java.awt.geom
Class Path2D

java.lang.Object
  java.awt.geom.Path2D

All Implemented Interfaces:

Shape, Cloneable

Direct Known Subclasses:

Path2D.Double, Path2D.Float

public abstract class Path2D
extends Object
implements Shape, Cloneable

The Path2D class provides a simple, yet flexible shape which represents an arbitrary geometric path. It can fully represent any path which can be iterated by the PathIterator interface including all of its segment types and winding rules and it implements all of the basic hit testing methods of the Shape interface.

Use Path2D.Float when dealing with data that can be represented and used with floating point precision. Use Path2D.Double for data that requires the accuracy or range of double precision.

Path2D provides exactly those facilities required for basic construction and management of a geometric path and implementation of the above interfaces with little added interpretation. If it is useful to manipulate the interiors of closed geometric shapes beyond simple hit testing then the Area class provides additional capabilities specifically targeted at closed figures. While both classes nominally implement the Shape interface, they differ in purpose and together they provide two useful views of a geometric shape where Path2D deals primarily with a trajectory formed by path segments and Area deals more with interpretation and manipulation of enclosed regions of 2D geometric space.

The PathIterator interface has more detailed descriptions of the types of segments that make up a path and the winding rules that control how to determine which regions are inside or outside the path.

Since:

1.6

Nested Class Summary

static class	Path2D.Double The Double class defines a geometric path with coordinates stored in double precision floating point.
static class	Path2D.Float The Float class defines a geometric path with coordinates stored in single precision floating point.

Field Summary

static int	WIND_EVEN_ODD An even-odd winding rule for determining the interior of a path.
static int	WIND_NON_ZERO A non-zero winding rule for determining the interior of a path.

Method Summary

abstract void	append(PathIterator pi, boolean connect) Appends the geometry of the specified PathIterator object to the path, possibly connecting the new geometry to the existing path segments with a line segment.
void	append(Shape s, boolean connect) Appends the geometry of the specified Shape object to the path, possibly connecting the new geometry to the existing path segments with a line segment.
abstract Object	clone() Creates a new object of the same class as this object.
void	closePath() Closes the current subpath by drawing a straight line back to the coordinates of the last moveTo.
boolean	contains(double x, double y) Tests if the specified coordinates are inside the boundary of the Shape.
boolean	contains(double x, double y, double w, double h) Tests if the interior of the Shape entirely contains the specified rectangular area.
static boolean	contains(PathIterator pi, double x, double y) Tests if the specified coordinates are inside the closed boundary of the specified PathIterator.
static boolean	contains(PathIterator pi, double x, double y, double w, double h) Tests if the specified rectangular area is entirely inside the closed boundary of the specified PathIterator.
static boolean	contains(PathIterator pi, Point2D p) Tests if the specified Point2D is inside the closed boundary of the specified PathIterator.
static boolean	contains(PathIterator pi, Rectangle2D r) Tests if the specified Rectangle2D is entirely inside the closed boundary of the specified PathIterator.
boolean	contains(Point2D p) Tests if a specified Point2D is inside the boundary of the Shape.
boolean	contains(Rectangle2D r) Tests if the interior of the Shape entirely contains the specified Rectangle2D.
Shape	createTransformedShape(AffineTransform at) Returns a new Shape representing a transformed version of this Path2D.
abstract void	curveTo(double x1, double y1, double x2, double y2, double x3, double y3) Adds a curved segment, defined by three new points, to the path by drawing a Bézier curve that intersects both the current coordinates and the specified coordinates (x3,y3), using the specified points (x1,y1) and (x2,y2) as Bézier control points.
Rectangle	getBounds() Returns an integer Rectangle that completely encloses the Shape.
Point2D	getCurrentPoint() Returns the coordinates most recently added to the end of the path as a Point2D object.
PathIterator	getPathIterator(AffineTransform at, double flatness) Returns an iterator object that iterates along the Shape boundary and provides access to a flattened view of the Shape outline geometry.
int	getWindingRule() Returns the fill style winding rule.
boolean	intersects(double x, double y, double w, double h) Tests if the interior of the Shape intersects the interior of a specified rectangular area.
static boolean	intersects(PathIterator pi, double x, double y, double w, double h) Tests if the interior of the specified PathIterator intersects the interior of a specified set of rectangular coordinates.
static boolean	intersects(PathIterator pi, Rectangle2D r) Tests if the interior of the specified PathIterator intersects the interior of a specified Rectangle2D.
boolean	intersects(Rectangle2D r) Tests if the interior of the Shape intersects the interior of a specified Rectangle2D.
abstract void	lineTo(double x, double y) Adds a point to the path by drawing a straight line from the current coordinates to the new specified coordinates specified in double precision.
abstract void	moveTo(double x, double y) Adds a point to the path by moving to the specified coordinates specified in double precision.
abstract void	quadTo(double x1, double y1, double x2, double y2) Adds a curved segment, defined by two new points, to the path by drawing a Quadratic curve that intersects both the current coordinates and the specified coordinates (x2,y2), using the specified point (x1,y1) as a quadratic parametric control point.
void	reset() Resets the path to empty.
void	setWindingRule(int rule) Sets the winding rule for this path to the specified value.
abstract void	transform(AffineTransform at) Transforms the geometry of this path using the specified AffineTransform.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.awt.Shape

