FreeFormDragDropManager.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / WF / Common / AuthoringOM / Design / MessageFilters / FreeFormDragDropManager.cs / 1305376 / FreeFormDragDropManager.cs
                        

                        
                            namespace System.Workflow.ComponentModel.Design 
{
 	using System;
	using System.Text;
	using System.Drawing; 
	using System.Diagnostics;
 	using System.Collections; 
	using System.Windows.Forms; 
 	using System.ComponentModel;
 	using System.Drawing.Drawing2D; 
	using System.Collections.Generic;
 	using System.ComponentModel.Design;

    #region Class FreeFormDragDropManager 
    internal sealed class FreeFormDragDropManager : DragDropManager
	{ 
		#region Members and Constructor 
        private static Cursor DragMoveCursor = new Cursor(typeof(WorkflowView), "Resources.DragMoveCursor.cur");
        private static Cursor DragCopyCursor = new Cursor(typeof(WorkflowView), "Resources.DragCopyCursor.cur"); 
        private static Cursor MoveCursor = new Cursor(typeof(WorkflowView), "Resources.MoveCursor.cur");

        private List draggedDesignerImages = null;
		private Cursor previousCursor = Cursors.Default; 
 		private Point movedDesignerImagePoint = Point.Empty;
 
        public FreeFormDragDropManager() 
		{
 		} 
 		#endregion

		#region Behavior Overrides
        protected override bool OnDragEnter(DragEventArgs eventArgs) 
 		{
			bool retVal = base.OnDragEnter(eventArgs); 
            if (this.draggedDesignerImages == null) 
			{
                WorkflowView parentView = ParentView; 
                Point clientPoint = parentView.PointToClient(new Point(eventArgs.X, eventArgs.Y));
                Point logicalPoint = parentView.ScreenPointToLogical(new Point(eventArgs.X, eventArgs.Y));
                if (parentView.IsClientPointInActiveLayout(clientPoint))
                    this.movedDesignerImagePoint = logicalPoint; 
				else
 					this.movedDesignerImagePoint = DragInitiationPoint; 
			}	 

 			return retVal; 
 		}

        protected override bool OnDragOver(DragEventArgs eventArgs)
		{ 
            //Invalidate the dragged images
            if (this.draggedDesignerImages != null) 
            { 
                Point[] previousLocations = GetDesignerLocations(DragInitiationPoint, this.movedDesignerImagePoint, DraggedActivities);
                InvalidateDraggedImages(previousLocations); 
            }

            bool retVal = base.OnDragOver(eventArgs);
 
            if (this.draggedDesignerImages != null)
 			{ 
                WorkflowView parentView = ParentView; 
                Point clientPoint = parentView.PointToClient(new Point(eventArgs.X, eventArgs.Y));
                Point logicalPoint = parentView.ScreenPointToLogical(new Point(eventArgs.X, eventArgs.Y)); 

                if (parentView.IsClientPointInActiveLayout(clientPoint))
                    this.movedDesignerImagePoint = logicalPoint;
				else 
                    this.movedDesignerImagePoint = DragInitiationPoint;
 
                //Invalidate the new locations where the image is shown 
				Point[] newLocations = GetDesignerLocations(DragInitiationPoint, this.movedDesignerImagePoint, DraggedActivities);
                InvalidateDraggedImages(newLocations); 
			}
 			return retVal;
		}
 
        protected override bool OnGiveFeedback(GiveFeedbackEventArgs gfbevent)
        { 
            base.OnGiveFeedback(gfbevent); 

            if (this.draggedDesignerImages != null) 
            {
                gfbevent.UseDefaultCursors = false;
                if ((gfbevent.Effect & DragDropEffects.Move) == DragDropEffects.Move)
                    Cursor.Current = FreeFormDragDropManager.DragMoveCursor; 
                else if ((gfbevent.Effect & DragDropEffects.Copy) == DragDropEffects.Copy)
                    Cursor.Current = FreeFormDragDropManager.DragCopyCursor; 
                else 
                    Cursor.Current = Cursors.No;
 
