Refactor and enhance cropping and shape detection logic

Refactored cropping rectangle adjustments for better scaling and bounds handling. Improved type safety and clarity in `DetectShapeButton_Click`. Enhanced error handling and user feedback. Added namespaces for file handling and helper utilities. Cleaned up rotate adorner logic and ensured proper resource management. General code cleanup for readability and maintainability.

Author: TheJoeFin

MagickCrop/Helpers/QuadrilateralDetector.cs

@@ -3,6 +3,7 @@
 using Emgu.CV.Structure;
 using Emgu.CV.Util;
 using System.Drawing;
+using System.IO;
 using System.Windows;
 
 namespace MagickCrop.Helpers;

MagickCrop/MainWindow.xaml.cs

@@ -1,5 +1,6 @@
 using ImageMagick;
 using MagickCrop.Controls;
+using MagickCrop.Helpers;
 using MagickCrop.Models;
 using MagickCrop.Models.MeasurementControls;
 using MagickCrop.Services;
@@ -548,7 +549,7 @@ private async void ApplyButton_Click(object sender, RoutedEventArgs e)
         Size originalDisplaySize = new(MainImage.ActualWidth, MainImage.ActualHeight);
         bool cropRectangleVisible = CroppingRectangle.Visibility == Visibility.Visible;
         double originalCropLeft = 0, originalCropTop = 0, originalCropWidth = 0, originalCropHeight = 0;
-        
+
         if (cropRectangleVisible)
         {
             originalCropLeft = Canvas.GetLeft(CroppingRectangle);
@@ -576,28 +577,28 @@ private async void ApplyButton_Click(object sender, RoutedEventArgs e)
         {
             // Force layout update to ensure MainImage has updated its ActualWidth/Height
             UpdateLayout();
-            
+
             Size newDisplaySize = new(MainImage.ActualWidth, MainImage.ActualHeight);
-            
-            if (newDisplaySize.Width > 0 && newDisplaySize.Height > 0 && 
+
+            if (newDisplaySize.Width > 0 && newDisplaySize.Height > 0 &&
                 originalDisplaySize.Width > 0 && originalDisplaySize.Height > 0)
             {
                 // Calculate scale factors for the display size change
                 double widthScale = newDisplaySize.Width / originalDisplaySize.Width;
                 double heightScale = newDisplaySize.Height / originalDisplaySize.Height;
-                
+
                 // Transform the crop rectangle position and size
                 double newCropLeft = originalCropLeft * widthScale;
                 double newCropTop = originalCropTop * heightScale;
                 double newCropWidth = originalCropWidth * widthScale;
                 double newCropHeight = originalCropHeight * heightScale;
-                
+
                 // Ensure the adjusted rectangle stays within bounds
                 newCropLeft = Math.Max(0, Math.Min(newCropLeft, newDisplaySize.Width - newCropWidth));
                 newCropTop = Math.Max(0, Math.Min(newCropTop, newDisplaySize.Height - newCropHeight));
                 newCropWidth = Math.Min(newCropWidth, newDisplaySize.Width - newCropLeft);
                 newCropHeight = Math.Min(newCropHeight, newDisplaySize.Height - newCropTop);
-                
+
                 // Apply the adjusted position and size
                 Canvas.SetLeft(CroppingRectangle, newCropLeft);
                 Canvas.SetTop(CroppingRectangle, newCropTop);
@@ -1813,7 +1814,7 @@ private async void DetectShapeButton_Click(object sender, RoutedEventArgs e)
     {
         if (string.IsNullOrEmpty(imagePath) || !File.Exists(imagePath))
         {
-            _ = System.Windows.MessageBox.Show("Please open an image first.", "No Image", MessageBoxButton.OK, MessageBoxImage.Warning);
+            _ = System.Windows.MessageBox.Show("Please open an image first.", "No Image", System.Windows.MessageBoxButton.OK, MessageBoxImage.Warning);
             return;
         }
 
@@ -1823,27 +1824,27 @@ private async void DetectShapeButton_Click(object sender, RoutedEventArgs e)
         try
         {
             // Detect quadrilaterals in background thread
-            var detectionResult = await Task.Run(() => 
-                Helpers.QuadrilateralDetector.DetectQuadrilateralsWithDimensions(imagePath, minArea: QuadDetectionMinArea, maxResults: QuadDetectionMaxResults));
+            QuadrilateralDetector.DetectionResult detectionResult = await Task.Run(() =>
+                QuadrilateralDetector.DetectQuadrilateralsWithDimensions(imagePath, minArea: QuadDetectionMinArea, maxResults: QuadDetectionMaxResults));
 
             if (detectionResult.Quadrilaterals.Count == 0)
             {
                 _ = System.Windows.MessageBox.Show(
-                    "No quadrilaterals detected in the image.\n\nPlease position the corner markers manually.", 
-                    "No Shapes Detected", 
-                    MessageBoxButton.OK, 
+                    "No quadrilaterals detected in the image.\n\nPlease position the corner markers manually.",
+                    "No Shapes Detected",
+                    System.Windows.MessageBoxButton.OK,
                     MessageBoxImage.Information);
             }
             else
             {
                 // Scale quadrilaterals to display coordinates
-                var scaledQuads = detectionResult.Quadrilaterals.Select(q =>
-                    Helpers.QuadrilateralDetector.ScaleToDisplay(
+                List<QuadrilateralDetector.DetectedQuadrilateral> scaledQuads = [.. detectionResult.Quadrilaterals.Select(q =>
+                    QuadrilateralDetector.ScaleToDisplay(
                         q,
                         detectionResult.ImageWidth,
                         detectionResult.ImageHeight,
                         MainImage.ActualWidth,
-                        MainImage.ActualHeight)).ToList();
+                        MainImage.ActualHeight))];
 
                 // Show selector
                 QuadrilateralSelectorControl.SetQuadrilaterals(scaledQuads);
@@ -1853,9 +1854,9 @@ private async void DetectShapeButton_Click(object sender, RoutedEventArgs e)
         catch (Exception ex)
         {
             _ = System.Windows.MessageBox.Show(
-                $"Error detecting quadrilaterals: {ex.Message}", 
-                "Detection Error", 
-                MessageBoxButton.OK, 
+                $"Error detecting quadrilaterals: {ex.Message}",
+                "Detection Error",
+                System.Windows.MessageBoxButton.OK,
                 MessageBoxImage.Error);
         }
         finally
@@ -3465,7 +3466,7 @@ private void ToggleRotateMode(bool enable)
             {
                 return;
             }
-            
+
             try
             {
                 rotateAdornerLayer ??= AdornerLayer.GetAdornerLayer(ImageGrid);
@@ -3660,7 +3661,7 @@ private void RemoveRotateAdorner()
         if (rotateAdornerLayer != null && rotateAdorner != null)
         {
             rotateAdorner.AngleChanging -= RotateAdorner_AngleChanging;
-            rotateAdorner.AngleChangedFinal -= RotateAdorner_AngleChangedFinal;            
+            rotateAdorner.AngleChangedFinal -= RotateAdorner_AngleChangedFinal;
             rotateAdornerLayer.Remove(rotateAdorner);
             rotateAdorner = null;
         }