diff java/src/uk/ac/qmul/eecs/ccmi/simpletemplate/ArrowHead.java @ 0:9418ab7b7f3f

Initial import

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/java/src/uk/ac/qmul/eecs/ccmi/simpletemplate/ArrowHead.java	Fri Dec 16 17:35:51 2011 +0000
@@ -0,0 +1,131 @@
+/*  
+ CCmI Editor - A Collaborative Cross-Modal Diagram Editing Tool
+	  
+ Copyright (C) 2002 Cay S. Horstmann (http://horstmann.com)
+ Copyright (C) 2011  Queen Mary University of London (http://ccmi.eecs.qmul.ac.uk/)
+
+ 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 3 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/>.
+*/
+
+package uk.ac.qmul.eecs.ccmi.simpletemplate;
+
+import java.awt.BasicStroke;
+import java.awt.Color;
+import java.awt.Graphics2D;
+import java.awt.Stroke;
+import java.awt.geom.GeneralPath;
+import java.awt.geom.Point2D;
+import java.io.IOException;
+
+/**
+   This class defines arrowheads of diverse shapes.
+*/
+public enum ArrowHead {
+	TAIL("Tail"),
+	TRIANGLE("Triangle"),
+    BLACK_TRIANGLE("Black Triangle"),
+    V("V"),
+	HALF_V("Half V"),
+	DIAMOND("Diamond"),
+	BLACK_DIAMOND("Black Diamond");
+	
+   private ArrowHead(String name) {
+	   this.lowerCaseName = name;
+   }
+   
+   public static ArrowHead getArrowHeadFromString(String arrowHeadName) throws IOException{
+	   ArrowHead h;
+	   String name = arrowHeadName.toUpperCase().replace(" ", "_");
+	   try {
+		   h = ArrowHead.valueOf(name);
+	   }catch (IllegalArgumentException e){
+		   throw new IOException(e);
+	   }
+	   return h;
+   }
+   
+   @Override
+   public String toString(){
+	   return lowerCaseName;
+   }
+   
+   /**
+      Draws the arrowhead.
+      @param g2 the graphics context
+      @param p a point on the axis of the arrow head
+      @param q the end point of the arrow head
+   */
+   public void draw(Graphics2D g2, Point2D p, Point2D q){
+      GeneralPath path = getPath(p, q);
+      Color oldColor = g2.getColor();
+      if (this == BLACK_DIAMOND || this == BLACK_TRIANGLE)
+         g2.setColor(Color.BLACK);
+      else
+         g2.setColor(Color.WHITE);
+      g2.fill(path);
+      g2.setColor(oldColor);
+      Stroke oldStroke = g2.getStroke();
+      g2.setStroke(new BasicStroke());
+      g2.draw(path);
+      g2.setStroke(oldStroke);
+   }
+
+   /**
+      Gets the path of the arrowhead
+      @param p a point on the axis of the arrow head
+      @param q the end point of the arrow head
+      @return the path
+   */
+   public GeneralPath getPath(Point2D p, Point2D q){
+      GeneralPath path = new GeneralPath();
+      final double ARROW_ANGLE = Math.PI / 6;
+      final double ARROW_LENGTH = 10;
+
+      double dx = q.getX() - p.getX();
+      double dy = q.getY() - p.getY();
+      double angle = Math.atan2(dy, dx);
+      double x1 = q.getX() 
+         - ARROW_LENGTH * Math.cos(angle + ARROW_ANGLE);
+      double y1 = q.getY() 
+         - ARROW_LENGTH * Math.sin(angle + ARROW_ANGLE);
+      double x2 = q.getX() 
+         - ARROW_LENGTH * Math.cos(angle - ARROW_ANGLE);
+      double y2 = q.getY() 
+         - ARROW_LENGTH * Math.sin(angle - ARROW_ANGLE);
+
+      path.moveTo((float)q.getX(), (float)q.getY());
+      path.lineTo((float)x1, (float)y1);
+      if (this == V)
+      {
+         path.moveTo((float)x2, (float)y2);
+         path.lineTo((float)q.getX(), (float)q.getY());
+      }
+      else if (this == TRIANGLE || this == BLACK_TRIANGLE)
+      {
+         path.lineTo((float)x2, (float)y2);
+         path.closePath();                  
+      }
+      else if (this == DIAMOND || this == BLACK_DIAMOND)
+      {
+         double x3 = x2 - ARROW_LENGTH * Math.cos(angle + ARROW_ANGLE);
+         double y3 = y2 - ARROW_LENGTH * Math.sin(angle + ARROW_ANGLE);
+         path.lineTo((float)x3, (float)y3);
+         path.lineTo((float)x2, (float)y2);
+         path.closePath();         
+      }      
+      return path;
+   }
+   
+   private String lowerCaseName;
+}