public final class LinearGradientPaint extends MultipleGradientPaint
LinearGradientPaint
class provides a way to fill
a Shape
with a linear color gradient pattern. The user may
specify 2 or more gradient colors, and this paint will provide an
interpolation between each color. The user also specifies start and end
points which define where in user space the color gradient should begin
and end.
The user must provide an array of floats specifying how to distribute the colors along the gradient. These values should range from 0.0 to 1.0 and act like keyframes along the gradient (they mark where the gradient should be exactly a particular color).
For example:
Point2D start = new Point2D.Float(0, 0);
Point2D end = new Point2D.Float(100,100);
float[] dist = {0.0, 0.2, 1.0};
Color[] colors = {Color.red, Color.white, Color.blue};
LinearGradientPaint p = new LinearGradientPaint(start, end, dist, colors);
This code will create a LinearGradientPaint which interpolates between red and white for the first 20% of the gradient and between white and blue for the remaining 80%.
In the event that the user does not set the first keyframe value equal
to 0 and the last keyframe value equal to 1, keyframes will be created at
these positions and the first and last colors will be replicated there.
So, if a user specifies the following arrays to construct a gradient:
{Color.blue, Color.red}, {.3, .7}
this will be converted to a gradient with the following keyframes:
{Color.blue, Color.blue, Color.red, Color.red}, {0, .3, .7, 1}
The user may also select what action the LinearGradientPaint should take when filling color outside the start and end points. If no cycle method is specified, NO_CYCLE will be chosen by default, so the endpoint colors will be used to fill the remaining area.
The following image demonstrates the options NO_CYCLE and REFLECT.
The colorSpace parameter allows the user to specify in which colorspace the interpolation should be performed, default sRGB or linearized RGB.
Paint
,
Graphics2D.setPaint(java.awt.Paint)
MultipleGradientPaint.ColorSpaceEnum, MultipleGradientPaint.CycleMethodEnum
colors, colorSpace, cycleMethod, fractions, gradientTransform, LINEAR_RGB, NO_CYCLE, REFLECT, REPEAT, SRGB, transparency
Constructor and Description |
---|
LinearGradientPaint(float startX,
float startY,
float endX,
float endY,
float[] fractions,
java.awt.Color[] colors)
Constructs an
LinearGradientPaint with the default
NO_CYCLE repeating method and SRGB colorspace. |
LinearGradientPaint(float startX,
float startY,
float endX,
float endY,
float[] fractions,
java.awt.Color[] colors,
MultipleGradientPaint.CycleMethodEnum cycleMethod)
Constructs an
LinearGradientPaint with default SRGB
colorspace. |
LinearGradientPaint(java.awt.geom.Point2D start,
java.awt.geom.Point2D end,
float[] fractions,
java.awt.Color[] colors)
Constructs a
LinearGradientPaint with the default
NO_CYCLE repeating method and SRGB colorspace. |
LinearGradientPaint(java.awt.geom.Point2D start,
java.awt.geom.Point2D end,
float[] fractions,
java.awt.Color[] colors,
MultipleGradientPaint.CycleMethodEnum cycleMethod,
MultipleGradientPaint.ColorSpaceEnum colorSpace)
Constructs a
LinearGradientPaint . |
LinearGradientPaint(java.awt.geom.Point2D start,
java.awt.geom.Point2D end,
float[] fractions,
java.awt.Color[] colors,
MultipleGradientPaint.CycleMethodEnum cycleMethod,
MultipleGradientPaint.ColorSpaceEnum colorSpace,
java.awt.geom.AffineTransform gradientTransform)
Constructs a
LinearGradientPaint . |
Modifier and Type | Method and Description |
---|---|
java.awt.PaintContext |
createContext(java.awt.image.ColorModel cm,
java.awt.Rectangle deviceBounds,
java.awt.geom.Rectangle2D userBounds,
java.awt.geom.AffineTransform transform,
java.awt.RenderingHints hints)
Creates and returns a PaintContext used to generate the color pattern,
for use by the internal rendering engine.
|
java.awt.geom.Point2D |
getEndPoint()
Returns a copy of the end point of the gradient axis
|
java.awt.geom.Point2D |
getStartPoint()
Returns a copy of the start point of the gradient axis
|
getColors, getColorSpace, getCycleMethod, getFractions, getTransform, getTransparency
public LinearGradientPaint(float startX, float startY, float endX, float endY, float[] fractions, java.awt.Color[] colors)
Constructs an LinearGradientPaint
with the default
NO_CYCLE repeating method and SRGB colorspace.
