libjava/java/awt/Shape.java

   1 /* Shape.java -- the classic Object-Oriented shape interface
   2    Copyright (C) 1999, 2002, 2005  Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package java.awt;
  40
  41 import java.awt.geom.AffineTransform;
  42 import java.awt.geom.PathIterator;
  43 import java.awt.geom.Point2D;
  44 import java.awt.geom.Rectangle2D;
  45
  46 /**
  47  * This interface represents an abstract shape. The shape is described by
  48  * a {@link PathIterator}, and has callbacks for determining bounding box,
  49  * where points and rectangles lie in relation to the shape, and tracing
  50  * the trajectory.
  51  *
  52  * <p>A point is inside if it is completely inside, or on the boundary and
  53  * adjacent points in the increasing x or y direction are completely inside.
  54  * Unclosed shapes are considered as implicitly closed when performing
  55  * <code>contains</code> or <code>intersects</code>.
  56  *
  57  * @author Aaron M. Renn (arenn@urbanophile.com)
  58  * @see PathIterator
  59  * @see AffineTransform
  60  * @see java.awt.geom.FlatteningPathIterator
  61  * @see java.awt.geom.GeneralPath
  62  * @since 1.0
  63  * @status updated to 1.4
  64  */
  65 public interface Shape
  66 {
  67   /**
  68    * Returns a <code>Rectange</code> that bounds the shape. There is no
  69    * guarantee that this is the minimum bounding box, particularly if
  70    * the shape overflows the finite integer range of a bound. Generally,
  71    * <code>getBounds2D</code> returns a tighter bound.
  72    *
  73    * @return the shape's bounding box
  74    * @see #getBounds2D()
  75    */
  76   Rectangle getBounds();
  77
  78   /**
  79    * Returns a high precision bounding box of the shape. There is no guarantee
  80    * that this is the minimum bounding box, but at least it never overflows.
  81    *
  82    * @return the shape's bounding box
  83    * @see #getBounds()
  84    * @since 1.2
  85    */
  86   Rectangle2D getBounds2D();
  87
  88   /**
  89    * Test if the coordinates lie in the shape.
  90    *
  91    * @param x the x coordinate
  92    * @param y the y coordinate
  93    * @return true if (x,y) lies inside the shape
  94    * @since 1.2
  95    */
  96   boolean contains(double x, double y);
  97
  98   /**
  99    * Test if the point lie in the shape.
 100    *
 101    * @param p the high-precision point
 102    * @return true if p lies inside the shape
 103    * @throws NullPointerException if p is null
 104    * @since 1.2
 105    */
 106   boolean contains(Point2D p);
 107
 108   /**
 109    * Test if a high-precision rectangle intersects the shape. This is true
 110    * if any point in the rectangle is in the shape, with the caveat that the
 111    * operation may include high probability estimates when the actual
 112    * calculation is prohibitively expensive. The {@link java.awt.geom.Area}
 113    * class can be used for more precise answers.
 114    *
 115    * @param x the x coordinate of the rectangle
 116    * @param y the y coordinate of the rectangle
 117    * @param w the width of the rectangle, undefined results if negative
 118    * @param h the height of the rectangle, undefined results if negative
 119    * @return true if the rectangle intersects this shape
 120    * @see java.awt.geom.Area
 121    * @since 1.2
 122    */
 123   boolean intersects(double x, double y, double w, double h);
 124
 125   /**
 126    * Test if a high-precision rectangle intersects the shape. This is true
 127    * if any point in the rectangle is in the shape, with the caveat that the
 128    * operation may include high probability estimates when the actual
 129    * calculation is prohibitively expensive. The {@link java.awt.geom.Area}
 130    * class can be used for more precise answers.
 131    *
 132    * @param r the rectangle
 133    * @return true if the rectangle intersects this shape
 134    * @throws NullPointerException if r is null
 135    * @see #intersects(double, double, double, double)
 136    * @since 1.2
 137    */
 138   boolean intersects(Rectangle2D r);
 139
 140   /**
 141    * Test if a high-precision rectangle lies completely in the shape. This is
 142    * true if all points in the rectangle are in the shape, with the caveat
 143    * that the operation may include high probability estimates when the actual
 144    * calculation is prohibitively expensive. The {@link java.awt.geom.Area}
 145    * class can be used for more precise answers.
 146    *
 147    * @param x the x coordinate of the rectangle
 148    * @param y the y coordinate of the rectangle
 149    * @param w the width of the rectangle, undefined results if negative
 150    * @param h the height of the rectangle, undefined results if negative
 151    * @return true if the rectangle is contained in this shape
 152    * @see java.awt.geom.Area
 153    * @since 1.2
 154    */
 155   boolean contains(double x, double y, double w, double h);
 156
 157   /**
 158    * Test if a high-precision rectangle lies completely in the shape. This is
 159    * true if all points in the rectangle are in the shape, with the caveat
 160    * that the operation may include high probability estimates when the actual
 161    * calculation is prohibitively expensive. The {@link java.awt.geom.Area}
 162    * class can be used for more precise answers.
 163    *
 164    * @param r the rectangle
 165    * @return true if the rectangle is contained in this shape
 166    * @throws NullPointerException if r is null
 167    * @see #contains(double, double, double, double)
 168    * @since 1.2
 169    */
 170   boolean contains(Rectangle2D r);
 171
 172   /**
 173    * Return an iterator along the shape boundary. If the optional transform
 174    * is provided, the iterator is transformed accordingly. Each call returns
 175    * a new object, independent from others in use. It is recommended, but
 176    * not required, that the Shape isolate iterations from future changes to
 177    * the boundary, and document this fact.
 178    *
 179    * @param transform an optional transform to apply to the iterator
 180    * @return a new iterator over the boundary
 181    * @since 1.2
 182    */
 183   PathIterator getPathIterator(AffineTransform transform);
 184
 185   /**
 186    * Return an iterator along the flattened version of the shape boundary.
 187    * Only SEG_MOVETO, SEG_LINETO, and SEG_CLOSE points are returned in the
 188    * iterator. The flatness paramter controls how far points are allowed to
 189    * differ from the real curve; although a limit on accuracy may cause this
 190    * parameter to be enlarged if needed.
 191    *
 192    * <p>If the optional transform is provided, the iterator is transformed
 193    * accordingly. Each call returns a new object, independent from others in
 194    * use. It is recommended, but not required, that the Shape isolate
 195    * iterations from future changes to the boundary, and document this fact.
 196    *
 197    * @param transform an optional transform to apply to the iterator
 198    * @param flatness the maximum distance for deviation from the real boundary
 199    * @return a new iterator over the boundary
 200    * @since 1.2
 201    */
 202   PathIterator getPathIterator(AffineTransform transform, double flatness);
 203 } // interface Shape