WPF - Allow setting Focus before the underlying browser has been initialized.

- Remove hacks from the ViewModel as Focus can now be set on Go().
- Creating a new viewmodel also sets focus

Changing tabs doesn't set focus currently.

Author: amaitland

CefSharp.Wpf.Example/ViewModels/BrowserTabViewModel.cs

@@ -187,19 +187,6 @@ private void OnPropertyChanged(object sender, PropertyChangedEventArgs e)
                     {
                         WebBrowser.ConsoleMessage += OnWebBrowserConsoleMessage;
                         WebBrowser.StatusMessage += OnWebBrowserStatusMessage;
-
-                        // TODO: This is a bit of a hack. It would be nicer/cleaner to give the webBrowser focus in the Go()
-                        // TODO: method, but it seems like "something" gets messed up (= doesn't work correctly) if we give it
-                        // TODO: focus "too early" in the loading process...
-                        WebBrowser.FrameLoadEnd += (s, args) =>
-                        {
-                            //Sender is the ChromiumWebBrowser object 
-                            var browser = s as ChromiumWebBrowser;
-                            if (browser != null && !browser.IsDisposed)
-                            {
-                                browser.Dispatcher.BeginInvoke((Action)(() => browser.Focus()));
-                            }
-                        };
                     }
 
                     break;
@@ -220,8 +207,7 @@ private void Go()
         {
             Address = AddressEditable;
 
-            // Part of the Focus hack further described in the OnPropertyChanged() method...
-            Keyboard.ClearFocus();
+            Keyboard.Focus((IInputElement)WebBrowser);
         }
 
         public void LoadCustomRequestExample()

CefSharp.Wpf.Example/Views/BrowserTabView.xaml

@@ -9,6 +9,7 @@
              mc:Ignorable="d"
              d:DesignWidth="640"
              d:DesignHeight="480"
+             FocusManager.FocusedElement="{Binding ElementName=browser}"
              d:DataContext="{d:DesignInstance local:BrowserTabViewModel}">
     <UserControl.Resources>
         <BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter" />

CefSharp.Wpf/ChromiumWebBrowser.cs

@@ -147,6 +147,12 @@ public partial class ChromiumWebBrowser : Control, IRenderWebBrowser, IWpfWebBro
         /// </summary>
         private int disposeSignaled;
 
+        /// <summary>
+        /// This flag is set when the browser gets focus before the underlying CEF browser
+        /// has been initialized.
+        /// </summary>
+        private bool initialFocus;
+
         /// <summary>
         /// Hack to work around issue https://github.com/cefsharp/CefSharp/issues/2779
         /// Enabled by default
@@ -1124,6 +1130,11 @@ void IWebBrowserInternal.OnAfterBrowserCreated(IBrowser browser)
                     }
                 }
             });
+
+            if(initialFocus)
+            {
+                browser.GetHost()?.SendFocusEvent(true);
+            }
         }
 
         #region CanGoBack dependency property
@@ -2162,7 +2173,11 @@ private void UpdateTooltip(string text)
         /// <param name="e">The <see cref="KeyboardFocusChangedEventArgs"/> instance containing the event data.</param>
         private void OnGotKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
         {
-            if (browser != null)
+            if (browser == null)
+            {
+                initialFocus = true;
+            }
+            else
             {
                 browser.GetHost().SendFocusEvent(true);
             }
@@ -2175,7 +2190,11 @@ private void OnGotKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
         /// <param name="e">The <see cref="KeyboardFocusChangedEventArgs"/> instance containing the event data.</param>
         private void OnLostKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
         {
-            if (browser != null)
+            if (browser == null)
+            {
+                initialFocus = false;
+            }
+            else
             {
                 browser.GetHost().SendFocusEvent(false);
             }