/* * Copyright (c) 1996, 2006, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.awt; import java.awt.geom.AffineTransform; import java.awt.geom.PathIterator; import java.awt.geom.Point2D; import java.awt.geom.Rectangle2D; /** {@collect.stats} * The <code>Shape</code> interface provides definitions for objects * that represent some form of geometric shape. The <code>Shape</code> * is described by a {@link PathIterator} object, which can express the * outline of the <code>Shape</code> as well as a rule for determining * how the outline divides the 2D plane into interior and exterior * points. Each <code>Shape</code> object provides callbacks to get the * bounding box of the geometry, determine whether points or * rectangles lie partly or entirely within the interior * of the <code>Shape</code>, and retrieve a <code>PathIterator</code> * object that describes the trajectory path of the <code>Shape</code> * outline. * <p> * <b>Definition of insideness:</b> * A point is considered to lie inside a * <code>Shape</code> if and only if: * <ul> * <li> it lies completely * inside the<code>Shape</code> boundary <i>or</i> * <li> * it lies exactly on the <code>Shape</code> boundary <i>and</i> the * space immediately adjacent to the * point in the increasing <code>X</code> direction is * entirely inside the boundary <i>or</i> * <li> * it lies exactly on a horizontal boundary segment <b>and</b> the * space immediately adjacent to the point in the * increasing <code>Y</code> direction is inside the boundary. * </ul> * <p>The <code>contains</code> and <code>intersects</code> methods * consider the interior of a <code>Shape</code> to be the area it * encloses as if it were filled. This means that these methods * consider * unclosed shapes to be implicitly closed for the purpose of * determining if a shape contains or intersects a rectangle or if a * shape contains a point. * * @see java.awt.geom.PathIterator * @see java.awt.geom.AffineTransform * @see java.awt.geom.FlatteningPathIterator * @see java.awt.geom.GeneralPath * * @author Jim Graham * @since 1.2 */ public interface Shape { /** {@collect.stats} * Returns an integer {@link Rectangle} that completely encloses the * <code>Shape</code>. Note that there is no guarantee that the * returned <code>Rectangle</code> is the smallest bounding box that * encloses the <code>Shape</code>, only that the <code>Shape</code> * lies entirely within the indicated <code>Rectangle</code>. The * returned <code>Rectangle</code> might also fail to completely * enclose the <code>Shape</code> if the <code>Shape</code> overflows * the limited range of the integer data type. The * <code>getBounds2D</code> method generally returns a * tighter bounding box due to its greater flexibility in * representation. * @return an integer <code>Rectangle</code> that completely encloses * the <code>Shape</code>. * @see #getBounds2D * @since 1.2 */ public Rectangle getBounds(); /** {@collect.stats} * Returns a high precision and more accurate bounding box of * the <code>Shape</code> than the <code>getBounds</code> method. * Note that there is no guarantee that the returned * {@link Rectangle2D} is the smallest bounding box that encloses * the <code>Shape</code>, only that the <code>Shape</code> lies * entirely within the indicated <code>Rectangle2D</code>. The * bounding box returned by this method is usually tighter than that * returned by the <code>getBounds</code> method and never fails due * to overflow problems since the return value can be an instance of * the <code>Rectangle2D</code> that uses double precision values to * store the dimensions. * @return an instance of <code>Rectangle2D</code> that is a * high-precision bounding box of the <code>Shape</code>. * @see #getBounds * @since 1.2 */ public Rectangle2D getBounds2D(); /** {@collect.stats} * Tests if the specified coordinates are inside the boundary of the * <code>Shape</code>. * @param x the specified X coordinate to be tested * @param y the specified Y coordinate to be tested * @return <code>true</code> if the specified coordinates are inside * the <code>Shape</code> boundary; <code>false</code> * otherwise. * @since 1.2 */ public boolean contains(double x, double y); /** {@collect.stats} * Tests if a specified {@link Point2D} is inside the boundary * of the <code>Shape</code>. * @param p the specified <code>Point2D</code> to be tested * @return <code>true</code> if the specified <code>Point2D</code> is * inside the boundary of the <code>Shape</code>; * <code>false</code> otherwise. * @since 1.2 */ public boolean contains(Point2D p); /** {@collect.stats} * Tests if the interior