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Class java.awt.LinearGradientPaint
Inherited members: ShowHide
Deprecated: ShowHide
View: ClientSubclassPackageImplementation
java.awt

Class LinearGradientPaint

  • java.lang.Object
    • java.awt.MultipleGradientPaint
      • java.awt.LinearGradientPaint
  • All Implemented Interfaces:
    Paint, Transparency
    public final class LinearGradientPaint extends MultipleGradientPaint
    The 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:

    Since:
    1.6
    See Also:
    Paint, Graphics2D.setPaint(java.awt.Paint)
    • Nested Classes 
      Modifier and Type Class and Description
      Inherited member indicator ColorSpaceType Reveal DetailHide Detail
      static class ColorSpaceType
      The color space in which to perform the gradient interpolation.
      static class ColorSpaceType
      The color space in which to perform the gradient interpolation.
      Since:
      1.6
      Inherited member indicator CycleMethod Reveal DetailHide Detail
      static class CycleMethod
      The method to use when painting outside the gradient bounds.
      static class CycleMethod
      The method to use when painting outside the gradient bounds.
      Since:
      1.6
    • Fields 
      Modifier and Type Field and Description
      Inherited member indicator BITMASK Reveal DetailHide Detail
      static int BITMASK
      Represents image data that is guaranteed to be either completely opaque, with an alpha value of 1.0, or completely transparent, with an alpha value of 0.0.
      public static final int BITMASK
      Represents image data that is guaranteed to be either completely opaque, with an alpha value of 1.0, or completely transparent, with an alpha value of 0.0.
      See Also:
      Constant Field Values
      Inherited member indicator OPAQUE Reveal DetailHide Detail
      static int OPAQUE
      Represents image data that is guaranteed to be completely opaque, meaning that all pixels have an alpha value of 1.0.
      public static final int OPAQUE
      Represents image data that is guaranteed to be completely opaque, meaning that all pixels have an alpha value of 1.0.
      See Also:
      Constant Field Values
      Inherited member indicator TRANSLUCENT Reveal DetailHide Detail
      static int TRANSLUCENT
      Represents image data that contains or might contain arbitrary alpha values between and including 0.0 and 1.0.
      public static final int TRANSLUCENT
      Represents image data that contains or might contain arbitrary alpha values between and including 0.0 and 1.0.
      See Also:
      Constant Field Values
    • Constructors 
      Constructor and Description
      Ordinary member indicator LinearGradientPaint Reveal DetailHide Detail
      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.
      public 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.
      Parameters:
      startX - the X coordinate of the gradient axis start point in user space
      startY - the Y coordinate of the gradient axis start point in user space
      endX - the X coordinate of the gradient axis end point in user space
      endY - the Y coordinate of the gradient axis end point in user space
      fractions - numbers ranging from 0.0 to 1.0 specifying the distribution of colors along the gradient
      colors - array of colors corresponding to each fractional value
      Throws:
      java.lang.NullPointerException - if fractions array is null, or colors array is null,
      java.lang.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 order
      Ordinary member indicator LinearGradientPaint Reveal DetailHide Detail
      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.
      public 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.
      Parameters:
      startX - the X coordinate of the gradient axis start point in user space
      startY - the Y coordinate of the gradient axis start point in user space
      endX - the X coordinate of the gradient axis end point in user space
      endY - the Y coordinate of the gradient axis end point in user space
      fractions - numbers ranging from 0.0 to 1.0 specifying the distribution of colors along the gradient
      colors - array of colors corresponding to each fractional value
      cycleMethod - either NO_CYCLE, REFLECT, or REPEAT
      Throws:
      java.lang.NullPointerException - if fractions array is null, or colors array is null, or cycleMethod is null
