drag and drop operations

4 files changed, 113 insertions, 34 deletions

diff --git a/src/DragDropEventArgs.cs b/src/DragDropEventArgs.cs
new file mode 100644
index 00000000..428a7363
--- /dev/null
+++ b/src/DragDropEventArgs.cs
@@ -0,0 +1,55 @@
+//
+// LayoutingEventArgs.cs
+//
+// Author:
+//       Jean-Philippe Bruyère <jp.bruyere@hotmail.com>
+//
+// Copyright (c) 2013-2017 Jean-Philippe Bruyère
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+using System;
+
+namespace Crow
+{
+	public class DragDropEventArgs: EventArgs
+	{
+		/// <summary>
+		/// Source of the drag and drop operation
+		/// </summary>
+		public GraphicObject DragSource;
+		/// <summary>
+		/// Target of the drag and drop operation
+		/// </summary>
+		public GraphicObject DropTarget;
+
+		//public DragDropEventArgs (GraphicObject source, GraphicObject target = null) : base()
+		public DragDropEventArgs (GraphicObject source = null, GraphicObject target = null) : base()
+		{
+			DragSource = source;
+			DropTarget = target;
+		}
+
+		public override string ToString ()
+		{
+			return string.Format ("{0} => {1}", DragSource,DropTarget);
+		}
+	}
+}
+
diff --git a/src/GraphicObjects/GraphicObject.cs b/src/GraphicObjects/GraphicObject.cs
index ef2e0197..65f8ed26 100644
--- a/src/GraphicObjects/GraphicObject.cs
+++ b/src/GraphicObjects/GraphicObject.cs
@@ -318,8 +318,10 @@ namespace Crow
 		/// <summary>Occurs when the enabled state this object is set to false</summary>
 		public event EventHandler Disabled;
 		public event EventHandler StartDrag;
+		public event EventHandler DragEnter;
+		public event EventHandler DragLeave;
 		public event EventHandler EndDrag;
-		public event EventHandler Dropped;
+		public event EventHandler Drop;
 		/// <summary>Occurs when one part of the rendering slot changed</summary>
 		public event EventHandler<LayoutingEventArgs> LayoutChanged;
 		/// <summary>Occurs when DataSource changed</summary>
@@ -1088,37 +1090,42 @@ namespace Crow
 					return;
 				isDragged = value;
 
-				if (isDragged) {
-					CurrentInterface.HoverWidget = null;
-					onStartDrag (this, null);
-				}
-
-				NotifyValueChanged ("IsDrag", IsDragged);
+				NotifyValueChanged ("IsDragged", IsDragged);
 			}
 		}
 		/// <summary>
-		/// start dragging
+		/// fired when drag and drop operation start
 		/// </summary>
-		protected virtual void onStartDrag (object sender, EventArgs e){
-			Debug.WriteLine("DRAG => " + this.ToString());
-			StartDrag.Raise (this, null);
+		protected virtual void onStartDrag (object sender, DragDropEventArgs e){
+			CurrentInterface.HoverWidget = this.focusParent;
+			IsDragged = true;
+			StartDrag.Raise (this, e);
+			Debug.WriteLine(this.ToString() + " : START DRAG => " + e.ToString());
 		}
 		/// <summary>
 		///  Occured when dragging ends without dropping
 		/// </summary>
-		protected virtual void onEndDrag (object sender, EventArgs e){
+		protected virtual void onEndDrag (object sender, DragDropEventArgs e){			
 			IsDragged = false;
-			EndDrag.Raise (this, null);
-			Debug.WriteLine("END DRAG => " + this.ToString());
+			EndDrag.Raise (this, e);
+			Debug.WriteLine(this.ToString() + " : END DRAG => " + e.ToString());
 		}
-		/// <summary>
-		/// Dragging end with a dropping
-		/// </summary>
-		protected virtual void onDrop (object sender, EventArgs e){
+		protected virtual void onDragEnter (object sender, DragDropEventArgs e){
+			e.DropTarget = this;
+			DragEnter.Raise (this, e);
+			Debug.WriteLine(this.ToString() + " : DRAG Enter => " + e.ToString());
+		}
+		protected virtual void onDragLeave (object sender, DragDropEventArgs e){			
+			e.DropTarget = null;
+			DragLeave.Raise (this, e);
+			Debug.WriteLine(this.ToString() + " : DRAG Leave => " + e.ToString());
+		}
+		protected virtual void onDrop (object sender, DragDropEventArgs e){			
 			IsDragged = false;
-			Debug.WriteLine("DROPPED => " + this.ToString());
-			Dropped.Raise (this, null);
+			Drop.Raise (this, e);
+			Debug.WriteLine(this.ToString() + " : DROP => " + e.ToString());
 		}
+
 		#endregion
 
