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Rectangle2D (Java 2 Platform SE 5.0) - JDK 5 Documentation v1.5.0, Java 2 SDK 英文文档

JavaTM 2 Platform
Standard Ed. 5.0

java.awt.geom
Class Rectangle2D

java.lang.Object
  extended by java.awt.geom.RectangularShape
      extended by java.awt.geom.Rectangle2D
All Implemented Interfaces:
Shape, Cloneable
Direct Known Subclasses:
Rectangle, Rectangle2D.Double, Rectangle2D.Float

public abstract class Rectangle2D
extends RectangularShape

The Rectangle2D class describes a rectangle defined by a location (x, y) and dimension (w x h).

This class is only the abstract superclass for all objects that store a 2D rectangle. The actual storage representation of the coordinates is left to the subclass.


Nested Class Summary
static class Rectangle2D.Double
          The Double class defines a rectangle specified in double coordinates.
static class Rectangle2D.Float
          The Float class defines a rectangle specified in float coordinates.
 
Field Summary
static int OUT_BOTTOM
          The bitmask that indicates that a point lies below this Rectangle2D.
static int OUT_LEFT
          The bitmask that indicates that a point lies to the left of this Rectangle2D.
static int OUT_RIGHT
          The bitmask that indicates that a point lies to the right of this Rectangle2D.
static int OUT_TOP
          The bitmask that indicates that a point lies above this Rectangle2D.
 
Constructor Summary
protected Rectangle2D()
          This is an abstract class that cannot be instantiated directly.
 
Method Summary
 void add(double newx, double newy)
          Adds a point, specified by the double precision arguments newx and newy, to this Rectangle2D.
 void add(Point2D pt)
          Adds the Point2D object pt to this Rectangle2D.
 void add(Rectangle2D r)
          Adds a Rectangle2D object to this Rectangle2D.
 boolean contains(double x, double y)
          Tests if a specified coordinate is inside the boundary of this Rectangle2D.
 boolean contains(double x, double y, double w, double h)
          Tests if the interior of this Rectangle2D entirely contains the specified set of rectangular coordinates.
abstract  Rectangle2D createIntersection(Rectangle2D r)
          Returns a new Rectangle2D object representing the intersection of this Rectangle2D with the specified Rectangle2D.
abstract  Rectangle2D createUnion(Rectangle2D r)
          Returns a new Rectangle2D object representing the union of this Rectangle2D with the specified Rectangle2D.
 boolean equals(Object obj)
          Determines whether or not the specified Object is equal to this Rectangle2D.
 Rectangle2D getBounds2D()
          Returns the high precision bounding box of this Rectangle2D.
 PathIterator getPathIterator(AffineTransform at)
          Returns an iteration object that defines the boundary of this Rectangle2D.
 PathIterator getPathIterator(AffineTransform at, double flatness)
          Returns an iteration object that defines the boundary of the flattened Rectangle2D.
 int hashCode()
          Returns the hashcode for this Rectangle2D.
static void intersect(Rectangle2D src1, Rectangle2D src2, Rectangle2D dest)
          Intersects the pair of specified source Rectangle2D objects and puts the result into the specified destination Rectangle2D object.
 boolean intersects(double x, double y, double w, double h)
          Tests if the interior of this Rectangle2D intersects the interior of a specified set of rectangular coordinates.
 boolean intersectsLine(double x1, double y1, double x2, double y2)
          Tests if the specified line segment intersects the interior of this Rectangle2D.
 boolean intersectsLine(Line2D l)
          Tests if the specified line segment intersects the interior of this Rectangle2D.
abstract  int outcode(double x, double y)
          Determines where the specified coordinates lie with respect to this Rectangle2D.
 int outcode(Point2D p)
          Determines where the specified Point2D lies with respect to this Rectangle2D.
 void setFrame(double x, double y, double w, double h)
          Sets the location and size of the outer bounds of this Rectangle2D to the specified rectangular values.
abstract  void setRect(double x, double y, double w, double h)
          Sets the location and size of this Rectangle2D to the specified double values.
 void setRect(Rectangle2D r)
          Sets this Rectangle2D to be the same as the specified Rectangle2D.
static void union(Rectangle2D src1, Rectangle2D src2, Rectangle2D dest)
          Unions the pair of source Rectangle2D objects and puts the result into the specified destination Rectangle2D object.
 