getBounds2D, getPathIterator

Field Detail

WIND_EVEN_ODD

public static final int WIND_EVEN_ODD

An even-odd winding rule for determining the interior of a path.

Since:

1.6

See Also:

PathIterator.WIND_EVEN_ODD, Constant Field Values

WIND_NON_ZERO

public static final int WIND_NON_ZERO

A non-zero winding rule for determining the interior of a path.

Since:

1.6

See Also:

PathIterator.WIND_NON_ZERO, Constant Field Values

Method Detail

moveTo

public abstract void moveTo(double x,
                            double y)

Adds a point to the path by moving to the specified coordinates specified in double precision.

Parameters:

x - the specified X coordinate

y - the specified Y coordinate

Since:

1.6

lineTo

public abstract void lineTo(double x,
                            double y)

Adds a point to the path by drawing a straight line from the current coordinates to the new specified coordinates specified in double precision.

Parameters:

x - the specified X coordinate

y - the specified Y coordinate

Since:

1.6

quadTo

public abstract void quadTo(double x1,
                            double y1,
                            double x2,
                            double y2)

Adds a curved segment, defined by two new points, to the path by drawing a Quadratic curve that intersects both the current coordinates and the specified coordinates (x2,y2), using the specified point (x1,y1) as a quadratic parametric control point. All coordinates are specified in double precision.

Parameters:

x1 - the X coordinate of the quadratic control point

y1 - the Y coordinate of the quadratic control point

x2 - the X coordinate of the final end point

y2 - the Y coordinate of the final end point

Since:

1.6

curveTo

public abstract void curveTo(double x1,
                             double y1,
                             double x2,
                             double y2,
                             double x3,
                             double y3)

Adds a curved segment, defined by three new points, to the path by drawing a Bézier curve that intersects both the current coordinates and the specified coordinates (x3,y3), using the specified points (x1,y1) and (x2,y2) as Bézier control points. All coordinates are specified in double precision.

Parameters:

x1 - the X coordinate of the first Bézier control point

y1 - the Y coordinate of the first Bézier control point

x2 - the X coordinate of the second Bézier control point

y2 - the Y coordinate of the second Bézier control point

x3 - the X coordinate of the final end point

y3 - the Y coordinate of the final end point

Since:

1.6

closePath

public final void closePath()

Closes the current subpath by drawing a straight line back to the coordinates of the last moveTo. If the path is already closed then this method has no effect.

Since:

1.6

append

public final void append(Shape s,
                         boolean connect)

Appends the geometry of the specified Shape object to the path, possibly connecting the new geometry to the existing path segments with a line segment. If the connect parameter is true and the path is not empty then any initial moveTo in the geometry of the appended Shape is turned into a lineTo segment. If the destination coordinates of such a connecting lineTo segment match the ending coordinates of a currently open subpath then the segment is omitted as superfluous. The winding rule of the specified Shape is ignored and the appended geometry is governed by the winding rule specified for this path.

