Set image default scale

Author: emako

src/GenshinWoodmen/Views/UIElement/ImageViewWindow.xaml

@@ -4,11 +4,12 @@
                  xmlns:local="clr-namespace:GenshinWoodmen.Views"
                  xmlns:mica="clr-namespace:MicaWPF.Controls;assembly=MicaWPF"
                  WindowStartupLocation="CenterScreen"
-        Icon="../../Resources/favicon.ico"
-        RenderOptions.BitmapScalingMode="Fant"
-        WindowState="Maximized" Cursor="Hand">
+                 TitleBarType="WinUI"
+                 Icon="../../Resources/favicon.ico"
+                 RenderOptions.BitmapScalingMode="Fant"
+                 WindowState="Maximized" Cursor="Hand">
     <Grid>
-        <local:PanAndZoomCanvas>
+        <local:PanAndZoomCanvas x:Name="imageCanvas" MinDeterminant="0.005" MaxDeterminant="4">
             <Image x:Name="imageControl" Stretch="Uniform">
                 <Image.RenderTransform>
                     <TransformGroup>

src/GenshinWoodmen/Views/UIElement/ImageViewWindow.xaml.cs

@@ -1,6 +1,7 @@
 using GenshinWoodmen.Core;
 using MicaWPF.Controls;
 using System;
+using System.Windows.Forms;
 using System.Windows.Media.Imaging;
 
 namespace GenshinWoodmen.Views
@@ -10,6 +11,11 @@ public partial class ImageViewWindow : MicaWindow
         public ImageViewWindow()
         {
             InitializeComponent();
+
+            imageControl.Loaded += (_, _) =>
+            {
+                imageCanvas.SetTransform(new(0.8d, 0d, 0d, 0.8d, (Width - imageControl.Source.Width * 0.8d) / 2d - 5, -SystemInformation.CaptionHeight - 8));
+            };
         }
 
         public void Load(string uriString)

src/GenshinWoodmen/Views/UIElement/PanAndZoomCanvas.cs

@@ -10,9 +10,12 @@ namespace GenshinWoodmen.Views
     /// </summary>
     public class PanAndZoomCanvas : Canvas
     {
-        public MatrixTransform? Transform { get; protected set; } = null!;
-        public float Zoomfactor { get; set; } = 1.25f;
+        public MatrixTransform Transform { get; set; } = new();
+        public float? MinDeterminant { get; set; } = null!;
+        public float? MaxDeterminant { get; set; } = null!;
+        public float Zoomfactor { get; set; } = 1.333f;
         protected Point MousePosition = new();
+        protected bool DownFlow = false;
 
         public PanAndZoomCanvas()
         {
@@ -24,21 +27,21 @@ public PanAndZoomCanvas()
 
         private void OnMouseDown(object sender, MouseButtonEventArgs e)
         {
-            if (e.ChangedButton == MouseButton.Left)
+            if (e.ChangedButton == MouseButton.Left && e.ClickCount == 1)
             {
-                Transform ??= new();
                 MousePosition = Transform.Inverse.Transform(e.GetPosition(this));
+                DownFlow = true;
             }
         }
 
         private void OnMouseUp(object sender, MouseButtonEventArgs e)
         {
+            DownFlow = false;
         }
 
         private void OnMouseMove(object sender, MouseEventArgs e)
         {
-            if (Transform == null) return;
-            if (e.LeftButton == MouseButtonState.Pressed)
+            if (e.LeftButton == MouseButtonState.Pressed && DownFlow)
             {
                 Point mousePosition = Transform.Inverse.Transform(e.GetPosition(this));
                 Vector delta = Point.Subtract(mousePosition, MousePosition);
@@ -62,23 +65,29 @@ private void OnMouseWheel(object sender, MouseWheelEventArgs e)
 
             Point mousePostion = e.GetPosition(this);
 
-            Matrix scaleMatrix = (Transform ??= new()).Matrix;
+            Matrix scaleMatrix = Transform.Matrix;
             scaleMatrix.ScaleAt(scaleFactor, scaleFactor, mousePostion.X, mousePostion.Y);
+            if (scaleMatrix.Determinant <= MinDeterminant || scaleMatrix.Determinant >= MaxDeterminant) return;
             Transform.Matrix = scaleMatrix;
 
+            SetTransform(Transform);
+        }
+
+        public void SetTransform(MatrixTransform transform)
+        {
             foreach (UIElement child in Children)
             {
                 double x = Canvas.GetLeft(child);
                 double y = Canvas.GetTop(child);
 
-                double sx = x * scaleFactor;
-                double sy = y * scaleFactor;
+                double sx = x ;
+                double sy = y;
 
                 Canvas.SetLeft(child, sx);
                 Canvas.SetTop(child, sy);
 
-                child.RenderTransform = Transform;
+                child.RenderTransform = Transform = transform;
             }
         }
     }
-}
+}