Methods inherited from class java.awt.geom.RectangularShape
clone, contains, contains, getBounds, getCenterX, getCenterY, getFrame, getHeight, getMaxX, getMaxY, getMinX, getMinY, getWidth, getX, getY, intersects, isEmpty, setFrame, setFrame, setFrameFromCenter, setFrameFromCenter, setFrameFromDiagonal, setFrameFromDiagonal
 
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

OUT_LEFT

public static final int OUT_LEFT
The bitmask that indicates that a point lies to the left of this Rectangle2D.

Since:
1.2
See Also:
Constant Field Values

OUT_TOP

public static final int OUT_TOP
The bitmask that indicates that a point lies above this Rectangle2D.

Since:
1.2
See Also:
Constant Field Values

OUT_RIGHT

public static final int OUT_RIGHT
The bitmask that indicates that a point lies to the right of this Rectangle2D.

Since:
1.2
See Also:
Constant Field Values

OUT_BOTTOM

public static final int OUT_BOTTOM
The bitmask that indicates that a point lies below this Rectangle2D.

Since:
1.2
See Also:
Constant Field Values
Constructor Detail

Rectangle2D

protected Rectangle2D()
This is an abstract class that cannot be instantiated directly. Type-specific implementation subclasses are available for instantiation and provide a number of formats for storing the information necessary to satisfy the various accessor methods below.

See Also:
Rectangle2D.Float, Rectangle2D.Double, Rectangle
Method Detail

setRect

public abstract void setRect(double x,
                             double y,
                             double w,
                             double h)
Sets the location and size of this Rectangle2D to the specified double values.

Parameters:
x, y - the coordinates to which to set the location of the upper left corner of this Rectangle2D
w - the value to use to set the width of this Rectangle2D
h - the value to use to set the height of this Rectangle2D
Since:
1.2

setRect

public void setRect(Rectangle2D r)
Sets this Rectangle2D to be the same as the specified Rectangle2D.

Parameters:
r - the specified Rectangle2D
Since:
1.2

intersectsLine

public boolean intersectsLine(double x1,
                              double y1,
                              double x2,
                              double y2)
Tests if the specified line segment intersects the interior of this Rectangle2D.

Parameters:
x1, y1 - the first endpoint of the specified line segment
x2, y2 - the second endpoint of the specified line segment
Returns:
true if the specified line segment intersects the interior of this Rectangle2D; false otherwise.
Since:
1.2

intersectsLine

public boolean intersectsLine(Line2D l)
Tests if the specified line segment intersects the interior of this Rectangle2D.

Parameters:
l - the specified Line2D to test for intersection with the interior of this Rectangle2D
Returns:
true if the specified Line2D intersects the interior of this Rectangle2D; false otherwise.
Since:
1.2

outcode

public abstract int outcode(double x,
                            double y)
Determines where the specified coordinates lie with respect to this Rectangle2D. This method computes a binary OR of the appropriate mask values indicating, for each side of this Rectangle2D, whether or not the specified coordinates are on the same side of the edge as the rest of this Rectangle2D.

Parameters:
x, y - the specified coordinates
Returns:
the logical OR of all appropriate out codes.
Since:
1.2
See Also:
OUT_LEFT, OUT_TOP, OUT_RIGHT, OUT_BOTTOM

outcode

public int outcode(Point2D p)
Determines where the specified Point2D lies with respect to this Rectangle2D. This method computes a binary OR of the appropriate mask values indicating, for each side of this Rectangle2D, whether or not the specified Point2D is on the same side of the edge as the rest of this Rectangle2D.

