fix #70, #126: switch between Light and Dark background

QuickLook.Plugin/QuickLook.Plugin.ImageViewer/ImagePanel.xaml

@@ -5,6 +5,7 @@
              xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
              xmlns:local="clr-namespace:QuickLook.Plugin.ImageViewer"
              xmlns:animatedImage="clr-namespace:QuickLook.Plugin.ImageViewer.AnimatedImage"
+             xmlns:plugin="clr-namespace:QuickLook.Common.Plugin;assembly=QuickLook.Common"
              mc:Ignorable="d"
              x:Name="imagePanel"
              d:DesignHeight="300" d:DesignWidth="300">
@@ -20,11 +21,32 @@
     <Grid>
         <Rectangle Visibility="{Binding BackgroundVisibility, ElementName=imagePanel}"
                    RenderOptions.BitmapScalingMode="NearestNeighbor">
-            <Rectangle.Fill>
+            <Rectangle.Style>
-                <ImageBrush x:Name="backgroundBrush" ImageSource="Resources/background-b.png" AlignmentY="Top"
+                <Style>
-                            Viewport="0,0,32,32"
+                    <Style.Triggers>
-                            ViewportUnits="Absolute" Stretch="UniformToFill" TileMode="Tile" />
+                        <DataTrigger Binding="{Binding ElementName=imagePanel,Path=Theme}" Value="{x:Static plugin:Themes.Dark}">
-            </Rectangle.Fill>
+                            <Setter Property="Rectangle.Fill">
+                                <Setter.Value>
+                                    <ImageBrush AlignmentY="Top" Viewport="0,0,32,32" RenderOptions.BitmapScalingMode="NearestNeighbor"
+                                                ImageSource="Resources/background-b.png"
+                                                ViewportUnits="Absolute" Stretch="UniformToFill" TileMode="Tile">
+                                    </ImageBrush>
+                                </Setter.Value>
+                            </Setter>
+                        </DataTrigger>
+                        <DataTrigger Binding="{Binding ElementName=imagePanel,Path=Theme}" Value="{x:Static plugin:Themes.Light}">
+                            <Setter Property="Rectangle.Fill">
+                                <Setter.Value>
+                                    <ImageBrush AlignmentY="Top" Viewport="0,0,32,32" RenderOptions.BitmapScalingMode="NearestNeighbor"
+                                                ImageSource="Resources/background.png"
+                                                ViewportUnits="Absolute" Stretch="UniformToFill" TileMode="Tile">
+                                    </ImageBrush>
+                                </Setter.Value>
+                            </Setter>
+                        </DataTrigger>
+                    </Style.Triggers>
+                </Style>
+            </Rectangle.Style>
         </Rectangle>
         <ScrollViewer x:Name="viewPanel" BorderThickness="0" HorizontalScrollBarVisibility="Auto"
                       VerticalScrollBarVisibility="Auto" Focusable="False" IsManipulationEnabled="True">
@@ -56,6 +78,11 @@
                 Visibility="{Binding ElementName=imagePanel, Path=MetaIconVisibility}"
                 Margin="0,8,8,0" Content="&#xE946;" />
 
+        <Button x:Name="buttonBackgroundColour" Style="{StaticResource CaptionButtonStyle}" Width="24" Height="24"
+                HorizontalAlignment="Right" VerticalAlignment="Top"
+                Visibility="{Binding ElementName=imagePanel, Path=BackgroundVisibility}"
+                Margin="0,8,40,0" Content="&#xEF1F;" />
+
         <TextBlock x:Name="textMeta" IsHitTestVisible="False" Visibility="Collapsed" HorizontalAlignment="Right"
                    VerticalAlignment="Top" FontSize="11"
                    Padding="5,5,5,5" Margin="0,40,8,0" Background="{DynamicResource CaptionBackground}"

QuickLook.Plugin/QuickLook.Plugin.ImageViewer/ImagePanel.xaml.cs

@@ -33,6 +33,7 @@ using System.Windows.Threading;
 using QuickLook.Common.Annotations;
 using QuickLook.Common.ExtensionMethods;
 using QuickLook.Common.Helpers;
+using QuickLook.Common.Plugin;
 using QuickLook.Plugin.ImageViewer.Exiv2;
 
 namespace QuickLook.Plugin.ImageViewer
@@ -42,6 +43,7 @@ namespace QuickLook.Plugin.ImageViewer
     /// </summary>
     public partial class ImagePanel : UserControl, INotifyPropertyChanged, IDisposable
     {
+        private readonly ContextObject _context;
         private Visibility _backgroundVisibility = Visibility.Visible;
         private Point? _dragInitPos;
         private Uri _imageSource;
@@ -70,10 +72,7 @@ namespace QuickLook.Plugin.ImageViewer
                     ? Visibility.Visible
                     : Visibility.Collapsed;
 
-            var scale = DpiHelper.GetCurrentScaleFactor();
+            buttonBackgroundColour.Click += OnBackgroundColourOnClick;
-            backgroundBrush.Viewport = new Rect(new Size(
-                backgroundBrush.ImageSource.Width / scale.Horizontal,
-                backgroundBrush.ImageSource.Height / scale.Vertical));
 
             SizeChanged += ImagePanel_SizeChanged;
 
@@ -86,11 +85,13 @@ namespace QuickLook.Plugin.ImageViewer
             viewPanel.ManipulationDelta += ViewPanel_ManipulationDelta;
         }
 
-        internal ImagePanel(Meta meta) : this()
+        internal ImagePanel(ContextObject context, Meta meta) : this()
         {
+            _context = context;
             Meta = meta;
 
             ShowMeta();
+            Theme = _context.Theme;
         }
 
         public bool ShowZoomLevelInfo
@@ -104,6 +105,16 @@ namespace QuickLook.Plugin.ImageViewer
             }
         }
 
+        public Themes Theme
+        {
+            get => _context?.Theme ?? Themes.Dark;
+            set
+            {
+                _context.Theme = value;
+                OnPropertyChanged();
+            }
+        }
+
         public BitmapScalingMode RenderMode
         {
             get => _renderMode;
@@ -235,6 +246,13 @@ namespace QuickLook.Plugin.ImageViewer
 
         public event PropertyChangedEventHandler PropertyChanged;
 
+        private void OnBackgroundColourOnClick(object sender, RoutedEventArgs e)
+        {
+            Theme = Theme == Themes.Dark ? Themes.Light : Themes.Dark;
+
+            SettingHelper.Set("LastTheme", (int) Theme);
+        }
+
         private void ShowMeta()
         {
             textMeta.Inlines.Clear();

QuickLook.Plugin/QuickLook.Plugin.ImageViewer/Plugin.cs

@@ -20,6 +20,7 @@ using System.IO;
 using System.Linq;
 using System.Windows;
 using ImageMagick;
+using QuickLook.Common.Helpers;
 using QuickLook.Common.Plugin;
 using QuickLook.Plugin.ImageViewer.Exiv2;
 
@@ -64,12 +65,12 @@ namespace QuickLook.Plugin.ImageViewer
             else
                 context.PreferredSize = new Size(800, 600);
 
-            context.Theme = Themes.Dark;
+            context.Theme = (Themes) SettingHelper.Get("LastTheme", 1);
         }
 
         public void View(string path, ContextObject context)
         {
-            _ip = new ImagePanel(_meta);
+            _ip = new ImagePanel(context, _meta);
 
             context.ViewerContent = _ip;
             context.Title = _imageSize.IsEmpty