greenshot/Greenshot/Drawing/Surface.cs

/*
 * Greenshot - a free and open source screenshot tool
 * Copyright (C) 2007-2015 Thomas Braun, Jens Klingen, Robin Krom
 * 
 * For more information see: http://getgreenshot.org/
 * The Greenshot project is hosted on Sourceforge: http://sourceforge.net/projects/greenshot/
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 1 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

using Greenshot.Configuration;
using Greenshot.Core;
using Greenshot.Drawing.Fields;
using Greenshot.Helpers;
using Greenshot.IniFile;
using Greenshot.Memento;
using Greenshot.Plugin;
using Greenshot.Plugin.Drawing;
using GreenshotPlugin.Controls;
using GreenshotPlugin.Core;
using log4net;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
using System.Windows.Forms;

namespace Greenshot.Drawing {

	/// <summary>
	/// Description of Surface.
	/// </summary>
	public class Surface : Control, ISurface {
		private static ILog LOG = LogManager.GetLogger(typeof(Surface));
		public static int Count = 0;
		private static CoreConfiguration conf = IniConfig.GetIniSection<CoreConfiguration>();

		// Property to identify the Surface ID
		private Guid _uniqueId = Guid.NewGuid();

		/// <summary>
		/// The GUID of the surface
		/// </summary>
		public Guid ID {
			get {
				return _uniqueId;
			}
			set {
				_uniqueId = value;
			}
		}

		/// <summary>
		/// Event handlers (do not serialize!)
		/// </summary>
		[NonSerialized]
		private SurfaceElementEventHandler _movingElementChanged;
		public event SurfaceElementEventHandler MovingElementChanged {
			add {
				_movingElementChanged += value;
			}
			remove {
				_movingElementChanged -= value;
			}
		}
		[NonSerialized]
		private SurfaceDrawingModeEventHandler _drawingModeChanged;
		public event SurfaceDrawingModeEventHandler DrawingModeChanged {
			add {
				_drawingModeChanged += value;
			}
			remove {
				_drawingModeChanged -= value;
			}
		}
		[NonSerialized]
		private SurfaceSizeChangeEventHandler _surfaceSizeChanged;
		public event SurfaceSizeChangeEventHandler SurfaceSizeChanged {
			add {
				_surfaceSizeChanged += value;
			}
			remove {
				_surfaceSizeChanged -= value;
			}
		}
		[NonSerialized]
		private SurfaceMessageEventHandler _surfaceMessage;
		public event SurfaceMessageEventHandler SurfaceMessage {
			add {
				_surfaceMessage += value;
			}
			remove {
				_surfaceMessage -= value;
			}
		}

		/// <summary>
		/// inUndoRedo makes sure we don't undo/redo while in a undo/redo action
		/// </summary>
		[NonSerialized]
		private bool _inUndoRedo;

		/// <summary>
		/// Make only one surfacemove cycle undoable, see SurfaceMouseMove
		/// </summary>
		[NonSerialized]
		private bool _isSurfaceMoveMadeUndoable;

		/// <summary>
		/// Undo/Redo stacks, should not be serialized as the file would be way to big
		/// </summary>
		[NonSerialized]
		private readonly Stack<IMemento> _undoStack = new Stack<IMemento>();
		[NonSerialized]
		private readonly Stack<IMemento> _redoStack = new Stack<IMemento>();

		/// <summary>
		/// Last save location, do not serialize!
		/// </summary>
		[NonSerialized]
		private string _lastSaveFullPath;

		/// <summary>
		/// current drawing mode, do not serialize!
		/// </summary>
		[NonSerialized]
		private DrawingModes _drawingMode = DrawingModes.None;

		/// <summary>
		/// the keyslocked flag helps with focus issues
		/// </summary>
		[NonSerialized]
		private bool _keysLocked;

		/// <summary>
		/// Location of the mouse-down (it "starts" here), do not serialize
		/// </summary>
		[NonSerialized]
		private Point _mouseStart = Point.Empty;

		/// <summary>
		/// are we in a mouse down, do not serialize
		/// </summary>
		[NonSerialized]
		private bool _mouseDown;

		/// <summary>
		/// The selected element for the mouse down, do not serialize
		/// </summary>
		[NonSerialized]
		private IDrawableContainer _mouseDownElement;

		/// <summary>
		/// all selected elements, do not serialize
		/// </summary>
		[NonSerialized]
		private DrawableContainerList selectedElements;

		/// <summary>
		/// the element we are drawing with, do not serialize
		/// </summary>
		[NonSerialized]
		private IDrawableContainer _drawingElement;

		/// <summary>
		/// the element we want to draw with (not yet drawn), do not serialize
		/// </summary>
		[NonSerialized]
		private IDrawableContainer _undrawnElement;

		/// <summary>
		/// the cropcontainer, when cropping this is set, do not serialize
		/// </summary>
		[NonSerialized]
		private IDrawableContainer _cropContainer;

		/// <summary>
		/// the brush which is used for transparent backgrounds, set by the editor, do not serialize
		/// </summary>
		[NonSerialized]
		private Brush _transparencyBackgroundBrush;

		/// <summary>
		/// The buffer is only for drawing on it when using filters (to supply access)
		/// This saves a lot of "create new bitmap" commands
		/// Should not be serialized, as it's generated.
		/// The actual bitmap is in the paintbox...
		/// TODO: Check if this buffer is still needed!
		/// </summary>
		[NonSerialized]
		private Bitmap _buffer;

		/// <summary>
		/// all stepLabels for the surface, needed with serialization
		/// </summary>
		private List<StepLabelContainer> _stepLabels = new List<StepLabelContainer>();

		public void AddStepLabel(StepLabelContainer stepLabel) {
			_stepLabels.Add(stepLabel);
		}
		public void RemoveStepLabel(StepLabelContainer stepLabel) {
			_stepLabels.Remove(stepLabel);
		}

		/// <summary>
		/// Count all the VISIBLE steplabels in the surface, up to the supplied one
		/// </summary>
		/// <param name="stopAtContainer">can be null, if not the counting stops here</param>
		/// <returns>number of steplabels before the supplied container</returns>
		public int CountStepLabels(IDrawableContainer stopAtContainer) {
			int number = 1;
			foreach (var possibleThis in _stepLabels) {
				if (possibleThis == stopAtContainer) {
					break;
				}
				if (IsOnSurface(possibleThis)) {
					number++;
				}
			}
			return number;
		}

		/// <summary>
		/// all elements on the surface, needed with serialization
		/// </summary>
		private readonly DrawableContainerList _elements;

		/// <summary>
		/// all elements on the surface, needed with serialization
		/// </summary>
		private FieldAggregator _fieldAggregator = new FieldAggregator();

		/// <summary>
		/// the cursor container, needed with serialization as we need a direct acces to it.
		/// </summary>
		private IDrawableContainer _cursorContainer;

		/// <summary>
		/// the capture details, needed with serialization
		/// </summary>
		private ICaptureDetails _captureDetails;

		/// <summary>
		/// the modified flag specifies if the surface has had modifications after the last export.
		/// Initial state is modified, as "it's not saved"
		/// After serialization this should actually be "false" (the surface came from a stream)
		/// For now we just serialize it...
		/// </summary>
		private bool _modified = true;

