Inconsistent hotkey behaviour for select tools

Pinta.Core/Managers/ToolManager.cs

@@ -37,13 +37,18 @@ public class ToolManager : IEnumerable<BaseTool>
 		int prev_index = -1;
 
 		private List<BaseTool> Tools;
+		private Dictionary<Gdk.Key, List<BaseTool>> groupedTools;
+		private Gdk.Key LastUsedKey;
+		private int PressedShortcutCounter;
 
 		public event EventHandler<ToolEventArgs> ToolAdded;
 		public event EventHandler<ToolEventArgs> ToolRemoved;
 
 		public ToolManager ()
 		{
 			Tools = new List<BaseTool> ();
+			groupedTools = new Dictionary<Gdk.Key, List<BaseTool>>();
+			PressedShortcutCounter = 0;
 		}
 
 		public void AddTool (BaseTool tool)
@@ -58,6 +63,11 @@ public void AddTool (BaseTool tool)
 
 			if (CurrentTool == null)
 				SetCurrentTool (tool);
+
+			if (!groupedTools.ContainsKey(tool.ShortcutKey))
+				groupedTools.Add(tool.ShortcutKey, new List<BaseTool>());
+
+			groupedTools[tool.ShortcutKey].Add(tool);
 		}
 
 		public void RemoveInstanceOfTool (System.Type tool_type)
@@ -73,11 +83,17 @@ public void RemoveInstanceOfTool (System.Type tool_type)
 
 					SetCurrentTool(new DummyTool());
 					OnToolRemoved (tool);
+
+					if (groupedTools[tool.ShortcutKey].Count > 1)
+						groupedTools[tool.ShortcutKey].Remove(tool);
+					else
+						groupedTools.Remove(tool.ShortcutKey);
+
 					return;
 				}
 			}
 		}
-		
+
 		void HandlePbToolItemClicked (object sender, EventArgs e)
 		{
 			ToggleToolButton tb = (ToggleToolButton)sender;
@@ -172,24 +188,32 @@ public void SetCurrentTool (Gdk.Key shortcut)
 			if (tool != null)
 				SetCurrentTool(tool);
 		}
-		
+
 		private BaseTool FindNextTool (Gdk.Key shortcut)
 		{
-			string key = shortcut.ToString ().ToUpperInvariant ();
-
-			// Begin looking at the tool after the current one
-			for (int i = index + 1; i < Tools.Count; i++) {
-				if (Tools[i].ShortcutKey.ToString ().ToUpperInvariant () == key)
-					return Tools[i];
-			}
-
-			// Begin at the beginning and look up to the current tool
-			for (int i = 0; i < index; i++) {
-				if (Tools[i].ShortcutKey.ToString ().ToUpperInvariant () == key)
-					return Tools[i];
+			shortcut = shortcut.ToUpper();
+
+			if (groupedTools.ContainsKey(shortcut))
+			{
+				for (int i = 0; i < groupedTools[shortcut].Count; i++)
+				{
+					if (LastUsedKey != shortcut)
+					{
+						// Return first tool in group.
+						PressedShortcutCounter = (1 % groupedTools[shortcut].Count);
+						LastUsedKey = shortcut;
+						return groupedTools[shortcut][0];
+					}
+					else if(i == PressedShortcutCounter)
+					{
+						var tool = groupedTools[shortcut][PressedShortcutCounter];
+						PressedShortcutCounter = (i + 1) % groupedTools[shortcut].Count;
+						return tool;
+					}
+				}
 			}
-			
-			return null;
+
+            return null;
 		}
 
 		private void OnToolAdded (BaseTool tool)
@@ -242,4 +266,21 @@ protected override void OnBuildToolBar (Toolbar tb)
 			tool_sep = null;
 		}
 	}
+
+	//Key extensions for more convenient usage of Gdk key enumerator
+	public static class KeyExtensions
+    {
+		public static Gdk.Key ToUpper(this Gdk.Key k1)
+		{
+            try
+            {
+				return (Gdk.Key)Enum.Parse(typeof(Gdk.Key), k1.ToString().ToUpperInvariant());
+			}
+            catch (ArgumentException)
+            {
+				//there is a need to catch argument exception because some buttons have not its UpperCase variant
+				return k1;
+            }
+		}
+	}
 }

Pinta.Tools/Tools/LassoSelectTool.cs

@@ -52,7 +52,8 @@ public LassoSelectTool ()
 		public override string Name { get { return Catalog.GetString ("Lasso Select"); } }
 		public override string Icon { get { return "Tools.LassoSelect.png"; } }
 		public override string StatusBarText { get { return Catalog.GetString ("Click and drag to draw the outline for a selection area."); } }
-        public override Gdk.Cursor DefaultCursor { get { return new Gdk.Cursor (Gdk.Display.Default, PintaCore.Resources.GetIcon ("Cursor.LassoSelect.png"), 9, 18); } }
+		public override Gdk.Key ShortcutKey { get { return Gdk.Key.S; } }
+		public override Gdk.Cursor DefaultCursor { get { return new Gdk.Cursor (Gdk.Display.Default, PintaCore.Resources.GetIcon ("Cursor.LassoSelect.png"), 9, 18); } }
 		public override int Priority { get { return 9; } }
 		#endregion