Parameters:
p - the specified Point2D
Returns:
the logical OR of all appropriate out codes.
Since:
1.2
See Also:
OUT_LEFT, OUT_TOP, OUT_RIGHT, OUT_BOTTOM

setFrame

public void setFrame(double x,
                     double y,
                     double w,
                     double h)
Sets the location and size of the outer bounds of this Rectangle2D to the specified rectangular values.

Specified by:
setFrame in class RectangularShape
Parameters:
x, y - the coordinates to which to set the location of the upper left corner of the outer bounds of this Rectangle2D
w - the value to use to set the width of the outer bounds of this Rectangle2D
h - the value to use to set the height of the outer bounds of this Rectangle2D
Since:
1.2
See Also:
RectangularShape.getFrame()

getBounds2D

public Rectangle2D getBounds2D()
Returns the high precision bounding box of this Rectangle2D.

Returns:
the bounding box of this Rectangle2D.
Since:
1.2
See Also:
Shape.getBounds()

contains

public boolean contains(double x,
                        double y)
Tests if a specified coordinate is inside the boundary of this Rectangle2D.

Parameters:
x, y - the coordinates to test
Returns:
true if the specified coordinates are inside the boundary of this Rectangle2D; false otherwise.
Since:
1.2

intersects

public boolean intersects(double x,
                          double y,
                          double w,
                          double h)
Tests if the interior of this Rectangle2D intersects the interior of a specified set of rectangular coordinates.

Parameters:
x, y - the coordinates of the upper left corner of the specified set of rectangular coordinates
w - the width of the specified set of rectangular coordinates
h - the height of the specified set of rectangular coordinates
Returns:
true if this Rectangle2D intersects the interior of a specified set of rectangular coordinates; false otherwise.
Since:
1.2
See Also:
Area

contains

public boolean contains(double x,
                        double y,
                        double w,
                        double h)
Tests if the interior of this Rectangle2D entirely contains the specified set of rectangular coordinates.

Parameters:
x, y - the coordinates of the upper left corner of the specified set of rectangular coordinates
w - the width of the specified set of rectangular coordinates
h - the height of the specified set of rectangular coordinates
Returns:
true if this Rectangle2D entirely contains specified set of rectangular coordinates; false otherwise.
Since:
1.2
See Also:
Area, Shape.intersects(double, double, double, double)

createIntersection

public abstract Rectangle2D createIntersection(Rectangle2D r)
Returns a new Rectangle2D object representing the intersection of this Rectangle2D with the specified Rectangle2D.

Parameters:
r - the Rectangle2D to be intersected with this Rectangle2D
Returns:
the largest Rectangle2D contained in both the specified Rectangle2D and in this Rectangle2D.
Since:
1.2

intersect

public static void intersect(Rectangle2D src1,
                             Rectangle2D src2,
                             Rectangle2D dest)
Intersects the pair of specified source Rectangle2D objects and puts the result into the specified destination Rectangle2D object. One of the source rectangles can also be the destination to avoid creating a third Rectangle2D object, but in this case the original points of this source rectangle will be overwritten by this method.

Parameters:
src1 - the first of a pair of Rectangle2D objects to be intersected with each other
src2 - the second of a pair of Rectangle2D objects to be intersected with each other
dest - the Rectangle2D that holds the results of the intersection of src1 and src2
Since:
1.2

createUnion

public abstract Rectangle2D createUnion(Rectangle2D r)
Returns a new Rectangle2D object representing the union of this Rectangle2D with the specified Rectangle2D.