		/// <summary>
		/// The image is the actual captured image, needed with serialization
		/// </summary>
		private Image _image;
		public Image Image {
			get {
				return _image;
			}
			set {
				_image = value;
				Size = _image.Size;
			}
		}

		/// <summary>
		/// The field aggregator is that which is used to have access to all the fields inside the currently selected elements.
		/// e.g. used to decided if and which line thickness is shown when multiple elements are selected.
		/// </summary>
		public FieldAggregator FieldAggregator {
			get {
				return _fieldAggregator;
			}
			set {
				_fieldAggregator = value;
			}
		}

		/// <summary>
		/// The cursor container has it's own accessor so we can find and remove this (when needed)
		/// </summary>
		public IDrawableContainer CursorContainer {
			get {
				return _cursorContainer;
			}
		}

		/// <summary>
		/// A simple getter to ask if this surface has a cursor
		/// </summary>
		public bool HasCursor {
			get {
				return _cursorContainer != null;
			}
		}

		/// <summary>
		/// A simple helper method to remove the cursor from the surface
		/// </summary>
		public void RemoveCursor() {
			RemoveElement(_cursorContainer, true);
			_cursorContainer = null;
		}

		/// <summary>
		/// The brush which is used to draw the transparent background
		/// </summary>
		public Brush TransparencyBackgroundBrush {
			get {
				return _transparencyBackgroundBrush;
			}
			set {
				_transparencyBackgroundBrush = value;
			}
		}

		/// <summary>
		/// Are the keys on this surface locked?
		/// </summary>
		public bool KeysLocked {
			get {
				return _keysLocked;
			}
			set {
				_keysLocked = value;
			}
		}

		/// <summary>
		/// Is this surface modified? This is only true if the surface has not been exported.
		/// </summary>
		public bool Modified {
			get {
				return _modified;
			}
			set {
				_modified = value;
			}
		}

		/// <summary>
		/// The DrawingMode property specifies the mode for drawing, more or less the element type.
		/// </summary>
		public DrawingModes DrawingMode {
			get {return _drawingMode;}
			set {
				_drawingMode = value;
				if (_drawingModeChanged != null) {
					SurfaceDrawingModeEventArgs eventArgs = new SurfaceDrawingModeEventArgs();
					eventArgs.DrawingMode = _drawingMode;
					_drawingModeChanged.Invoke(this, eventArgs);
				}
				DeselectAllElements();
				CreateUndrawnElement();
			}
		}

		/// <summary>
		/// Property for accessing the last save "full" path
		/// </summary>
		public string LastSaveFullPath {
			get {
				return _lastSaveFullPath;
			}
			set {
				_lastSaveFullPath = value;
			}
		}

		/// <summary>
		/// Property for accessing the URL to which the surface was recently uploaded
		/// </summary>
		public string UploadURL {
			get;
			set;
		}

		/// <summary>
		/// Property for accessing the capture details
		/// </summary>
		public ICaptureDetails CaptureDetails {
			get {
				return _captureDetails;
			}
			set {
				_captureDetails = value;
			}
		}

		/// <summary>
		/// Base Surface constructor
		/// </summary>
		public Surface() : base(){
			Count++;
			_elements = new DrawableContainerList(_uniqueId);
			selectedElements = new DrawableContainerList(_uniqueId);
			LOG.Debug("Creating surface!");
			MouseDown += SurfaceMouseDown;
			MouseUp += SurfaceMouseUp;
			MouseMove += SurfaceMouseMove;
			MouseDoubleClick += SurfaceDoubleClick;
			Paint += SurfacePaint;
			AllowDrop = true;
			DragDrop += OnDragDrop;
			DragEnter += OnDragEnter;
			// bind selected & elements to this, otherwise they can't inform of modifications
			selectedElements.Parent = this;
			_elements.Parent = this;
			// Make sure we are visible
			Visible = true;
			TabStop = false;
			// Enable double buffering
			DoubleBuffered = true;
			SetStyle(ControlStyles.UserPaint | ControlStyles.AllPaintingInWmPaint | ControlStyles.ResizeRedraw | ControlStyles.ContainerControl | ControlStyles.OptimizedDoubleBuffer | ControlStyles.SupportsTransparentBackColor, true);
		}
		
		/// <summary>
		/// Private method, the current image is disposed the new one will stay.
		/// </summary>
		/// <param name="newImage">The new image</param>
		/// <param name="dispose">true if the old image needs to be disposed, when using undo this should not be true!!</param>
		private void SetImage(Image newImage, bool dispose) {
			// Dispose
			if (_image != null && dispose) {
				_image.Dispose();
			}

			// Set new values
			Image = newImage;
			Size = newImage.Size;

			_modified = true;
		}

		/// <summary>
		/// Surface constructor with an image
		/// </summary>
		/// <param name="newImage"></param>
		public Surface(Image newImage) : this() {
			LOG.DebugFormat("Got image with dimensions {0} and format {1}", newImage.Size, newImage.PixelFormat);
			SetImage(newImage, true);
		}

		/// <summary>
		/// Surface contructor with a capture
		/// </summary>
		/// <param name="capture"></param>
		public Surface(ICapture capture) : this(capture.Image) {
			// check if cursor is captured, and visible
			if (capture.Cursor != null && capture.CursorVisible) {
				Rectangle cursorRect = new Rectangle(capture.CursorLocation, capture.Cursor.Size);
				Rectangle captureRect = new Rectangle(Point.Empty, capture.Image.Size);
				// check if cursor is on the capture, otherwise we leave it out.
				if (cursorRect.IntersectsWith(captureRect)) {
					_cursorContainer = AddIconContainer(capture.Cursor, capture.CursorLocation.X, capture.CursorLocation.Y);
					SelectElement(_cursorContainer);
				}
			}
			// Make sure the image is NOT disposed, we took the reference directly into ourselves
			((Capture)capture).NullImage();

			_captureDetails = capture.CaptureDetails;
		}

		protected override void Dispose(bool disposing) {
			if (disposing) {
				Count--;
				LOG.Debug("Disposing surface!");
				if (_buffer != null) {
					_buffer.Dispose();
					_buffer = null;
				}
				if (_transparencyBackgroundBrush != null) {
					_transparencyBackgroundBrush.Dispose();
					_transparencyBackgroundBrush = null;
				}

				// Cleanup undo/redo stacks
				while (_undoStack != null && _undoStack.Count > 0) {
					_undoStack.Pop().Dispose();
				}
				while (_redoStack != null && _redoStack.Count > 0) {
					_redoStack.Pop().Dispose();
				}
				foreach (IDrawableContainer container in _elements) {
					container.Dispose();
				}
				if (_undrawnElement != null) {
					_undrawnElement.Dispose();
					_undrawnElement = null;
				}
				if (_cropContainer != null) {
					_cropContainer.Dispose();
					_cropContainer = null;
				}
			}
			base.Dispose(disposing);
		}

