#region ================== Copyright (c) 2007 Pascal vd Heiden

/*
 * Copyright (c) 2007 Pascal vd Heiden, www.codeimp.com
 * This program is released under GNU General Public License
 * 
 * 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.
 * 
 */

#endregion

#region ================== Namespaces

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;
using CodeImp.DoomBuilder.Actions;
using CodeImp.DoomBuilder.Editing;
using CodeImp.DoomBuilder.Geometry;
using CodeImp.DoomBuilder.Map;
using CodeImp.DoomBuilder.Rendering;
using CodeImp.DoomBuilder.Windows;

#endregion

namespace CodeImp.DoomBuilder.BuilderModes
{
	[EditMode(DisplayName = "Draw Lines Mode",
			  SwitchAction = "drawlinesmode",
			  ButtonImage = "DrawGeometryMode.png", //mxd	
			  ButtonOrder = int.MinValue + 1, //mxd
			  ButtonGroup = "000_drawing", //mxd
			  AllowCopyPaste = false,
			  Volatile = true,
			  UseByDefault = true,
			  Optional = false)]

	public class DrawGeometryMode : BaseClassicMode
	{
		#region ================== Constants

		protected const float LINE_THICKNESS = 0.8f;

		#endregion

		#region ================== Variables

		// Drawing points
		protected List<DrawnVertex> points;
		protected List<LineLengthLabel> labels;

		// Keep track of view changes (never used. mxd)
		//protected float lastoffsetx;
		//protected float lastoffsety;
		//protected float lastscale;

		// Options
		protected bool snaptogrid;		// SHIFT to toggle
		protected bool snaptonearest;	// CTRL to enable
		protected bool snaptocardinaldirection; //mxd. ALT-SHIFT to enable
		protected static bool usefourcardinaldirections;
		protected bool continuousdrawing; //mxd. Restart after finishing drawing?
		protected bool autoclosedrawing;  //mxd. Finish drawing when new points and existing geometry form a closed shape
		protected bool drawingautoclosed; //mxd

		//mxd. Labels display style
		protected bool labelshowangle = true;
		protected bool labeluseoffset = true;

		//mxd. Interface
		private DrawLineOptionsPanel panel;
		
		#endregion

		#region ================== Properties

		#endregion

		#region ================== Constructor / Disposer

		// Constructor
		public DrawGeometryMode()
		{
			// Initialize
			points = new List<DrawnVertex>();
			labels = new List<LineLengthLabel>();
			
			// No selection in this mode
			General.Map.Map.ClearAllSelected();
			General.Map.Map.ClearAllMarks(false);

			//mxd
			SetupInterface();
			
			// We have no destructor
			GC.SuppressFinalize(this);
		}

		// Disposer
		public override void Dispose()
		{
			// Not already disposed?
			if(!isdisposed)
			{
				// Clean up
				if(labels != null)
					foreach(LineLengthLabel l in labels) l.Dispose();
				
				// Done
				base.Dispose();
			}
		}

		#endregion

		#region ================== Methods

		// This checks if the view offset/zoom changed and updates the check (never used. mxd)
		/*protected bool CheckViewChanged()
		{
			// View changed?
			bool viewchanged = (renderer.OffsetX != lastoffsetx || renderer.OffsetY != lastoffsety || renderer.Scale != lastscale);

			// Keep view information
			lastoffsetx = renderer.OffsetX;
			lastoffsety = renderer.OffsetY;
			lastscale = renderer.Scale;

			// Return result
			return viewchanged;
		}*/
		
		// This updates the dragging
		protected virtual void Update()
		{
			PixelColor stitchcolor = General.Colors.Highlight;
			PixelColor losecolor = General.Colors.Selection;

			snaptocardinaldirection = General.Interface.ShiftState && General.Interface.AltState; //mxd
			snaptogrid = (snaptocardinaldirection || General.Interface.ShiftState ^ General.Interface.SnapToGrid);
			snaptonearest = General.Interface.CtrlState ^ General.Interface.AutoMerge;

			DrawnVertex curp = GetCurrentPosition();
			float vsize = (renderer.VertexSize + 1.0f) / renderer.Scale;

			// Update label positions (mxd)
			if(labels.Count > 0)
			{
				// Update labels for already drawn lines
				for(int i = 0; i < labels.Count - 1; i++)
					labels[i].Move(points[i].pos, points[i + 1].pos);

