ui: support dark theme base colour resources

Support dark theme resource dictionaries.

Author: mjcheetham

src/shared/Core/UI/Assets/Base.axaml

@@ -0,0 +1,18 @@
+<ResourceDictionary xmlns="https://github.com/avaloniaui"
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <ResourceDictionary.ThemeDictionaries>
+
+        <ResourceDictionary x:Key="Default">
+            <Color x:Key="WindowBackgroundColor">#F6F6F6</Color>
+            <SolidColorBrush x:Key="WindowBackgroundBrush" Color="{StaticResource WindowBackgroundColor}"/>
+            <SolidColorBrush x:Key="DialogWindowCloseButtonBrush" Color="Black"/>
+        </ResourceDictionary>
+
+        <ResourceDictionary x:Key="Dark">
+            <Color x:Key="WindowBackgroundColor">#282828</Color>
+            <SolidColorBrush x:Key="WindowBackgroundBrush" Color="{StaticResource WindowBackgroundColor}"/>
+            <SolidColorBrush x:Key="DialogWindowCloseButtonBrush" Color="White"/>
+        </ResourceDictionary>
+
+    </ResourceDictionary.ThemeDictionaries>
+</ResourceDictionary>

src/shared/Core/UI/Assets/DarkBase.axaml

@@ -9,7 +9,7 @@
     <Application.Resources>
         <ResourceDictionary>
             <ResourceDictionary.MergedDictionaries>
-                <ResourceInclude Source="avares://gcmcore/UI/Assets/LightBase.axaml"/>
+                <ResourceInclude Source="avares://gcmcore/UI/Assets/Base.axaml"/>
                 <ResourceInclude Source="avares://gcmcore/UI/Assets/Images.axaml"/>
             </ResourceDictionary.MergedDictionaries>
         </ResourceDictionary>

src/shared/Core/UI/Assets/LightBase.axaml

@@ -6,14 +6,11 @@
         x:Class="GitCredentialManager.UI.Controls.AboutWindow"
         Title="About Git Credential Manager"
         CanResize="False" Width="300" SizeToContent="Height"
-        Background="#F6F6F6">
-    <Window.Styles>
-        <StyleInclude Source="avares://gcmcore/UI/Assets/Controls.axaml"/>
-    </Window.Styles>
+        Background="{DynamicResource WindowBackgroundBrush}">
     <StackPanel Margin="20">
         <Image HorizontalAlignment="Center"
                Margin="0,10,0,10"
-               Source="{StaticResource GcmLogo}" Width="128" Height="128" />
+               Source="{DynamicResource GcmLogo}" Width="128" Height="128" />
         <TextBlock HorizontalAlignment="Center"
                    Margin="0,5"
                    FontWeight="Bold" FontSize="13"

src/shared/Core/UI/AvaloniaApp.axaml

@@ -39,7 +39,7 @@
                         </Style>
                     </Button.Styles>
                     <Path Width="16" Height="16"
-                          Fill="Black"
+                          Fill="{DynamicResource DialogWindowCloseButtonBrush}"
                           Data="F1M8.583,8L13,12.424 12.424,13 8,8.583 3.576,13 3,12.424 7.417,8 3,3.576 3.576,3 8,7.417 12.424,3 13,3.576z"/>
                 </Button>
                 <TextBlock DockPanel.Dock="Left" Margin="10,0,0,0"

src/shared/Core/UI/Controls/AboutWindow.axaml

@@ -17,7 +17,7 @@
                         IsVisible="{Binding ShowProductHeader}">
                 <Image Margin="0,0,10,0"
                        VerticalAlignment="Center"
-                       Source="{StaticResource GcmLogo}"
+                       Source="{DynamicResource GcmLogo}"
                        Width="32" Height="32" />
                 <TextBlock Text="Git Credential Manager"
                            VerticalAlignment="Center"

src/shared/Core/UI/Controls/DialogWindow.axaml

@@ -16,7 +16,7 @@
                         IsVisible="{Binding ShowProductHeader}">
                 <Image Margin="0,0,10,0"
                        VerticalAlignment="Center"
-                       Source="{StaticResource GcmLogo}"
+                       Source="{DynamicResource GcmLogo}"
                        Width="32" Height="32" />
                 <TextBlock Text="Git Credential Manager"
                            VerticalAlignment="Center"

src/shared/Core/UI/Views/CredentialsView.axaml

@@ -16,7 +16,7 @@
                         IsVisible="{Binding ShowProductHeader}">
                 <Image Margin="0,0,10,0"
                        VerticalAlignment="Center"
-                       Source="{StaticResource GcmLogo}"
+                       Source="{DynamicResource GcmLogo}"
                        Width="32" Height="32" />
                 <TextBlock Text="Git Credential Manager"
                            VerticalAlignment="Center"