		/// <summary>
		/// Undo the last action
		/// </summary>
		public void Undo() {
			if (_undoStack.Count > 0) {
				_inUndoRedo = true;
				IMemento top = _undoStack.Pop();
				_redoStack.Push(top.Restore());
				_inUndoRedo = false;
			}
		} 

		/// <summary>
		/// Undo an undo (=redo)
		/// </summary>
		public void Redo() {
			if (_redoStack.Count > 0) {
				_inUndoRedo = true;
				IMemento top = _redoStack.Pop();
				_undoStack.Push(top.Restore());
				_inUndoRedo = false;
			}
		}
		
		/// <summary>
		/// Returns if the surface can do a undo
		/// </summary>
		public bool CanUndo {
			get {
				return _undoStack.Count > 0;
			}
		}

		/// <summary>
		/// Returns if the surface can do a redo
		/// </summary>
		public bool CanRedo {
			get {
				return _redoStack.Count > 0;
			}
		}

		/// <summary>
		/// Get the language key for the undo action
		/// </summary>
		public LangKey UndoActionLanguageKey {
			get {
				if (CanUndo) {
					return _undoStack.Peek().ActionLanguageKey;
				}
				return LangKey.none;
			}
		}

		/// <summary>
		/// Get the language key for redo action
		/// </summary>
		public LangKey RedoActionLanguageKey {
			get {
				if (CanRedo) {
					return _redoStack.Peek().ActionLanguageKey;
				}
				return LangKey.none;
			}
		}

		/// <summary>
		/// Make an action undo-able
		/// </summary>
		/// <param name="memento">The memento implementing the undo</param>
		/// <param name="allowMerge">Allow changes to be merged</param>
		public void MakeUndoable(IMemento memento, bool allowMerge) {
			if (_inUndoRedo) {
				throw new InvalidOperationException("Invoking do within an undo/redo action.");
			}
			if (memento != null) {
				bool allowPush = true;
				if (_undoStack.Count > 0 && allowMerge) {
					// Check if merge is possible
					allowPush = !_undoStack.Peek().Merge(memento);
				}
				if (allowPush) {
					// Clear the redo-stack and dispose
					while(_redoStack.Count > 0) {
						_redoStack.Pop().Dispose();
					}
					_undoStack.Push(memento);
				}
			}
		}

		/// <summary>
		/// This saves the elements of this surface to a stream.
		/// Is used to save a template of the complete surface
		/// </summary>
		/// <param name="streamWrite"></param>
		/// <returns></returns>
		public long SaveElementsToStream(Stream streamWrite) {
			long bytesWritten = 0;
			try {
				long lengtBefore = streamWrite.Length;
				BinaryFormatter binaryWrite = new BinaryFormatter();
				binaryWrite.Serialize(streamWrite, _elements);
				bytesWritten = streamWrite.Length - lengtBefore;
			} catch (Exception e) {
				LOG.Error("Error serializing elements to stream.", e);
			}
			return bytesWritten;
		}

		/// <summary>
		/// This loads elements from a stream, among others this is used to load a surface.
		/// </summary>
		/// <param name="streamRead"></param>
		public void LoadElementsFromStream(Stream streamRead) {
			try {
				BinaryFormatter binaryRead = new BinaryFormatter();
				DrawableContainerList loadedElements = (DrawableContainerList) binaryRead.Deserialize(streamRead);
				loadedElements.Parent = this;
				// Make sure the steplabels are sorted accoring to their number
				_stepLabels.Sort(delegate(StepLabelContainer p1, StepLabelContainer p2) {
					return p1.Number.CompareTo(p2.Number);
				});
				DeselectAllElements();
				AddElements(loadedElements);
				SelectElements(loadedElements);
				FieldAggregator.BindElements(loadedElements);
			} catch (Exception e) {
				LOG.Error("Error serializing elements from stream.", e);
			}
		}

		/// <summary>
		/// This is called from the DrawingMode setter, which is not very correct...
		/// But here an element is created which is not yet draw, thus "undrawnElement".
		/// The element is than used while drawing on the surface.
		/// </summary>
		private void CreateUndrawnElement() {
			if(_undrawnElement != null) {
				FieldAggregator.UnbindElement(_undrawnElement);
			}
			switch (DrawingMode) {
				case DrawingModes.Rect:
					_undrawnElement = new RectangleContainer(this);
					break;
				case DrawingModes.Ellipse:
					_undrawnElement = new EllipseContainer(this);
					break;
				case DrawingModes.Text:
					_undrawnElement = new TextContainer(this);
					break;
				case DrawingModes.SpeechBubble:
					_undrawnElement = new SpeechbubbleContainer(this);
					break;
				case DrawingModes.StepLabel:
					_undrawnElement = new StepLabelContainer(this);
					break;
				case DrawingModes.Line:
					_undrawnElement = new LineContainer(this);
					break;
				case DrawingModes.Arrow:
					_undrawnElement = new ArrowContainer(this);
					break;
				case DrawingModes.Highlight:
					_undrawnElement = new HighlightContainer(this);
					break;
				case DrawingModes.Obfuscate:
					_undrawnElement = new ObfuscateContainer(this);
					break;
				case DrawingModes.Crop:
					_cropContainer = new CropContainer(this);
					_undrawnElement = _cropContainer;
					break;
				case DrawingModes.Bitmap:
					_undrawnElement = new ImageContainer(this);
					break;
				case DrawingModes.Path:
					_undrawnElement = new FreehandContainer(this);
					break;
				case DrawingModes.None:
					_undrawnElement = null;
					break;
			}
			if (_undrawnElement != null) {
				FieldAggregator.BindElement(_undrawnElement);
			}
		}

		#region Plugin interface implementations
		public IImageContainer AddImageContainer(Image image, int x, int y) {
			ImageContainer bitmapContainer = new ImageContainer(this);
			bitmapContainer.Image = image;
			bitmapContainer.Left = x;
			bitmapContainer.Top = y;
			AddElement(bitmapContainer);
			return bitmapContainer;
		}

		public IImageContainer AddImageContainer(string filename, int x, int y) {
			ImageContainer bitmapContainer = new ImageContainer(this);
			bitmapContainer.Load(filename);
			bitmapContainer.Left = x;
			bitmapContainer.Top = y;
			AddElement(bitmapContainer);
			return bitmapContainer;
		}
		public IIconContainer AddIconContainer(Icon icon, int x, int y) {
			IconContainer iconContainer = new IconContainer(this);
			iconContainer.Icon = icon;
			iconContainer.Left = x;
			iconContainer.Top = y;
			AddElement(iconContainer);
			return iconContainer;
		}
		public IIconContainer AddIconContainer(string filename, int x, int y) {
			IconContainer iconContainer = new IconContainer(this);
			iconContainer.Load(filename);
			iconContainer.Left = x;
			iconContainer.Top = y;
			AddElement(iconContainer);
			return iconContainer;
		}
		public ICursorContainer AddCursorContainer(Cursor cursor, int x, int y) {
			CursorContainer cursorContainer = new CursorContainer(this);
			cursorContainer.Cursor = cursor;
			cursorContainer.Left = x;
			cursorContainer.Top = y;
			AddElement(cursorContainer);
			return cursorContainer;
		}
		public ICursorContainer AddCursorContainer(string filename, int x, int y) {
			CursorContainer cursorContainer = new CursorContainer(this);
			cursorContainer.Load(filename);
			cursorContainer.Left = x;
			cursorContainer.Top = y;
			AddElement(cursorContainer);
			return cursorContainer;
		}

