0N/A/*
3909N/A * Copyright (c) 2006, 2011, Oracle and/or its affiliates. All rights reserved.
0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
0N/A *
0N/A * This code is free software; you can redistribute it and/or modify it
0N/A * under the terms of the GNU General Public License version 2 only, as
2362N/A * published by the Free Software Foundation. Oracle designates this
0N/A * particular file as subject to the "Classpath" exception as provided
2362N/A * by Oracle in the LICENSE file that accompanied this code.
0N/A *
0N/A * This code is distributed in the hope that it will be useful, but WITHOUT
0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
0N/A * version 2 for more details (a copy is included in the LICENSE file that
0N/A * accompanied this code).
0N/A *
0N/A * You should have received a copy of the GNU General Public License version
0N/A * 2 along with this work; if not, write to the Free Software Foundation,
0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
0N/A *
2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
2362N/A * or visit www.oracle.com if you need additional information or have any
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0N/A */
0N/A
0N/Apackage java.awt;
0N/A
0N/Aimport java.awt.geom.AffineTransform;
0N/Aimport java.awt.geom.Point2D;
0N/Aimport java.awt.geom.Rectangle2D;
0N/Aimport java.awt.image.ColorModel;
2965N/Aimport java.beans.ConstructorProperties;
0N/A
0N/A/**
0N/A * The {@code LinearGradientPaint} class provides a way to fill
0N/A * a {@link java.awt.Shape} with a linear color gradient pattern. The user
0N/A * may specify two or more gradient colors, and this paint will provide an
0N/A * interpolation between each color. The user also specifies start and end
0N/A * points which define where in user space the color gradient should begin
0N/A * and end.
0N/A * <p>
0N/A * The user must provide an array of floats specifying how to distribute the
0N/A * colors along the gradient. These values should range from 0.0 to 1.0 and
0N/A * act like keyframes along the gradient (they mark where the gradient should
0N/A * be exactly a particular color).
0N/A * <p>
0N/A * In the event that the user does not set the first keyframe value equal
0N/A * to 0 and/or the last keyframe value equal to 1, keyframes will be created
0N/A * at these positions and the first and last colors will be replicated there.
0N/A * So, if a user specifies the following arrays to construct a gradient:<br>
0N/A * <pre>
0N/A * {Color.BLUE, Color.RED}, {.3f, .7f}
0N/A * </pre>
0N/A * this will be converted to a gradient with the following keyframes:<br>
0N/A * <pre>
0N/A * {Color.BLUE, Color.BLUE, Color.RED, Color.RED}, {0f, .3f, .7f, 1f}
0N/A * </pre>
0N/A *
0N/A * <p>
3724N/A * The user may also select what action the {@code LinearGradientPaint} object
3724N/A * takes when it is filling the space outside the start and end points by
3724N/A * setting {@code CycleMethod} to either {@code REFLECTION} or {@code REPEAT}.
3724N/A * The distances between any two colors in any of the reflected or repeated
3724N/A * copies of the gradient are the same as the distance between those same two
3724N/A * colors between the start and end points.
3724N/A * Note that some minor variations in distances may occur due to sampling at
3724N/A * the granularity of a pixel.
0N/A * If no cycle method is specified, {@code NO_CYCLE} will be chosen by
0N/A * default, which means the endpoint colors will be used to fill the
0N/A * remaining area.
0N/A * <p>
0N/A * The colorSpace parameter allows the user to specify in which colorspace
0N/A * the interpolation should be performed, default sRGB or linearized RGB.
0N/A *
0N/A * <p>
0N/A * The following code demonstrates typical usage of
0N/A * {@code LinearGradientPaint}:
0N/A * <p>
0N/A * <pre>
0N/A * Point2D start = new Point2D.Float(0, 0);
0N/A * Point2D end = new Point2D.Float(50, 50);
0N/A * float[] dist = {0.0f, 0.2f, 1.0f};
0N/A * Color[] colors = {Color.RED, Color.WHITE, Color.BLUE};
0N/A * LinearGradientPaint p =
0N/A * new LinearGradientPaint(start, end, dist, colors);
0N/A * </pre>
0N/A * <p>
0N/A * This code will create a {@code LinearGradientPaint} which interpolates
0N/A * between red and white for the first 20% of the gradient and between white
0N/A * and blue for the remaining 80%.
