Adds a colored grid control.

.idea/.idea.DiscImageChef/.idea/contentModel.xml

@@ -1677,6 +1677,7 @@
         </e>
         <e p="ConsoleHandler.cs" t="Include" />
         <e p="Controls" t="Include">
+          <e p="ColoredGrid.cs" t="Include" />
           <e p="SvgImageView.cs" t="Include" />
         </e>
         <e p="Dialogs" t="Include">

DiscImageChef.Gui/Controls/ColoredGrid.cs

@@ -0,0 +1,92 @@
+using System.Collections.ObjectModel;
+using Eto.Drawing;
+using Eto.Forms;
+
+namespace DiscImageChef.Gui.Controls
+{
+    /// <summary>
+    ///     Draws a grid of colored blocks
+    /// </summary>
+    public class ColoredGrid : Drawable
+    {
+        /// <summary>
+        ///     Size of the block, including its top and left border, in pixels
+        /// </summary>
+        const int BLOCK_SIZE = 5;
+
+        public ColoredGrid()
+        {
+            ColoredBlocks                   =  new ObservableCollection<ColoredBlock>();
+            ColoredBlocks.CollectionChanged += (sender, args) => Invalidate();
+        }
+
+        new bool CanFocus => false;
+        /// <summary>
+        ///     How many columns are in the grid
+        /// </summary>
+        public int Columns { get; private set; }
+        /// <summary>
+        ///     How many rows are in the grid
+        /// </summary>
+        public int Rows { get; private set; }
+        /// <summary>
+        ///     How many blocks are in the grid
+        /// </summary>
+        public int Blocks { get; private set; }
+
+        public ObservableCollection<ColoredBlock> ColoredBlocks { get; }
+
+        protected override void OnPaint(PaintEventArgs e)
+        {
+            base.OnPaint(e);
+
+            Graphics   graphics = e.Graphics;
+            RectangleF rect     = e.ClipRectangle;
+
+            int remainder = (int)rect.Width % (BLOCK_SIZE + 1);
+            int width     = (int)rect.Width - remainder - 1;
+            remainder = (int)rect.Height % (BLOCK_SIZE  + 1);
+            int height = (int)rect.Height - remainder   - 1;
+
+            for(float i = rect.X; i <= width; i += 5)
+                graphics.DrawLine(Color.FromRgb(0x00000000), i, rect.Y, i, height);
+
+            for(float i = rect.Y; i <= height; i += 5)
+                graphics.DrawLine(Color.FromRgb(0x00000000), rect.X, i, width, i);
+
+            Columns = width   / BLOCK_SIZE;
+            Rows    = height  / BLOCK_SIZE;
+            Blocks  = Columns * Rows;
+
+            foreach(ColoredBlock coloredBlock in ColoredBlocks)
+                PaintBlock(graphics, coloredBlock.Color, coloredBlock.Block);
+        }
+
+        void PaintBlock(Graphics graphics, Color color, int block)
+        {
+            if(block > Blocks) return;
+
+            int row = block / Columns;
+            int col = block % Columns;
+            int x   = col   * BLOCK_SIZE;
+            int y   = row   * BLOCK_SIZE;
+
+            graphics.FillRectangle(color, x + 1, y + 1, BLOCK_SIZE - 1, BLOCK_SIZE - 1);
+        }
+    }
+
+    /// <summary>
+    ///     Defines a block that has a corresponding color
+    /// </summary>
+    public class ColoredBlock
+    {
+        public readonly int   Block;
+        public readonly Color Color;
+
+        public ColoredBlock(int block, Color color)
+        {
+            Block = block;
+            Color = color;
+        }
+    }
+}