      java.lang.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 order
      Ordinary member indicator LinearGradientPaint Reveal DetailHide Detail
      LinearGradientPaint(java.awt.geom.Point2D start, java.awt.geom.Point2D end, float[] fractions, Color[] colors)
      Constructs a LinearGradientPaint with a default NO_CYCLE repeating method and SRGB color space.
      public LinearGradientPaint(java.awt.geom.Point2D start, java.awt.geom.Point2D end, float[] fractions, Color[] colors)
      Constructs a LinearGradientPaint with a default NO_CYCLE repeating method and SRGB color space.
      Parameters:
      start - the gradient axis start Point2D in user space
      end - the gradient axis end Point2D in user space
      fractions - numbers ranging from 0.0 to 1.0 specifying the distribution of colors along the gradient
      colors - array of colors corresponding to each fractional value
      Throws:
      java.lang.NullPointerException - if one of the points is null, or fractions array is null, or colors array is null
      java.lang.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 order
      Ordinary member indicator LinearGradientPaint Reveal DetailHide Detail
      LinearGradientPaint(java.awt.geom.Point2D start, java.awt.geom.Point2D end, float[] fractions, Color[] colors, MultipleGradientPaint.CycleMethod cycleMethod)
      Constructs a LinearGradientPaint with a default SRGB color space.
      public LinearGradientPaint(java.awt.geom.Point2D start, java.awt.geom.Point2D end, float[] fractions, Color[] colors, MultipleGradientPaint.CycleMethod cycleMethod)
      Constructs a LinearGradientPaint with a default SRGB color space.
      Parameters:
      start - the gradient axis start Point2D in user space
      end - the gradient axis end Point2D in user space
      fractions - numbers ranging from 0.0 to 1.0 specifying the distribution of colors along the gradient
      colors - array of colors corresponding to each fractional value
      cycleMethod - either NO_CYCLE, REFLECT, or REPEAT
      Throws:
      java.lang.NullPointerException - if one of the points is null, or fractions array is null, or colors array is null, or cycleMethod is null
      java.lang.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 order
      Ordinary member indicator LinearGradientPaint Reveal DetailHide Detail
      LinearGradientPaint(java.awt.geom.Point2D start, java.awt.geom.Point2D end, float[] fractions, Color[] colors, MultipleGradientPaint.CycleMethod cycleMethod, MultipleGradientPaint.ColorSpaceType colorSpace, java.awt.geom.AffineTransform gradientTransform)
      Constructs a LinearGradientPaint.
      @ConstructorProperties(value={"startPoint","endPoint","fractions","colors","cycleMethod","colorSpace","transform"}) public LinearGradientPaint(java.awt.geom.Point2D start, java.awt.geom.Point2D end, float[] fractions, Color[] colors, MultipleGradientPaint.CycleMethod cycleMethod, MultipleGradientPaint.ColorSpaceType colorSpace, java.awt.geom.AffineTransform gradientTransform)
      Constructs a LinearGradientPaint.
      Parameters:
      start - the gradient axis start Point2D in user space
      end - the gradient axis end Point2D in user space
      fractions - numbers ranging from 0.0 to 1.0 specifying the distribution of colors along the gradient
      colors - array of colors corresponding to each fractional value
      cycleMethod - either NO_CYCLE, REFLECT, or REPEAT
      colorSpace - which color space to use for interpolation, either SRGB or LINEAR_RGB
      gradientTransform - transform to apply to the gradient
      Throws:
      java.lang.NullPointerException - 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 null
      java.lang.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 order
    • Methods 
      Modifier and Type Method and Description
      Ordinary member indicator createContext Reveal DetailHide Detail
      PaintContext createContext(java.awt.image.ColorModel cm, Rectangle deviceBounds, java.awt.geom.Rectangle2D userBounds, java.awt.geom.AffineTransform transform, RenderingHints hints)
      Creates and returns a PaintContext used to generate a linear color gradient pattern.
      public PaintContext createContext(java.awt.image.ColorModel cm, Rectangle deviceBounds, java.awt.geom.Rectangle2D userBounds, java.awt.geom.AffineTransform transform, RenderingHints hints)
      Creates and returns a 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.
      Parameters:
      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.