0N/A *
0N/A * <p>
0N/A * This image demonstrates the example code above for each
0N/A * of the three cycle methods:
0N/A * <p>
0N/A * <center>
0N/A * <img src = "doc-files/LinearGradientPaint.png">
0N/A * </center>
0N/A *
0N/A * @see java.awt.Paint
0N/A * @see java.awt.Graphics2D#setPaint
0N/A * @author Nicholas Talian, Vincent Hardy, Jim Graham, Jerry Evans
0N/A * @since 1.6
0N/A */
0N/Apublic final class LinearGradientPaint extends MultipleGradientPaint {
0N/A
0N/A /** Gradient start and end points. */
0N/A private final Point2D start, end;
0N/A
0N/A /**
0N/A * Constructs a {@code LinearGradientPaint} with a default
0N/A * {@code NO_CYCLE} repeating method and {@code SRGB} color space.
0N/A *
0N/A * @param startX the X coordinate of the gradient axis start point
0N/A * in user space
0N/A * @param startY the Y coordinate of the gradient axis start point
0N/A * in user space
0N/A * @param endX the X coordinate of the gradient axis end point
0N/A * in user space
0N/A * @param endY the Y coordinate of the gradient axis end point
0N/A * in user space
0N/A * @param fractions numbers ranging from 0.0 to 1.0 specifying the
0N/A * distribution of colors along the gradient
0N/A * @param colors array of colors corresponding to each fractional value
0N/A *
0N/A * @throws NullPointerException
0N/A * if {@code fractions} array is null,
0N/A * or {@code colors} array is null,
0N/A * @throws IllegalArgumentException
0N/A * if start and end points are the same points,
0N/A * or {@code fractions.length != colors.length},
0N/A * or {@code colors} is less than 2 in size,
0N/A * or a {@code fractions} value is less than 0.0 or greater than 1.0,
0N/A * or the {@code fractions} are not provided in strictly increasing order
0N/A */
0N/A public LinearGradientPaint(float startX, float startY,
0N/A float endX, float endY,
0N/A float[] fractions, Color[] colors)
0N/A {
0N/A this(new Point2D.Float(startX, startY),
0N/A new Point2D.Float(endX, endY),
0N/A fractions,
0N/A colors,
0N/A CycleMethod.NO_CYCLE);
0N/A }
0N/A
0N/A /**
0N/A * Constructs a {@code LinearGradientPaint} with a default {@code SRGB}
0N/A * color space.
0N/A *
0N/A * @param startX the X coordinate of the gradient axis start point
0N/A * in user space
0N/A * @param startY the Y coordinate of the gradient axis start point
0N/A * in user space
0N/A * @param endX the X coordinate of the gradient axis end point
0N/A * in user space
0N/A * @param endY the Y coordinate of the gradient axis end point
0N/A * in user space
0N/A * @param fractions numbers ranging from 0.0 to 1.0 specifying the
0N/A * distribution of colors along the gradient
0N/A * @param colors array of colors corresponding to each fractional value
0N/A * @param cycleMethod either {@code NO_CYCLE}, {@code REFLECT},
0N/A * or {@code REPEAT}
0N/A *
0N/A * @throws NullPointerException
0N/A * if {@code fractions} array is null,
0N/A * or {@code colors} array is null,
0N/A * or {@code cycleMethod} is null
0N/A * @throws IllegalArgumentException
0N/A * if start and end points are the same points,
0N/A * or {@code fractions.length != colors.length},
0N/A * or {@code colors} is less than 2 in size,
0N/A * or a {@code fractions} value is less than 0.0 or greater than 1.0,
0N/A * or the {@code fractions} are not provided in strictly increasing order
0N/A */
0N/A public LinearGradientPaint(float startX, float startY,
0N/A float endX, float endY,
0N/A float[] fractions, Color[] colors,
0N/A CycleMethod cycleMethod)
0N/A {
0N/A this(new Point2D.Float(startX, startY),
0N/A new Point2D.Float(endX, endY),
0N/A fractions,
0N/A colors,
0N/A cycleMethod);
0N/A }
0N/A
0N/A /**
0N/A * Constructs a {@code LinearGradientPaint} with a default
0N/A * {@code NO_CYCLE} repeating method and {@code SRGB} color space.