Parameters:
r - the Rectangle2D to be combined with this Rectangle2D
Returns:
the smallest Rectangle2D containing both the specified Rectangle2D and this Rectangle2D.
Since:
1.2

union

public static void union(Rectangle2D src1,
                         Rectangle2D src2,
                         Rectangle2D dest)
Unions the pair of source Rectangle2D objects and puts the result into the specified destination Rectangle2D object. One of the source rectangles can also be the destination to avoid creating a third Rectangle2D object, but in this case the original points of this source rectangle will be overwritten by this method.

Parameters:
src1 - the first of a pair of Rectangle2D objects to be combined with each other
src2 - the second of a pair of Rectangle2D objects to be combined with each other
dest - the Rectangle2D that holds the results of the union of src1 and src2
Since:
1.2

add

public void add(double newx,
                double newy)
Adds a point, specified by the double precision arguments newx and newy, to this Rectangle2D. The resulting Rectangle2D is the smallest Rectangle2D that contains both the original Rectangle2D and the specified point.

After adding a point, a call to contains with the added point as an argument does not necessarily return true. The contains method does not return true for points on the right or bottom edges of a rectangle. Therefore, if the added point falls on the left or bottom edge of the enlarged rectangle, contains returns false for that point.

Parameters:
newx, newy - the coordinates of the new point
Since:
JDK1.0

add

public void add(Point2D pt)
Adds the Point2D object pt to this Rectangle2D. The resulting Rectangle2D is the smallest Rectangle2D that contains both the original Rectangle2D and the specified Point2D.

After adding a point, a call to contains with the added point as an argument does not necessarily return true. The contains method does not return true for points on the right or bottom edges of a rectangle. Therefore, if the added point falls on the left or bottom edge of the enlarged rectangle, contains returns false for that point.

Parameters:
pt - the new Point2D to add to this Rectangle2D.
Since:
JDK1.0

add

public void add(Rectangle2D r)
Adds a Rectangle2D object to this Rectangle2D. The resulting Rectangle2D is the union of the two Rectangle2D objects.

Parameters:
r - the Rectangle2D to add to this Rectangle2D.
Since:
JDK1.0

getPathIterator

public PathIterator getPathIterator(AffineTransform at)
Returns an iteration object that defines the boundary of this Rectangle2D. The iterator for this class is multi-threaded safe, which means that this Rectangle2D class guarantees that modifications to the geometry of this Rectangle2D object do not affect any iterations of that geometry that are already in process.

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
Returns:
the PathIterator object that returns the geometry of the outline of this Rectangle2D, one segment at a time.
Since:
1.2

getPathIterator

public PathIterator getPathIterator(AffineTransform at,
                                    double flatness)
Returns an iteration object that defines the boundary of the flattened Rectangle2D. Since rectangles are already flat, the flatness parameter is ignored. The iterator for this class is multi-threaded safe, which means that this Rectangle2D class guarantees that modifications to the geometry of this Rectangle2D object do not affect any iterations of that geometry that are already in process.

Specified by:
getPathIterator in interface Shape
Overrides:
getPathIterator in class RectangularShape
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. Since rectangles are already flat, the flatness parameter is ignored.
Returns:
the PathIterator object that returns the geometry of the outline of this Rectangle2D, one segment at a time.
Since:
1.2

hashCode

public int hashCode()
Returns the hashcode for this Rectangle2D.

Overrides:
hashCode in class Object
Returns:
the hashcode for this Rectangle2D.
See Also:
Object.equals(java.lang.Object), Hashtable

equals

public boolean equals(Object obj)
Determines whether or not the specified Object is equal to this Rectangle2D. The specified Object is equal to this Rectangle2D if it is an instance of Rectangle2D and if its location and size are the same as this Rectangle2D.

Overrides:
equals in class Object
Parameters:
obj - an Object to be compared with this Rectangle2D.
Returns:
true if obj is an instance of Rectangle2D and has the same values; false otherwise.
Since:
1.2
See Also:
Object.hashCode(), Hashtable

JavaTM 2 Platform
Standard Ed. 5.0

Submit a bug or feature
For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

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