		public ITextContainer AddTextContainer(string text, HorizontalAlignment horizontalAlignment, VerticalAlignment verticalAlignment, FontFamily family, float size, bool italic, bool bold, bool shadow, int borderSize, Color color, Color fillColor) {
			TextContainer textContainer = new TextContainer(this);
			textContainer.Text = text;
			textContainer.SetFieldValue(FieldType.FONT_FAMILY, family.Name);
			textContainer.SetFieldValue(FieldType.FONT_BOLD, bold);
			textContainer.SetFieldValue(FieldType.FONT_ITALIC, italic);
			textContainer.SetFieldValue(FieldType.FONT_SIZE, size);
			textContainer.SetFieldValue(FieldType.FILL_COLOR, fillColor);
			textContainer.SetFieldValue(FieldType.LINE_COLOR, color);
			textContainer.SetFieldValue(FieldType.LINE_THICKNESS, borderSize);
			textContainer.SetFieldValue(FieldType.SHADOW, shadow);
			// Make sure the Text fits
			textContainer.FitToText();
			// Align to Surface
			textContainer.AlignToParent(horizontalAlignment, verticalAlignment);

			//AggregatedProperties.UpdateElement(textContainer);
			AddElement(textContainer);
			return textContainer;
		}
		#endregion

		#region DragDrop

		private void OnDragEnter(object sender, DragEventArgs e) {
			if(LOG.IsDebugEnabled) {
				LOG.Debug("DragEnter got following formats: ");
				foreach(string format in ClipboardHelper.GetFormats(e.Data)) {
					LOG.Debug(format);
				}
			}
			if ((e.AllowedEffect & DragDropEffects.Copy) != DragDropEffects.Copy) {
				e.Effect=DragDropEffects.None;
			} else {
				if (ClipboardHelper.ContainsImage(e.Data) || ClipboardHelper.ContainsFormat(e.Data, "DragImageBits")) {
					e.Effect = DragDropEffects.Copy;
				} else {
					e.Effect = DragDropEffects.None;
				}
			}
		}

		/// <summary>
		/// Handle the drag/drop
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void OnDragDrop(object sender, DragEventArgs e) {
			Point mouse = PointToClient(new Point(e.X, e.Y));
			if (e.Data.GetDataPresent("Text")) {
				string possibleUrl = ClipboardHelper.GetText(e.Data);
				// Test if it's an url and try to download the image so we have it in the original form
				if (possibleUrl != null && possibleUrl.StartsWith("http")) {
					using (Image image = NetworkHelper.DownloadImage(possibleUrl)) {
						if (image != null) {
							AddImageContainer(image, mouse.X, mouse.Y);
							return;
						}
					}
				}
			}

			foreach (Image image in ClipboardHelper.GetImages(e.Data)) {
				AddImageContainer(image, mouse.X, mouse.Y);
				mouse.Offset(10, 10);
				image.Dispose();
			}
		}
		
		#endregion

		/// <summary>
		/// Auto crop the image
		/// </summary>
		/// <returns>true if cropped</returns>
		public bool AutoCrop() {
			Rectangle cropRectangle;
			using (Image tmpImage = GetImageForExport()) {
				cropRectangle = ImageHelper.FindAutoCropRectangle(tmpImage, conf.AutoCropDifference);
			}
			if (!IsCropPossible(ref cropRectangle)) {
				return false;
			}
			DeselectAllElements();
			// Maybe a bit obscure, but the following line creates a drop container
			// It's available as "undrawnElement"
			DrawingMode = DrawingModes.Crop;
			_undrawnElement.Left = cropRectangle.X;
			_undrawnElement.Top = cropRectangle.Y;
			_undrawnElement.Width = cropRectangle.Width;
			_undrawnElement.Height = cropRectangle.Height;
			_undrawnElement.Status = EditStatus.UNDRAWN;
			AddElement(_undrawnElement);
			SelectElement(_undrawnElement);
			_drawingElement = null;
			_undrawnElement = null;
			return true;
		}

		/// <summary>
		/// A simple clear
		/// </summary>
		/// <param name="newColor">The color for the background</param>
		public void Clear(Color newColor) {
			//create a blank bitmap the same size as original
			Bitmap newBitmap = ImageHelper.CreateEmptyLike(Image, Color.Empty);
			if (newBitmap != null) {
				// Make undoable
				MakeUndoable(new SurfaceBackgroundChangeMemento(this, null), false);
				SetImage(newBitmap, false);
				Invalidate();
			}
		}

		/// <summary>
		/// Apply a bitmap effect to the surface
		/// </summary>
		/// <param name="effect"></param>
		public void ApplyBitmapEffect(IEffect effect) {
			BackgroundForm backgroundForm = new BackgroundForm("Effect", "Please wait");
			backgroundForm.Show();
			Application.DoEvents();
			try {
				Rectangle imageRectangle = new Rectangle(Point.Empty, Image.Size);
				Matrix matrix = new Matrix();
				Image newImage = ImageHelper.ApplyEffect(Image, effect, matrix);
				if (newImage != null) {
					// Make sure the elements move according to the offset the effect made the bitmap move
					_elements.Transform(matrix);
					// Make undoable
					MakeUndoable(new SurfaceBackgroundChangeMemento(this, matrix), false);
					SetImage(newImage, false);
					Invalidate();
					if (_surfaceSizeChanged != null && !imageRectangle.Equals(new Rectangle(Point.Empty, newImage.Size))) {
						_surfaceSizeChanged(this, null);
					}
				} else {
					// clean up matrix, as it hasn't been used in the undo stack.
					matrix.Dispose();
				}
			} finally {
				// Always close the background form
				backgroundForm.CloseDialog();
			}
		}

		/// <summary>
		/// check if a crop is possible
		/// </summary>
		/// <param name="cropRectangle"></param>
		/// <returns>true if this is possible</returns>
		public bool IsCropPossible(ref Rectangle cropRectangle) {
			cropRectangle = GuiRectangle.GetGuiRectangle(cropRectangle.Left, cropRectangle.Top, cropRectangle.Width, cropRectangle.Height);
			if (cropRectangle.Left < 0) {
				cropRectangle = new Rectangle(0, cropRectangle.Top, cropRectangle.Width + cropRectangle.Left, cropRectangle.Height);
			}
			if (cropRectangle.Top < 0) {
				cropRectangle = new Rectangle(cropRectangle.Left, 0, cropRectangle.Width, cropRectangle.Height + cropRectangle.Top);
			}
			if (cropRectangle.Left + cropRectangle.Width > Width) {
				cropRectangle = new Rectangle(cropRectangle.Left, cropRectangle.Top, Width - cropRectangle.Left, cropRectangle.Height);
			}
			if (cropRectangle.Top + cropRectangle.Height > Height) {
				cropRectangle = new Rectangle(cropRectangle.Left, cropRectangle.Top, cropRectangle.Width, Height - cropRectangle.Top);
			}
			if (cropRectangle.Height > 0 && cropRectangle.Width > 0) {
				return true;
			}
			return false;
		}
		