Parameters:

s - the Shape whose geometry is appended to this path

connect - a boolean to control whether or not to turn an initial moveTo segment into a lineTo segment to connect the new geometry to the existing path

Since:

1.6

append

public abstract void append(PathIterator pi,
                            boolean connect)

Appends the geometry of the specified PathIterator object to the path, possibly connecting the new geometry to the existing path segments with a line segment. If the connect parameter is true and the path is not empty then any initial moveTo in the geometry of the appended Shape is turned into a lineTo segment. If the destination coordinates of such a connecting lineTo segment match the ending coordinates of a currently open subpath then the segment is omitted as superfluous. The winding rule of the specified Shape is ignored and the appended geometry is governed by the winding rule specified for this path.

Parameters:

pi - the PathIterator whose geometry is appended to this path

connect - a boolean to control whether or not to turn an initial moveTo segment into a lineTo segment to connect the new geometry to the existing path

Since:

1.6

getWindingRule

public final int getWindingRule()

Returns the fill style winding rule.

Returns:

an integer representing the current winding rule.

Since:

1.6

See Also:

WIND_EVEN_ODD, WIND_NON_ZERO, setWindingRule(int)

setWindingRule

public final void setWindingRule(int rule)

Sets the winding rule for this path to the specified value.

Parameters:

rule - an integer representing the specified winding rule

Throws:

IllegalArgumentException - if rule is not either WIND_EVEN_ODD or WIND_NON_ZERO

Since:

1.6

See Also:

getWindingRule()

getCurrentPoint

public final Point2D getCurrentPoint()

Returns the coordinates most recently added to the end of the path as a Point2D object.

Returns:

a Point2D object containing the ending coordinates of the path or null if there are no points in the path.

Since:

1.6

reset

public final void reset()

Resets the path to empty. The append position is set back to the beginning of the path and all coordinates and point types are forgotten.

Since:

1.6

transform

public abstract void transform(AffineTransform at)

Transforms the geometry of this path using the specified AffineTransform. The geometry is transformed in place, which permanently changes the boundary defined by this object.

Parameters:

at - the AffineTransform used to transform the area

Since:

1.6

createTransformedShape

public final Shape createTransformedShape(AffineTransform at)

Returns a new Shape representing a transformed version of this Path2D. Note that the exact type and coordinate precision of the return value is not specified for this method. The method will return a Shape that contains no less precision for the transformed geometry than this Path2D currently maintains, but it may contain no more precision either. If the tradeoff of precision vs. storage size in the result is important then the convenience constructors in the Path2D.Float and Path2D.Double subclasses should be used to make the choice explicit.

Parameters:

at - the AffineTransform used to transform a new Shape.

Returns:

a new Shape, transformed with the specified AffineTransform.

Since:

1.6

getBounds

public final Rectangle getBounds()

Returns an integer Rectangle that completely encloses the Shape. Note that there is no guarantee that the returned Rectangle is the smallest bounding box that encloses the Shape, only that the Shape lies entirely within the indicated Rectangle. The returned Rectangle might also fail to completely enclose the Shape if the Shape overflows the limited range of the integer data type. The getBounds2D method generally returns a tighter bounding box due to its greater flexibility in representation.

Specified by:

getBounds in interface Shape

Returns:

an integer Rectangle that completely encloses the Shape.

Since:

1.6

See Also:

Shape.getBounds2D()

contains

public static boolean contains(PathIterator pi,
                               double x,
                               double y)

Tests if the specified coordinates are inside the closed boundary of the specified PathIterator.

This method provides a basic facility for implementors of the Shape interface to implement support for the Shape.contains(double, double) method.

Parameters:

pi - the specified PathIterator

x - the specified X coordinate

y - the specified Y coordinate

Returns:

true if the specified coordinates are inside the specified PathIterator; false otherwise

Since:

1.6

contains

public static boolean contains(PathIterator pi,
                               Point2D p)

Tests if the specified Point2D is inside the closed boundary of the specified PathIterator.

