API java : GradientPaint

java.awt
Class GradientPaint

java.lang.Object
  java.awt.GradientPaint

All Implemented Interfaces:

Paint, Transparency

public class GradientPaint
extends Object
implements Paint

The GradientPaint class provides a way to fill a Shape with a linear color gradient pattern. If Point P1 with Color C1 and Point P2 with Color C2 are specified in user space, the Color on the P1, P2 connecting line is proportionally changed from C1 to C2. Any point P not on the extended P1, P2 connecting line has the color of the point P' that is the perpendicular projection of P on the extended P1, P2 connecting line. Points on the extended line outside of the P1, P2 segment can be colored in one of two ways.

• If the gradient is cyclic then the points on the extended P1, P2 connecting line cycle back and forth between the colors C1 and C2.
• If the gradient is acyclic then points on the P1 side of the segment have the constant Color C1 while points on the P2 side have the constant Color C2.

See Also:

Paint, Graphics2D.setPaint(java.awt.Paint)

Field Summary

 

Fields inherited from interface java.awt.Transparency
BITMASK, OPAQUE, TRANSLUCENT

 

Constructor Summary
GradientPaint(float x1, float y1, Color color1, float x2, float y2, Color color2)           Constructs a simple acyclic GradientPaint object.
GradientPaint(float x1, float y1, Color color1, float x2, float y2, Color color2, boolean cyclic)           Constructs either a cyclic or acyclic GradientPaint object depending on the boolean parameter.
GradientPaint(Point2D pt1, Color color1, Point2D pt2, Color color2)           Constructs a simple acyclic GradientPaint object.
GradientPaint(Point2D pt1, Color color1, Point2D pt2, Color color2, boolean cyclic)           Constructs either a cyclic or acyclic GradientPaint object depending on the boolean parameter.

 

Method Summary
PaintContext	createContext(ColorModel cm, Rectangle deviceBounds, Rectangle2D userBounds, AffineTransform xform, RenderingHints hints)           Creates and returns a context used to generate the color pattern.
Color	getColor1()           Returns the color C1 anchored by the point P1.
Color	getColor2()           Returns the color C2 anchored by the point P2.
Point2D	getPoint1()           Returns a copy of the point P1 that anchors the first color.
Point2D	getPoint2()           Returns a copy of the point P2 which anchors the second color.
int	getTransparency()           Returns the transparency mode for this GradientPaint.
boolean	isCyclic()           Returns true if the gradient cycles repeatedly between the two colors C1 and C2.

 

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

 

Constructor Detail

GradientPaint

public GradientPaint(float x1,
                     float y1,
                     Color color1,
                     float x2,
                     float y2,
                     Color color2)

Constructs a simple acyclic GradientPaint object.

Parameters:

x1 - x coordinate of the first specified Point in user space

y1 - y coordinate of the first specified Point in user space

color1 - Color at the first specified Point

x2 - x coordinate of the second specified Point in user space

y2 - y coordinate of the second specified Point in user space

color2 - Color at the second specified Point

Throws:

NullPointerException - if either one of colors is null

GradientPaint

public GradientPaint(Point2D pt1,
                     Color color1,
                     Point2D pt2,
                     Color color2)

Constructs a simple acyclic GradientPaint object.

Parameters:

pt1 - the first specified Point in user space

color1 - Color at the first specified Point

pt2 - the second specified Point in user space

color2 - Color at the second specified Point

Throws:

NullPointerException - if either one of colors or points is null

GradientPaint

public GradientPaint(float x1,
                     float y1,
                     Color color1,
                     float x2,
                     float y2,
                     Color color2,
                     boolean cyclic)

Constructs either a cyclic or acyclic GradientPaint object depending on the boolean parameter.

Parameters:

x1 - x coordinate of the first specified Point in user space

y1 - y coordinate of the first specified Point in user space

color1 - Color at the first specified Point

x2 - x coordinate of the second specified Point in user space

y2 - y coordinate of the second specified Point in user space

color2 - Color at the second specified Point

cyclic - true if the gradient pattern should cycle repeatedly between the two colors; false otherwise

GradientPaint

public GradientPaint(Point2D pt1,
                     Color color1,
                     Point2D pt2,
                     Color color2,
                     boolean cyclic)

Constructs either a cyclic or acyclic GradientPaint object depending on the boolean parameter.

Parameters:

pt1 - the first specified Point in user space

color1 - Color at the first specified Point

pt2 - the second specified Point in user space

color2 - Color at the second specified Point

cyclic - true if the gradient pattern should cycle repeatedly between the two colors; false otherwise

Throws:

NullPointerException - if either one of colors or points is null

getPoint1

public Point2D getPoint1()

Returns a copy of the point P1 that anchors the first color.

Returns:

a Point2D object that is a copy of the point that anchors the first color of this GradientPaint.

getColor1

public Color getColor1()

Returns the color C1 anchored by the point P1.

Returns:

a Color object that is the color anchored by P1.

getPoint2

public Point2D getPoint2()

Returns a copy of the point P2 which anchors the second color.

Returns:

a Point2D object that is a copy of the point that anchors the second color of this GradientPaint.

getColor2

public Color getColor2()

Returns the color C2 anchored by the point P2.

Returns:

a Color object that is the color anchored by P2.

isCyclic

public boolean isCyclic()

Returns true if the gradient cycles repeatedly between the two colors C1 and C2.

Returns:

true if the gradient cycles repeatedly between the two colors; false otherwise.

createContext

public PaintContext createContext(ColorModel cm,
                                  Rectangle deviceBounds,
                                  Rectangle2D userBounds,
                                  AffineTransform xform,
                                  RenderingHints hints)

Creates and returns a context used to generate the color pattern.

Specified by:

createContext in interface Paint

Parameters:

cm - ColorModel that receives the Paint data. This is used only as a hint.

deviceBounds - the device space bounding box of the graphics primitive being rendered

userBounds - the user space bounding box of the graphics primitive being rendered

xform - the AffineTransform from user space into device space

hints - the hints that the context object uses to choose between rendering alternatives

Returns:

the PaintContext that generates color patterns.

See Also:

PaintContext

getTransparency

public int getTransparency()

Returns the transparency mode for this GradientPaint.

Specified by:

getTransparency in interface Transparency

Returns:

an integer value representing this GradientPaint object's transparency mode.

See Also:

Transparency