		/// <summary>
		/// Use to send any registered SurfaceMessageEventHandler a message, e.g. used for the notification area
		/// </summary>
		/// <param name="source">Who send</param>
		/// <param name="messageType">Type of message</param>
		/// <param name="message">Message itself</param>
		public void SendMessageEvent(object source, SurfaceMessageTyp messageType, string message) {
			if (_surfaceMessage != null) {
				SurfaceMessageEventArgs eventArgs = new SurfaceMessageEventArgs();
				eventArgs.Message = message;
				eventArgs.MessageType = messageType;
				eventArgs.Surface = this;
				_surfaceMessage(source, eventArgs);
			}
		}

		/// <summary>
		/// Crop the surface
		/// </summary>
		/// <param name="cropRectangle"></param>
		/// <returns></returns>
		public bool ApplyCrop(Rectangle cropRectangle) {
			if (IsCropPossible(ref cropRectangle)) {
				Rectangle imageRectangle = new Rectangle(Point.Empty, Image.Size);
				Bitmap tmpImage;
				// Make sure we have information, this this fails
				try {
					tmpImage = ImageHelper.CloneArea(Image, cropRectangle, PixelFormat.DontCare);
				} catch (Exception ex) {
					ex.Data.Add("CropRectangle", cropRectangle);
					ex.Data.Add("Width", Image.Width);
					ex.Data.Add("Height", Image.Height);
					ex.Data.Add("Pixelformat", Image.PixelFormat);
					throw;
				}

				Matrix matrix = new Matrix();
				matrix.Translate(-cropRectangle.Left, -cropRectangle.Top, MatrixOrder.Append);
				// Make undoable
				MakeUndoable(new SurfaceBackgroundChangeMemento(this, matrix), false);

				// Do not dispose otherwise we can't undo the image!
				SetImage(tmpImage, false);
				_elements.Transform(matrix);
				if (_surfaceSizeChanged != null && !imageRectangle.Equals(new Rectangle(Point.Empty, tmpImage.Size))) {
					_surfaceSizeChanged(this, null);
				}
				Invalidate();
				return true;
			}
			return false;
		}

		/// <summary>
		/// The background here is the captured image.
		/// This is called from the SurfaceBackgroundChangeMemento.
		/// </summary>
		/// <param name="previous"></param>
		/// <param name="matrix"></param>
		public void UndoBackgroundChange(Image previous, Matrix matrix) {
			SetImage(previous, false);
			if (matrix != null) {
				_elements.Transform(matrix);
			}
			if (_surfaceSizeChanged != null) {
				_surfaceSizeChanged(this, null);
			}
			Invalidate();
		}

		/// <summary>
		/// This event handler is called when someone presses the mouse on a surface.
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		void SurfaceMouseDown(object sender, MouseEventArgs e) {
			_mouseStart = e.Location;
		
			// check contextmenu
			if (e.Button == MouseButtons.Right) {
				DrawableContainerList selectedList = null;
				if (selectedElements != null && selectedElements.Count > 0) {
					selectedList = selectedElements;
				} else {
					// Single element
					IDrawableContainer rightClickedContainer = _elements.ClickableElementAt(_mouseStart.X, _mouseStart.Y);
					if (rightClickedContainer != null) {
						selectedList = new DrawableContainerList(ID);
						selectedList.Add(rightClickedContainer);
					}
				}
				if (selectedList != null && selectedList.Count > 0) {
					selectedList.ShowContextMenu(e, this);
				}
				return;
			}

			_mouseDown = true;
			_isSurfaceMoveMadeUndoable = false;

			if (_cropContainer != null && ((_undrawnElement == null) || (_undrawnElement != null && DrawingMode != DrawingModes.Crop))) {
				RemoveElement(_cropContainer, false);
				_cropContainer = null;
				_drawingElement = null;
			}

			if (_drawingElement == null && DrawingMode != DrawingModes.None) {
				if (_undrawnElement == null) {
					DeselectAllElements();
					if (_undrawnElement == null) {
						CreateUndrawnElement();
					}
				}
				_drawingElement = _undrawnElement;
				// if a new element has been drawn, set location and register it
				if (_drawingElement != null) {
					_drawingElement.Status = _undrawnElement.DefaultEditMode;
					_drawingElement.PropertyChanged += ElementPropertyChanged;
					if (!_drawingElement.HandleMouseDown(_mouseStart.X, _mouseStart.Y)) {
						_drawingElement.Left = _mouseStart.X;
						_drawingElement.Top = _mouseStart.Y;
					}
					AddElement(_drawingElement);
					_drawingElement.Selected = true;
				}
				_undrawnElement = null;
			} else {
				// check whether an existing element was clicked
				// we save mouse down element separately from selectedElements (checked on mouse up),
				// since it could be moved around before it is actually selected
				_mouseDownElement = _elements.ClickableElementAt(_mouseStart.X, _mouseStart.Y);

				if (_mouseDownElement != null) {
					_mouseDownElement.Status = EditStatus.MOVING;
				}
			}
		}

		/// <summary>
		/// This event handle is called when the mouse button is unpressed
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		void SurfaceMouseUp(object sender, MouseEventArgs e) {
			Point currentMouse = new Point(e.X, e.Y);

			_elements.Status = EditStatus.IDLE;
			if (_mouseDownElement != null) {
				_mouseDownElement.Status = EditStatus.IDLE;
			}
			_mouseDown = false;
			_mouseDownElement = null;
			if (DrawingMode == DrawingModes.None) {
				// check whether an existing element was clicked
				IDrawableContainer element = _elements.ClickableElementAt(currentMouse.X, currentMouse.Y);
				bool shiftModifier = (ModifierKeys & Keys.Shift) == Keys.Shift;
				if (element != null) {
					element.Invalidate();
					bool alreadySelected = selectedElements.Contains(element);
					if (shiftModifier) {
						if (alreadySelected) {
							DeselectElement(element);
						} else {
							SelectElement(element);
						}
					} else {
						if (!alreadySelected) {
							DeselectAllElements();
							SelectElement(element);
						}
					}
				} else if(!shiftModifier) {
					DeselectAllElements();
				}
			}
			
			if (selectedElements.Count > 0) {
				selectedElements.ShowGrippers();
				selectedElements.Selected = true;
			}

			if (_drawingElement != null) {
				if (!_drawingElement.InitContent()) {
					_elements.Remove(_drawingElement);
					_drawingElement.Invalidate();
				} else {
					_drawingElement.HandleMouseUp(currentMouse.X, currentMouse.Y);
					_drawingElement.Invalidate();
					if (Math.Abs(_drawingElement.Width) < 5 && Math.Abs(_drawingElement.Height) < 5) {
						_drawingElement.Width = 25;
						_drawingElement.Height = 25;
					}
					SelectElement(_drawingElement);
					_drawingElement.Selected = true;
				}
				_drawingElement = null;
			}
		}

