share Picture resource data among widgets

3 files changed, 138 insertions, 23 deletions

diff --git a/src/BmpPicture.cs b/src/BmpPicture.cs
index ea83095c..79302354 100644
--- a/src/BmpPicture.cs
+++ b/src/BmpPicture.cs
@@ -30,20 +30,47 @@ using Cairo;
 
 namespace Crow
 {
+
+	/// <summary>
+	/// Derived from FILL for loading and drawing bitmaps in the interface
+	/// </summary>
 	public class BmpPicture : Picture
 	{
-		byte[] image;
+		byte[] image = null;
 
+		#region CTOR
+		/// <summary>
+		/// Initializes a new instance of BmpPicture.
+		/// </summary>
 		public BmpPicture ()
 		{}
+		/// <summary>
+		/// Initializes a new instance of BmpPicture by loading the image pointed by the path argument
+		/// </summary>
+		/// <param name="path">image path, may be embedded</param>
 		public BmpPicture (string path) : base(path)
 		{}
-		protected override void loadFromStream (Stream stream)
+		#endregion
+		/// <summary>
+		/// load the image for rendering from the path given as argument
+		/// </summary>
+		/// <param name="path">image path, may be embedded</param>
+		public override void Load (string path)
 		{
-			using (MemoryStream ms = new MemoryStream ()) {
-				stream.CopyTo (ms);
-				loadBitmap (new System.Drawing.Bitmap (ms));	
+			Path = path;
+			if (sharedResources.ContainsKey (path)) {
+				sharedPicture sp = sharedResources [path];
+				image = (byte[])sp.Data;
+				Dimensions = sp.Dims;
+				return;
+			}
+			using (Stream stream = Interface.GetStreamFromPath (path)) {
+				using (MemoryStream ms = new MemoryStream ()) {
+					stream.CopyTo (ms);
+					loadBitmap (new System.Drawing.Bitmap (ms));	
+				}
 			}
+			sharedResources [path] = new sharedPicture (image, Dimensions);
 		}
 
 		//load image via System.Drawing.Bitmap, cairo load png only
@@ -103,6 +130,13 @@ namespace Crow
 		}
 		#endregion
 
+		/// <summary>
+		/// paint the image in the rectangle given in arguments according
+		/// to the Scale and keepProportion parameters.
+		/// </summary>
+		/// <param name="gr">drawing Backend context</param>
+		/// <param name="rect">bounds of the target surface to paint</param>
+		/// <param name="subPart">used for svg only</param>
 		public override void Paint (Cairo.Context gr, Rectangle rect, string subPart = "")
 		{
 			float widthRatio = 1f;
diff --git a/src/Picture.cs b/src/Picture.cs
index 0e5212ab..fe7007c7 100644
--- a/src/Picture.cs
+++ b/src/Picture.cs
@@ -27,38 +27,88 @@
 using System;
 using System.IO;
 using Cairo;
+using System.Collections.Generic;
 
 namespace Crow
 {
+	/// <summary>
+	/// store data and dimensions for resource sharing
+	/// </summary>
+	internal class sharedPicture {
+		//TODO: restructure this whith clever conceptual classes
+		public object Data;
+		public Size Dims;
+		public sharedPicture (object _data, Size _dims){
+			Data = _data;
+			Dims = _dims;
+		}
+	}
+	/// <summary>
+	/// virtual class for loading and drawing picture in the interface
+	/// 
+	/// Every loaded resources are stored in a dictonary with their path as key and shared
+	/// among interface elements
+	/// </summary>
 	public abstract class Picture : Fill
 	{
+		/// <summary>
+		/// share a single store for picture resources among usage in different controls
+		/// </summary>
+		internal static Dictionary<string, sharedPicture> sharedResources = new Dictionary<string, sharedPicture>();
+
+		/// <summary>
+		/// path of the picture
+		/// </summary>
 		public string Path;
+		/// <summary>
+		/// unscaled dimensions fetched on loading
+		/// </summary>
 		public Size Dimensions;
+		/// <summary>
+		/// if true and image has to be scalled, it will be scaled in both direction
+		/// equaly
+		/// </summary>
 		public bool KeepProportions = false;
+		/// <summary>
+		/// allow or not the picture to be scalled on request by the painter
+		/// </summary>
 		public bool Scaled = true;
 
