From 18eefa0037aae483b852b44505c72c9ecaab33e2 Mon Sep 17 00:00:00 2001
From: Yimeng Wu <me@kinnara.cn>
Date: Mon, 21 Dec 2020 01:15:26 +0800
Subject: [PATCH] Progressbar: Fix issue with color changing when updating
 value while error state (microsoft/microsoft-ui-xaml#3201)

---
 ModernWpf/Controls/Primitives/BindingProxy.cs | 28 +++++++++
 ModernWpf/ProgressBar/ProgressBar.cs          | 57 ++++++++++++-------
 ModernWpf/ProgressBar/ProgressBar.xaml        | 39 ++++++++++---
 3 files changed, 94 insertions(+), 30 deletions(-)
 create mode 100644 ModernWpf/Controls/Primitives/BindingProxy.cs

diff --git a/ModernWpf/Controls/Primitives/BindingProxy.cs b/ModernWpf/Controls/Primitives/BindingProxy.cs
new file mode 100644
index 00000000..5cca8369
--- /dev/null
+++ b/ModernWpf/Controls/Primitives/BindingProxy.cs
@@ -0,0 +1,28 @@
+using System.Windows;
+
+namespace ModernWpf.Controls.Primitives
+{
+    public class BindingProxy : Freezable
+    {
+        #region Value
+
+        public static readonly DependencyProperty ValueProperty =
+            DependencyProperty.Register(
+                nameof(Value),
+                typeof(object),
+                typeof(BindingProxy));
+
+        public object Value
+        {
+            get => GetValue(ValueProperty);
+            set => SetValue(ValueProperty, value);
+        }
+
+        #endregion
+
+        protected override Freezable CreateInstanceCore()
+        {
+            return new BindingProxy();
+        }
+    }
+}
diff --git a/ModernWpf/ProgressBar/ProgressBar.cs b/ModernWpf/ProgressBar/ProgressBar.cs
index e133d1c0..a39ef3c9 100644
--- a/ModernWpf/ProgressBar/ProgressBar.cs
+++ b/ModernWpf/ProgressBar/ProgressBar.cs
@@ -270,31 +270,38 @@ private void OnShowErrorPropertyChanged(DependencyPropertyChangedEventArgs args)
 
         private void UpdateStates(bool useTransitions = true)
         {
-            if (ShowError && IsIndeterminate)
-            {
-                VisualStateManager.GoToState(this, s_IndeterminateErrorStateName, useTransitions);
-            }
-            else if (ShowError)
-            {
-                VisualStateManager.GoToState(this, s_ErrorStateName, useTransitions);
-            }
-            else if (ShowPaused && IsIndeterminate)
-            {
-                VisualStateManager.GoToState(this, s_IndeterminatePausedStateName, useTransitions);
-            }
-            else if (ShowPaused)
-            {
-                VisualStateManager.GoToState(this, s_PausedStateName, useTransitions);
-            }
-            else if (IsIndeterminate)
+            if (IsIndeterminate)
             {
+                if (ShowError)
+                {
+                    VisualStateManager.GoToState(this, s_IndeterminateErrorStateName, true);
+                }
+                else if (ShowPaused)
+                {
+                    VisualStateManager.GoToState(this, s_IndeterminatePausedStateName, true);
+                }
+                else
+                {
+                    VisualStateManager.GoToState(this, s_IndeterminateStateName, true);
+                }
                 UpdateWidthBasedTemplateSettings();
-                VisualStateManager.GoToState(this, s_IndeterminateStateName, useTransitions);
             }
-            else if (!IsIndeterminate)
+            else
             {
-                VisualStateManager.GoToState(this, s_DeterminateStateName, useTransitions);
+                if (ShowError)
+                {
+                    VisualStateManager.GoToState(this, s_ErrorStateName, true);
+                }
+                else if (ShowPaused)
+                {
+                    VisualStateManager.GoToState(this, s_PausedStateName, true);
+                }
+                else
+                {
+                    VisualStateManager.GoToState(this, s_DeterminateStateName, true);
+                }
             }
+
         }
 
         private void SetProgressBarIndicatorWidth()
@@ -315,7 +322,14 @@ private void SetProgressBarIndicatorWidth()
 
                     // Adds "Updating" state in between to trigger RepositionThemeAnimation Visual Transition
                     // in ProgressBar.xaml when reverting back to previous state
-                    VisualStateManager.GoToState(this, s_UpdatingStateName, true);
+                    if (ShowError)
+                    {
+                        VisualStateManager.GoToState(this, s_UpdatingWithErrorStateName, true);
+                    }
+                    else
+                    {
+                        VisualStateManager.GoToState(this, s_UpdatingStateName, true);
+                    }
 
