Add ability to show image markers.

PortfolioManager/Cache/ImageCache.cs

@@ -0,0 +1,79 @@
+using System;
+using System.Collections.Generic;
+using Avalonia.Media;
+using Avalonia.Media.Imaging;
+using System.Linq;
+using System.IO;
+using Axiom.Utils;
+
+namespace PortfolioManager.Cache
+{
+  public class ImageCache : IDisposable
+  {
+    public enum ImageType {BlueTriangleUp,GreenTriangleUp,GreenTriangleDown,RedTriangleUp,RedTriangleDown,YellowTriangleUp }
+    private Dictionary<ImageType,Bitmap> imageCache = new Dictionary<ImageType,Bitmap>();
+    private Object thisLock=new Object();
+    private static ImageCache imageCacheInstance=null;
+
+    private ImageCache()
+    {
+      String currentDirectory = Directory.GetCurrentDirectory();
+      String pathToAssets = currentDirectory;
+      if (!Directory.Exists(currentDirectory + "/Assets"))
+      {
+        pathToAssets = currentDirectory + "/publish" + "/Assets";
+      }
+      else
+      {
+        pathToAssets = currentDirectory + "/Assets";
+      }
+      MDTrace.WriteLine(LogLevel.DEBUG,$"Reading assets from {pathToAssets}");
+      imageCache.Add(ImageCache.ImageType.BlueTriangleUp,new Bitmap(pathToAssets+"/BlueTriangleUp.png"));
+      imageCache.Add(ImageCache.ImageType.GreenTriangleUp,new Bitmap(pathToAssets+"/GreenTriangleUp.png"));
+      imageCache.Add(ImageCache.ImageType.GreenTriangleDown,new Bitmap(pathToAssets+"/GreenTriangleDown.png"));
+      imageCache.Add(ImageCache.ImageType.RedTriangleUp,new Bitmap(pathToAssets+"/RedTriangleUp.png"));
+      imageCache.Add(ImageCache.ImageType.RedTriangleDown,new Bitmap(pathToAssets+"/RedTriangleDown.png"));
+      imageCache.Add(ImageCache.ImageType.YellowTriangleUp,new Bitmap(pathToAssets+"/YellowTriangleUp.png"));
+    }
+    
+    public static ImageCache GetInstance()
+    {
+      lock (typeof(SymbolCache))
+      {
+        if (null == imageCacheInstance) imageCacheInstance = new ImageCache();
+        return imageCacheInstance;
+      }
+    }
+    
+    public void Clear()
+    {
+      lock (thisLock)
+      {
+        imageCache = new Dictionary<ImageType, Bitmap>();
+      }
+    }
+    
+    public void Dispose()
+    {
+      lock (thisLock)
+      {
+        if (null == imageCacheInstance) return;
+        List<Bitmap> bitmaps = imageCache.Values.ToList();
+        foreach (Bitmap bitmap in bitmaps)
+        {
+          bitmap.Dispose();
+        }
+        imageCache = null;
+        imageCacheInstance = null;
+      }
+    }
+
+    public IImage GetImage(ImageCache.ImageType imageType)
+    {
+      lock(this)
+      {
+        return imageCache[imageType];
+      }
+    }
+  }
+}