Add icon selector feature to Intersect Editor

- Add FrmIconSelector form with paginated icon grid (160/page, 32px thumbnails)
- Replace cmbPic dropdown in Item editor with Select Icon button + icon selector
- Replace cmbSprite dropdown in Spell editor with Select Icon button + icon selector
- Uses DarkUI controls, MemoryStream for file-lock-free image loading

Author: KaTOxDev

Intersect.Editor/Forms/Editors/frmIconSelector.Designer.cs

@@ -0,0 +1,191 @@
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.IO;
+using System.Linq;
+using System.Windows.Forms;
+
+namespace Intersect.Editor.Forms.Editors
+{
+    public partial class FrmIconSelector : Form
+    {
+        private const int IconsPerPage = 160; // Perfect fit for 16 columns x 10 rows
+        private const int IconSize = 32;
+
+        private readonly string _iconDirectory;
+
+        private List<string> _allIcons = new List<string>();
+        private List<string> _filteredIcons = new List<string>();
+        private int _currentPage = 0;
+        private PictureBox _selectedPictureBox;
+        private List<PictureBox> _pictureBoxPool = new List<PictureBox>();
+
+        public string SelectedIcon { get; private set; }
+
+        public FrmIconSelector(string iconDirectory, string currentIcon = null)
+        {
+            InitializeComponent();
+            
+            _iconDirectory = iconDirectory;
+            SelectedIcon = currentIcon;
+
+            LoadIcons();
+            UpdatePagination();
+            LoadCurrentPage();
+        }
+
+        private void LoadIcons()
+        {
+            if (!Directory.Exists(_iconDirectory)) return;
+
+            _allIcons = Directory.GetFiles(_iconDirectory, "*.png")
+                .Concat(Directory.GetFiles(_iconDirectory, "*.jpg"))
+                .Concat(Directory.GetFiles(_iconDirectory, "*.jpeg"))
+                .ToList();
+
+            _filteredIcons = new List<string>(_allIcons);
+        }
+
+        private void LoadCurrentPage()
+        {
+            flowIconPanel.SuspendLayout();
+
+            var startIndex = _currentPage * IconsPerPage;
+            var endIndex = Math.Min(startIndex + IconsPerPage, _filteredIcons.Count);
+            var itemsToDisplay = endIndex - startIndex;
+
+            // Dispose old images to prevent memory leaks and lag
+            foreach (var picBox in _pictureBoxPool)
+            {
+                if (picBox.Image != null)
+                {
+                    var img = picBox.Image;
+                    picBox.Image = null;
+                    img.Dispose();
+                }
+            }
+
+            // Ensure we have enough controls in the pool
+            while (_pictureBoxPool.Count < itemsToDisplay)
+            {
+                var picBox = new PictureBox
+                {
+                    Width = IconSize,
+                    Height = IconSize,
+                    SizeMode = PictureBoxSizeMode.StretchImage,
+                    Margin = new Padding(2),
+                    Cursor = Cursors.Hand,
+                    BackColor = System.Drawing.Color.FromArgb(60, 63, 65)
+                };
+                picBox.Click += IconButton_Click;
+                _pictureBoxPool.Add(picBox);
+                flowIconPanel.Controls.Add(picBox);
+            }
+
+            int poolIndex = 0;
+            for (int i = startIndex; i < endIndex; i++)
+            {
+                var iconPath = _filteredIcons[i];
+                
+                Image img = null;
+                try
+                {
+                    // Use MemoryStream to avoid file locking on disk
+                    if (File.Exists(iconPath))
+                    {
+                        var bytes = File.ReadAllBytes(iconPath);
+                        using (var ms = new MemoryStream(bytes))
+                        {
+                            img = Image.FromStream(ms);
+                        }
+                    }
+                }
+                catch
+                {
+                    continue;
+                }
+
+                if (img == null) continue;
+
+                var picBox = _pictureBoxPool[poolIndex];
+                picBox.Image = img;
+                picBox.Tag = iconPath;
+                picBox.Visible = true;
+                
+                // Clear selection visuals if not selected
+                if (SelectedIcon == Path.GetFileName(iconPath))
+                {
+                    picBox.BorderStyle = BorderStyle.FixedSingle;
+                    picBox.BackColor = System.Drawing.Color.FromArgb(100, 100, 100);
+                    _selectedPictureBox = picBox;
+                }
+                else
+                {
+                    picBox.BorderStyle = BorderStyle.None;
+                    picBox.BackColor = System.Drawing.Color.FromArgb(60, 63, 65);
+                }
+
+                poolIndex++;
+            }
+
+            // Hide unused controls in the pool
+            for (int i = poolIndex; i < _pictureBoxPool.Count; i++)
+            {
+                _pictureBoxPool[i].Visible = false;
+            }
+
+            flowIconPanel.ResumeLayout();
+        }
+
+        private void UpdatePagination()
+        {
+            int totalPages = Math.Max(1, (int)Math.Ceiling(_filteredIcons.Count / (double)IconsPerPage));
+            
+            lblPageInfo.Text = $"Page {_currentPage + 1} / {totalPages}";
+            btnPrevPage.Enabled = _currentPage > 0;
+            btnNextPage.Enabled = _currentPage < totalPages - 1;
+        }
+
+        private void IconButton_Click(object sender, EventArgs e)
+        {
+            if (sender is PictureBox picBox && picBox.Tag is string iconPath)
+            {
+                // Clear previous selection
+                if (_selectedPictureBox != null)
+                {
+                    _selectedPictureBox.BorderStyle = BorderStyle.None;
+                    _selectedPictureBox.BackColor = System.Drawing.Color.FromArgb(60, 63, 65);
+                }
+
+                // Set new selection with visual feedback
+                _selectedPictureBox = picBox;
+                picBox.BorderStyle = BorderStyle.FixedSingle;
+                picBox.BackColor = System.Drawing.Color.FromArgb(100, 100, 100);
+                SelectedIcon = Path.GetFileName(iconPath);
+            }
+        }
+
+        private void btnPrevPage_Click(object sender, EventArgs e)
+        {
+            _currentPage--;
+            UpdatePagination();
+            LoadCurrentPage();
+        }
+
+        private void btnNextPage_Click(object sender, EventArgs e)
+        {
+            _currentPage++;
+            UpdatePagination();
+            LoadCurrentPage();
+        }
+
+        private void btnOK_Click(object sender, EventArgs e)
+        {
+            if (!string.IsNullOrEmpty(SelectedIcon))
+            {
+                DialogResult = DialogResult.OK;
+                Close();
+            }
+        }
+    }
+}