PencilTool.cs

// 
// PencilTool.cs
//  
// Author:
//       Jonathan Pobst <monkey@jpobst.com>
// 
// Copyright (c) 2010 Jonathan Pobst
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

using System;
using Cairo;
using Gtk;
using Pinta.Core;
using Mono.Unix;

namespace Pinta.Tools
{
	public class PencilTool : BaseTool
	{		
		private Point last_point = point_empty;
		
		private ImageSurface undo_surface;
		private bool surface_modified;
        protected uint mouse_button;

		public PencilTool ()
		{
		}

		#region Properties
		public override string Name { get { return Catalog.GetString ("Pencil"); } }
		public override string Icon { get { return "Tools.Pencil.png"; } }
		public override string StatusBarText { get { return Catalog.GetString ("Left click to draw freeform one-pixel wide lines with the primary color. Right click to use the secondary color."); } }
		public override Gdk.Cursor DefaultCursor { get { return new Gdk.Cursor (PintaCore.Chrome.Canvas.Display, PintaCore.Resources.GetIcon ("Cursor.Pencil.png"), 7, 24); } }
		public override Gdk.Key ShortcutKey { get { return Gdk.Key.P; } }
		public override int Priority { get { return 29; } }
		#endregion

		#region Mouse Handlers
		protected override void OnMouseDown (Gtk.DrawingArea canvas, Gtk.ButtonPressEventArgs args, Cairo.PointD point)
		{
            // If we are already drawing, ignore any additional mouse down events
            if (mouse_button > 0)
                return;

			surface_modified = false;
			undo_surface = PintaCore.Workspace.ActiveDocument.CurrentUserLayer.Surface.Clone ();
            mouse_button = args.Event.Button;
			Color tool_color;

            if (mouse_button == 1)
            {
                tool_color = PintaCore.Palette.PrimaryColor;
            }
            else if (mouse_button == 3)
            {
                tool_color = PintaCore.Palette.SecondaryColor;
            }
            else
            {
                last_point = point_empty;
                return;
            }

			Draw (canvas, tool_color, point, true);
		}

		protected override void OnMouseMove (object o, Gtk.MotionNotifyEventArgs args, Cairo.PointD point)
		{
			Color tool_color;
		
            if (mouse_button == 1)
            {
                tool_color = PintaCore.Palette.PrimaryColor;
            }
            else if (mouse_button == 3)
            {
                tool_color = PintaCore.Palette.SecondaryColor;
            }
            else
            {
                last_point = point_empty;
				return;
			}
			
			Draw ((DrawingArea) o, tool_color, point, false);
		}
		
		private void Draw (DrawingArea drawingarea1, Color tool_color, Cairo.PointD point, bool first_pixel)
		{
			int x = (int)point.X;
			int y = (int) point.Y;
			
			if (last_point.Equals (point_empty)) {
				last_point = new Point (x, y);
				
				if (!first_pixel)
					return;
			}
			
			Document doc = PintaCore.Workspace.ActiveDocument;

			if (doc.Workspace.PointInCanvas (point))
				surface_modified = true;

			ImageSurface surf = doc.CurrentUserLayer.Surface;
			
			if (first_pixel && doc.Workspace.PointInCanvas (point)) {
				// Does Cairo really not support a single-pixel-long single-pixel-wide line?
				surf.Flush ();
				int shiftedX = (int)point.X;
				int shiftedY = (int)point.Y;
				ColorBgra source = surf.GetColorBgraUnchecked (shiftedX, shiftedY);
				source = UserBlendOps.NormalBlendOp.ApplyStatic (source, tool_color.ToColorBgra ());
				surf.SetColorBgra (source, shiftedX, shiftedY);
				surf.MarkDirty ();
			} else {
				using (Context g = new Context (surf)) {
					g.AppendPath (doc.Selection.SelectionPath);
					g.FillRule = FillRule.EvenOdd;
					g.Clip ();
				
					g.Antialias = Antialias.None;
				
					// Adding 0.5 forces cairo into the correct square:
					// See https://bugs.launchpad.net/bugs/672232
					g.MoveTo (last_point.X + 0.5, last_point.Y + 0.5);
					g.LineTo (x + 0.5, y + 0.5);

					g.SetSourceColor (tool_color);
					g.LineWidth = 1;
					g.LineCap = LineCap.Square;
				
					g.Stroke ();
				}
			}
			
			Gdk.Rectangle r = GetRectangleFromPoints (last_point, new Point (x, y));

			doc.Workspace.Invalidate (doc.ClampToImageSize (r));
			
			last_point = new Point (x, y);
		}
		
		protected override void OnMouseUp (Gtk.DrawingArea canvas, Gtk.ButtonReleaseEventArgs args, Cairo.PointD point)
		{
			Document doc = PintaCore.Workspace.ActiveDocument;

            if (undo_surface != null)
            {
                if (surface_modified)
                    doc.History.PushNewItem(new SimpleHistoryItem(Icon, Name, undo_surface, doc.CurrentUserLayerIndex));
                else if (undo_surface != null)
                    (undo_surface as IDisposable).Dispose();
            }

			surface_modified = false;
            undo_surface = null;
            mouse_button = 0;
		}
		#endregion

		#region Private Methods
		private Gdk.Rectangle GetRectangleFromPoints (Point a, Point b)
		{
			int x = Math.Min (a.X, b.X) - 2 - 2;
			int y = Math.Min (a.Y, b.Y) - 2 - 2;
			int w = Math.Max (a.X, b.X) - x + (2 * 2) + 4;
			int h = Math.Max (a.Y, b.Y) - y + (2 * 2) + 4;
			
			return new Gdk.Rectangle (x, y, w, h);
		}
		#endregion
	}
}