org.jfree.util

Class ShapeUtilities


public class ShapeUtilities
extends java.lang.Object

Utility methods for Shape objects.
Author:
David Gilbert

Method Summary

static Shape
clone(Shape shape)
Returns a clone of the specified shape, or null.
static boolean
contains(Rectangle2D rect1, Rectangle2D rect2)
Checks, whether the given rectangle1 fully contains rectangle 2 (even if rectangle 2 has a height or width of zero!).
static Shape
createDiagonalCross(float l, float t)
Creates a diagonal cross shape.
static Shape
createDiamond(float s)
Creates a diamond shape.
static Shape
createDownTriangle(float s)
Creates a triangle shape that points downwards.
static Shape
createLineRegion(Line2D line, float width)
Creates a region surrounding a line segment by 'widening' the line segment.
static Shape
createRegularCross(float l, float t)
Creates a diagonal cross shape.
static Shape
createTranslatedShape(Shape shape, double transX, double transY)
Creates and returns a translated shape.
static Shape
createTranslatedShape(Shape shape, RectangleAnchor anchor, double locationX, double locationY)
Translates a shape to a new location such that the anchor point (relative to the rectangular bounds of the shape) aligns with the specified (x, y) coordinate in Java2D space.
static Shape
createUpTriangle(float s)
Creates a triangle shape that points upwards.
static void
drawRotatedShape(Graphics2D g2, Shape shape, double angle, float x, float y)
Draws a shape with the specified rotation about (x, y).
static boolean
equal(Arc2D a1, Arc2D a2)
Compares two arcs and returns true if they are equal or both null.
static boolean
equal(Ellipse2D e1, Ellipse2D e2)
Compares two ellipses and returns true if they are equal or both null.
static boolean
equal(GeneralPath p1, GeneralPath p2)
Tests two polygons for equality.
static boolean
equal(Line2D l1, Line2D l2)
Compares two lines are returns true if they are equal or both null.
static boolean
equal(Polygon p1, Polygon p2)
Tests two polygons for equality.
static boolean
equal(Shape s1, Shape s2)
Tests two shapes for equality.
static Point2D
getPointInRectangle(double x, double y, Rectangle2D area)
Returns a point based on (x, y) but constrained to be within the bounds of a given rectangle.
static boolean
intersects(Rectangle2D rect1, Rectangle2D rect2)
Checks, whether the given rectangle1 fully contains rectangle 2 (even if rectangle 2 has a height or width of zero!).
static Shape
rotateShape(Shape base, double angle, float x, float y)
Rotates a shape about the specified coordinates.

Method Details

clone

public static Shape clone(Shape shape)
Returns a clone of the specified shape, or null. At the current time, this method supports cloning for instances of Line2D, RectangularShape, Area and GeneralPath.

RectangularShape includes Arc2D, Ellipse2D, Rectangle2D, RoundRectangle2D.

Parameters:
shape - the shape to clone (null permitted, returns null).
Returns:
A clone or null.

contains

public static boolean contains(Rectangle2D rect1,
                               Rectangle2D rect2)
Checks, whether the given rectangle1 fully contains rectangle 2 (even if rectangle 2 has a height or width of zero!).
Parameters:
rect1 - the first rectangle.
rect2 - the second rectangle.
Returns:
A boolean.

createDiagonalCross

public static Shape createDiagonalCross(float l,
                                        float t)
Creates a diagonal cross shape.
Parameters:
l - the length of each 'arm'.
t - the thickness.
Returns:
A diagonal cross shape.

createDiamond

public static Shape createDiamond(float s)
Creates a diamond shape.
Parameters:
s - the size factor (equal to half the height of the diamond).
Returns:
A diamond shape.

createDownTriangle

public static Shape createDownTriangle(float s)
Creates a triangle shape that points downwards.
Parameters:
s - the size factor (equal to half the height of the triangle).
Returns:
A triangle shape.

createLineRegion

public static Shape createLineRegion(Line2D line,
                                     float width)
Creates a region surrounding a line segment by 'widening' the line segment. A typical use for this method is the creation of a 'clickable' region for a line that is displayed on-screen.
Parameters:
line - the line (null not permitted).
width - the width of the region.
Returns:
A region that surrounds the line.