                return true;
            }

            return false; 
        }
 
        protected override bool OnMouseMove(MouseEventArgs eventArgs) 
 		{
 			bool retval = base.OnMouseMove(eventArgs); 
            if (eventArgs.Button == MouseButtons.None)
			{
                bool showMoveCursor = false;
                showMoveCursor |= (MessageHitTestContext != null && MessageHitTestContext.AssociatedDesigner != null && ActivityDesigner.GetParentDesigner(MessageHitTestContext.AssociatedDesigner.Activity) is FreeformActivityDesigner && (MessageHitTestContext.HitLocation & HitTestLocations.ActionArea) == 0); 
 				UpdateCursor(showMoveCursor);
			} 
			return retval; 
		}
 
        protected override bool OnMouseLeave()
 		{
			UpdateCursor(false);
 			return false; 
 		}
 
        protected override bool OnScroll(ScrollBar sender, int value) 
        {
            if (this.draggedDesignerImages != null) 
            {
                Point[] previousLocations = GetDesignerLocations(DragInitiationPoint, this.movedDesignerImagePoint, DraggedActivities);
                InvalidateDraggedImages(previousLocations);
            } 

            bool retVal = base.OnScroll(sender, value); 
 
            if (this.draggedDesignerImages != null)
            { 
                WorkflowView parentView = ParentView;
                Point clientPoint = parentView.PointToClient(Control.MousePosition);
                Point logicalPoint = parentView.ScreenPointToLogical(Control.MousePosition);
 
                if (parentView.IsClientPointInActiveLayout(clientPoint))
                    this.movedDesignerImagePoint = logicalPoint; 
                else 
                    this.movedDesignerImagePoint = DragInitiationPoint;
 
                //Invalidate the new locations where the image is shown
                Point[] newLocations = GetDesignerLocations(DragInitiationPoint, this.movedDesignerImagePoint, DraggedActivities);
                InvalidateDraggedImages(newLocations);
            } 

            return retVal; 
        } 

        protected override bool OnPaintWorkflowAdornments(PaintEventArgs eventArgs, Rectangle viewPort, AmbientTheme ambientTheme) 
        {
            bool messageHandled = false;
            if (this.draggedDesignerImages == null || this.draggedDesignerImages.Count == 0 || !(DropTargetDesigner is FreeformActivityDesigner))
                messageHandled = base.OnPaintWorkflowAdornments(eventArgs, viewPort, ambientTheme); 
            return messageHandled;
        } 
 
        protected override bool OnPaint(PaintEventArgs eventArgs, Rectangle viewPort, AmbientTheme ambientTheme)
        { 
            bool messageHandled = false;
            if (this.draggedDesignerImages != null && DropTargetDesigner is FreeformActivityDesigner)
            {
                using (Region clipRegion = new Region(ActivityDesignerPaint.GetDesignerPath(ParentView.RootDesigner, false))) 
                {
                    Region oldRegion = eventArgs.Graphics.Clip; 
                    eventArgs.Graphics.Clip = clipRegion; 

                    Point[] locations = GetDesignerLocations(DragInitiationPoint, this.movedDesignerImagePoint, DraggedActivities); 
                    Debug.Assert(locations.Length == DraggedActivities.Count);
                    Debug.Assert(this.draggedDesignerImages.Count == DraggedActivities.Count);

                    for (int i = 0; i < this.draggedDesignerImages.Count; i++) 
                    {
                        Size imageSize = this.draggedDesignerImages[i].Size; 
                        ActivityDesignerPaint.DrawImage(eventArgs.Graphics, this.draggedDesignerImages[i], new Rectangle(new Point(locations[i].X - 2 * ambientTheme.Margin.Width, locations[i].Y - 2 * ambientTheme.Margin.Height), imageSize), new Rectangle(Point.Empty, imageSize), DesignerContentAlignment.Fill, 0.4f, false); 
                    }
 
                    eventArgs.Graphics.Clip = oldRegion;
                }
            }
            else 
            {
                messageHandled = base.OnPaint(eventArgs, viewPort, ambientTheme); 
            } 

            return messageHandled; 
		}

        protected override void CreateDragFeedbackImages(IList draggedActivities)
        { 
            base.CreateDragFeedbackImages(draggedActivities);
 