0N/A *
0N/A * @param start the gradient axis start {@code Point2D} in user space
0N/A * @param end the gradient axis end {@code Point2D} in user space
0N/A * @param fractions numbers ranging from 0.0 to 1.0 specifying the
0N/A * distribution of colors along the gradient
0N/A * @param colors array of colors corresponding to each fractional value
0N/A *
0N/A * @throws NullPointerException
0N/A * if one of the points is null,
0N/A * or {@code fractions} array is null,
0N/A * or {@code colors} array is null
0N/A * @throws IllegalArgumentException
0N/A * if start and end points are the same points,
0N/A * or {@code fractions.length != colors.length},
0N/A * or {@code colors} is less than 2 in size,
0N/A * or a {@code fractions} value is less than 0.0 or greater than 1.0,
0N/A * or the {@code fractions} are not provided in strictly increasing order
0N/A */
0N/A public LinearGradientPaint(Point2D start, Point2D end,
0N/A float[] fractions, Color[] colors)
0N/A {
0N/A this(start, end,
0N/A fractions, colors,
0N/A CycleMethod.NO_CYCLE);
0N/A }
0N/A
0N/A /**
0N/A * Constructs a {@code LinearGradientPaint} with a default {@code SRGB}
0N/A * color space.
0N/A *
0N/A * @param start the gradient axis start {@code Point2D} in user space
0N/A * @param end the gradient axis end {@code Point2D} in user space
0N/A * @param fractions numbers ranging from 0.0 to 1.0 specifying the
0N/A * distribution of colors along the gradient
0N/A * @param colors array of colors corresponding to each fractional value
0N/A * @param cycleMethod either {@code NO_CYCLE}, {@code REFLECT},
0N/A * or {@code REPEAT}
0N/A *
0N/A * @throws NullPointerException
0N/A * if one of the points is null,
0N/A * or {@code fractions} array is null,
0N/A * or {@code colors} array is null,
0N/A * or {@code cycleMethod} is null
0N/A * @throws IllegalArgumentException
0N/A * if start and end points are the same points,
0N/A * or {@code fractions.length != colors.length},
0N/A * or {@code colors} is less than 2 in size,
0N/A * or a {@code fractions} value is less than 0.0 or greater than 1.0,
0N/A * or the {@code fractions} are not provided in strictly increasing order
0N/A */
0N/A public LinearGradientPaint(Point2D start, Point2D end,
0N/A float[] fractions, Color[] colors,
0N/A CycleMethod cycleMethod)
0N/A {
0N/A this(start, end,
0N/A fractions, colors,
0N/A cycleMethod,
0N/A ColorSpaceType.SRGB,
0N/A new AffineTransform());
0N/A }
0N/A
0N/A /**
0N/A * Constructs a {@code LinearGradientPaint}.
0N/A *
0N/A * @param start the gradient axis start {@code Point2D} in user space
0N/A * @param end the gradient axis end {@code Point2D} in user space
0N/A * @param fractions numbers ranging from 0.0 to 1.0 specifying the
0N/A * distribution of colors along the gradient
0N/A * @param colors array of colors corresponding to each fractional value
0N/A * @param cycleMethod either {@code NO_CYCLE}, {@code REFLECT},
0N/A * or {@code REPEAT}
0N/A * @param colorSpace which color space to use for interpolation,
0N/A * either {@code SRGB} or {@code LINEAR_RGB}
0N/A * @param gradientTransform transform to apply to the gradient
0N/A *
0N/A * @throws NullPointerException
0N/A * if one of the points is null,
0N/A * or {@code fractions} array is null,
0N/A * or {@code colors} array is null,
0N/A * or {@code cycleMethod} is null,
0N/A * or {@code colorSpace} is null,
0N/A * or {@code gradientTransform} is null
0N/A * @throws IllegalArgumentException
0N/A * if start and end points are the same points,
0N/A * or {@code fractions.length != colors.length},
0N/A * or {@code colors} is less than 2 in size,
0N/A * or a {@code fractions} value is less than 0.0 or greater than 1.0,
0N/A * or the {@code fractions} are not provided in strictly increasing order
0N/A */
2965N/A @ConstructorProperties({ "startPoint", "endPoint", "fractions", "colors", "cycleMethod", "colorSpace", "transform" })
0N/A public LinearGradientPaint(Point2D start, Point2D end,
0N/A float[] fractions, Color[] colors,
0N/A CycleMethod cycleMethod,
0N/A ColorSpaceType colorSpace,
0N/A AffineTransform gradientTransform)
0N/A {
0N/A super(fractions, colors, cycleMethod, colorSpace, gradientTransform);
0N/A
0N/A // check input parameters
0N/A if (start == null || end == null) {
0N/A throw new NullPointerException("Start and end points must be" +
0N/A "non-null");
0N/A }
0N/A
0N/A if (start.equals(end)) {
0N/A throw new IllegalArgumentException("Start point cannot equal" +
0N/A "endpoint");
0N/A }
0N/A
0N/A // copy the points...
