f@0: /*  
f@0:  CCmI Editor - A Collaborative Cross-Modal Diagram Editing Tool
f@0: 	  
f@0:  Copyright (C) 2002 Cay S. Horstmann (http://horstmann.com)
f@0:  Copyright (C) 2011  Queen Mary University of London (http://ccmi.eecs.qmul.ac.uk/)
f@0: 
f@0:  This program is free software: you can redistribute it and/or modify
f@0:  it under the terms of the GNU General Public License as published by
f@0:  the Free Software Foundation, either version 3 of the License, or
f@0:  (at your option) any later version.
f@0: 
f@0:  This program is distributed in the hope that it will be useful,
f@0:  but WITHOUT ANY WARRANTY; without even the implied warranty of
f@0:  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
f@0:  GNU General Public License for more details.
f@0: 
f@0:  You should have received a copy of the GNU General Public License
f@0:  along with this program.  If not, see <http://www.gnu.org/licenses/>.
f@0: */
f@0: 
f@0: package uk.ac.qmul.eecs.ccmi.gui;
f@0: 
f@0: import java.awt.Color;
f@0: import java.awt.Graphics2D;
f@0: import java.awt.Stroke;
f@0: import java.awt.geom.Line2D;
f@0: import java.awt.geom.Point2D;
f@0: import java.awt.geom.Rectangle2D;
f@0: import java.awt.geom.RectangularShape;
f@0: 
f@0: /**
f@0:    A grid to which nodes can be "snapped". The
f@0:    snapping operation moves a point to the nearest grid point.
f@0: */
f@0: public class Grid
f@0: {
f@0:    /**
f@0:       Constructs a grid with no grid points.
f@0:    */
f@0:    public Grid()
f@0:    {
f@0:       setGrid(0, 0);
f@0:    }
f@0:    
f@0:    /**
f@0:       Sets the grid point distances in x- and y-direction
f@0:       @param x the grid point distance in x-direction
f@0:       @param y the grid point distance in y-direction
f@0:    */
f@0:    public void setGrid(double x, double y)
f@0:    {
f@0:       gridx = x;
f@0:       gridy = y;
f@0:    }
f@0:    
f@0:    /**
f@0:       Draws this grid inside a rectangle.
f@0:       @param g2 the graphics context
f@0:       @param bounds the bounding rectangle
f@0:    */
f@0:    public void draw(Graphics2D g2, Rectangle2D bounds)
f@0:    {
f@0:       Color PALE_BLUE = new Color(0.9F, 0.8F, 0.9F);
f@0:       Color oldColor = g2.getColor();
f@0:       g2.setColor(PALE_BLUE);
f@0:       Stroke oldStroke = g2.getStroke();
f@0:       for (double x = bounds.getX(); x < bounds.getMaxX(); x += gridx)
f@0:          g2.draw(new Line2D.Double(x, bounds.getY(), x, bounds.getMaxY()));
f@0:       for (double y = bounds.getY(); y < bounds.getMaxY(); y += gridy)
f@0:          g2.draw(new Line2D.Double(bounds.getX(), y, bounds.getMaxX(), y));
f@0:       g2.setStroke(oldStroke);
f@0:       g2.setColor(oldColor);
f@0:    }
f@0: 
f@0:    /**
f@0:       Snaps a point to the nearest grid point
f@0:       @param p the point to snap. After the call, the 
f@0:       coordinates of p are changed so that p falls on the grid.
f@0:    */
f@0:    public void snap(Point2D p)
f@0:    {
f@0:       double x;
f@0:       if (gridx == 0)
f@0:          x = p.getX();
f@0:       else
f@0:          x = Math.round(p.getX() / gridx) * gridx;
f@0:       double y;
f@0:       if (gridy == 0)
f@0:          y = p.getY();
f@0:       else
f@0:          y = Math.round(p.getY() / gridy) * gridy;
f@0:          
f@0:       p.setLocation(x, y);
f@0:    }
f@0: 
f@0:    /**
f@0:       Snaps a rectangle to the nearest grid points
f@0:       @param r the rectangle to snap. After the call, the 
f@0:       coordinates of r are changed so that all of its corners
f@0:       falls on the grid.
f@0:    */
f@0:    public void snap(RectangularShape r)
f@0:    {
f@0:       double x;
f@0:       double w;
f@0:       w = r.getWidth();
f@0:       if (gridx == 0)
f@0:       {
f@0:          x = r.getX();
f@0:       }
f@0:       else
f@0:       {
f@0:          x = Math.round(r.getX() / gridx) * gridx;
f@0: //         w = Math.ceil(r.getWidth() / (2 * gridx)) * (2 * gridx);
f@0:       }
f@0:       double y;
f@0:       double h;
f@0:       h = r.getHeight();
f@0:       if (gridy == 0)
f@0:       {
f@0:          y = r.getY();
f@0:       }
f@0:       else
f@0:       {
f@0:          y = Math.round(r.getY() / gridy) * gridy;
f@0: //         h = Math.ceil(r.getHeight() / (2 * gridy)) * (2 * gridy);
f@0:       }
f@0:          
f@0:       r.setFrame(x, y, w, h);      
f@0:    }
f@0: 
f@0:    private double gridx;
f@0:    private double gridy;
f@0: }