HawkeyeVision/Hawkeye.VisionBuilder/Features/ImagesStrip/Components/ImageThumbnailControl.cs

using System;
using System.Drawing;
using System.IO;
using System.Windows.Forms;
using OpenCvSharp;
using OpenCvSharp.Extensions;

namespace Hawkeye.VisionBuilder.Features.ImagesStrip.Components
{
    /// <summary>
    /// Represents a single image thumbnail item with an image and filename label.
    /// </summary>
    public class ImageThumbnailControl : Panel
    {
        private const int ThumbnailSize = 108;
        private const int BorderWidth = 3;

        private readonly PictureBox _pictureBox;
        private readonly Label _label;
        private bool _isSelected;
        private string _imagePath;

        public string ImagePath
        {
            get => _imagePath;
            set
            {
                _imagePath = value;
                LoadImage(value);
                _label.Text = Path.GetFileNameWithoutExtension(value);
            }
        }

        public bool IsSelected
        {
            get => _isSelected;
            set
            {
                if (_isSelected != value)
                {
                    _isSelected = value;
                    Invalidate(); // Trigger repaint to show/hide border
                }
            }
        }

        public event EventHandler ThumbnailClicked;

        public ImageThumbnailControl()
        {
            // Set up the container panel
            Width = ThumbnailSize + (BorderWidth * 2);
            Height = ThumbnailSize + 25 + (BorderWidth * 2); // Extra space for label
            Margin = new Padding(5);
            Cursor = Cursors.Hand;

            // Create PictureBox for the image
            _pictureBox = new PictureBox
            {
                Width = ThumbnailSize,
                Height = ThumbnailSize,
                SizeMode = PictureBoxSizeMode.StretchImage,
                Location = new System.Drawing.Point(BorderWidth, BorderWidth),
                BackColor = Color.Black
            };
            _pictureBox.Click += OnThumbnailClick;

            // Create Label for the filename
            _label = new Label
            {
                Width = ThumbnailSize,
                Height = 20,
                Location = new System.Drawing.Point(BorderWidth, ThumbnailSize + BorderWidth + 2),
                TextAlign = ContentAlignment.MiddleCenter,
                AutoEllipsis = true,
                Font = new Font("Segoe UI", 8f)
            };
            _label.Click += OnThumbnailClick;

            Controls.Add(_pictureBox);
            Controls.Add(_label);

            // Enable double buffering to reduce flicker
            DoubleBuffered = true;
        }

        private void LoadImage(string imagePath)
        {
            try
            {
                if (File.Exists(imagePath))
                {
                    using (var mat = new Mat(imagePath))
                    {
                        var resized = mat.Resize(new OpenCvSharp.Size(ThumbnailSize, ThumbnailSize));
                        var bitmap = resized.ToBitmap();

                        // Dispose old image if exists
                        var oldImage = _pictureBox.Image;
                        _pictureBox.Image = bitmap;
                        oldImage?.Dispose();
                    }
                }
            }
            catch (Exception ex)
            {
                // If image loading fails, show error in label
                _label.Text = "Error loading image";
                _label.ForeColor = Color.Red;
            }
        }

        private void OnThumbnailClick(object sender, EventArgs e)
        {
            ThumbnailClicked?.Invoke(this, EventArgs.Empty);
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);

            // Draw selection border if selected
            if (_isSelected)
            {
                using (var pen = new Pen(Color.DodgerBlue, BorderWidth))
                {
                    var rect = new Rectangle(
                        BorderWidth / 2,
                        BorderWidth / 2,
                        Width - BorderWidth,
                        Height - BorderWidth
                    );
                    e.Graphics.DrawRectangle(pen, rect);
                }
            }
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                // Dispose the image to free memory
                _pictureBox?.Image?.Dispose();
                _pictureBox?.Dispose();
                _label?.Dispose();
            }
            base.Dispose(disposing);
        }
    }
}