| /* |
| * Copyright (c) 2006, 2008, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.awt; |
| |
| import java.awt.geom.AffineTransform; |
| import java.awt.geom.Point2D; |
| import java.awt.geom.Rectangle2D; |
| import java.awt.image.ColorModel; |
| |
| /** |
| * The {@code RadialGradientPaint} class provides a way to fill a shape with |
| * a circular radial color gradient pattern. The user may specify 2 or more |
| * gradient colors, and this paint will provide an interpolation between |
| * each color. |
| * <p> |
| * The user must specify the circle controlling the gradient pattern, |
| * which is described by a center point and a radius. The user can also |
| * specify a separate focus point within that circle, which controls the |
| * location of the first color of the gradient. By default the focus is |
| * set to be the center of the circle. |
| * <p> |
| * This paint will map the first color of the gradient to the focus point, |
| * and the last color to the perimeter of the circle, interpolating |
| * smoothly for any in-between colors specified by the user. Any line drawn |
| * from the focus point to the circumference will thus span all the gradient |
| * colors. |
| * <p> |
| * Specifying a focus point outside of the circle's radius will result in the |
| * focus being set to the intersection point of the focus-center line and the |
| * perimeter of the circle. |
| * <p> |
| * 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). |
| * <p> |
| * 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:<br> |
| * <pre> |
| * {Color.BLUE, Color.RED}, {.3f, .7f} |
| * </pre> |
| * this will be converted to a gradient with the following keyframes:<br> |
| * <pre> |
| * {Color.BLUE, Color.BLUE, Color.RED, Color.RED}, {0f, .3f, .7f, 1f} |
| * </pre> |
| * |
| * <p> |
| * The user may also select what action the {@code RadialGradientPaint} |
| * should take when filling color outside the bounds of the circle's radius. |
| * If no cycle method is specified, {@code NO_CYCLE} will be chosen by |
| * default, which means the the last keyframe color will be used to fill the |
| * remaining area. |
| * <p> |
| * The colorSpace parameter allows the user to specify in which colorspace |
| * the interpolation should be performed, default sRGB or linearized RGB. |
| * |
| * <p> |
| * The following code demonstrates typical usage of |
| * {@code RadialGradientPaint}, where the center and focus points are |
| * the same: |
| * <p> |
| * <pre> |
| * Point2D center = new Point2D.Float(50, 50); |
| * float radius = 25; |
| * float[] dist = {0.0f, 0.2f, 1.0f}; |
| * Color[] colors = {Color.RED, Color.WHITE, Color.BLUE}; |
| * RadialGradientPaint p = |
| * new RadialGradientPaint(center, radius, dist, colors); |
| * </pre> |
| * |
| * <p> |
| * This image demonstrates the example code above, with default |
| * (centered) focus for each of the three cycle methods: |
| * <p> |
| * <center> |
| * <img src = "doc-files/RadialGradientPaint-1.png"> |
| * </center> |
| * |
| * <p> |
| * It is also possible to specify a non-centered focus point, as |
| * in the following code: |
| * <p> |
| * <pre> |
| * Point2D center = new Point2D.Float(50, 50); |
| * float radius = 25; |
| * Point2D focus = new Point2D.Float(40, 40); |
| * float[] dist = {0.0f, 0.2f, 1.0f}; |
| * Color[] colors = {Color.RED, Color.WHITE, Color.BLUE}; |
| * RadialGradientPaint p = |
| * new RadialGradientPaint(center, radius, focus, |
| * dist, colors, |
| * CycleMethod.NO_CYCLE); |
| * </pre> |
| * |
| * <p> |
| * This image demonstrates the previous example code, with non-centered |
| * focus for each of the three cycle methods: |
| * <p> |
| * <center> |
| * <img src = "doc-files/RadialGradientPaint-2.png"> |
| * </center> |
| * |
| * @see java.awt.Paint |
| * @see java.awt.Graphics2D#setPaint |
| * @author Nicholas Talian, Vincent Hardy, Jim Graham, Jerry Evans |
| * @since 1.6 |
| */ |
| public final class RadialGradientPaint extends MultipleGradientPaint { |
| |
| /** Focus point which defines the 0% gradient stop X coordinate. */ |
| private final Point2D focus; |
| |
| /** Center of the circle defining the 100% gradient stop X coordinate. */ |