				// Update label for active line
				labels[labels.Count - 1].Move(points[points.Count - 1].pos, curp.pos);
			}

			// Render drawing lines
			if(renderer.StartOverlay(true))
			{
				// Go for all points to draw lines
				PixelColor color;
				if(points.Count > 0)
				{
					// Render lines
					DrawnVertex lastp = points[0];
					for(int i = 1; i < points.Count; i++)
					{
						// Determine line color
						if(lastp.stitchline && points[i].stitchline) color = stitchcolor;
						else color = losecolor;

						// Render line
						renderer.RenderLine(lastp.pos, points[i].pos, LINE_THICKNESS, color, true);
						RenderLinedefDirectionIndicator(lastp.pos, points[i].pos, color); //mxd
						lastp = points[i];
					}

					// Determine line color
					color = (lastp.stitchline && snaptonearest ? stitchcolor : losecolor);

					// Render line to cursor
					renderer.RenderLine(lastp.pos, curp.pos, LINE_THICKNESS, color, true);
					RenderLinedefDirectionIndicator(lastp.pos, curp.pos, color); //mxd

					// Render vertices
					for(int i = 0; i < points.Count; i++)
					{
						// Determine vertex color
						color = points[i].stitch ? stitchcolor : losecolor;

						// Render vertex
						renderer.RenderRectangleFilled(new RectangleF(points[i].pos.x - vsize, points[i].pos.y - vsize, vsize * 2.0f, vsize * 2.0f), color, true);
					}
				}

				// Determine point color
				color = snaptonearest ? stitchcolor : losecolor;

				// Render vertex at cursor
				renderer.RenderRectangleFilled(new RectangleF(curp.pos.x - vsize, curp.pos.y - vsize, vsize * 2.0f, vsize * 2.0f), color, true);

				// Go for all labels
				foreach(LineLengthLabel l in labels) renderer.RenderText(l.TextLabel);

				// Done
				renderer.Finish();
			}

			// Done
			renderer.Present();
		}

		//mxd
		private void RenderLinedefDirectionIndicator(Vector2D start, Vector2D end, PixelColor color) 
		{
			Vector2D delta = end - start;
			Vector2D middlePoint = new Vector2D(start.x + delta.x / 2, start.y + delta.y / 2);
			Vector2D scaledPerpendicular = delta.GetPerpendicular().GetNormal().GetScaled(18f / renderer.Scale);
			renderer.RenderLine(middlePoint, new Vector2D(middlePoint.x - scaledPerpendicular.x, middlePoint.y - scaledPerpendicular.y), LINE_THICKNESS, color, true);
		}
		
		// This returns the aligned and snapped draw position
		public static DrawnVertex GetCurrentPosition(Vector2D mousemappos, bool snaptonearest, bool snaptogrid, bool snaptocardinal, IRenderer2D renderer, List<DrawnVertex> points)
		{
			DrawnVertex p = new DrawnVertex();
			p.stitch = true; //mxd. Setting these to false seems to be a good way to create invalid geometry...
			p.stitchline = true; //mxd

			//mxd. If snap to cardinal directions is enabled and we have points, modify mouse position
			Vector2D vm;
			if(snaptocardinal && points.Count > 0)
			{
				Vector2D offset = mousemappos - points[points.Count - 1].pos;
				
				float angle;
				if(usefourcardinaldirections)
					angle = Angle2D.DegToRad((General.ClampAngle((int)Angle2D.RadToDeg(offset.GetAngle()))) / 90 * 90 + 45);
				else
					angle = Angle2D.DegToRad((General.ClampAngle((int)Angle2D.RadToDeg(offset.GetAngle()) + 22)) / 45 * 45);

				offset = new Vector2D(0, -offset.GetLength()).GetRotated(angle);
				vm = points[points.Count - 1].pos + offset;
			}
			else
			{
				vm = mousemappos;
			}
			
			float vrange = BuilderPlug.Me.StitchRange / renderer.Scale;

			// Snap to nearest?
			if(snaptonearest)
			{
				// Go for all drawn points
				foreach(DrawnVertex v in points)
				{
					if(Vector2D.DistanceSq(mousemappos, v.pos) < (vrange * vrange))
					{
						p.pos = v.pos;
						//p.stitch = true;
						//p.stitchline = true;
						return p;
					}
				}

