annotations/Azaion.Common/Controls/DetectionControl.cs

using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Shapes;
using Azaion.Common.DTO;
using Azaion.Common.Extensions;
using Annotation = Azaion.Common.Database.Annotation;

namespace Azaion.Common.Controls;

public class DetectionControl : Border
{
    private readonly Action<object, MouseButtonEventArgs> _resizeStart;
    private const double RESIZE_RECT_SIZE = 10;

    private readonly Grid _grid;
    private readonly DetectionLabelPanel _detectionLabelPanel;
    public readonly Canvas DetectionLabelContainer;

    public TimeSpan Time { get; set; }
    private readonly List<Rectangle> _resizedRectangles = new();

    private DetectionClass _detectionClass = null!;
    public DetectionClass DetectionClass
    {
        get => _detectionClass;
        set
        {
            var brush = new SolidColorBrush(value.Color.ToConfidenceColor());
            BorderBrush = brush;
            BorderThickness = new Thickness(1);
            foreach (var rect in _resizedRectangles)
                rect.Stroke = brush;
            
            _detectionLabelPanel.DetectionClass = value;
            _detectionClass = value;
        }
    }
    
    private readonly Rectangle _selectionFrame;

    private bool _isSelected;
    
    public bool IsSelected
    {
        get => _isSelected;
        set
        {
            _selectionFrame.Visibility = value ? Visibility.Visible : Visibility.Collapsed;
            _isSelected = value;
        }
    }

    public void UpdateAdornerScale(double scale)
    {
        if (Math.Abs(scale) < 0.0001) 
            return;
        
        var inverseScale = 1.0 / scale;
        BorderThickness = new Thickness(4 * inverseScale);
        foreach (var rect in _resizedRectangles)
        {
            rect.Width = 2 * RESIZE_RECT_SIZE * inverseScale;
            rect.Height = 2 * RESIZE_RECT_SIZE * inverseScale;;
            rect.Margin = new Thickness(-RESIZE_RECT_SIZE * 0.7);
        }
    }
    
    public (HorizontalAlignment Horizontal, VerticalAlignment Vertical) DetectionLabelPosition
    {
        get => (DetectionLabelContainer.HorizontalAlignment, DetectionLabelContainer.VerticalAlignment);
        set
        {
            DetectionLabelContainer.HorizontalAlignment = value.Horizontal;
            DetectionLabelContainer.VerticalAlignment = value.Vertical;
        }
    }
    
    public DetectionControl(DetectionClass detectionClass, TimeSpan time, Action<object,
        MouseButtonEventArgs> resizeStart, CanvasLabel canvasLabel)
    {
        Width = canvasLabel.Width;
        Height = canvasLabel.Height;
        Time = time;
        _resizeStart = resizeStart;
        
        DetectionLabelContainer = new Canvas
        {
            HorizontalAlignment = HorizontalAlignment.Right,
            VerticalAlignment = VerticalAlignment.Top,
            ClipToBounds = false,
        };
        _detectionLabelPanel = new DetectionLabelPanel
        {
            Confidence = canvasLabel.Confidence,
            DetectionClass = Annotation.DetectionClassesDict[canvasLabel.ClassNumber]
        };
        
        DetectionLabelContainer.Children.Add(_detectionLabelPanel);

        _selectionFrame = new Rectangle
        {
            Margin = new Thickness(-3),
            HorizontalAlignment = HorizontalAlignment.Stretch,
            VerticalAlignment = VerticalAlignment.Stretch,
            Stroke = new SolidColorBrush(Colors.Black),
            StrokeThickness = 2,
            Visibility = Visibility.Collapsed
        };
        _resizedRectangles =
        [
            CreateResizeRect("rLT", HorizontalAlignment.Left, VerticalAlignment.Top, Cursors.SizeNWSE),
            CreateResizeRect("rCT", HorizontalAlignment.Center, VerticalAlignment.Top, Cursors.SizeNS),
            CreateResizeRect("rRT", HorizontalAlignment.Right, VerticalAlignment.Top, Cursors.SizeNESW),
            CreateResizeRect("rLC", HorizontalAlignment.Left, VerticalAlignment.Center, Cursors.SizeWE),
            CreateResizeRect("rRC", HorizontalAlignment.Right, VerticalAlignment.Center, Cursors.SizeWE),
            CreateResizeRect("rLB", HorizontalAlignment.Left, VerticalAlignment.Bottom, Cursors.SizeNESW),
            CreateResizeRect("rCB", HorizontalAlignment.Center, VerticalAlignment.Bottom, Cursors.SizeNS),
            CreateResizeRect("rRB", HorizontalAlignment.Right, VerticalAlignment.Bottom, Cursors.SizeNWSE)
        ];
        _grid = new Grid
        {
            Background = Brushes.Transparent,
            HorizontalAlignment = HorizontalAlignment.Stretch,
            VerticalAlignment = VerticalAlignment.Stretch,
            Children = { _selectionFrame }
        };
        _grid.Children.Add(DetectionLabelContainer);
        foreach (var rect in _resizedRectangles)
            _grid.Children.Add(rect);

        Child = _grid;
        Cursor = Cursors.SizeAll;
        DetectionClass = detectionClass;
    }
    
    //small corners
    private Rectangle CreateResizeRect(string name, HorizontalAlignment ha, VerticalAlignment va, Cursor crs)
    {
        var rect = new Rectangle()   // small rectangles at the corners and sides
        {
            ClipToBounds = false,
            Margin = new Thickness(-1.1 * RESIZE_RECT_SIZE),
            HorizontalAlignment = ha,
            VerticalAlignment = va,
            Width = RESIZE_RECT_SIZE,
            Height = RESIZE_RECT_SIZE,
            Stroke = new SolidColorBrush(Color.FromArgb(230, 20, 20, 20)), // small rectangles color
            StrokeThickness = 0.8,
            Fill = new SolidColorBrush(Color.FromArgb(150, 80, 80, 80)),
            Cursor = crs,
            Name = name,
        };
        rect.MouseDown += (sender, args) => _resizeStart(sender, args);
        rect.MouseUp += (sender, args) => { (sender as UIElement)?.ReleaseMouseCapture(); };
        return rect;
    }

    public CanvasLabel ToCanvasLabel() => 
        new(DetectionClass.YoloId, Canvas.GetLeft(this), Canvas.GetTop(this), Width, Height);

    public YoloLabel ToYoloLabel(Size canvasSize, Size? videoSize = null) => 
        new(ToCanvasLabel(), canvasSize, videoSize);
}