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package java.awt;
import java.awt.geom.AffineTransform;
import java.awt.geom.PathIterator;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
/**
* The {@code Shape} interface provides definitions for objects
* that represent some form of geometric shape. The {@code Shape}
* is described by a {@link PathIterator} object, which can express the
* outline of the {@code Shape} as well as a rule for determining
* how the outline divides the 2D plane into interior and exterior
* points. Each {@code Shape} 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}, and retrieve a {@code PathIterator}
* object that describes the trajectory path of the {@code Shape}
* outline.
* <p>
* <a name="def_insideness"><b>Definition of insideness:</b></a>
* A point is considered to lie inside a
* {@code Shape} if and only if:
* <ul>
* <li> it lies completely
* inside the {@code Shape} boundary <i>or</i>
* <li>
* it lies exactly on the {@code Shape} boundary <i>and</i> the
* space immediately adjacent to the
* point in the increasing {@code X} 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} direction is inside the boundary.
* </ul>
* <p>The {@code contains} and {@code intersects} methods
* consider the interior of a {@code Shape} 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 {
/**
* Returns an integer {@link Rectangle} that completely encloses the
* {@code Shape}. Note that there is no guarantee that the
* returned {@code Rectangle} is the smallest bounding box that
* encloses the {@code Shape}, only that the {@code Shape}
* lies entirely within the indicated {@code Rectangle}. The
* returned {@code Rectangle} might also fail to completely
* enclose the {@code Shape} if the {@code Shape} overflows
* the limited range of the integer data type. The
* {@code getBounds2D} method generally returns a
* tighter bounding box due to its greater flexibility in
* representation.
*
* <p>
* Note that the <a href="{@docRoot}/java/awt/Shape.html#def_insideness">
* definition of insideness</a> can lead to situations where points
* on the defining outline of the {@code shape} may not be considered
* contained in the returned {@code bounds} object, but only in cases
* where those points are also not considered contained in the original
* {@code shape}.
* </p>
* <p>
* If a {@code point} is inside the {@code shape} according to the
* {@link #contains(double x, double y) contains(point)} method, then
* it must be inside the returned {@code Rectangle} bounds object
* according to the {@link #contains(double x, double y) contains(point)}
* method of the {@code bounds}. Specifically:
* </p>
* <p>
* {@code shape.contains(x,y)} requires {@code bounds.contains(x,y)}
* </p>
* <p>
* If a {@code point} is not inside the {@code shape}, then it might
* still be contained in the {@code bounds} object:
* </p>
* <p>
* {@code bounds.contains(x,y)} does not imply {@code shape.contains(x,y)}
* </p>
* @return an integer {@code Rectangle} that completely encloses
* the {@code Shape}.
* @see #getBounds2D
* @since 1.2
*/
public Rectangle getBounds();
/**
* Returns a high precision and more accurate bounding box of
* the {@code Shape} than the {@code getBounds} method.
* Note that there is no guarantee that the returned
* {@link Rectangle2D} is the smallest bounding box that encloses
* the {@code Shape}, only that the {@code Shape} lies
* entirely within the indicated {@code Rectangle2D}. The
* bounding box returned by this method is usually tighter than that
* returned by the {@code getBounds} method and never fails due
* to overflow problems since the return value can be an instance of
* the {@code Rectangle2D} that uses double precision values to
* store the dimensions.
*
* <p>
* Note that the <a href="{@docRoot}/java/awt/Shape.html#def_insideness">
* definition of insideness</a> can lead to situations where points
* on the defining outline of the {@code shape} may not be considered
* contained in the returned {@code bounds} object, but only in cases
* where those points are also not considered contained in the original
* {@code shape}.
* </p>
* <p>
* If a {@code point} is inside the {@code shape} according to the
* {@link #contains(Point2D p) contains(point)} method, then it must
* be inside the returned {@code Rectangle2D} bounds object according
* to the {@link #contains(Point2D p) contains(point)} method of the
* {@code bounds}. Specifically:
* </p>
* <p>
* {@code shape.contains(p)} requires {@code bounds.contains(p)}
* </p>
* <p>
* If a {@code point} is not inside the {@code shape}, then it might
* still be contained in the {@code bounds} object:
* </p>
* <p>
* {@code bounds.contains(p)} does not imply {@code shape.contains(p)}
* </p>
* @return an instance of {@code Rectangle2D} that is a
* high-precision bounding box of the {@code Shape}.
* @see #getBounds
* @since 1.2
*/
public Rectangle2D getBounds2D();
/**
* Tests if the specified coordinates are inside the boundary of the
* {@code Shape}, as described by the
* <a href="{@docRoot}/java/awt/Shape.html#def_insideness">
* definition of insideness</a>.
