1908-V100-KDGV-Column-indicator-image-class

Source/Krypton Components/Krypton.Toolkit/Controls Toolkit/KryptonDataGridViewCellIndicatorImage.cs

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+#region BSD License
+/*
+ *  New BSD 3-Clause License (https://github.com/Krypton-Suite/Standard-Toolkit/blob/master/LICENSE)
+ *  Modifications by Peter Wagner (aka Wagnerp), Simon Coghlan (aka Smurf-IV), Giduac & Ahmed Abdelhameed et al. 2017 - 2025. All rights reserved.
+ *  
+ */
+#endregion
+
+namespace Krypton.Toolkit
+{
+    /// <summary>
+    /// This class is used  within advanved columns that make use of embedded controls.
+    /// </summary>
+    [ToolboxItem(false)]
+    internal class KryptonDataGridViewCellIndicatorImage : IDisposable
+    {
+        #region Fields
+        // Cell indicator image
+        private Image? _image = null;
+        // Size of the image which is always square
+        private int _size;
+        // Datagridview the column belongs to.
+        private KryptonDataGridView? _dataGridView;
+        // Concurrency lock
+        private ReaderWriterLockSlim _rwls;
+        // State of disposal
+        private bool _disposed = false;
+
+        // type and state of the image
+        private PaletteRibbonGalleryButton _paletteRibbonGalleryButton = PaletteRibbonGalleryButton.Down;
+        private PaletteState _paletteState = PaletteState.Normal;
+        #endregion Fields
+
+        #region Identity
+        /// <summary>
+        /// Default constructor.
+        /// </summary>
+        /// <param name="imageSize">The image size in pixels. Which will always be used to square the image. Default is 14.</param>
+        public KryptonDataGridViewCellIndicatorImage(int imageSize = 14)
+        {
+            _size = imageSize;
+            _rwls = new();
+
+            UpdateCellIndicatorImage(true);
+            KryptonManager.GlobalPaletteChanged += OnKryptonManagerGlobalPaletteChanged;
+        }
+        #endregion Identity
+
+        #region Public
+        /// <summary>
+        /// Reference to the column's DataGridView.<br/>
+        /// Set this property via the column's 'protected override void OnDataGridViewChanged()'.
+        /// </summary>
+        public KryptonDataGridView? DataGridView
+        { 
+            get => _dataGridView;
+
+            set
+            {
+                if (_dataGridView != value)
+                {
+                    if (_dataGridView is not null)
+                    {
+                        _dataGridView.PaletteChanged -= OnDataGridViewPaletteChanged;
+                    }
+
+                    _dataGridView = value;
+
+                    if (_dataGridView is not null)
+                    {
+                        _dataGridView.PaletteChanged += OnDataGridViewPaletteChanged;
+                        UpdateCellIndicatorImage(false);
+                    }
+                }
+            }
+        }
+
+        public virtual Image? Image
+        {
+            get
+            {
+                _rwls.EnterReadLock();
+                Image? image = _image;
+                _rwls.ExitReadLock();
+
+                return image;
+            }
+        }
+
+        /// <inheritdoc/>>
+        public void Dispose()
+        {
+            Dispose(true);
+        }
+
+        /// <inheritdoc cref="Dispose()"/>
+        public void Dispose(bool disposing)
+        {
+            // If the column is disposed at runtime the eventhandlers need to unsubscribe from the grid and kmananger
+            try
+            {
+                if (!_disposed && disposing)
+                {
+                    // Since the DataGridView property is controlled internally,
+                    // use the cached reference to unsubscribe from the event
+                    if (_dataGridView is not null)
+                    {
+                        _dataGridView.PaletteChanged -= OnDataGridViewPaletteChanged;
+                    }
+
+                    KryptonManager.GlobalPaletteChanged -= OnKryptonManagerGlobalPaletteChanged;
+                    _dataGridView = null;
+
+                    _disposed = true;
+                }
+            }
+            catch { }
+        }
+        #endregion Public
+
+        #region Private
+        /// <summary>
+        /// Subscribe this handler to: KryptonDataGridView.PaletteChanged
+        /// </summary>
+        /// <param name="sender">Not used.</param>
+        /// <param name="e">Not used.</param>
+        private void OnDataGridViewPaletteChanged(object? sender, EventArgs e) => UpdateCellIndicatorImage(false);
+
+        /// <summary>
+        /// Subscribe this handler to: KryptonManager.GlobalPaletteChanged
+        /// </summary>
+        /// <param name="sender">Not used.</param>
+        /// <param name="e">Not used.</param>
+        private void OnKryptonManagerGlobalPaletteChanged(object? sender, EventArgs e) => UpdateCellIndicatorImage(true);
+
+        /// <summary>
+        /// Updates the cell indicator image based on the source from where the theme change originated.
+        /// </summary>
+        /// <param name="updateFromKryptonManager">True if KryptonManager fired the theme change, otherwise from KryptonDataGridView.</param>
+        private void UpdateCellIndicatorImage(bool updateFromKryptonManager)
+        {
+            if (updateFromKryptonManager)
+            {
+                _rwls.EnterWriteLock();
+
+                // Probably the case used most, so first to check.
+                _image = KryptonManager.CurrentGlobalPalette.GetGalleryButtonImage(_paletteRibbonGalleryButton, _paletteState)!;
+                ResizeCellIndicatorImage();
+
+                _rwls.ExitWriteLock();
+            }
+            else if (DataGridView is KryptonDataGridView dataGridView)
+            {
+                _rwls.EnterWriteLock();
+
+                if (dataGridView.Palette is not null && dataGridView.PaletteMode == PaletteMode.Custom)
+                {
+                    // The grid has a custom palette instance assigned to it and PaletteMode is Custom
+                    _image = dataGridView.Palette.GetGalleryButtonImage(_paletteRibbonGalleryButton, _paletteState);
+                }
+                else
+                {
+                    // Fetch through KryptonManager using the locally set palette mode
+                    _image = KryptonManager
+                        .GetPaletteForMode(dataGridView.PaletteMode)
+                        .GetGalleryButtonImage(_paletteRibbonGalleryButton, _paletteState)!;
+                }
+
+                ResizeCellIndicatorImage();
+
+                _rwls.ExitWriteLock();
+            }
+        }
+
+        /// <summary>
+        /// This method may only be used by UpdateCellIndicatorImage()
+        /// </summary>
+        private void ResizeCellIndicatorImage()
+        {
+            if (_image is not null && (_image.Width != _size || _image.Height != _size))
+            {
+                _image = new Bitmap(_image, _size, _size);
+            }
+        }
+        #endregion Private
+    }
+}