				// Try the nearest vertex
				Vertex nv = General.Map.Map.NearestVertexSquareRange(mousemappos, vrange);
				if(nv != null)
				{
					p.pos = nv.Position;
					//p.stitch = true;
					//p.stitchline = true;
					return p;
				}

				// Try the nearest linedef
				Linedef nl = General.Map.Map.NearestLinedefRange(mousemappos, BuilderPlug.Me.StitchRange / renderer.Scale);
				if(nl != null)
				{
					// Snap to grid?
					if(snaptogrid)
					{
						// Get grid intersection coordinates
						List<Vector2D> coords = nl.GetGridIntersections();

						// Find nearest grid intersection
						bool found = false;
						float found_distance = float.MaxValue;
						Vector2D found_coord = new Vector2D();
						foreach(Vector2D v in coords)
						{
							Vector2D delta = mousemappos - v;
							if(delta.GetLengthSq() < found_distance)
							{
								found_distance = delta.GetLengthSq();
								found_coord = v;
								found = true;
							}
						}

						if(found)
						{
							// Align to the closest grid intersection
							p.pos = found_coord;
							//p.stitch = true;
							//p.stitchline = true;
							return p;
						}
					}
					else
					{
						// Aligned to line
						p.pos = nl.NearestOnLine(mousemappos);
						//p.stitch = true;
						//p.stitchline = true;
						return p;
					}
				}
			}
			else
			{
				// Always snap to the first drawn vertex so that the user can finish a complete sector without stitching
				if(points.Count > 0)
				{
					if(Vector2D.DistanceSq(mousemappos, points[0].pos) < (vrange * vrange))
					{
						p.pos = points[0].pos;
						//p.stitch = true;
						//p.stitchline = false;
						return p;
					}
				}
			}

			// if the mouse cursor is outside the map bondaries check if the line between the last set point and the
			// mouse cursor intersect any of the boundary lines. If it does, set the position to this intersection
			if(points.Count > 0 &&
				(mousemappos.x < General.Map.Config.LeftBoundary || mousemappos.x > General.Map.Config.RightBoundary ||
				mousemappos.y > General.Map.Config.TopBoundary || mousemappos.y < General.Map.Config.BottomBoundary))
			{
				Line2D dline = new Line2D(mousemappos, points[points.Count - 1].pos);
				bool foundintersection = false;
				float u = 0.0f;
				List<Line2D> blines = new List<Line2D>();

				// lines for left, top, right and bottom boundaries
				blines.Add(new Line2D(General.Map.Config.LeftBoundary, General.Map.Config.BottomBoundary, General.Map.Config.LeftBoundary, General.Map.Config.TopBoundary));
				blines.Add(new Line2D(General.Map.Config.LeftBoundary, General.Map.Config.TopBoundary, General.Map.Config.RightBoundary, General.Map.Config.TopBoundary));
				blines.Add(new Line2D(General.Map.Config.RightBoundary, General.Map.Config.TopBoundary, General.Map.Config.RightBoundary, General.Map.Config.BottomBoundary));
				blines.Add(new Line2D(General.Map.Config.RightBoundary, General.Map.Config.BottomBoundary, General.Map.Config.LeftBoundary, General.Map.Config.BottomBoundary));

				// check for intersections with boundaries
				for(int i = 0; i < blines.Count; i++)
				{
					if(!foundintersection)
					{
						// only check for intersection if the last set point is not on the
						// line we are checking against
						if(blines[i].GetSideOfLine(points[points.Count - 1].pos) != 0.0f)
						{
							foundintersection = blines[i].GetIntersection(dline, out u);
						}
					}
				}

				// if there was no intersection set the position to the last set point
				if(!foundintersection)
					vm = points[points.Count - 1].pos;
				else
					vm = dline.GetCoordinatesAt(u);

			}


			// Snap to grid?
			if(snaptogrid)
			{
				// Aligned to grid
				p.pos = General.Map.Grid.SnappedToGrid(vm);

