/*******************************************************************************
* Copyright (c) 2006-2012
* Software Technology Group, Dresden University of Technology
* DevBoost GmbH, Berlin, Amtsgericht Charlottenburg, HRB 140026
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Software Technology Group - TU Dresden, Germany;
* DevBoost GmbH - Berlin, Germany
* - initial API and implementation
******************************************************************************/
/*
* @(#)Constrainer.java 5.0 2007-12-17
*
* Copyright (c) 1996-2007 by the original authors of JHotDraw
* and all its contributors.
* All rights reserved.
*
* The copyright of this software is owned by the authors and
* contributors of the JHotDraw project ("the copyright holders").
* You may not use, copy or modify this software, except in
* accordance with the license agreement you entered into with
* the copyright holders. For details see accompanying license terms.
*/
package org.jhotdraw.draw;
import java.awt.*;
import java.awt.geom.*;
import javax.swing.event.ChangeListener;
/**
* Interface to constrain points and figures on a Drawing.
* This can be used to implement different kinds of grids.
*
* @author Werner Randelshofer
* @version 5.0 2007-04-29 Werner Randelshofer: Refactored interface.
* Huw Jones: Added constrainAngle() method.
* <br>4.0 2007-07-31 Werner Randelshofer: Redesigned to support the
* constrainement of rectangles.
* <br>3.0 2007-04-29 Werner Randelshofer: Method constrainPoint(Point2D.Double, Direction) added.
* <br>2.1 2006-07-03 Werner Randelshofer: Method isVisible() added.
* <br>2.0 2006-01-17 Werner Randelshofer: Changed to support double precision coordinates.
* <br>1.0 2004-03-14 Werner Randelshofer: Created.
*/
public interface Constrainer {
/**
* Constrains the placement of a point towards the closest constraint
* in any direction.
* <p>
* This method changes the point which is passed as a parameter.
*
* @param p A point on the drawing.
* @return Returns the constrained point.
*/
public Point2D.Double constrainPoint(Point2D.Double p);
/**
* Moves a point to the closest constrained location in the specified
* direction.
* <p>
* This method changes the point which is passed as a parameter.
*
* @param p A point on the drawing.
* @param dir A direction.
* @return Returns the constrained point.
*/
public Point2D.Double translatePoint(Point2D.Double p, TranslationDirection dir);
/**
* Constrains the placement of a rectangle towards the closest constrainment
* in any direction.
* <p>
* This method changes the location of the rectangle which is passed as a
* parameter. This method does not change the size of the rectangle.
*
* @param r A rectangle on the drawing.
* @return Returns the constrained rectangle.
*/
public Rectangle2D.Double constrainRectangle(Rectangle2D.Double r);
/**
* Moves a rectangle to the closest constrained location in the
* specified direction.
* <p>
* This method changes the location of the rectangle which is passed as a
* parameter. This method only performs a translation - it does not change
* the size of the rectangle.
*
* @param r A rectangle on the drawing.
* @param dir A direction.
* @return Returns the constrained rectangle.
*/
public Rectangle2D.Double translateRectangle(Rectangle2D.Double r, TranslationDirection dir);
/**
* Constrains the given angle (in radians).
* This method changes the angle which is passed as a parameter.
*
* @param angle The angle (in radians).
* @return The closest constrained angle (in radians).
*/
public double constrainAngle(double angle);
/**
* Moves the given angle (in radians) to the closest constrained orientation
* in the specified direction.
*
* @param angle The angle (in radians).
* @return The closest constrained angle (in radians) in the specified
* direction.
*/
public double rotateAngle(double angle, RotationDirection dir);
/**
* Draws the constrainer grid for the specified drawing view.
*/
public void draw(Graphics2D g, DrawingView view);
/**
* Adds a change listener.
*/
public void addChangeListener(ChangeListener listener);
/**
* Removes a change listener.
*/
public void removeChangeListener(ChangeListener listener);
}