 		#region Queuing
@@ -1544,8 +1551,12 @@ namespace Crow
 		}
 		public virtual void onMouseMove(object sender, MouseMoveEventArgs e)
 		{
-			if (AllowDrag & !IsDragged & IsActive)
-				IsDragged = true;
+			if (AllowDrag & HasFocus & e.Mouse.LeftButton == ButtonState.Pressed) {
+				if (CurrentInterface.DragAndDropOperation == null) {
+					CurrentInterface.DragAndDropOperation = new DragDropEventArgs (this);
+					onStartDrag (this, CurrentInterface.DragAndDropOperation);
+				}
+			}
 
 			//bubble event to the top
 			GraphicObject p = focusParent;
@@ -1582,16 +1593,14 @@ namespace Crow
 			Debug.WriteLine("MOUSE UP => " + this.ToString());
 			#endif
 
-			if (IsDragged){
-				bool dropOK = false;
-				if (CurrentInterface.HoverWidget!=null) {
-					if (CurrentInterface.HoverWidget.AllowDrop)
-						dropOK = true;
+			if (CurrentInterface.DragAndDropOperation != null){
+				if (CurrentInterface.DragAndDropOperation.DragSource == this) {
+					if (CurrentInterface.DragAndDropOperation.DropTarget != null)
+						onDrop (this, CurrentInterface.DragAndDropOperation);
+					else
+						onEndDrag (this, CurrentInterface.DragAndDropOperation);
+					CurrentInterface.DragAndDropOperation = null;
 				}
-				if (dropOK)
-					onDrop (this, null);
-				else
-					onEndDrag (this, null);
 			}
 
 			//bubble event to the top
@@ -1631,6 +1640,14 @@ namespace Crow
 			#if DEBUG_FOCUS
 			Debug.WriteLine("MouseEnter => " + this.ToString());
 			#endif
+
+			if (CurrentInterface.DragAndDropOperation != null) {
+				if (this.AllowDrop) {
+					if (CurrentInterface.DragAndDropOperation.DragSource != this && CurrentInterface.DragAndDropOperation.DropTarget != this)
+						onDragEnter (this, CurrentInterface.DragAndDropOperation);					
+				}
+			}
+
 			MouseEnter.Raise (this, e);
 		}
 		public virtual void onMouseLeave(object sender, MouseMoveEventArgs e)
@@ -1638,6 +1655,10 @@ namespace Crow
 			#if DEBUG_FOCUS
 			Debug.WriteLine("MouseLeave => " + this.ToString());
 			#endif
+			if (CurrentInterface.DragAndDropOperation != null) {
+				if (CurrentInterface.DragAndDropOperation.DropTarget == this)
+					onDragLeave (this, CurrentInterface.DragAndDropOperation);
+			}
 			MouseLeave.Raise (this, e);
 		}
 		#endregion
diff --git a/src/Input/MouseState.cs b/src/Input/MouseState.cs
index 594619ac..f6db21ea 100644
--- a/src/Input/MouseState.cs
+++ b/src/Input/MouseState.cs
@@ -46,6 +46,8 @@ namespace Crow
 
 	#endregion
 
+
+
 	#region Public Members
 
 	/// <summary>
diff --git a/src/Interface.cs b/src/Interface.cs
index e1bd7533..becd37ce 100644
--- a/src/Interface.cs
+++ b/src/Interface.cs
@@ -206,6 +206,8 @@ namespace Crow
 		/// </summary>
 		public static Dictionary<String, Instantiator> Instantiators = new Dictionary<string, Instantiator>();
 		public List<CrowThread> CrowThreads = new List<CrowThread>();//used to monitor thread finished
+
+		public DragDropEventArgs DragAndDropOperation = null;
 		#endregion
 
 		#region Private Fields
@@ -824,12 +826,11 @@ namespace Crow
 			MouseMoveEventArgs e = new MouseMoveEventArgs (x, y, deltaX, deltaY);
 			e.Mouse = Mouse;
 
-			if (ActiveWidget != null) {
+			if (ActiveWidget != null&& DragAndDropOperation == null) {
 				//TODO, ensure object is still in the graphic tree
 				//send move evt even if mouse move outside bounds
 				ActiveWidget.onMouseMove (this, e);
-				if (!ActiveWidget.IsDragged)//if active is dragged, process mouse move as it was not visible.
-					return true;
+				return true;
 			}
 
 			if (HoverWidget != null) {