This method provides a basic facility for implementors of the Shape interface to implement support for the Shape.contains(Point2D) method.

Parameters:

pi - the specified PathIterator

p - the specified Point2D

Returns:

true if the specified coordinates are inside the specified PathIterator; false otherwise

Since:

1.6

contains

public final boolean contains(double x,
                              double y)

Tests if the specified coordinates are inside the boundary of the Shape.

Specified by:

contains in interface Shape

Parameters:

x - the specified X coordinate to be tested

y - the specified Y coordinate to be tested

Returns:

true if the specified coordinates are inside the Shape boundary; false otherwise.

Since:

1.6

contains

public final boolean contains(Point2D p)

Tests if a specified Point2D is inside the boundary of the Shape.

Specified by:

contains in interface Shape

Parameters:

p - the specified Point2D to be tested

Returns:

true if the specified Point2D is inside the boundary of the Shape; false otherwise.

Since:

1.6

contains

public static boolean contains(PathIterator pi,
                               double x,
                               double y,
                               double w,
                               double h)

Tests if the specified rectangular area is entirely inside the closed boundary of the specified PathIterator.

This method provides a basic facility for implementors of the Shape interface to implement support for the Shape.contains(double, double, double, double) method.

This method object may conservatively return false in cases where the specified rectangular area intersects a segment of the path, but that segment does not represent a boundary between the interior and exterior of the path. Such segments could lie entirely within the interior of the path if they are part of a path with a WIND_NON_ZERO winding rule or if the segments are retraced in the reverse direction such that the two sets of segments cancel each other out without any exterior area falling between them. To determine whether segments represent true boundaries of the interior of the path would require extensive calculations involving all of the segments of the path and the winding rule and are thus beyond the scope of this implementation.

Parameters:

pi - the specified PathIterator

x - the specified X coordinate

y - the specified Y coordinate

w - the width of the specified rectangular area

h - the height of the specified rectangular area

Returns:

true if the specified PathIterator contains the specified rectangluar area; false otherwise.

Since:

1.6

contains

public static boolean contains(PathIterator pi,
                               Rectangle2D r)

Tests if the specified Rectangle2D is entirely inside the closed boundary of the specified PathIterator.

This method provides a basic facility for implementors of the Shape interface to implement support for the Shape.contains(Rectangle2D) method.

This method object may conservatively return false in cases where the specified rectangular area intersects a segment of the path, but that segment does not represent a boundary between the interior and exterior of the path. Such segments could lie entirely within the interior of the path if they are part of a path with a WIND_NON_ZERO winding rule or if the segments are retraced in the reverse direction such that the two sets of segments cancel each other out without any exterior area falling between them. To determine whether segments represent true boundaries of the interior of the path would require extensive calculations involving all of the segments of the path and the winding rule and are thus beyond the scope of this implementation.

Parameters:

pi - the specified PathIterator

r - a specified Rectangle2D

Returns:

true if the specified PathIterator contains the specified Rectangle2D; false otherwise.

Since:

1.6

contains

public final boolean contains(double x,
                              double y,
                              double w,
                              double h)

Tests if the interior of the Shape entirely contains the specified rectangular area. All coordinates that lie inside the rectangular area must lie within the Shape for the entire rectanglar area to be considered contained within the Shape.

The Shape.contains() method allows a Shape implementation to conservatively return false when:

• the intersect method returns true and
• the calculations to determine whether or not the Shape entirely contains the rectangular area are prohibitively expensive.

This means that for some Shapes this method might return false even though the Shape contains the rectangular area. The Area class performs more accurate geometric computations than most Shape objects and therefore can be used if a more precise answer is required.

This method object may conservatively return false in cases where the specified rectangular area intersects a segment of the path, but that segment does not represent a boundary between the interior and exterior of the path. Such segments could lie entirely within the interior of the path if they are part of a path with a WIND_NON_ZERO winding rule or if the segments are retraced in the reverse direction such that the two sets of segments cancel each other out without any exterior area falling between them. To determine whether segments represent true boundaries of the interior of the path would require extensive calculations involving all of the segments of the path and the winding rule and are thus beyond the scope of this implementation.