createRegularCross

public static Shape createRegularCross(float l,
                                       float t)
Creates a diagonal cross shape.
Parameters:
l - the length of each 'arm'.
t - the thickness.
Returns:
A diagonal cross shape.

createTranslatedShape

public static Shape createTranslatedShape(Shape shape,
                                          double transX,
                                          double transY)
Creates and returns a translated shape.
Parameters:
shape - the shape (null not permitted).
transX - the x translation (in Java2D space).
transY - the y translation (in Java2D space).
Returns:
The translated shape.

createTranslatedShape

public static Shape createTranslatedShape(Shape shape,
                                          RectangleAnchor anchor,
                                          double locationX,
                                          double locationY)
Translates a shape to a new location such that the anchor point (relative to the rectangular bounds of the shape) aligns with the specified (x, y) coordinate in Java2D space.
Parameters:
shape - the shape (null not permitted).
anchor - the anchor (null not permitted).
locationX - the x-coordinate (in Java2D space).
locationY - the y-coordinate (in Java2D space).
Returns:
A new and translated shape.

createUpTriangle

public static Shape createUpTriangle(float s)
Creates a triangle shape that points upwards.
Parameters:
s - the size factor (equal to half the height of the triangle).
Returns:
A triangle shape.

drawRotatedShape

public static void drawRotatedShape(Graphics2D g2,
                                    Shape shape,
                                    double angle,
                                    float x,
                                    float y)
Draws a shape with the specified rotation about (x, y).
Parameters:
g2 - the graphics device (null not permitted).
shape - the shape (null not permitted).
angle - the angle (in radians).
x - the x coordinate for the rotation point.
y - the y coordinate for the rotation point.

equal

public static boolean equal(Arc2D a1,
                            Arc2D a2)
Compares two arcs and returns true if they are equal or both null.
Parameters:
a1 - the first arc (null permitted).
a2 - the second arc (null permitted).
Returns:
A boolean.

equal

public static boolean equal(Ellipse2D e1,
                            Ellipse2D e2)
Compares two ellipses and returns true if they are equal or both null.
Parameters:
e1 - the first ellipse (null permitted).
e2 - the second ellipse (null permitted).
Returns:
A boolean.

equal

public static boolean equal(GeneralPath p1,
                            GeneralPath p2)
Tests two polygons for equality. If both are null this method returns true.
Parameters:
p1 - path 1 (null permitted).
p2 - path 2 (null permitted).
Returns:
A boolean.

equal

public static boolean equal(Line2D l1,
                            Line2D l2)
Compares two lines are returns true if they are equal or both null.
Parameters:
l1 - the first line (null permitted).
l2 - the second line (null permitted).
Returns:
A boolean.

equal

public static boolean equal(Polygon p1,
                            Polygon p2)
Tests two polygons for equality. If both are null this method returns true.
Parameters:
p1 - polygon 1 (null permitted).
p2 - polygon 2 (null permitted).
Returns:
A boolean.

equal

public static boolean equal(Shape s1,
                            Shape s2)
Tests two shapes for equality. If both shapes are null, this method will return true.

In the current implementation, the following shapes are supported: Ellipse2D, Line2D and Rectangle2D (implicit).

Parameters:
s1 - the first shape (null permitted).
s2 - the second shape (null permitted).
Returns:
A boolean.

getPointInRectangle

public static Point2D getPointInRectangle(double x,
                                          double y,
                                          Rectangle2D area)
Returns a point based on (x, y) but constrained to be within the bounds of a given rectangle.
Parameters:
x - the x-coordinate.
y - the y-coordinate.
area - the constraining rectangle (null not permitted).
Returns:
A point within the rectangle.

intersects

public static boolean intersects(Rectangle2D rect1,
                                 Rectangle2D rect2)
Checks, whether the given rectangle1 fully contains rectangle 2 (even if rectangle 2 has a height or width of zero!).
Parameters:
rect1 - the first rectangle.
rect2 - the second rectangle.
Returns:
A boolean.

rotateShape

public static Shape rotateShape(Shape base,
                                double angle,
                                float x,
                                float y)
Rotates a shape about the specified coordinates.
Parameters:
base - the shape (null permitted, returns null).
angle - the angle (in radians).
x - the x coordinate for the rotation point (in Java2D space).
y - the y coordinate for the rotation point (in Java2D space).
Returns:
the rotated shape.