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 two 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).
In the event that the user does not set the first keyframe value equal
to 0 and/or 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}, {.3f, .7f}
this will be converted to a gradient with the following keyframes:
{Color.BLUE, Color.BLUE, Color.RED, Color.RED}, {0f, .3f, .7f, 1f}
The user may also select what action the LinearGradientPaint object
takes when it is filling the space outside the start and end points by
setting CycleMethod to either REFLECTION or REPEAT.
The distances between any two colors in any of the reflected or repeated
copies of the gradient are the same as the distance between those same two
colors between the start and end points.
Note that some minor variations in distances may occur due to sampling at
the granularity of a pixel.
If no cycle method is specified, NO_CYCLE will be chosen by
default, which means the endpoint colors will be used to fill the
remaining area.
The colorSpace parameter allows the user to specify in which colorspace the interpolation should be performed, default sRGB or linearized RGB.
The following code demonstrates typical usage of
LinearGradientPaint:
Point2D start = new Point2D.Float(0, 0);
Point2D end = new Point2D.Float(50, 50);
float[] dist = {0.0f, 0.2f, 1.0f};
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%.
This image demonstrates the example code above for each of the three cycle methods:
Paint,
Graphics2D.setPaint(java.awt.Paint)MultipleGradientPaint.ColorSpaceType, MultipleGradientPaint.CycleMethodBITMASK, OPAQUE, TRANSLUCENT| Constructor and Description |
|---|
LinearGradientPaint(float startX,
float startY,
float endX,
float endY,
float[] fractions,
Color[] colors)
Constructs a
LinearGradientPaint with a default
NO_CYCLE repeating method and SRGB color space. |
LinearGradientPaint(float startX,
float startY,
float endX,
float endY,
float[] fractions,
Color[] colors,
MultipleGradientPaint.CycleMethod cycleMethod)
Constructs a
LinearGradientPaint with a default SRGB
color space. |
LinearGradientPaint(Point2D start,
Point2D end,
float[] fractions,
Color[] colors)
Constructs a
LinearGradientPaint with a default
NO_CYCLE repeating method and SRGB color space. |
LinearGradientPaint(Point2D start,
Point2D end,
float[] fractions,
Color[] colors,
MultipleGradientPaint.CycleMethod cycleMethod)
Constructs a
LinearGradientPaint with a default SRGB
color space. |
LinearGradientPaint(Point2D start,
Point2D end,
float[] fractions,
Color[] colors,
MultipleGradientPaint.CycleMethod cycleMethod,
MultipleGradientPaint.ColorSpaceType colorSpace,
AffineTransform gradientTransform)
Constructs a
LinearGradientPaint. |
| Modifier and Type | Method and Description |
|---|---|
PaintContext |
createContext(ColorModel cm,
Rectangle deviceBounds,
Rectangle2D userBounds,
AffineTransform transform,
RenderingHints hints)
Creates and returns a
PaintContext used to
generate a linear color gradient pattern. |
Point2D |
getEndPoint()
Returns a copy of the end point of the gradient axis.
|
Point2D |
getStartPoint()
Returns a copy of the start point of the gradient axis.
|
getColors, getColorSpace, getCycleMethod, getFractions, getTransform, getTransparencypublic LinearGradientPaint(float startX,
float startY,
float endX,
float endY,
float[] fractions,
Color[] colors)
LinearGradientPaint with a default
NO_CYCLE repeating method and SRGB color space.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 valueNullPointerException - if fractions array is null,
or colors array is null,IllegalArgumentException - if start and end points are the same points,
or fractions.length != colors.length,
or colors is less than 2 in size,
or a fractions value is less than 0.0 or greater than 1.0,
or the fractions are not provided in strictly increasing orderpublic LinearGradientPaint(float startX,
float startY,
float endX,
float endY,
float[] fractions,
Color[] colors,
MultipleGradientPaint.CycleMethod cycleMethod)
LinearGradientPaint with a default SRGB
color space.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 REPEATNullPointerException - if fractions array is null,
or colors array is null,
or cycleMethod is nullIllegalArgumentException - if start and end points are the same points,
or fractions.length != colors.length,
or colors is less than 2 in size,
or a fractions value is less than 0.0 or greater than 1.0,
or the fractions are not provided in strictly increasing orderpublic LinearGradientPaint(Point2D start, Point2D end, float[] fractions, Color[] colors)
LinearGradientPaint with a default
NO_CYCLE repeating method and SRGB color space.start - the gradient axis start Point2D in user spaceend - the gradient axis end Point2D 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 valueNullPointerException - if one of the points is null,
or fractions array is null,
or colors array is nullIllegalArgumentException - if start and end points are the same points,
or fractions.length != colors.length,
or colors is less than 2 in size,
or a fractions value is less than 0.0 or greater than 1.0,
or the fractions are not provided in strictly increasing orderpublic LinearGradientPaint(Point2D start, Point2D end, float[] fractions, Color[] colors, MultipleGradientPaint.CycleMethod cycleMethod)
LinearGradientPaint with a default SRGB
color space.start - the gradient axis start Point2D in user spaceend - the gradient axis end Point2D 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 REPEATNullPointerException - if one of the points is null,
or fractions array is null,
or colors array is null,
or cycleMethod is nullIllegalArgumentException - if start and end points are the same points,
or fractions.length != colors.length,
or colors is less than 2 in size,
or a fractions value is less than 0.0 or greater than 1.0,
or the fractions are not provided in strictly increasing order@ConstructorProperties(value={"startPoint","endPoint","fractions","colors","cycleMethod","colorSpace","transform"}) public LinearGradientPaint(Point2D start, Point2D end, float[] fractions, Color[] colors, MultipleGradientPaint.CycleMethod cycleMethod, MultipleGradientPaint.ColorSpaceType colorSpace, AffineTransform gradientTransform)
LinearGradientPaint.start - the gradient axis start Point2D in user spaceend - the gradient axis end Point2D 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 color space to use for interpolation,
either SRGB or LINEAR_RGBgradientTransform - transform to apply to the gradientNullPointerException - if one of the points is null,
or fractions array is null,
or colors array is null,
or cycleMethod is null,
or colorSpace is null,
or gradientTransform is nullIllegalArgumentException - if start and end points are the same points,
or fractions.length != colors.length,
or colors is less than 2 in size,
or a fractions value is less than 0.0 or greater than 1.0,
or the fractions are not provided in strictly increasing orderpublic PaintContext createContext(ColorModel cm, Rectangle deviceBounds, Rectangle2D userBounds, AffineTransform transform, RenderingHints hints)
PaintContext used to
generate a linear color gradient pattern.
See the specification of the
method in the Paint interface for information
on null parameter handling.cm - the preferred ColorModel which represents the most convenient
format for the caller to receive the pixel data, or null
if there is no preference.deviceBounds - the device space bounding box
of the graphics primitive being rendered.userBounds - the user space bounding box
of the graphics primitive being rendered.transform - the AffineTransform from user
space into device space.hints - the set of hints that the context object can use to
choose between rendering alternatives.PaintContext for
generating color patterns.Paint,
PaintContext,
ColorModel,
Rectangle,
Rectangle2D,
AffineTransform,
RenderingHintspublic Point2D getStartPoint()
Point2D object that is a copy of the point
that anchors the first color of this LinearGradientPaintpublic Point2D getEndPoint()
Point2D object that is a copy of the point
that anchors the last color of this LinearGradientPaint Submit a bug or feature
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