Specified by:

contains in interface Shape

Parameters:

x - the X coordinate of the upper-left corner of the specified rectangular area

y - the Y coordinate of the upper-left corner of the specified rectangular area

w - the width of the specified rectangular area

h - the height of the specified rectangular area

Returns:

true if the interior of the Shape entirely contains the specified rectangular area; false otherwise or, if the Shape contains the rectangular area and the intersects method returns true and the containment calculations would be too expensive to perform.

Since:

1.6

See Also:

Area, Shape.intersects(double, double, double, double)

contains

public final boolean contains(Rectangle2D r)

Tests if the interior of the Shape entirely contains the specified Rectangle2D. The Shape.contains() method allows a Shape implementation to conservatively return false when:

• the intersect method returns true and
• the calculations to determine whether or not the Shape entirely contains the Rectangle2D are prohibitively expensive.

This means that for some Shapes this method might return false even though the Shape contains the Rectangle2D. The Area class performs more accurate geometric computations than most Shape objects and therefore can be used if a more precise answer is required.

This method object may conservatively return false in cases where the specified rectangular area intersects a segment of the path, but that segment does not represent a boundary between the interior and exterior of the path. Such segments could lie entirely within the interior of the path if they are part of a path with a WIND_NON_ZERO winding rule or if the segments are retraced in the reverse direction such that the two sets of segments cancel each other out without any exterior area falling between them. To determine whether segments represent true boundaries of the interior of the path would require extensive calculations involving all of the segments of the path and the winding rule and are thus beyond the scope of this implementation.

Specified by:

contains in interface Shape

Parameters:

r - The specified Rectangle2D

Returns:

true if the interior of the Shape entirely contains the Rectangle2D; false otherwise or, if the Shape contains the Rectangle2D and the intersects method returns true and the containment calculations would be too expensive to perform.

Since:

1.6

See Also:

Shape.contains(double, double, double, double)

intersects

public static boolean intersects(PathIterator pi,
                                 double x,
                                 double y,
                                 double w,
                                 double h)

Tests if the interior of the specified PathIterator intersects the interior of a specified set of rectangular coordinates.

This method provides a basic facility for implementors of the Shape interface to implement support for the Shape.intersects(double, double, double, double) method.

This method object may conservatively return true in cases where the specified rectangular area intersects a segment of the path, but that segment does not represent a boundary between the interior and exterior of the path. Such a case may occur if some set of segments of the path are retraced in the reverse direction such that the two sets of segments cancel each other out without any interior area between them. To determine whether segments represent true boundaries of the interior of the path would require extensive calculations involving all of the segments of the path and the winding rule and are thus beyond the scope of this implementation.

Parameters:

pi - the specified PathIterator

x - the specified X coordinate

y - the specified Y coordinate

w - the width of the specified rectangular coordinates

h - the height of the specified rectangular coordinates

Returns:

true if the specified PathIterator and the interior of the specified set of rectangular coordinates intersect each other; false otherwise.

Since:

1.6

intersects

public static boolean intersects(PathIterator pi,
                                 Rectangle2D r)

Tests if the interior of the specified PathIterator intersects the interior of a specified Rectangle2D.

This method provides a basic facility for implementors of the Shape interface to implement support for the Shape.intersects(Rectangle2D) method.

This method object may conservatively return true in cases where the specified rectangular area intersects a segment of the path, but that segment does not represent a boundary between the interior and exterior of the path. Such a case may occur if some set of segments of the path are retraced in the reverse direction such that the two sets of segments cancel each other out without any interior area between them. To determine whether segments represent true boundaries of the interior of the path would require extensive calculations involving all of the segments of the path and the winding rule and are thus beyond the scope of this implementation.

Parameters:

pi - the specified PathIterator

r - the specified Rectangle2D

Returns:

true if the specified PathIterator and the interior of the specified Rectangle2D intersect each other; false otherwise.