            List imageList = new List(); 
            using (Graphics graphics = ParentView.CreateGraphics())
            { 
                foreach (Activity activity in draggedActivities)
                {
                    ActivityDesigner previewDesigner = ActivityDesigner.GetDesigner(activity);
                    if (previewDesigner == null) 
                        previewDesigner = ActivityDesigner.CreateDesigner(ParentView, activity);
                    imageList.Add(previewDesigner.GetPreviewImage(graphics)); 
                } 
            }
 
            //We create the designer images for designers associates with existing activities
            ParentView.InvalidateClientRectangle(Rectangle.Empty);
            this.draggedDesignerImages = imageList;
        } 

        protected override void DestroyDragFeedbackImages() 
        { 
            base.DestroyDragFeedbackImages();
 
            if (this.draggedDesignerImages != null)
            {
                foreach (Bitmap image in this.draggedDesignerImages)
                    image.Dispose(); 
                this.draggedDesignerImages = null;
                ParentView.InvalidateClientRectangle(Rectangle.Empty); 
            } 
        }
        #endregion 

 		#region Helpers
        private void InvalidateDraggedImages(Point[] locations)
        { 
            if (this.draggedDesignerImages != null)
            { 
                if (locations.Length == this.draggedDesignerImages.Count) 
                {
                    AmbientTheme ambientTheme = WorkflowTheme.CurrentTheme.AmbientTheme; 
                    WorkflowView parentView = ParentView;

                    //Invalidate the previous location where image was shown
                    for (int i = 0; i < this.draggedDesignerImages.Count; i++) 
                    {
                        Rectangle rectangle = new Rectangle(locations[i], this.draggedDesignerImages[i].Size); 
                        rectangle.Inflate(2 * ambientTheme.Margin.Width, 2 * ambientTheme.Margin.Height); 
                        parentView.InvalidateLogicalRectangle(rectangle);
                    } 
                }
                else
                {
                    Debug.Assert(false); 
                }
            } 
        } 

		internal static Point[] GetDesignerLocations(Point startPoint, Point endPoint, ICollection activitiesToMove) 
		{
			List locations = new List();

 			//We move all the designers 
			foreach (Activity activityToMove in activitiesToMove)
 			{ 
 				Point location = endPoint; 
                ActivityDesigner designerToMove = ActivityDesigner.GetDesigner(activityToMove);
				if (designerToMove != null && !startPoint.IsEmpty) 
 				{
					Size delta = new Size(endPoint.X - startPoint.X, endPoint.Y - startPoint.Y);
					location = new Point(designerToMove.Location.X + delta.Width, designerToMove.Location.Y + delta.Height);
				} 

                location = DesignerHelpers.SnapToGrid(location); 
 				locations.Add(location); 
			}
 
 			return locations.ToArray();
 		}

		private void UpdateCursor(bool showMoveCursor) 
 		{
			if (showMoveCursor) 
			{ 
                if (ParentView.Cursor != FreeFormDragDropManager.MoveCursor && ParentView.Cursor == Cursors.Default)
				{ 
                    this.previousCursor = ParentView.Cursor;
                    ParentView.Cursor = FreeFormDragDropManager.MoveCursor;
 				}
			} 
 			else
 			{ 
                ParentView.Cursor = this.previousCursor; 
			}
 		} 
		#endregion
    }
	#endregion
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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