of the <code>Shape</code> intersects the * interior of a specified rectangular area. * The rectangular area is considered to intersect the <code>Shape</code> * if any point is contained in both the interior of the * <code>Shape</code> and the specified rectangular area. * <p> * The {@code Shape.intersects()} method allows a {@code Shape} * implementation to conservatively return {@code true} when: * <ul> * <li> * there is a high probability that the rectangular area and the * <code>Shape</code> intersect, but * <li> * the calculations to accurately determine this intersection * are prohibitively expensive. * </ul> * This means that for some {@code Shapes} this method might * return {@code true} even though the rectangular area does not * intersect the {@code Shape}. * The {@link java.awt.geom.Area Area} class performs * more accurate computations of geometric intersection than most * {@code Shape} objects and therefore can be used if a more precise * answer is required. * * @param x the X coordinate of the upper-left corner * of the specified rectangular area * @param y the Y coordinate of the upper-left corner * of the specified rectangular area * @param w the width of the specified rectangular area * @param h the height of the specified rectangular area * @return <code>true</code> if the interior of the <code>Shape</code> and * the interior of the rectangular area intersect, or are * both highly likely to intersect and intersection calculations * would be too expensive to perform; <code>false</code> otherwise. * @see java.awt.geom.Area * @since 1.2 */ public boolean intersects(double x, double y, double w, double h); /** {@collect.stats} * Tests if the interior of the <code>Shape</code> intersects the * interior of a specified <code>Rectangle2D</code>. * The {@code Shape.intersects()} method allows a {@code Shape} * implementation to conservatively return {@code true} when: * <ul> * <li> * there is a high probability that the <code>Rectangle2D</code> and the * <code>Shape</code> intersect, but * <li> * the calculations to accurately determine this intersection * are prohibitively expensive. * </ul> * This means that for some {@code Shapes} this method might * return {@code true} even though the {@code Rectangle2D} does not * intersect the {@code Shape}. * The {@link java.awt.geom.Area Area} class performs * more accurate computations of geometric intersection than most * {@code Shape} objects and therefore can be used if a more precise * answer is required. * * @param r the specified <code>Rectangle2D</code> * @return <code>true</code> if the interior of the <code>Shape</code> and * the interior of the specified <code>Rectangle2D</code> * intersect, or are both highly likely to intersect and intersection * calculations would be too expensive to perform; <code>false</code> * otherwise. * @see #intersects(double, double, double, double) * @since 1.2 */ public boolean intersects(Rectangle2D r); /** {@collect.stats} * Tests if the interior of the <code>Shape</code> entirely contains * the specified rectangular area. All coordinates that lie inside * the rectangular area must lie within the <code>Shape</code> for the * entire rectanglar area to be considered contained within the * <code>Shape</code>. * <p> * The {@code Shape.contains()} method allows a {@code Shape} * implementation to conservatively return {@code false} when: * <ul> * <li> * the <code>intersect</code> method returns <code>true</code> and * <li> * the calculations to determine whether or not the * <code>Shape</code> entirely contains the rectangular area are * prohibitively expensive. * </ul> * This means that for some {@code Shapes} this method might * return {@code false} even though the {@code Shape} contains * the rectangular area. * The {@link java.awt.geom.Area Area} class performs * more accurate geometric computations than most * {@code Shape} objects and therefore can be used if a more precise * answer is required. * * @param x the X coordinate of the upper-left corner * of the specified rectangular area * @param y the Y coordinate of the upper-left corner * of the specified rectangular area * @param w the width of the specified rectangular area * @param h the height of the specified rectangular area * @return <code>true</code> if the interior of the <code>Shape</code> * entirely contains the specified rectangular area; * <code>false</code> otherwise or, if the <code>Shape</code> * contains the rectangular area and the * <code>intersects</code> method returns <code>true</code> * and the containment calculations would be too expensive to * perform. * @see java.awt.geom.Area * @see #intersects * @since 1.2 */ public boolean contains(double x, double y, double w, double h); /** {@collect.stats} * Tests if the interior of the <code>Shape</code> entirely contains the * specified <code>Rectangle2D</code>. * The {@code Shape.contains()} method allows a {@code Shape} * implementation to conservatively return {@code false} when: * <ul> * <li> * the <code>intersect</code> method returns <code>true</code> and * <li> * the calculations to determine whether or not the * <code>Shape</code> entirely contains the <code>Rectangle2D</code> * are prohibitively expensive. * </ul> * This means that for some {@code Shapes} this method might * return {@code false} even though the {@code Shape} contains * the {@code Rectangle2D}. * The {@link java.awt.geom.Area Area} class performs * more accurate geometric computations than most * {@code Shape} objects and therefore can be used if a more precise * answer is required. * * @param r The specified <code>Rectangle2D</code> * @return <code>true</code> if the interior of the <code>Shape</code> * entirely contains the <code>Rectangle2D</code>; * <code>false</code> otherwise or, if the <code>Shape</code> * contains the <code>Rectangle2D</code> and the * <code>intersects</code> method returns <code>true</code> * and the containment calculations would be too expensive to * perform. * @see #contains(double, double, double, double) * @since 1.2 */ public boolean contains(Rectangle2D r); /** {@collect.stats} * Returns an iterator object that iterates along the * <code>Shape</code> boundary and provides access to the geometry of the * <code>Shape</code> outline. If an optional {@link AffineTransform} * is specified, the coordinates returned in the iteration are * transformed accordingly. * <p> * Each call to this method returns a fresh <code>PathIterator</code> * object that traverses the geometry of the <code>Shape</code> object * independently from any other <code>PathIterator</code> objects in use * at the same time. * <p> * It is recommended, but not guaranteed, that objects * implementing the <code>Shape</code> interface isolate iterations * that are in process from any changes that might occur to the original * object's geometry during such iterations. * * @param at an optional <code>AffineTransform</code> to be applied to the * coordinates as they are returned in the iteration, or * <code>null</code> if untransformed coordinates are desired * @return a new <code>PathIterator</code> object, which independently * traverses the geometry of the <code>Shape</code>. * @since 1.2 */ public PathIterator getPathIterator(AffineTransform at); /** {@collect.stats} * Returns an iterator object that iterates along the <code>Shape</code> * boundary and provides access to a flattened view of the * <code>Shape</code> outline geometry. * <p> * Only SEG_MOVETO, SEG_LINETO, and SEG_CLOSE point types are * returned by the iterator. * <p> * If an optional <code>AffineTransform</code> is specified, * the coordinates returned in the iteration are transformed * accordingly. * <p> * The amount of subdivision of the curved segments is controlled * by the <code>flatness</code> parameter, which specifies the * maximum distance that any point on the unflattened transformed * curve can deviate from the returned flattened path segments. * Note that a limit on the accuracy of the flattened path might be * silently imposed, causing very small flattening parameters to be * treated as larger values. This limit, if there is one, is * defined by the particular implementation that is used. * <p> * Each call to this method returns a fresh <code>PathIterator</code> * object that traverses the <code>Shape</code> object geometry * independently from any other <code>PathIterator</code> objects in use at * the same time. * <p> * It is recommended, but not guaranteed, that objects * implementing the <code>Shape</code> interface isolate iterations * that are in process from any changes that might occur to the original * object's geometry during such iterations. * * @param at an optional <code>AffineTransform</code> to be applied to the * coordinates as they are returned in the iteration, or * <code>null</code> if untransformed coordinates are desired * @param flatness the maximum distance that the line segments used to * approximate the curved segments are allowed to deviate * from any point on the original curve * @return a new <code>PathIterator</code> that independently traverses * a flattened view of the geometry of the <code>Shape</code>. * @since 1.2 */ public PathIterator getPathIterator(AffineTransform at, double flatness); }