		/// <summary>
		/// This event handler is called when the mouse moves over the surface
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		void SurfaceMouseMove(object sender, MouseEventArgs e) {
			Point currentMouse = e.Location;

			if (DrawingMode != DrawingModes.None) {
				Cursor = Cursors.Cross;
			} else {
				Cursor = Cursors.Default;
			}

			if (_mouseDown) {
				if (_mouseDownElement != null) { // an element is currently dragged
					_mouseDownElement.Invalidate();
					selectedElements.HideGrippers();
					// Move the element
					if (_mouseDownElement.Selected) {
						if (!_isSurfaceMoveMadeUndoable) {
							// Only allow one undoable per mouse-down/move/up "cycle"
							_isSurfaceMoveMadeUndoable = true;
							selectedElements.MakeBoundsChangeUndoable(false);
						}
						// dragged element has been selected before -> move all
						selectedElements.MoveBy(currentMouse.X - _mouseStart.X, currentMouse.Y - _mouseStart.Y);
					} else {
						if (!_isSurfaceMoveMadeUndoable) {
							// Only allow one undoable per mouse-down/move/up "cycle"
							_isSurfaceMoveMadeUndoable = true;
							_mouseDownElement.MakeBoundsChangeUndoable(false);
						}
						// dragged element is not among selected elements -> just move dragged one
						_mouseDownElement.MoveBy(currentMouse.X - _mouseStart.X, currentMouse.Y - _mouseStart.Y);
					}
					_mouseStart = currentMouse;
					_mouseDownElement.Invalidate();
					_modified = true;
				} else if (_drawingElement != null) {
					_drawingElement.HandleMouseMove(currentMouse.X, currentMouse.Y);
					_modified = true;
				}
			}
		}
		
		/// <summary>
		/// This event handler is called when the surface is double clicked.
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		void SurfaceDoubleClick(object sender, MouseEventArgs e) {
			selectedElements.OnDoubleClick();
			selectedElements.Invalidate();
		}

		/// <summary>
		/// Privately used to get the rendered image with all the elements on it.
		/// </summary>
		/// <param name="renderMode"></param>
		/// <returns></returns>
		private Image GetImage(RenderMode renderMode) {
			// Generate a copy of the original image with a dpi equal to the default...
			Bitmap clone = ImageHelper.Clone(_image, PixelFormat.DontCare);
			// otherwise we would have a problem drawing the image to the surface... :(
			using (Graphics graphics = Graphics.FromImage(clone)) {
				// Do not set the following, the containers need to decide themselves
				//graphics.SmoothingMode = SmoothingMode.HighQuality;
				//graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;
				//graphics.CompositingQuality = CompositingQuality.HighQuality;
				//graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
				_elements.Draw(graphics, clone, renderMode, new Rectangle(Point.Empty, clone.Size));
			}
			return clone;
		}

		/// <summary>
		/// This returns the image "result" of this surface, with all the elements rendered on it.
		/// </summary>
		/// <returns></returns>
		public Image GetImageForExport() {
			return GetImage(RenderMode.EXPORT);
		}
		
		/// <summary>
		/// This is the event handler for the Paint Event, try to draw as little as possible!
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		void SurfacePaint(object sender, PaintEventArgs e) {
			Graphics targetGraphics = e.Graphics;
			Rectangle clipRectangle = e.ClipRectangle;
			if (Rectangle.Empty.Equals(clipRectangle)) {
				LOG.Debug("Empty cliprectangle??");
				return;
			}

			if (_elements.HasIntersectingFilters(clipRectangle)) {
				if (_buffer != null) {
					if (_buffer.Width != Image.Width || _buffer.Height != Image.Height || _buffer.PixelFormat != Image.PixelFormat) {
						_buffer.Dispose();
						_buffer = null;
					}
				}
				if (_buffer == null) {
					_buffer = ImageHelper.CreateEmpty(Image.Width, Image.Height, Image.PixelFormat, Color.Empty, Image.HorizontalResolution, Image.VerticalResolution);
					LOG.DebugFormat("Created buffer with size: {0}x{1}", Image.Width, Image.Height);
				}
				// Elements might need the bitmap, so we copy the part we need
				using (Graphics graphics = Graphics.FromImage(_buffer)) {
					// do not set the following, the containers need to decide this themselves!
					//graphics.SmoothingMode = SmoothingMode.HighQuality;
					//graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;
					//graphics.CompositingQuality = CompositingQuality.HighQuality;
					//graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
					DrawBackground(graphics, clipRectangle);
					graphics.DrawImage(Image, clipRectangle, clipRectangle, GraphicsUnit.Pixel);
					graphics.SetClip(targetGraphics);
					_elements.Draw(graphics, _buffer, RenderMode.EDIT, clipRectangle);
				}
				targetGraphics.DrawImage(_buffer, clipRectangle, clipRectangle, GraphicsUnit.Pixel);
			} else {
				DrawBackground(targetGraphics, clipRectangle);
				targetGraphics.DrawImage(Image, clipRectangle, clipRectangle, GraphicsUnit.Pixel);
				_elements.Draw(targetGraphics, null, RenderMode.EDIT, clipRectangle);
			}
		}

		private void DrawBackground(Graphics targetGraphics, Rectangle clipRectangle) {
			// check if we need to draw the checkerboard
			if (Image.IsAlphaPixelFormat(Image.PixelFormat) && _transparencyBackgroundBrush != null) {
				targetGraphics.FillRectangle(_transparencyBackgroundBrush, clipRectangle);
			} else {
				targetGraphics.Clear(BackColor);
			}
		}
		
		/// <summary>
		/// Draw a checkboard when capturing with transparency 
		/// </summary>
		/// <param name="e">PaintEventArgs</param>
		protected override void OnPaintBackground(PaintEventArgs e) {
		} 

		/// <summary>
		/// Wrapper for makeUndoable flag which was introduced later, will call AddElement with makeundoable set to true
		/// </summary>
		/// <param name="element">the new element</param>
		public void AddElement(IDrawableContainer element) {
			AddElement(element, true);
		}

		/// <summary>
		/// Add a new element to the surface
		/// </summary>
		/// <param name="element">the new element</param>
		/// <param name="makeUndoable">true if the adding should be undoable</param>
		public void AddElement(IDrawableContainer element, bool makeUndoable) {
			_elements.Add(element);
			DrawableContainer container = element as DrawableContainer;
			if (container != null) {
				container.FieldChanged += element_FieldChanged;
			}
			element.PropertyChanged += ElementPropertyChanged;
			if (element.Status == EditStatus.UNDRAWN) {
				element.Status = EditStatus.IDLE;
			}
			element.Invalidate();
			if (makeUndoable) {
				MakeUndoable(new AddElementMemento(this, element), false);
			}
			_modified = true;
		}

