[f-spot] added DragDrop.cs

[Stephane Delcroix <sdelcroix src gnome org>]

commit cac504df38bca3b3db801f7be79f291c93006dfc
Author: Mike Gemuende <mike gemuende de>
Date:   Mon Jun 22 09:37:50 2009 +0200

    added DragDrop.cs

 src/DragDrop.cs |  147 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 147 insertions(+), 0 deletions(-)
---
diff --git a/src/DragDrop.cs b/src/DragDrop.cs
new file mode 100644
index 0000000..e79ecd7
--- /dev/null
+++ b/src/DragDrop.cs
@@ -0,0 +1,147 @@
+/*
+ * DragDrop.cs
+ *
+ * Author(s)
+ * 	Mike Gemuende <mike gemuende de>
+ *
+ * This is free software. See COPYING for details.
+ */
+
+
+using System;
+using System.Text;
+
+using Gtk;
+
+using Gdk;
+
+using FSpot;
+using FSpot.Utils;
+
+
+
+namespace FSpot.GuiUtils
+{	
+	public static class DragDrop
+	{
+		public enum TargetType {
+			UriList,
+			TagList,
+			TagQueryItem,
+			UriQueryItem,
+			PhotoList,
+			RootWindow
+		};
+
+		public static readonly TargetEntry PhotoListEntry =
+			new TargetEntry ("application/x-fspot-photos", 0, (uint) TargetType.PhotoList);
+		
+		public static readonly TargetEntry UriListEntry =
+			new TargetEntry ("text/uri-list", 0, (uint) TargetType.UriList);
+		
+		public static readonly TargetEntry TagListEntry =
+			new TargetEntry ("application/x-fspot-tags", 0, (uint) TargetType.TagList);
+		
+		/* FIXME: maybe we need just one fspot-query-item */
+		public static readonly TargetEntry UriQueryEntry =
+			new TargetEntry ("application/x-fspot-uri-query-item", 0, (uint) TargetType.UriQueryItem);
+		
+		public static readonly TargetEntry TagQueryEntry =
+			new TargetEntry ("application/x-fspot-tag-query-item", 0, (uint) TargetType.TagQueryItem);
+		
+		public static readonly TargetEntry RootWindowEntry =
+			new TargetEntry ("application/x-root-window-drop", 0, (uint) TargetType.RootWindow);
+		
+		/* FIXME: we use a list of photo ids. Maybe this can be encoded more efficiently */
+		public static void SetPhotosData (Photo [] photos, SelectionData selection_data)
+		{
+			StringBuilder builder = new StringBuilder ();
+			foreach (Photo photo in photos) {
+
+				if (builder.Length == 0)
+					builder.Append (photo.Id);
+				else
+					builder.AppendFormat (" {0}", photo.Id);
+			}
+			
+			Byte [] data = Encoding.UTF8.GetBytes (builder.ToString ());
+			Gdk.Atom [] targets = args.Context.Targets;
+			
+			selection_data.Set (targets[0], 8, data, data.Length);
+		}
+		
+		public static Photo [] GetPhotosData (SelectionData data)
+		{
+			string [] values = GetStringData (data).Split (' ');
+			
+			Photo [] photos = new Photo [values.Length];
+			
+			for (int i = 0; i < values.Length; i++) {
+				uint id = Convert.ToUInt32 (values[i]);
+				
+				photos[i] = MainWindow.Toplevel.Database.Photos.Get (id);
+			}
+
+			return photos;
+		}
+		
+		public static void SetTagsData (Tag [] tags, SelectionData selection_data)
+		{
+			StringBuilder builder = new StringBuilder ();
+			foreach (Tag tag in tags) {
+
+				if (builder.Length == 0)
+					builder.Append (tag.Id);
+				else
+					builder.AppendFormat (" {0}", tag.Id);
+			}
+			
+			Byte [] data = Encoding.UTF8.GetBytes (builder.ToString ());
+			Gdk.Atom [] targets = args.Context.Targets;
+			
+			selection_data.Set (targets[0], 8, data, data.Length);
+		}
+		
+		public static Tag [] GetTagsData (SelectionData data)
+		{
+			string [] values = GetStringData (data).Split (' ');
+			
+			Tag [] tags = new Tag [values.Length];
+			
+			for (int i = 0; i < values.Length; i++) {
+				uint id = Convert.ToUInt32 (values[i]);
+				
+				tags[i] = MainWindow.Toplevel.Database.Tags.Get (id);
+			}
+
+			return tags;
+		}
+		
+		public static string GetStringData (SelectionData data)
+		{
+			if (data.Length <= 0)
+				return String.Empty;
+			
+			try {
+				return Encoding.UTF8.GetString (data.Data);
+			} catch (Exception) {
+				return String.Empty;
+			}
+		}
+		
+		public static void SetUriListData (UriList uri_list, DragDataGetArgs args)
+		{
+			Byte [] data = Encoding.UTF8.GetBytes (uri_list.ToString ());
+			Gdk.Atom [] targets = args.Context.Targets;
+			
+			args.SelectionData.Set (targets[0], 8, data, data.Length);
+		}
+		
+		public static UriList GetUriListData (SelectionData data)
+		{
+			string [] uris = GetStringData (data).Split ('\n');
+			
+			return new UriList (uris);
+		}
+	}
+}