0N/A this.start = new Point2D.Double(start.getX(), start.getY());
0N/A this.end = new Point2D.Double(end.getX(), end.getY());
0N/A }
0N/A
0N/A /**
213N/A * Creates and returns a {@link PaintContext} used to
213N/A * generate a linear color gradient pattern.
213N/A * See the {@link Paint#createContext specification} of the
213N/A * method in the {@link Paint} interface for information
213N/A * on null parameter handling.
213N/A *
213N/A * @param cm the preferred {@link ColorModel} which represents the most convenient
213N/A * format for the caller to receive the pixel data, or {@code null}
213N/A * if there is no preference.
213N/A * @param deviceBounds the device space bounding box
213N/A * of the graphics primitive being rendered.
213N/A * @param userBounds the user space bounding box
213N/A * of the graphics primitive being rendered.
213N/A * @param transform the {@link AffineTransform} from user
213N/A * space into device space.
213N/A * @param hints the set of hints that the context object can use to
213N/A * choose between rendering alternatives.
213N/A * @return the {@code PaintContext} for
213N/A * generating color patterns.
213N/A * @see Paint
213N/A * @see PaintContext
213N/A * @see ColorModel
213N/A * @see Rectangle
213N/A * @see Rectangle2D
213N/A * @see AffineTransform
213N/A * @see RenderingHints
0N/A */
0N/A public PaintContext createContext(ColorModel cm,
0N/A Rectangle deviceBounds,
0N/A Rectangle2D userBounds,
0N/A AffineTransform transform,
0N/A RenderingHints hints)
0N/A {
0N/A // avoid modifying the user's transform...
0N/A transform = new AffineTransform(transform);
0N/A // incorporate the gradient transform
0N/A transform.concatenate(gradientTransform);
0N/A
0N/A if ((fractions.length == 2) &&
0N/A (cycleMethod != CycleMethod.REPEAT) &&
0N/A (colorSpace == ColorSpaceType.SRGB))
0N/A {
0N/A // faster to use the basic GradientPaintContext for this
0N/A // common case
0N/A boolean cyclic = (cycleMethod != CycleMethod.NO_CYCLE);
0N/A return new GradientPaintContext(cm, start, end,
0N/A transform,
0N/A colors[0], colors[1],
0N/A cyclic);
0N/A } else {
0N/A return new LinearGradientPaintContext(this, cm,
0N/A deviceBounds, userBounds,
0N/A transform, hints,
0N/A start, end,
0N/A fractions, colors,
0N/A cycleMethod, colorSpace);
0N/A }
0N/A }
0N/A
0N/A /**
0N/A * Returns a copy of the start point of the gradient axis.
0N/A *
0N/A * @return a {@code Point2D} object that is a copy of the point
0N/A * that anchors the first color of this {@code LinearGradientPaint}
0N/A */
0N/A public Point2D getStartPoint() {
0N/A return new Point2D.Double(start.getX(), start.getY());
0N/A }
0N/A
0N/A /**
0N/A * Returns a copy of the end point of the gradient axis.
0N/A *
0N/A * @return a {@code Point2D} object that is a copy of the point
0N/A * that anchors the last color of this {@code LinearGradientPaint}
0N/A */
0N/A public Point2D getEndPoint() {
0N/A return new Point2D.Double(end.getX(), end.getY());
0N/A }
0N/A}