PanningMessageFilter.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 / PanningMessageFilter.cs / 1305376 / PanningMessageFilter.cs
                        

                        
                            namespace System.Workflow.ComponentModel.Design 
{
 	using System;
	using System.Drawing;
	using System.Windows.Forms; 
	using System.ComponentModel.Design;
 
 	#region Class PanningMessageFilter 
	///This behavior needs and stores coordinates in client coordinates
 	internal sealed class PanningMessageFilter : WorkflowDesignerMessageFilter 
 	{
		#region Members and Constructor
        private static Cursor PanBeganCursor = new Cursor(typeof(WorkflowView), "Resources.panClosed.cur");
 		private static Cursor PanReadyCursor = new Cursor(typeof(WorkflowView), "Resources.panOpened.cur"); 

		private Point panPoint = Point.Empty; 
		private bool panningActive = false; 

		private CommandID previousCommand; 
 		private Cursor previousCursor = Cursors.Default;

		internal PanningMessageFilter()
 		{ 
 		}
		#endregion 
 
 		#region MessageFilter Overrides
		protected override void Initialize(WorkflowView parentView) 
		{
			base.Initialize(parentView);

 			StoreUIState(); 
			RefreshUIState();
 		} 
 
 		protected override void Dispose(bool disposing)
		{ 
 			try
			{
				RestoreUIState();
			} 
 			finally
			{ 
 				base.Dispose(disposing); 
 			}
		} 

 		protected override bool OnShowContextMenu(Point menuPoint)
		{
			IMenuCommandService menuCommandService = (IMenuCommandService)GetService(typeof(IMenuCommandService)); 
			if (menuCommandService != null)
 				menuCommandService.ShowContextMenu(WorkflowMenuCommands.ZoomMenu, menuPoint.X, menuPoint.Y); 
 
			return true;
 		} 

 		protected override bool OnMouseEnter(MouseEventArgs eventArgs)
		{
 			RefreshUIState(); 
			return true;
		} 
 
		protected override bool OnMouseDown(MouseEventArgs eventArgs)
 		{ 
			if (eventArgs.Button == MouseButtons.Left)
 				SetPanPoint(new Point(eventArgs.X, eventArgs.Y));
 			return true;
		} 

 		protected override bool OnMouseMove(MouseEventArgs eventArgs) 
		{ 
			if (this.panningActive && (eventArgs.Button & MouseButtons.Left) > 0)
			{ 
 				Size panSize = new Size(eventArgs.X - this.panPoint.X, eventArgs.Y - this.panPoint.Y);
				WorkflowView parentView = ParentView;
 				parentView.ScrollPosition = new Point(parentView.ScrollPosition.X - panSize.Width, parentView.ScrollPosition.Y - panSize.Height);
 				SetPanPoint(new Point(eventArgs.X, eventArgs.Y)); 
			}
 
 			return true; 
		}
 
		protected override bool OnMouseUp(MouseEventArgs eventArgs)
		{
 			SetPanPoint(Point.Empty);
			return true; 
 		}
 
 		protected override bool OnDragEnter(DragEventArgs eventArgs) 
		{
 			ParentView.RemoveDesignerMessageFilter(this); 
			return false;
		}

		protected override bool OnKeyDown(KeyEventArgs eventArgs) 
 		{
			if (eventArgs.KeyValue == (int)Keys.Escape) 
 				ParentView.RemoveDesignerMessageFilter(this); 
            return true;
 		} 
		#endregion

 		#region Helpers
		private void SetPanPoint(Point value) 
		{
			this.panPoint = value; 
 			this.panningActive = (this.panPoint != Point.Empty); 
			ParentView.Capture = this.panningActive;
 			RefreshUIState(); 
 		}

		private void RefreshUIState()
 		{ 
			//Update the cursor
			ParentView.Cursor = (this.panningActive) ? PanningMessageFilter.PanBeganCursor : PanningMessageFilter.PanReadyCursor; 
 
			//Update the menu command
 			IMenuCommandService menuCommandService = GetService(typeof(IMenuCommandService)) as IMenuCommandService; 
			if (menuCommandService != null)
 			{
 				CommandID[] affectedCommands = new CommandID[] { WorkflowMenuCommands.ZoomIn, WorkflowMenuCommands.ZoomOut, WorkflowMenuCommands.Pan, WorkflowMenuCommands.DefaultFilter };
				foreach (CommandID affectedCommand in affectedCommands) 
 				{
					MenuCommand menuCommand = menuCommandService.FindCommand(affectedCommand); 
					if (menuCommand != null && menuCommand.Enabled) 
						menuCommand.Checked = (menuCommand.CommandID == WorkflowMenuCommands.Pan);
 				} 
			}
 		}

 		private void StoreUIState() 
		{
 			IMenuCommandService menuCommandService = GetService(typeof(IMenuCommandService)) as IMenuCommandService; 
			if (menuCommandService != null) 
			{
                foreach (CommandID affectedCommand in CommandSet.NavigationToolCommandIds) 
                {
					MenuCommand menuCommand = menuCommandService.FindCommand(affectedCommand);
 					if (menuCommand != null && menuCommand.Enabled && menuCommand.Checked)
					{ 
 						this.previousCommand = menuCommand.CommandID;
 						break; 
					} 
 				}
			} 

			this.previousCursor = ParentView.Cursor;
		}
 
 		private void RestoreUIState()
		{ 
 			IMenuCommandService menuCommandService = GetService(typeof(IMenuCommandService)) as IMenuCommandService; 
 			if (menuCommandService != null)
			{ 
                foreach (CommandID affectedCommand in CommandSet.NavigationToolCommandIds)
                {
 					MenuCommand menuCommand = menuCommandService.FindCommand(affectedCommand);
					if (menuCommand != null && menuCommand.Enabled) 
						menuCommand.Checked = (menuCommand.CommandID == this.previousCommand);
				} 
 			} 

			ParentView.Cursor = this.previousCursor; 
 		}
 		#endregion
	}
 	#endregion 
}

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

Link Menu

Network programming in C#, Network Programming in VB.NET, Network Programming in .NET
This book is available now!
Buy at Amazon US or
Buy at Amazon UK