		/// <summary>
		/// Remove an element of the elements list
		/// </summary>
		/// <param name="elementToRemove">Element to remove</param>
		/// <param name="makeUndoable">flag specifying if the remove needs to be undoable</param>
		public void RemoveElement(IDrawableContainer elementToRemove, bool makeUndoable) {
			DeselectElement(elementToRemove);
			_elements.Remove(elementToRemove);
			DrawableContainer element = elementToRemove as DrawableContainer;
			if (element != null) {
				element.FieldChanged -= element_FieldChanged;
			}
			elementToRemove.PropertyChanged -= ElementPropertyChanged;
			// Do not dispose, the memento should!! element.Dispose();
			Invalidate();
			if (makeUndoable) {
				MakeUndoable(new DeleteElementMemento(this, elementToRemove), false);
			}
			_modified = true;
		}

		/// <summary>
		/// Add the supplied elements to the surface
		/// </summary>
		/// <param name="elementsToAdd"></param>
		public void AddElements(DrawableContainerList elementsToAdd) {
			foreach(IDrawableContainer element in elementsToAdd) {
				AddElement(element, true);
			}
		}

		/// <summary>
		/// Returns if this surface has selected elements
		/// </summary>
		/// <returns></returns>
		public bool HasSelectedElements {
			get {
				return (selectedElements != null && selectedElements.Count > 0);				
			}
		}

		/// <summary>
		/// Remove all the selected elements
		/// </summary>
		public void RemoveSelectedElements() {
			if (HasSelectedElements) {
				// As RemoveElement will remove the element from the selectedElements list we need to copy the element
				// to another list.
				List<DrawableContainer> elementsToRemove = new List<DrawableContainer>();
				foreach (DrawableContainer element in selectedElements) {
					// Collect to remove later
					elementsToRemove.Add(element);
				}
				// Remove now
				foreach(DrawableContainer element in elementsToRemove) {
					RemoveElement(element, true);
				}
				selectedElements.Clear();
				if (_movingElementChanged != null) {
					SurfaceElementEventArgs eventArgs = new SurfaceElementEventArgs();
					eventArgs.Elements = selectedElements;
					_movingElementChanged(this, eventArgs);
				}
			}
		}

		/// <summary>
		/// Cut the selected elements from the surface to the clipboard
		/// </summary>
		public void CutSelectedElements() {
			if (HasSelectedElements) {
				ClipboardHelper.SetClipboardData(typeof(DrawableContainerList), selectedElements);
				RemoveSelectedElements();
			}
		}

		/// <summary>
		/// Copy the selected elements to the clipboard
		/// </summary>
		public void CopySelectedElements() {
			if (HasSelectedElements) {
				ClipboardHelper.SetClipboardData(typeof(DrawableContainerList), selectedElements);
			}
		}

		/// <summary>
		/// This method is called to confirm/cancel "confirmable" elements, like the crop-container.
		/// Called when pressing enter or using the "check" in the editor.
		/// </summary>
		/// <param name="confirm"></param>
		public void ConfirmSelectedConfirmableElements(bool confirm){
			// create new collection so that we can iterate safely (selectedElements might change due with confirm/cancel)
			List<IDrawableContainer> selectedDCs = new List<IDrawableContainer>(selectedElements);
			foreach (IDrawableContainer dc in selectedDCs){
				if (dc.Equals(_cropContainer)){
					DrawingMode = DrawingModes.None;
					// No undo memento for the cropcontainer itself, only for the effect
					RemoveElement(_cropContainer, false);
					if (confirm) {
						ApplyCrop(_cropContainer.Bounds);
					}
					_cropContainer.Dispose();
					_cropContainer = null;
				}
			}
		}

		/// <summary>
		/// Paste all the elements that are on the clipboard
		/// </summary>
		public void PasteElementFromClipboard() {
			IDataObject clipboard = ClipboardHelper.GetDataObject();

			List<string> formats = ClipboardHelper.GetFormats(clipboard);
			if (formats == null || formats.Count == 0) {
				return;
			}
			if (LOG.IsDebugEnabled) {
				LOG.Debug("List of clipboard formats available for pasting:");
				foreach(string format in formats) {
					LOG.Debug("\tgot format: " + format);
				}
			}

			if (formats.Contains(typeof(DrawableContainerList).FullName)) {
				DrawableContainerList dcs = (DrawableContainerList)ClipboardHelper.GetFromDataObject(clipboard, typeof(DrawableContainerList));
				if (dcs != null) {
					// Make element(s) only move 10,10 if the surface is the same
					Point moveOffset;
					bool isSameSurface = (dcs.ParentID == _uniqueId);
					dcs.Parent = this;
					if (isSameSurface) {
						moveOffset = new Point(10, 10);
					} else {
						moveOffset = Point.Empty;
					}
					// Here a fix for bug #1475, first calculate the bounds of the complete DrawableContainerList
					Rectangle drawableContainerListBounds = Rectangle.Empty;
					foreach (IDrawableContainer element in dcs) {
						if (drawableContainerListBounds == Rectangle.Empty) {
							drawableContainerListBounds = element.DrawingBounds;
						} else {
							drawableContainerListBounds = Rectangle.Union(drawableContainerListBounds, element.DrawingBounds);
						}
					}
					// And find a location inside the target surface to paste to
					bool containersCanFit = drawableContainerListBounds.Width < Bounds.Width && drawableContainerListBounds.Height < Bounds.Height;
					if (!containersCanFit) {
						Point containersLocation = drawableContainerListBounds.Location;
						containersLocation.Offset(moveOffset);
						if (!Bounds.Contains(containersLocation)) {
							// Easy fix for same surface
							if (isSameSurface) {
								moveOffset = new Point(-10, -10);
							} else {
								// For different surface, which is most likely smaller, we move to "10,10"
								moveOffset = new Point(-drawableContainerListBounds.Location.X + 10, -drawableContainerListBounds.Location.Y + 10);
							}
						}
					} else {
						Rectangle moveContainerListBounds = drawableContainerListBounds;
						moveContainerListBounds.Offset(moveOffset);
						// check if the element is inside
						if (!Bounds.Contains(moveContainerListBounds)) {
							// Easy fix for same surface
							if (isSameSurface) {
								moveOffset = new Point(-10, -10);
							} else {
								// For different surface, which is most likely smaller
								int offsetX = 0;
								int offsetY = 0;
								if (drawableContainerListBounds.Right > Bounds.Right) {
									offsetX = Bounds.Right - drawableContainerListBounds.Right;
									// Correction for the correction
									if (drawableContainerListBounds.Left + offsetX < 0) {
										offsetX += Math.Abs(drawableContainerListBounds.Left + offsetX);
									}
								}
								if (drawableContainerListBounds.Bottom > Bounds.Bottom) {
									offsetY = Bounds.Bottom - drawableContainerListBounds.Bottom;
									// Correction for the correction
									if (drawableContainerListBounds.Top + offsetY < 0) {
										offsetY += Math.Abs(drawableContainerListBounds.Top + offsetY);
									}
								}
								moveOffset = new Point(offsetX, offsetY);
							}
						}
					}
					dcs.MoveBy(moveOffset.X, moveOffset.Y);
					AddElements(dcs);
					FieldAggregator.BindElements(dcs);
					DeselectAllElements();
					SelectElements(dcs);
				}
			} else if (ClipboardHelper.ContainsImage(clipboard)) {
				int x = 10;
				int y = 10;
				foreach (Image clipboardImage in ClipboardHelper.GetImages(clipboard)) {
					if (clipboardImage != null) {
						DeselectAllElements();
						IImageContainer container = AddImageContainer(clipboardImage as Bitmap, x, y);
						SelectElement(container);
						clipboardImage.Dispose();
						x += 10;
						y += 10;
					}
				}
			} else if (ClipboardHelper.ContainsText(clipboard)) {
				string text = ClipboardHelper.GetText(clipboard);
				if (text != null) {
					DeselectAllElements();
					ITextContainer textContainer = AddTextContainer(text, HorizontalAlignment.Center, VerticalAlignment.CENTER,
						FontFamily.GenericSansSerif, 12f, false, false, false, 2, Color.Black, Color.Transparent);
					SelectElement(textContainer);
				}
			}
		}
		