* @param x the specified X coordinate to be tested
* @param y the specified Y coordinate to be tested
* @return {@code true} if the specified coordinates are inside
* the {@code Shape} boundary; {@code false}
* otherwise.
* @since 1.2
*/
public boolean contains(double x, double y);
/**
* Tests if a specified {@link Point2D} is inside the boundary
* of the {@code Shape}, as described by the
* <a href="{@docRoot}/java/awt/Shape.html#def_insideness">
* definition of insideness</a>.
* @param p the specified {@code Point2D} to be tested
* @return {@code true} if the specified {@code Point2D} is
* inside the boundary of the {@code Shape};
* {@code false} otherwise.
* @since 1.2
*/
public boolean contains(Point2D p);
/**
* Tests if the interior of the {@code Shape} intersects the
* interior of a specified rectangular area.
* The rectangular area is considered to intersect the {@code Shape}
* if any point is contained in both the interior of the
* {@code Shape} 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} 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} if the interior of the {@code Shape} 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} otherwise.
* @see java.awt.geom.Area
* @since 1.2
*/
public boolean intersects(double x, double y, double w, double h);
/**
* Tests if the interior of the {@code Shape} intersects the
* interior of a specified {@code Rectangle2D}.
* 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} and the
* {@code Shape} 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}
* @return {@code true} if the interior of the {@code Shape} and
* the interior of the specified {@code Rectangle2D}
* intersect, or are both highly likely to intersect and intersection
* calculations would be too expensive to perform; {@code false}
* otherwise.
* @see #intersects(double, double, double, double)
* @since 1.2
*/
public boolean intersects(Rectangle2D r);
/**
* Tests if the interior of the {@code Shape} entirely contains
* the specified rectangular area. All coordinates that lie inside
* the rectangular area must lie within the {@code Shape} for the
* entire rectangular area to be considered contained within the
* {@code Shape}.
* <p>
* The {@code Shape.contains()} method allows a {@code Shape}
* implementation to conservatively return {@code false} when:
* <ul>
* <li>
* the {@code intersect} method returns {@code true} and
* <li>
* the calculations to determine whether or not the
* {@code Shape} 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} if the interior of the {@code Shape}
* entirely contains the specified rectangular area;
* {@code false} otherwise or, if the {@code Shape}
* contains the rectangular area and the
* {@code intersects} method returns {@code true}
* 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);
/**
* Tests if the interior of the {@code Shape} entirely contains the
* specified {@code Rectangle2D}.
* The {@code Shape.contains()} method allows a {@code Shape}
* implementation to conservatively return {@code false} when:
* <ul>
* <li>
* the {@code intersect} method returns {@code true} and
* <li>
* the calculations to determine whether or not the
* {@code Shape} entirely contains the {@code Rectangle2D}
* 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}
* @return {@code true} if the interior of the {@code Shape}
* entirely contains the {@code Rectangle2D};
* {@code false} otherwise or, if the {@code Shape}
* contains the {@code Rectangle2D} and the
* {@code intersects} method returns {@code true}
* and the containment calculations would be too expensive to
* perform.
* @see #contains(double, double, double, double)
* @since 1.2
*/
public boolean contains(Rectangle2D r);
/**
* Returns an iterator object that iterates along the
* {@code Shape} boundary and provides access to the geometry of the
* {@code Shape} 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}
* object that traverses the geometry of the {@code Shape} object
* independently from any other {@code PathIterator} objects in use
* at the same time.
* <p>
* It is recommended, but not guaranteed, that objects
* implementing the {@code Shape} 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} to be applied to the
* coordinates as they are returned in the iteration, or
* {@code null} if untransformed coordinates are desired
* @return a new {@code PathIterator} object, which independently
* traverses the geometry of the {@code Shape}.
* @since 1.2
*/
public PathIterator getPathIterator(AffineTransform at);
/**
* Returns an iterator object that iterates along the {@code Shape}
* boundary and provides access to a flattened view of the
* {@code Shape} outline geometry.
* <p>
* Only SEG_MOVETO, SEG_LINETO, and SEG_CLOSE point types are
* returned by the iterator.
* <p>
* If an optional {@code AffineTransform} 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} 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}
* object that traverses the {@code Shape} object geometry
* independently from any other {@code PathIterator} objects in use at
* the same time.
* <p>
* It is recommended, but not guaranteed, that objects
* implementing the {@code Shape} 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} to be applied to the
* coordinates as they are returned in the iteration, or
* {@code null} 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} that independently traverses
* a flattened view of the geometry of the {@code Shape}.
* @since 1.2
*/
public PathIterator getPathIterator(AffineTransform at, double flatness);
}