Fix bug where losing focus removes color; Closes #144;

XamlControlsGallery/ControlPages/RichEditBoxPage.xaml

@@ -155,8 +155,9 @@
                              RelativePanel.Below="openFileButton" 
                              RelativePanel.AlignLeftWithPanel="True" 
                              RelativePanel.AlignRightWithPanel="True" 
-                             TextChanged="Editor_TextChanged"
-                             GotFocus="Editor_GotFocus"/>
+                             TextChanging="Editor_TextChanging"
+                             GotFocus="Editor_GotFocus"
+                             LosingFocus="Editor_LosingFocus"/>
                 <StackPanel Orientation="Horizontal" 
                             RelativePanel.Below="editor" 
                             RelativePanel.AlignLeftWith="editor" 

XamlControlsGallery/ControlPages/RichEditBoxPage.xaml.cs

@@ -1,4 +1,4 @@
-//*********************************************************
+//*********************************************************
 //
 // Copyright (c) Microsoft. All rights reserved.
 // THIS CODE IS PROVIDED *AS IS* WITHOUT WARRANTY OF
@@ -25,7 +25,9 @@ namespace AppUIBasics.ControlPages
     public sealed partial class RichEditBoxPage : Page
     {
         private Color currentColor = Colors.Black;
-
+        // String used to restore the colors when the focus gets reenabled
+        // See #144 for more info https://github.com/microsoft/Xaml-Controls-Gallery/issues/144
+        private string LastFormattedText = "";
         public RichEditBoxPage()
         {
             this.InitializeComponent();
@@ -160,10 +162,34 @@ private void Editor_GotFocus(object sender, RoutedEventArgs e)
             SolidColorBrush background = (SolidColorBrush)App.Current.Resources["TextControlBackgroundFocused"];
             SolidColorBrush foreground = (SolidColorBrush)App.Current.Resources["TextControlForegroundFocused"];
 
+            editor.Document.ApplyDisplayUpdates();
+
             if (background != null && foreground != null)
             {
                 documentRange.CharacterFormat.BackgroundColor = background.Color;
             }
+            // saving selection span
+            var caretPosition = editor.Document.Selection.GetIndex(TextRangeUnit.Character) - 1;
+            if(caretPosition <= 0)
+            {
+                // User has not entered text, prevent invalid values and just set index to 1
+                caretPosition = 1;
+            }
+            var selectionLength = editor.Document.Selection.Length;
+            // restoring text styling, unintentionally sets caret position at beginning of text
+            editor.Document.SetText(TextSetOptions.FormatRtf, LastFormattedText);
+            // restoring selection position
+            editor.Document.Selection.SetIndex(TextRangeUnit.Character, caretPosition, false);
+            editor.Document.Selection.SetRange(caretPosition, caretPosition + selectionLength);
+            // Editor might have gained focus because user changed color.
+            // Change selection color
+            // Note that only way to regain with selection containing text is using the change color button
+            editor.Document.Selection.CharacterFormat.ForegroundColor = currentColor;
+        }
+
+        private void Editor_LosingFocus(object sender, RoutedEventArgs e)
+        {
+            editor.Document.GetText(TextGetOptions.FormatRtf, out LastFormattedText);
         }
 
         private void Page_SizeChanged(object sender, SizeChangedEventArgs e)
@@ -201,9 +227,13 @@ private void REBCustom_Unloaded(object sender, RoutedEventArgs e)
             }
         }
 
-        private void Editor_TextChanged(object sender, RoutedEventArgs e)
+        private void Editor_TextChanging(object sender, RichEditBoxTextChangingEventArgs e)
         {
-            editor.Document.Selection.CharacterFormat.ForegroundColor = currentColor;
+            // Fix bug where selected text would get colored when editor loses focus
+            if (FocusManager.GetFocusedElement() == editor)
+            {
+                editor.Document.Selection.CharacterFormat.ForegroundColor = currentColor;
+            }
         }
     }
 }

XamlControlsGallery/ControlPagesSampleCode/Text/RichEditBox/RichEditBoxSample3_cs.txt

@@ -1,4 +1,6 @@
-
+private Color currentColor = Colors.Black;
+private string LastFormattedText = "";
+
 private async void OpenButton_Click(object sender, RoutedEventArgs e)
 {
     // Open a text file.
@@ -78,6 +80,7 @@ private void ColorButton_Click(object sender, RoutedEventArgs e)
 
     fontColorButton.Flyout.Hide();
     editor.Focus(Windows.UI.Xaml.FocusState.Keyboard);
+    currentColor = color;
 }
 
 private void FindBoxHighlightMatches()
@@ -116,9 +119,40 @@ private void Editor_GotFocus(object sender, RoutedEventArgs e)
     SolidColorBrush background = (SolidColorBrush)App.Current.Resources["TextControlBackgroundFocused"];
     SolidColorBrush foreground = (SolidColorBrush)App.Current.Resources["TextControlForegroundFocused"];
 
+    editor.Document.ApplyDisplayUpdates();
+
     if (background != null && foreground != null)
     {
         documentRange.CharacterFormat.BackgroundColor = background.Color;
-        documentRange.CharacterFormat.ForegroundColor = foreground.Color;
     }
+    // saving selection span
+    var caretPosition = editor.Document.Selection.GetIndex(TextRangeUnit.Character) - 1;
+    if(caretPosition <= 0)
+    {
+        caretPosition = 1;
+    }
+    var selectionLength = editor.Document.Selection.Length;
+    // restoring text styling, unintentionally sets caret position at beginning of text
+    editor.Document.SetText(TextSetOptions.FormatRtf, LastFormattedText);
+    // restoring selection position
+    editor.Document.Selection.SetIndex(TextRangeUnit.Character, caretPosition, false);
+    editor.Document.Selection.SetRange(caretPosition, caretPosition + selectionLength);
+    // Editor might have gained focus because user changed color.
+    // Change selection color
+    // Note that only way to regain with selection containing text is using the change color button
+    editor.Document.Selection.CharacterFormat.ForegroundColor = currentColor;
 }
+
+private void Editor_LosingFocus(object sender, RoutedEventArgs e)
+{
+    editor.Document.GetText(TextGetOptions.FormatRtf, out LastFormattedText);
+}
+
+private void Editor_TextChanging(object sender, RichEditBoxTextChangingEventArgs e)
+{
+    // Fix bug where selected text would get colored when editor loses focus
+    if (FocusManager.GetFocusedElement() == editor)
+    {
+        editor.Document.Selection.CharacterFormat.ForegroundColor = currentColor;
+    }
+}

XamlControlsGallery/ControlPagesSampleCode/Text/RichEditBox/RichEditBoxSample3_xaml.txt

@@ -104,7 +104,9 @@
                  RelativePanel.Below="openFileButton" 
                  RelativePanel.AlignLeftWithPanel="True" 
                  RelativePanel.AlignRightWithPanel="True"
-                 GotFocus="Editor_GotFocus" />
+                 TextChanging="Editor_TextChanging"
+                 GotFocus="Editor_GotFocus"
+                 LosingFocus="Editor_LosingFocus"/>
     <StackPanel Orientation="Horizontal" 
                 RelativePanel.Below="editor" 
                 RelativePanel.AlignLeftWith="editor"