Since:

1.6

intersects

public final boolean intersects(double x,
                                double y,
                                double w,
                                double h)

Tests if the interior of the Shape intersects the interior of a specified rectangular area. The rectangular area is considered to intersect the Shape if any point is contained in both the interior of the Shape and the specified rectangular area.

The Shape.intersects() method allows a Shape implementation to conservatively return true when:

• there is a high probability that the rectangular area and the Shape intersect, but
• the calculations to accurately determine this intersection are prohibitively expensive.

This means that for some Shapes this method might return true even though the rectangular area does not intersect the Shape. The Area class performs more accurate computations of geometric intersection than most Shape objects and therefore can be used if a more precise answer is required.

This method object may conservatively return true in cases where the specified rectangular area intersects a segment of the path, but that segment does not represent a boundary between the interior and exterior of the path. Such a case may occur if some set of segments of the path are retraced in the reverse direction such that the two sets of segments cancel each other out without any interior area between them. To determine whether segments represent true boundaries of the interior of the path would require extensive calculations involving all of the segments of the path and the winding rule and are thus beyond the scope of this implementation.

Specified by:

intersects in interface Shape

Parameters:

x - the X coordinate of the upper-left corner of the specified rectangular area

y - the Y coordinate of the upper-left corner of the specified rectangular area

w - the width of the specified rectangular area

h - the height of the specified rectangular area

Returns:

true if the interior of the 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; false otherwise.

Since:

1.6

See Also:

Area

intersects

public final boolean intersects(Rectangle2D r)

Tests if the interior of the Shape intersects the interior of a specified Rectangle2D. The Shape.intersects() method allows a Shape implementation to conservatively return true when:

• there is a high probability that the Rectangle2D and the Shape intersect, but
• the calculations to accurately determine this intersection are prohibitively expensive.

This means that for some Shapes this method might return true even though the Rectangle2D does not intersect the Shape. The Area class performs more accurate computations of geometric intersection than most Shape objects and therefore can be used if a more precise answer is required.

This method object may conservatively return true in cases where the specified rectangular area intersects a segment of the path, but that segment does not represent a boundary between the interior and exterior of the path. Such a case may occur if some set of segments of the path are retraced in the reverse direction such that the two sets of segments cancel each other out without any interior area between them. To determine whether segments represent true boundaries of the interior of the path would require extensive calculations involving all of the segments of the path and the winding rule and are thus beyond the scope of this implementation.

Specified by:

intersects in interface Shape

Parameters:

r - the specified Rectangle2D

Returns:

true if the interior of the Shape and the interior of the specified Rectangle2D intersect, or are both highly likely to intersect and intersection calculations would be too expensive to perform; false otherwise.

Since:

1.6

See Also:

Shape.intersects(double, double, double, double)

getPathIterator

public PathIterator getPathIterator(AffineTransform at,
                                    double flatness)

Returns an iterator object that iterates along the Shape boundary and provides access to a flattened view of the Shape outline geometry.

Only SEG_MOVETO, SEG_LINETO, and SEG_CLOSE point types are returned by the iterator.

If an optional AffineTransform is specified, the coordinates returned in the iteration are transformed accordingly.

The amount of subdivision of the curved segments is controlled by the 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.

Each call to this method returns a fresh PathIterator object that traverses the Shape object geometry independently from any other PathIterator objects in use at the same time.

It is recommended, but not guaranteed, that objects implementing the Shape interface isolate iterations that are in process from any changes that might occur to the original object's geometry during such iterations.

The iterator for this class is not multi-threaded safe, which means that this Path2D class does not guarantee that modifications to the geometry of this Path2D object do not affect any iterations of that geometry that are already in process.

Specified by:

getPathIterator in interface Shape

Parameters:

at - an optional AffineTransform to be applied to the coordinates as they are returned in the iteration, or null if untransformed coordinates are desired

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

Returns:

a new PathIterator that independently traverses a flattened view of the geometry of the Shape.

Since:

1.6

clone

public abstract Object clone()

Creates a new object of the same class as this object.

Overrides:

clone in class Object

Returns:

a clone of this instance.

Throws:

OutOfMemoryError - if there is not enough memory.

Since:

1.6

See Also:

Cloneable