+		#region CTOR
+		/// <summary>
+		/// Initializes a new instance of Picture.
+		/// </summary>
 		public Picture ()
 		{
 		}
+		/// <summary>
+		/// Initializes a new instance of Picture by loading the image pointed by the path argument
+		/// </summary>
+		/// <param name="path">image path, may be embedded</param>
 		public Picture (string path)
 		{
-			LoadImage (path);
+			Load (path);
 		}
+		#endregion
 
 		#region Image Loading
-		public void LoadImage (string path)
-		{
-			loadFromStream (Interface.GetStreamFromPath (path));
-
-			Path = path;
-		}
-			
-		protected abstract void loadFromStream(Stream stream);
+		/// <summary>
+		/// load the image for rendering from the stream given as argument
+		/// </summary>
+		/// <param name="stream">picture stream</param>
+		public abstract void Load(string path);
 		#endregion
 
+		/// <summary>
+		/// abstract method to paint the image in the rectangle given in arguments according
+		/// to the Scale and keepProportion parameters.
+		/// </summary>
+		/// <param name="gr">drawing Backend context</param>
+		/// <param name="rect">bounds of the target surface to paint</param>
+		/// <param name="subPart">used for svg only</param>
 		public abstract void Paint(Context ctx, Rectangle rect, string subPart = "");
 
-
+		#region Operators
 		public static implicit operator Picture(string path)
 		{
 			if (string.IsNullOrEmpty (path))
@@ -71,7 +121,7 @@ namespace Crow
 			else 
 				_pic = new BmpPicture ();
 
-			_pic.LoadImage (path);			
+			_pic.Load (path);			
 
 			return _pic;
 		}
@@ -79,6 +129,7 @@ namespace Crow
 		{
 			return _pic == null ? null : _pic.Path;
 		}
+		#endregion
 
 		public static object Parse(string path)
 		{
@@ -92,7 +143,7 @@ namespace Crow
 			else 
 				_pic = new BmpPicture ();
 
-			_pic.LoadImage (path);			
+			_pic.Load (path);			
 
 			return _pic;
 		}
diff --git a/src/SvgPicture.cs b/src/SvgPicture.cs
index b398d523..b4026852 100644
--- a/src/SvgPicture.cs
+++ b/src/SvgPicture.cs
@@ -30,22 +30,45 @@ using Cairo;
 
 namespace Crow
 {
+	/// <summary>
+	/// Derived from FILL for loading and drawing SVG images in the interface
+	/// </summary>
 	public class SvgPicture : Picture
 	{
 		Rsvg.Handle hSVG;
 
+		#region CTOR
+		/// <summary>
+		/// Initializes a new instance of SvgPicture.
+		/// </summary>
 		public SvgPicture ()
 		{}
+		/// <summary>
+		/// Initializes a new instance of SvgPicture by loading the SVG file pointed by the path argument
+		/// </summary>
+		/// <param name="path">image path, may be embedded</param>
 		public SvgPicture (string path) : base(path)
 		{}
-		protected override void loadFromStream (Stream stream)
+		#endregion
+
+		public override void Load (string path)
 		{
-			using (MemoryStream ms = new MemoryStream ()) {
-				stream.CopyTo (ms);
+			Path = path;
+			if (sharedResources.ContainsKey (path)) {
+				sharedPicture sp = sharedResources [path];
+				hSVG = (Rsvg.Handle)sp.Data;
+				Dimensions = sp.Dims;
+				return;
+			}
+			using (Stream stream = Interface.GetStreamFromPath (path)) {
+				using (MemoryStream ms = new MemoryStream ()) {
+					stream.CopyTo (ms);
 
-				hSVG = new Rsvg.Handle (ms.ToArray ());
-				Dimensions = new Size (hSVG.Dimensions.Width, hSVG.Dimensions.Height);
+					hSVG = new Rsvg.Handle (ms.ToArray ());
+					Dimensions = new Size (hSVG.Dimensions.Width, hSVG.Dimensions.Height);
+				}
 			}
+			sharedResources [path] = new sharedPicture (hSVG, Dimensions);
 		}
 
 		#region implemented abstract members of Fill
@@ -79,7 +102,14 @@ namespace Crow
 			}	
 		}
 		#endregion
-			
+
+		/// <summary>
+		/// paint the image in the rectangle given in arguments according
+		/// to the Scale and keepProportion parameters.
+		/// </summary>
+		/// <param name="gr">drawing Backend context</param>
+		/// <param name="rect">bounds of the target surface to paint</param>
+		/// <param name="subPart">limit rendering to svg part named 'subPart'</param>
 		public override void Paint (Cairo.Context gr, Rectangle rect, string subPart = "")
 		{
 			float widthRatio = 1f;