				// special handling 
				if(p.pos.x > General.Map.Config.RightBoundary) p.pos.x = General.Map.Config.RightBoundary;
				if(p.pos.y < General.Map.Config.BottomBoundary) p.pos.y = General.Map.Config.BottomBoundary;
				//p.stitch = snaptonearest;
				//p.stitchline = snaptonearest;
				return p;
			}
			else
			{
				// Normal position
				vm.x = (float)Math.Round(vm.x); //mxd
				vm.y = (float)Math.Round(vm.y); //mxd
				p.pos = vm;
				//p.stitch = snaptonearest;
				//p.stitchline = snaptonearest;
				return p;
			}
		}
		
		// This gets the aligned and snapped draw position
		protected DrawnVertex GetCurrentPosition()
		{
			return GetCurrentPosition(mousemappos, snaptonearest, snaptogrid, snaptocardinaldirection, renderer, points);
		}
		
		// This draws a point at a specific location
		public bool DrawPointAt(DrawnVertex p)
		{
			return DrawPointAt(p.pos, p.stitch, p.stitchline);
		}
		
		// This draws a point at a specific location
		public virtual bool DrawPointAt(Vector2D pos, bool stitch, bool stitchline)
		{
			if(pos.x < General.Map.Config.LeftBoundary || pos.x > General.Map.Config.RightBoundary ||
				pos.y > General.Map.Config.TopBoundary || pos.y < General.Map.Config.BottomBoundary)
				return false;

			DrawnVertex newpoint = new DrawnVertex();
			newpoint.pos = pos;
			newpoint.stitch = stitch;
			newpoint.stitchline = stitchline;
			points.Add(newpoint);
			labels.Add(new LineLengthLabel(labelshowangle, labeluseoffset));
			Update();

			if(points.Count > 1)
			{
				// Check if point stitches with the first
				if(points[points.Count - 1].stitch)
				{
					Vector2D p1 = points[0].pos;
					Vector2D p2 = points[points.Count - 1].pos;
					Vector2D delta = p1 - p2;
					if((Math.Abs(delta.x) <= 0.001f) && (Math.Abs(delta.y) <= 0.001f))
					{
						//mxd. Seems... logical?
						if(points.Count == 2)
						{
							OnCancel();
							return true;
						}

						// Finish drawing
						FinishDraw();
						return true;
					}
				}
				
				//mxd. Points and existing geometry form a closed shape?
				if(continuousdrawing && autoclosedrawing)
				{
					// Determive center point
					float minx = float.MaxValue;
					float maxx = float.MinValue;
					float miny = float.MaxValue;
					float maxy = float.MinValue;

					foreach(DrawnVertex v in points)
					{
						if(v.pos.x < minx) minx = v.pos.x;
						if(v.pos.x > maxx) maxx = v.pos.x;
						if(v.pos.y < miny) miny = v.pos.y;
						if(v.pos.y > maxy) maxy = v.pos.y;
					}

					Vector2D shapecenter = new Vector2D(minx + (maxx - minx) / 2, miny + (maxy - miny) / 2);
					
					// Determine center point between start and end points
					minx = Math.Min(points[0].pos.x, points[points.Count - 1].pos.x);
					maxx = Math.Max(points[0].pos.x, points[points.Count - 1].pos.x);
					miny = Math.Min(points[0].pos.y, points[points.Count - 1].pos.y);
					maxy = Math.Max(points[0].pos.y, points[points.Count - 1].pos.y);

					Vector2D startendcenter = new Vector2D(minx + (maxx - minx) / 2, miny + (maxy - miny) / 2);

					// Offset the center perpendicular to the start -> end line direction...
					if(shapecenter == startendcenter)
					{
						shapecenter -= new Line2D(points[0].pos, points[points.Count - 1].pos).GetPerpendicular().GetNormal();
					}

					// Do the check
					if(CanFinishDrawing(points[0].pos, points[points.Count - 1].pos, shapecenter))
					{
						drawingautoclosed = true;
						FinishDraw();
					}
				}
			}

			return true;
		}

		//mxd
		private static bool CanFinishDrawing(Vector2D start, Vector2D end, Vector2D center)
		{
			Linedef startline = FindPotentialLine(start, center);
			if(startline == null) return false;

			Linedef endline = FindPotentialLine(end, center);
			if(endline == null) return false;

			// Can finish drawing if a path between startline and endline exists
			return Tools.FindClosestPath(startline, startline.SideOfLine(center) < 0.0f, endline, endline.SideOfLine(center) < 0.0f, true) != null;
		}