                     if (IsIndeterminate)
                     {
@@ -473,5 +487,6 @@ private void ReapplyIndeterminateStoryboard()
         const string s_IndeterminatePausedStateName = "IndeterminatePaused";
         const string s_DeterminateStateName = "Determinate";
         const string s_UpdatingStateName = "Updating";
+        const string s_UpdatingWithErrorStateName = "UpdatingError";
     }
 }
diff --git a/ModernWpf/ProgressBar/ProgressBar.xaml b/ModernWpf/ProgressBar/ProgressBar.xaml
index b735463f..9beeb011 100644
--- a/ModernWpf/ProgressBar/ProgressBar.xaml
+++ b/ModernWpf/ProgressBar/ProgressBar.xaml
@@ -28,14 +28,20 @@
                         x:Name="LayoutRoot"
                         SnapsToDevicePixels="True">
                         <Grid.Resources>
+                            <primitives:BindingProxy
+                                x:Key="SystemControlErrorTextForegroundBrushProxy"
+                                Value="{DynamicResource SystemControlErrorTextForegroundBrush}" />
                             <Storyboard x:Key="UpdatingToDeterminateStoryboard">
-                                <!-- Using a nested Storyboard to work around https://stackoverflow.com/questions/5002501 -->
-                                <Storyboard>
-                                    <DoubleAnimationUsingKeyFrames Storyboard.TargetName="DeterminateProgressBarIndicator" Storyboard.TargetProperty="(UIElement.RenderTransform).(TranslateTransform.X)">
-                                        <DiscreteDoubleKeyFrame KeyTime="0" Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=TemplateSettings.IndicatorLengthDelta}" />
-                                        <SplineDoubleKeyFrame KeyTime="0:0:0.367" Value="0" KeySpline="0.1,0.9 0.2,1" />
-                                    </DoubleAnimationUsingKeyFrames>
-                                </Storyboard>
+                                <DoubleAnimationUsingKeyFrames Storyboard.TargetName="DeterminateProgressBarIndicator" Storyboard.TargetProperty="(UIElement.RenderTransform).(TranslateTransform.X)">
+                                    <DiscreteDoubleKeyFrame KeyTime="0" Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=TemplateSettings.IndicatorLengthDelta}" />
+                                    <SplineDoubleKeyFrame KeyTime="0:0:0.367" Value="0" KeySpline="0.1,0.9 0.2,1" />
+                                </DoubleAnimationUsingKeyFrames>
+                            </Storyboard>
+                            <Storyboard x:Key="UpdatingErrorToErrorStoryboard">
+                                <DoubleAnimationUsingKeyFrames Storyboard.TargetName="DeterminateProgressBarIndicator" Storyboard.TargetProperty="(UIElement.RenderTransform).(TranslateTransform.X)">
+                                    <DiscreteDoubleKeyFrame KeyTime="0" Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=TemplateSettings.IndicatorLengthDelta}" />
+                                    <SplineDoubleKeyFrame KeyTime="0:0:0.367" Value="0" KeySpline="0.1,0.9 0.2,1" />
+                                </DoubleAnimationUsingKeyFrames>
                             </Storyboard>
                             <Storyboard x:Key="IndeterminateStoryboard" RepeatBehavior="Forever">
                                 <DoubleAnimationUsingKeyFrames Storyboard.TargetName="IndeterminateProgressBarIndicator" Storyboard.TargetProperty="(UIElement.RenderTransform).(TranslateTransform.X)">
@@ -87,7 +93,7 @@
                                         Value="{DynamicResource SystemAccentColor}"
                                         KeyTime="0:0:2.75" />
                                     <LinearColorKeyFrame
-                                        Value="{DynamicResource SystemErrorTextColor}"
+                                        Value="{Binding Source={StaticResource SystemControlErrorTextForegroundBrushProxy}, Path=Value.Color}"
                                         KeyTime="0:0:3" />
                                 </ColorAnimationUsingKeyFrames>
                                 <ColorAnimationUsingKeyFrames
@@ -106,7 +112,7 @@
                                 <ColorAnimation
                                     Storyboard.TargetName="DeterminateProgressBarIndicator"
                                     Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)"
-                                    To="{DynamicResource SystemErrorTextColor}"
+                                    To="{Binding Source={StaticResource SystemControlErrorTextForegroundBrushProxy}, Path=Value.Color}"
                                     Duration="0:0:0.25" />
                                 <ColorAnimation
                                     Storyboard.TargetName="ProgressBarRoot"
@@ -167,6 +173,7 @@
 
                                 <VisualStateGroup.Transitions>
                                     <VisualTransition From="Updating" To="Determinate" Storyboard="{StaticResource UpdatingToDeterminateStoryboard}" />
+                                    <VisualTransition From="UpdatingError" To="Error" Storyboard="{StaticResource UpdatingErrorToErrorStoryboard}" />
                                     <VisualTransition From="Paused" To="Determinate">
                                         <Storyboard>
                                             <Storyboard>
@@ -190,6 +197,20 @@
                                 </VisualStateGroup.Transitions>
                                 <VisualState x:Name="Determinate" />
                                 <VisualState x:Name="Updating" />
+                                <VisualState x:Name="UpdatingError">
+                                    <Storyboard>
+                                        <ColorAnimation
+                                            Storyboard.TargetName="DeterminateProgressBarIndicator"
+                                            Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)"
+                                            To="{Binding Source={StaticResource SystemControlErrorTextForegroundBrushProxy}, Path=Value.Color}"
+                                            Duration="0:0:0.0" />
+                                        <ColorAnimation
+                                            Storyboard.TargetName="ProgressBarRoot"
+                                            Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)"
+                                            To="{DynamicResource SystemControlErrorBackgroundColor}"
+                                            Duration="0:0:0.0" />
+                                    </Storyboard>
+                                </VisualState>
                                 <VisualState x:Name="Indeterminate" Storyboard="{StaticResource IndeterminateStoryboard}" />
                                 <VisualState x:Name="IndeterminateError" Storyboard="{StaticResource IndeterminateErrorStoryboard}" />
                                 <VisualState x:Name="Error" Storyboard="{StaticResource ErrorStoryboard}" />