
            _created = true;
            _browser = browser;

            var handler = Created;
            if (handler != null)
            {
                handler(this, EventArgs.Empty);
            }
        }