		//mxd
		private static Linedef FindPotentialLine(Vector2D target, Vector2D center)
		{
			// Target position on top of existing vertex?
			Vertex v = General.Map.Map.NearestVertex(target);
			if(v == null) return null;

			Linedef result = null;
			if(v.Position == target)
			{
				float mindistance = float.MaxValue;
				foreach(Linedef l in v.Linedefs)
				{
					if(result == null)
					{
						result = l;
						mindistance = Vector2D.DistanceSq(l.GetCenterPoint(), center);
					}
					else
					{
						float curdistance = Vector2D.DistanceSq(l.GetCenterPoint(), center);
						if(curdistance < mindistance)
						{
							mindistance = curdistance;
							result = l;
						}
					}
				}
			}
			else
			{
				// Result position will split a line?
				result = General.Map.Map.NearestLinedef(target);
				if(result.DistanceTo(target, true) > BuilderPlug.Me.StitchRange) return null;
			}

			return result;
		}
		
		#endregion

		#region ================== mxd. Settings panel

		protected virtual void SetupInterface()
		{
			//Add options docker
			panel = new DrawLineOptionsPanel();
			panel.OnContinuousDrawingChanged += OnContinuousDrawingChanged;
			panel.OnAutoCloseDrawingChanged += OnAutoCloseDrawingChanged;

			// Needs to be set after adding the events...
			panel.ContinuousDrawing = General.Settings.ReadPluginSetting("drawlinesmode.continuousdrawing", false);
			panel.AutoCloseDrawing = General.Settings.ReadPluginSetting("drawlinesmode.autoclosedrawing", false);
		}

		protected virtual void AddInterface()
		{
			panel.Register();
		}

		protected virtual void RemoveInterface()
		{
			General.Settings.WritePluginSetting("drawlinesmode.continuousdrawing", panel.ContinuousDrawing);
			General.Settings.WritePluginSetting("drawlinesmode.autoclosedrawing", panel.AutoCloseDrawing);
			panel.Unregister();
		}

		#endregion

		#region ================== Events

		public override void OnHelp()
		{
			General.ShowHelp("e_drawgeometry.html");
		}

		// Engaging
		public override void OnEngage()
		{
			base.OnEngage();
			EnableAutoPanning();
			AddInterface(); //mxd
			renderer.SetPresentation(Presentation.Standard);
			
			// Set cursor
			General.Interface.SetCursor(Cursors.Cross);
		}

		// Disengaging
		public override void OnDisengage()
		{
			RemoveInterface(); //mxd
			base.OnDisengage();
			DisableAutoPanning();
		}
		
		// Cancelled
		public override void OnCancel()
		{
			//mxd. Cannot leave this way when continuous drawing is enabled
			if(continuousdrawing)
			{
				drawingautoclosed = false;
				return;
			}
			
			// Cancel base class
			base.OnCancel();
			
			// Return to original mode
			General.Editing.ChangeMode(General.Editing.PreviousStableMode.Name);
		}

		// Accepted
		public override void OnAccept()
		{
			Cursor.Current = Cursors.AppStarting;
			General.Settings.FindDefaultDrawSettings();

			// When points have been drawn
			if(points.Count > 0)
			{
				// Make undo for the draw
				General.Map.UndoRedo.CreateUndo("Line draw");
				
				// Make an analysis and show info
				string[] adjectives = new[]
				{ "beautiful", "lovely", "romantic", "stylish", "cheerful", "comical",
				  "awesome", "accurate", "adorable", "adventurous", "attractive", "cute",
				  "elegant", "glamorous", "gorgeous", "handsome", "magnificent", "unusual",
				  "outstanding", "mysterious", "amusing", "charming", "fantastic", "jolly" };
				string word = adjectives[points.Count % adjectives.Length];
				word = (points.Count > adjectives.Length) ? "very " + word : word;
				string a = ((word[0] == 'a') || (word[0] == 'e') || (word[0] == 'o') || (word[0] == 'u')) ? "an " : "a ";
				General.Interface.DisplayStatus(StatusType.Action, "Created " + a + word + " drawing.");
				
				// Make the drawing
				if(Tools.DrawLines(points, true, BuilderPlug.Me.AutoAlignTextureOffsetsOnCreate)) //mxd
				{
					// Snap to map format accuracy
					General.Map.Map.SnapAllToAccuracy();

