Fix for UI app to auto select first example + scale properly on start

Author: MichaC

viz/CDT.Viz/CDT.Viz.csproj

@@ -18,7 +18,7 @@
   <ItemGroup>
     <Resource Include="Resources\cdt.ico" Condition="Exists('Resources\cdt.ico')" />
     <!-- Copy test input files so the file list is populated at runtime -->
-    <Content Include="..\..\test\CDT.Tests\inputs\*.txt"
+    <Content Include="data\*.txt"
              CopyToOutputDirectory="PreserveNewest"
              Link="inputs\%(Filename)%(Extension)" />
   </ItemGroup>

viz/CDT.Viz/MainWindow.xaml.cs

@@ -205,15 +205,13 @@ public MainWindow()
     private void OnLoaded(object sender, RoutedEventArgs e)
     {
         // Add the visual element to fill the canvas border
-        _visual.Width = double.NaN;
-        _visual.Height = double.NaN;
         TriCanvas.Children.Add(_visual);
         Canvas.SetLeft(_visual, 0);
         Canvas.SetTop(_visual, 0);
 
-        // Stretch visual to fill the border
-        _visual.HorizontalAlignment = HorizontalAlignment.Stretch;
-        _visual.VerticalAlignment = VerticalAlignment.Stretch;
+        // Set size immediately so FitView works correctly before SizeChanged fires
+        _visual.Width = CanvasBorder.ActualWidth;
+        _visual.Height = CanvasBorder.ActualHeight;
         CanvasBorder.SizeChanged += (_, _) =>
         {
             _visual.Width = CanvasBorder.ActualWidth;
@@ -224,6 +222,10 @@ private void OnLoaded(object sender, RoutedEventArgs e)
         PopulateFileList();
 
         _initializing = false;
+
+        // Auto-load the first example
+        if (FileList.Items.Count > 0)
+            FileList.SelectedIndex = 0;
     }
 
     private void PopulateFileList()
@@ -484,8 +486,11 @@ private void FitView()
         if (dx == 0) dx = 1;
         if (dy == 0) dy = 1;
 
-        double w = Math.Max(_visual.ActualWidth, 1);
-        double h = Math.Max(_visual.ActualHeight, 1);
+        // Use CanvasBorder dimensions directly: the visual always fills it and
+        // CanvasBorder.ActualWidth/Height are correct even before the visual's
+        // own ActualWidth/Height have been updated by the layout pass.
+        double w = Math.Max(CanvasBorder.ActualWidth, 1);
+        double h = Math.Max(CanvasBorder.ActualHeight, 1);
 
         _visual.Scale = Math.Min(w / dx, h / dy) * 0.9;
         _visual.Translation = new Vector(-_visual.Scale * cx, _visual.Scale * cy);

viz/CDT.Viz/data/Capital A.txt

@@ -0,0 +1,59 @@
+29 29
+0.200000  -0.776400
+0.220000  -0.773200
+0.245600  -0.756400
+0.277600  -0.702000
+0.488800  -0.207600
+0.504800  -0.207600
+0.740800  -0.7396
+0.756000  -0.761200
+0.774400  -0.7724
+0.800000  -0.776400
+0.800000  -0.792400
+0.579200  -0.792400
+0.579200  -0.776400
+0.621600  -0.771600
+0.633600  -0.762800
+0.639200  -0.744400
+0.620800  -0.684400
+0.587200  -0.604400
+0.360800  -0.604400
+0.319200  -0.706800
+0.312000  -0.739600
+0.318400  -0.761200
+0.334400  -0.771600
+0.371200  -0.776400
+0.371200  -0.792400
+0.374400  -0.570000
+0.574400  -0.5700
+0.473600  -0.330800
+0.200000  -0.792400
+28   0
+ 0   1
+ 1   2
+ 2   3
+ 3   4
+ 4   5
+ 5   6
+ 6   7
+ 7   8
+ 8   9
+ 9  10
+10  11
+11  12
+12  13
+13  14
+14  15
+15  16
+16  17
+17  18
+18  19
+19  20
+20  21
+21  22
+22  23
+23  24
+24  28
+25  26
+26  27
+27  25