		/// <summary>
		/// Duplicate all the selecteded elements
		/// </summary>
		public void DuplicateSelectedElements() {
			LOG.DebugFormat("Duplicating {0} selected elements", selectedElements.Count);
			DrawableContainerList dcs = selectedElements.Clone();
			dcs.Parent = this;
			dcs.MoveBy(10,10);
			AddElements(dcs);
			DeselectAllElements();
			SelectElements(dcs);
		}
		
		/// <summary>
		/// Deselect the specified element
		/// </summary>
		/// <param name="container"></param>
		public void DeselectElement(IDrawableContainer container) {
			container.HideGrippers();
			container.Selected = false;
			selectedElements.Remove(container);
			FieldAggregator.UnbindElement(container);
			if (_movingElementChanged != null) {
				SurfaceElementEventArgs eventArgs = new SurfaceElementEventArgs();
				eventArgs.Elements = selectedElements;
				_movingElementChanged(this, eventArgs);
			}
		}

		/// <summary>
		/// Deselect all the selected elements
		/// </summary>
		public void DeselectAllElements() {
			if (HasSelectedElements) {
				while(selectedElements.Count > 0) {
					IDrawableContainer element = selectedElements[0];
					element.Invalidate();
					element.HideGrippers();
					element.Selected = false;
					selectedElements.Remove(element);
					FieldAggregator.UnbindElement(element);
				}
				if (_movingElementChanged != null) {
					SurfaceElementEventArgs eventArgs = new SurfaceElementEventArgs();
					eventArgs.Elements = selectedElements;
					_movingElementChanged(this, eventArgs);
				}
			}
		}

		/// <summary>
		/// Select the supplied element
		/// </summary>
		/// <param name="container"></param>
		public void SelectElement(IDrawableContainer container) {
			if (!selectedElements.Contains(container)) {
				selectedElements.Add(container);
				container.ShowGrippers();
				container.Selected = true;
				FieldAggregator.BindElement(container);
				if (_movingElementChanged != null) {
					SurfaceElementEventArgs eventArgs = new SurfaceElementEventArgs();
					eventArgs.Elements = selectedElements;
					_movingElementChanged(this, eventArgs);
				}
				container.Invalidate();
			}
		}

		/// <summary>
		/// Select all elements, this is called when Ctrl+A is pressed
		/// </summary>
		public void SelectAllElements() {
			SelectElements(_elements);
		}

		/// <summary>
		/// Select the supplied elements
		/// </summary>
		/// <param name="elements"></param>
		public void SelectElements(DrawableContainerList elements) {
			foreach(DrawableContainer element in elements) {
				SelectElement(element);
			}
		}

		/// <summary>
		/// Process key presses on the surface, this is called from the editor (and NOT an override from the Control)
		/// </summary>
		/// <param name="k">Keys</param>
		/// <returns>false if no keys were processed</returns>
		public bool ProcessCmdKey(Keys k) {
			if (selectedElements.Count > 0) {
				bool shiftModifier = (ModifierKeys & Keys.Shift) == Keys.Shift;
				int px = shiftModifier ? 10 : 1;
				Point moveBy = Point.Empty;
				
				switch (k) {
					case Keys.Left:
					case Keys.Left | Keys.Shift:
						moveBy = new Point(-px, 0);
						break;
					case Keys.Up:
					case Keys.Up | Keys.Shift:
						moveBy = new Point(0, -px);
						break;
					case Keys.Right:
					case Keys.Right | Keys.Shift:
						moveBy = new Point(px, 0);
						break;
					case Keys.Down:
					case Keys.Down | Keys.Shift:
						moveBy = new Point(0, px);
						break;
					case Keys.PageUp:
						PullElementsUp();
						break;
					case Keys.PageDown:
						PushElementsDown();
						break;
					case Keys.Home:
						PullElementsToTop();
						break;
					case Keys.End:
						PushElementsToBottom();
						break;
					case Keys.Enter:
						ConfirmSelectedConfirmableElements(true);
						break;
					case Keys.Escape:
						ConfirmSelectedConfirmableElements(false);
						break;
					/*case Keys.Delete:
						RemoveSelectedElements();
						break;*/
					default:
						return false;
				}
				if (!Point.Empty.Equals(moveBy)) {
					selectedElements.MakeBoundsChangeUndoable(true);
					selectedElements.MoveBy(moveBy.X, moveBy.Y);
				}
				return true;
			}
			return false;
		}

		/// <summary>
		/// Property for accessing the elements on the surface
		/// </summary>
		public DrawableContainerList Elements {
			get {
				return _elements;
			}
		}

		/// <summary>
		/// pulls selected elements up one level in hierarchy
		/// </summary>
		public void PullElementsUp() {
			_elements.PullElementsUp(selectedElements);
			_elements.Invalidate();
		}
		
		/// <summary>
		/// pushes selected elements up to top in hierarchy
		/// </summary>
		public void PullElementsToTop() {
			_elements.PullElementsToTop(selectedElements);
			_elements.Invalidate();
		}
		
		/// <summary>
		/// pushes selected elements down one level in hierarchy
		/// </summary>
		public void PushElementsDown() {
			_elements.PushElementsDown(selectedElements);
			_elements.Invalidate();
		}
		
		/// <summary>
		/// pushes selected elements down to bottom in hierarchy
		/// </summary>
		public void PushElementsToBottom() {
			_elements.PushElementsToBottom(selectedElements);
			_elements.Invalidate();
		}
		
		/// <summary>
		/// indicates whether the selected elements could be pulled up in hierarchy
		/// </summary>
		/// <returns>true if selected elements could be pulled up, false otherwise</returns>
		public bool CanPullSelectionUp() {
			return _elements.CanPullUp(selectedElements);
		}
		
		/// <summary>
		/// indicates whether the selected elements could be pushed down in hierarchy
		/// </summary>
		/// <returns>true if selected elements could be pushed down, false otherwise</returns>
		public bool CanPushSelectionDown() {
			return _elements.CanPushDown(selectedElements);
		}
		
		public void ElementPropertyChanged(object sender, PropertyChangedEventArgs e) {
			//Invalidate();
		}
		
		public void element_FieldChanged(object sender, FieldChangedEventArgs e) {
			selectedElements.HandleFieldChangedEvent(sender, e);
		}

		public bool IsOnSurface(IDrawableContainer container) {
			return _elements.Contains(container);
		}
	}
}