LinearGradientPaint

Class Overview

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}
 

     {Color.BLUE, Color.BLUE, Color.RED, Color.RED}, {0f, .3f, .7f, 1f}
 

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, 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:

Summary

[Expand] Inherited Constants

From interface java.awt.Transparency 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. int OPAQUE Represents image data that is guaranteed to be completely opaque, meaning that all pixels have an alpha value of 1.0. int TRANSLUCENT Represents image data that contains or might contain arbitrary alpha values between and including 0.0 and 1.0.

[Expand] Inherited Methods
From class java.awt.MultipleGradientPaint final MultipleGradientPaint.ColorSpaceType getColorSpace() Returns the enumerated type which specifies color space for interpolation. final Color[] getColors() Returns a copy of the array of colors used by this gradient. final MultipleGradientPaint.CycleMethod getCycleMethod() Returns the enumerated type which specifies cycling behavior. final float[] getFractions() Returns a copy of the array of floats used by this gradient to calculate color distribution. final AffineTransform getTransform() Returns a copy of the transform applied to the gradient. final int getTransparency() Returns the transparency mode for this Paint object.
From class java.lang.Object Object clone() Creates and returns a copy of this object. boolean equals(Object obj) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait() Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object. final void wait(long timeout, int nanos) Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed. final void wait(long timeout) Causes the current thread to wait until either another thread invokes the notify() method or the notifyAll() method for this object, or a specified amount of time has elapsed.
From interface java.awt.Paint abstract PaintContext createContext(ColorModel cm, Rectangle deviceBounds, Rectangle2D userBounds, AffineTransform xform, RenderingHints hints) Creates and returns a PaintContext used to generate the color pattern.
From interface java.awt.Transparency abstract int getTransparency() Returns the type of this Transparency.