					// Clear selection
					General.Map.Map.ClearAllSelected();

					// Update cached values
					General.Map.Map.Update();

					// Edit new sectors?
					List<Sector> newsectors = General.Map.Map.GetMarkedSectors(true);
					if(BuilderPlug.Me.EditNewSector && (newsectors.Count > 0))
						General.Interface.ShowEditSectors(newsectors);

					// Update the used textures
					General.Map.Data.UpdateUsedTextures();

					//mxd
					General.Map.Renderer2D.UpdateExtraFloorFlag();

					// Map is changed
					General.Map.IsChanged = true;
				}
				else
				{
					// Drawing failed
					// NOTE: I have to call this twice, because the first time only cancels this volatile mode
					General.Map.UndoRedo.WithdrawUndo();
					General.Map.UndoRedo.WithdrawUndo();
				}
			}

			// Done
			Cursor.Current = Cursors.Default;

			if(continuousdrawing)
			{
				//mxd. Reset settings
				points.Clear();
				labels.Clear();
				drawingautoclosed = false;

				//mxd. Redraw display
				General.Interface.RedrawDisplay();
			}
			else
			{
				// Return to original mode
				General.Editing.ChangeMode(General.Editing.PreviousStableMode.Name);
			}
		}

		// This redraws the display
		public override void OnRedrawDisplay()
		{
			renderer.RedrawSurface();

			// Render lines
			if(renderer.StartPlotter(true))
			{
				renderer.PlotLinedefSet(General.Map.Map.Linedefs);
				renderer.PlotVerticesSet(General.Map.Map.Vertices);
				renderer.Finish();
			}

			// Render things
			if(renderer.StartThings(true))
			{
				renderer.RenderThingSet(General.Map.Map.Things, Presentation.THINGS_ALPHA);
				renderer.Finish();
			}

			// Normal update
			Update();
		}
		
		// Mouse moving
		public override void OnMouseMove(MouseEventArgs e)
		{
			base.OnMouseMove(e);
			if(panning) return; //mxd. Skip all this jazz while panning
			Update();
		}

		// When a key is released
		public override void OnKeyUp(KeyEventArgs e)
		{
			base.OnKeyUp(e);
			if((snaptogrid != (General.Interface.ShiftState ^ General.Interface.SnapToGrid)) ||
			   (snaptonearest != (General.Interface.CtrlState ^ General.Interface.AutoMerge)) ||
			   (snaptocardinaldirection != (General.Interface.AltState && General.Interface.ShiftState))) Update();
		}

		// When a key is pressed
		public override void OnKeyDown(KeyEventArgs e)
		{
			base.OnKeyDown(e);
			if((snaptogrid != (General.Interface.ShiftState ^ General.Interface.SnapToGrid)) ||
			   (snaptonearest != (General.Interface.CtrlState ^ General.Interface.AutoMerge)) ||
			   (snaptocardinaldirection != (General.Interface.AltState && General.Interface.ShiftState))) Update();
		}

		//mxd
		protected void OnContinuousDrawingChanged(object value, EventArgs e)
		{
			continuousdrawing = (bool)value;
		}

		//mxd
		protected void OnAutoCloseDrawingChanged(object value, EventArgs e)
		{
			autoclosedrawing = (bool)value;
		}
		
		#endregion
		
		#region ================== Actions
		
		// Drawing a point
		[BeginAction("drawpoint")]
		public void DrawPoint()
		{
			// Mouse inside window?
			if(General.Interface.MouseInDisplay)
			{
				DrawnVertex newpoint = GetCurrentPosition();
				if(!DrawPointAt(newpoint)) General.Interface.DisplayStatus(StatusType.Warning, "Failed to draw point: outside of map boundaries.");
			}
		}
		
		// Remove a point
		[BeginAction("removepoint")]
		public virtual void RemovePoint()
		{
			if(points.Count > 0) points.RemoveAt(points.Count - 1);
			if(labels.Count > 0)
			{
				labels[labels.Count - 1].Dispose();
				labels.RemoveAt(labels.Count - 1);
			}
			
			Update();
		}
		
		// Finish drawing
		[BeginAction("finishdraw")]
		public void FinishDraw()
		{
			// Accept the changes
			General.Editing.AcceptMode();
		}
		
		#endregion
	}
}