From 00c1125124713b2bbcb945bd75e433d4455197da Mon Sep 17 00:00:00 2001
From: Neakita <thekatterdev@gmail.com>
Date: Wed, 23 Oct 2024 22:32:41 +0500
Subject: [PATCH] Adaptive annotation Thumbnail scaling

---
 .../Annotation/ScreenshotViewModel.cs         |  2 +-
 .../Annotation/Screenshots.axaml              | 22 ++++++++----
 .../ScreenshotToScaledBitmapConverter.cs      | 36 +++++++++++++++++++
 3 files changed, 52 insertions(+), 8 deletions(-)
 create mode 100644 SightKeeper.Avalonia/ScreenshotToScaledBitmapConverter.cs

diff --git a/SightKeeper.Avalonia/Annotation/ScreenshotViewModel.cs b/SightKeeper.Avalonia/Annotation/ScreenshotViewModel.cs
index 4a8c18a7..18253352 100644
--- a/SightKeeper.Avalonia/Annotation/ScreenshotViewModel.cs
+++ b/SightKeeper.Avalonia/Annotation/ScreenshotViewModel.cs
@@ -43,7 +43,7 @@ private unsafe WriteableBitmap LoadImage()
 		return bitmap;
 	}
 
-	private unsafe WriteableBitmap LoadImage(int maximumLargestDimension)
+	internal unsafe WriteableBitmap LoadImage(int maximumLargestDimension)
 	{
 		PixelSize size = ComputeThumbnailSize(maximumLargestDimension);
 		WriteableBitmap bitmap = _bitmapPool.Rent(size, PixelFormat.Rgb32);
diff --git a/SightKeeper.Avalonia/Annotation/Screenshots.axaml b/SightKeeper.Avalonia/Annotation/Screenshots.axaml
index 2629342e..b923e90e 100644
--- a/SightKeeper.Avalonia/Annotation/Screenshots.axaml
+++ b/SightKeeper.Avalonia/Annotation/Screenshots.axaml
@@ -4,6 +4,7 @@
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
              xmlns:local="clr-namespace:SightKeeper.Avalonia.Annotation"
              xmlns:behaviors="clr-namespace:SightKeeper.Avalonia.Behaviors"
+             xmlns:instance="clr-namespace:SightKeeper.Avalonia"
              mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
              x:Class="SightKeeper.Avalonia.Annotation.Screenshots"
              x:DataType="local:ScreenshotsViewModel">
@@ -18,13 +19,20 @@
         </ListBox.ItemsPanel>
         <ListBox.ItemTemplate>
             <DataTemplate>
-                <Image Name="Image"
-                       Source="{Binding Thumbnail}"
-                       Stretch="UniformToFill">
-                    <Interaction.Behaviors>
-                        <behaviors:ExecuteCommandOnSourceChanged Command="{Binding ReturnBitmapToPoolCommand}"/>
-                    </Interaction.Behaviors>
-                </Image>
+                <Decorator Name="ImageContainer">
+                    <Image Name="Image"
+                           Stretch="UniformToFill">
+                        <Interaction.Behaviors>
+                            <behaviors:ExecuteCommandOnSourceChanged Command="{Binding ReturnBitmapToPoolCommand}"/>
+                        </Interaction.Behaviors>
+                        <Image.Source>
+                            <MultiBinding Converter="{x:Static instance:ScreenshotToScaledBitmapConverter.Instance}">
+                                <Binding/>
+                                <Binding Path="#ImageContainer.Bounds.Size"/>
+                            </MultiBinding>
+                        </Image.Source>
+                    </Image>
+                </Decorator>
             </DataTemplate>
         </ListBox.ItemTemplate>
     </ListBox>
diff --git a/SightKeeper.Avalonia/ScreenshotToScaledBitmapConverter.cs b/SightKeeper.Avalonia/ScreenshotToScaledBitmapConverter.cs
new file mode 100644
index 00000000..e85eee96
--- /dev/null
+++ b/SightKeeper.Avalonia/ScreenshotToScaledBitmapConverter.cs
@@ -0,0 +1,36 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using Avalonia;
+using Avalonia.Data.Converters;
+using SightKeeper.Avalonia.Annotation;
+
+namespace SightKeeper.Avalonia;
+
+internal sealed class ScreenshotToScaledBitmapConverter : IMultiValueConverter
+{
+	private const int SizeStep = 20;
+	private const int MinimumSize = 20;
+
+	public static ScreenshotToScaledBitmapConverter Instance { get; } = new();
+
+	public object Convert(IList<object?> values, Type targetType, object? parameter, CultureInfo culture)
+	{
+		if (values[0] is not ScreenshotViewModel screenshot ||
+		    values[1] is not Size targetSize ||
+		    targetSize.Width == 0 ||
+		    targetSize.Height == 0)
+			return AvaloniaProperty.UnsetValue;
+		var largestSizeDimension = Math.Max(targetSize.Width, targetSize.Height);
+		var roundedLargestSizeDimension = RoundSize(largestSizeDimension);
+		return screenshot.LoadImage(roundedLargestSizeDimension);
+	}
+
+	private static int RoundSize(double size)
+	{
+		var rounded = (int)Math.Round(size / SizeStep) * SizeStep;
+		if (rounded < MinimumSize)
+			return MinimumSize;
+		return rounded;
+	}
+}
\ No newline at end of file