startX
- the x coordinate of the gradient axis start point
in user spacestartY
- the y coordinate of the gradient axis start point
in user spaceendX
- the x coordinate of the gradient axis end point
in user spaceendY
- the y coordinate of the gradient axis end point
in user spacefractions
- numbers ranging from 0.0 to 1.0 specifying the
distribution of colors along the gradientcolors
- array of colors corresponding to each fractional valuejava.lang.IllegalArgumentException
- if start and end points are the
same points, or if fractions.length != colors.length, or if colors
is less than 2 in size.public LinearGradientPaint(float startX, float startY, float endX, float endY, float[] fractions, java.awt.Color[] colors, MultipleGradientPaint.CycleMethodEnum cycleMethod)
Constructs an LinearGradientPaint
with default SRGB
colorspace.
startX
- the x coordinate of the gradient axis start point
in user spacestartY
- the y coordinate of the gradient axis start point
in user spaceendX
- the x coordinate of the gradient axis end point
in user spaceendY
- the y coordinate of the gradient axis end point
in user spacefractions
- numbers ranging from 0.0 to 1.0 specifying the
distribution of colors along the gradientcolors
- array of colors corresponding to each fractional valuecycleMethod
- either NO_CYCLE, REFLECT, or REPEATjava.lang.IllegalArgumentException
- if start and end points are the
same points, or if fractions.length != colors.length, or if colors
is less than 2 in size.public LinearGradientPaint(java.awt.geom.Point2D start, java.awt.geom.Point2D end, float[] fractions, java.awt.Color[] colors)
Constructs a LinearGradientPaint
with the default
NO_CYCLE repeating method and SRGB colorspace.
start
- the gradient axis start Point
in user spaceend
- the gradient axis end Point
in user spacefractions
- numbers ranging from 0.0 to 1.0 specifying the
distribution of colors along the gradientcolors
- array of colors corresponding to each fractional valuejava.lang.NullPointerException
- if one of the points is nulljava.lang.IllegalArgumentException
- if start and end points are the
same points, or if fractions.length != colors.length, or if colors
is less than 2 in size.public LinearGradientPaint(java.awt.geom.Point2D start, java.awt.geom.Point2D end, float[] fractions, java.awt.Color[] colors, MultipleGradientPaint.CycleMethodEnum cycleMethod, MultipleGradientPaint.ColorSpaceEnum colorSpace)
Constructs a LinearGradientPaint
.
start
- the gradient axis start Point
in user spaceend
- the gradient axis end Point
in user spacefractions
- numbers ranging from 0.0 to 1.0 specifying the
distribution of colors along the gradientcolors
- array of colors corresponding to each fractional valuecycleMethod
- either NO_CYCLE, REFLECT, or REPEATcolorSpace
- which colorspace to use for interpolation,
either SRGB or LINEAR_RGBjava.lang.NullPointerException
- if one of the points is nulljava.lang.IllegalArgumentException
- if start and end points are the
same points, or if fractions.length != colors.length, or if colors
is less than 2 in size.public LinearGradientPaint(java.awt.geom.Point2D start, java.awt.geom.Point2D end, float[] fractions, java.awt.Color[] colors, MultipleGradientPaint.CycleMethodEnum cycleMethod, MultipleGradientPaint.ColorSpaceEnum colorSpace, java.awt.geom.AffineTransform gradientTransform)
Constructs a LinearGradientPaint
.
start
- the gradient axis start Point
in user spaceend
- the gradient axis end Point
in user spacefractions
- numbers ranging from 0.0 to 1.0 specifying the
distribution of colors along the gradientcolors
- array of colors corresponding to each fractional valuecycleMethod
- either NO_CYCLE, REFLECT, or REPEATcolorSpace
- which colorspace to use for interpolation,
either SRGB or LINEAR_RGBgradientTransform
- transform to apply to the gradientjava.lang.NullPointerException
- if one of the points is null,
or gradientTransform is nulljava.lang.IllegalArgumentException
- if start and end points are the
same points, or if fractions.length != colors.length, or if colors
is less than 2 in size.public java.awt.PaintContext createContext(java.awt.image.ColorModel cm, java.awt.Rectangle deviceBounds, java.awt.geom.Rectangle2D userBounds, java.awt.geom.AffineTransform transform, java.awt.RenderingHints hints)
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 rendereduserBounds
- the user space bounding box of the
graphics primitive being renderedtransform
- the AffineTransform
from user
space into device spacehints
- the hints that the context object uses to choose
between rendering alternativesPaintContext
that generates color patterns.PaintContext
public java.awt.geom.Point2D getStartPoint()
Point2D
object that is a copy of the point
that anchors the first color of this
LinearGradientPaint
.public java.awt.geom.Point2D getEndPoint()
Point2D
object that is a copy of the point
that anchors the last color of this
LinearGradientPaint
.Copyright © 2022 Apache Software Foundation. All Rights Reserved.