      Returns:
      the PaintContext for generating color patterns.
      See Also:
      Paint, PaintContext, ColorModel, Rectangle, Rectangle2D, AffineTransform, RenderingHints
      Inherited member indicator getColors Reveal DetailHide Detail
      Color[] getColors()
      Returns a copy of the array of colors used by this gradient.
      public final Color[] getColors()
      Description copied from class: MultipleGradientPaint
      Returns a copy of the array of colors used by this gradient. The first color maps to the first value in the fractions array, and the last color maps to the last value in the fractions array.
      Returns:
      a copy of the array of colors used by this gradient
      Inherited member indicator getColorSpace Reveal DetailHide Detail
      MultipleGradientPaint.ColorSpaceType getColorSpace()
      Returns the enumerated type which specifies color space for interpolation.
      public final MultipleGradientPaint.ColorSpaceType getColorSpace()
      Description copied from class: MultipleGradientPaint
      Returns the enumerated type which specifies color space for interpolation.
      Returns:
      the enumerated type which specifies color space for interpolation
      Inherited member indicator getCycleMethod Reveal DetailHide Detail
      MultipleGradientPaint.CycleMethod getCycleMethod()
      Returns the enumerated type which specifies cycling behavior.
      public final MultipleGradientPaint.CycleMethod getCycleMethod()
      Description copied from class: MultipleGradientPaint
      Returns the enumerated type which specifies cycling behavior.
      Returns:
      the enumerated type which specifies cycling behavior
      Ordinary member indicator getEndPoint Reveal DetailHide Detail
      java.awt.geom.Point2D getEndPoint()
      Returns a copy of the end point of the gradient axis.
      public java.awt.geom.Point2D getEndPoint()
      Returns a copy of the end point of the gradient axis.
      Returns:
      a Point2D object that is a copy of the point that anchors the last color of this LinearGradientPaint
      Inherited member indicator getFractions Reveal DetailHide Detail
      float[] getFractions()
      Returns a copy of the array of floats used by this gradient to calculate color distribution.
      public final float[] getFractions()
      Description copied from class: MultipleGradientPaint
      Returns a copy of the array of floats used by this gradient to calculate color distribution. The returned array always has 0 as its first value and 1 as its last value, with increasing values in between.
      Returns:
      a copy of the array of floats used by this gradient to calculate color distribution
      Ordinary member indicator getStartPoint Reveal DetailHide Detail
      java.awt.geom.Point2D getStartPoint()
      Returns a copy of the start point of the gradient axis.
      public java.awt.geom.Point2D getStartPoint()
      Returns a copy of the start point of the gradient axis.
      Returns:
      a Point2D object that is a copy of the point that anchors the first color of this LinearGradientPaint
      Inherited member indicator getTransform Reveal DetailHide Detail
      java.awt.geom.AffineTransform getTransform()
      Returns a copy of the transform applied to the gradient.
      public final java.awt.geom.AffineTransform getTransform()
      Description copied from class: MultipleGradientPaint
      Returns a copy of the transform applied to the gradient.

      Note that if no transform is applied to the gradient when it is created, the identity transform is used.

      Returns:
      a copy of the transform applied to the gradient
      Inherited member indicator getTransparency Reveal DetailHide Detail
      int getTransparency()
      Returns the transparency mode for this Paint object.
      public final int getTransparency()
      Description copied from class: MultipleGradientPaint
      Returns the transparency mode for this Paint object.
      Specified by:
      getTransparency in interface Transparency
      Returns:
      OPAQUE if all colors used by this Paint object are opaque, TRANSLUCENT if at least one of the colors used by this Paint object is not opaque.
      See Also:
      Transparency
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
This document was created by Dulcet from the OpenJDK sources. Copyright © 1993, 2012 Oracle and/or its affiliates. All rights reserved.

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