| private final Point2D center; |
| |
| /** Radius of the outermost circle defining the 100% gradient stop. */ |
| private final float radius; |
| |
| /** |
| * Constructs a {@code RadialGradientPaint} with a default |
| * {@code NO_CYCLE} repeating method and {@code SRGB} color space, |
| * using the center as the focus point. |
| * |
| * @param cx the X coordinate in user space of the center point of the |
| * circle defining the gradient. The last color of the |
| * gradient is mapped to the perimeter of this circle. |
| * @param cy the Y coordinate in user space of the center point of the |
| * circle defining the gradient. The last color of the |
| * gradient is mapped to the perimeter of this circle. |
| * @param radius the radius of the circle defining the extents of the |
| * color gradient |
| * @param fractions numbers ranging from 0.0 to 1.0 specifying the |
| * distribution of colors along the gradient |
| * @param colors array of colors to use in the gradient. The first color |
| * is used at the focus point, the last color around the |
| * perimeter of the circle. |
| * |
| * @throws NullPointerException |
| * if {@code fractions} array is null, |
| * or {@code colors} array is null |
| * @throws IllegalArgumentException |
| * if {@code radius} is non-positive, |
| * or {@code fractions.length != colors.length}, |
| * or {@code colors} is less than 2 in size, |
| * or a {@code fractions} value is less than 0.0 or greater than 1.0, |
| * or the {@code fractions} are not provided in strictly increasing order |
| */ |
| public RadialGradientPaint(float cx, float cy, float radius, |
| float[] fractions, Color[] colors) |
| { |
| this(cx, cy, |
| radius, |
| cx, cy, |
| fractions, |
| colors, |
| CycleMethod.NO_CYCLE); |
| } |
| |
| /** |
| * Constructs a {@code RadialGradientPaint} with a default |
| * {@code NO_CYCLE} repeating method and {@code SRGB} color space, |
| * using the center as the focus point. |
| * |
| * @param center the center point, in user space, of the circle defining |
| * the gradient |
| * @param radius the radius of the circle defining the extents of the |
| * color gradient |
| * @param fractions numbers ranging from 0.0 to 1.0 specifying the |
| * distribution of colors along the gradient |
| * @param colors array of colors to use in the gradient. The first color |
| * is used at the focus point, the last color around the |
| * perimeter of the circle. |
| * |
| * @throws NullPointerException |
| * if {@code center} point is null, |
| * or {@code fractions} array is null, |
| * or {@code colors} array is null |
| * @throws IllegalArgumentException |
| * if {@code radius} is non-positive, |
| * or {@code fractions.length != colors.length}, |
| * or {@code colors} is less than 2 in size, |
| * or a {@code fractions} value is less than 0.0 or greater than 1.0, |
| * or the {@code fractions} are not provided in strictly increasing order |
| */ |
| public RadialGradientPaint(Point2D center, float radius, |
| float[] fractions, Color[] colors) |
| { |
| this(center, |
| radius, |
| center, |
| fractions, |
| colors, |
| CycleMethod.NO_CYCLE); |
| } |
| |
| /** |
| * Constructs a {@code RadialGradientPaint} with a default |
| * {@code SRGB} color space, using the center as the focus point. |
| * |
| * @param cx the X coordinate in user space of the center point of the |
| * circle defining the gradient. The last color of the |
| * gradient is mapped to the perimeter of this circle. |
| * @param cy the Y coordinate in user space of the center point of the |
| * circle defining the gradient. The last color of the |
| * gradient is mapped to the perimeter of this circle. |
| * @param radius the radius of the circle defining the extents of the |
| * color gradient |
| * @param fractions numbers ranging from 0.0 to 1.0 specifying the |
| * distribution of colors along the gradient |
| * @param colors array of colors to use in the gradient. The first color |
| * is used at the focus point, the last color around the |
| * perimeter of the circle. |
| * @param cycleMethod either {@code NO_CYCLE}, {@code REFLECT}, |
| * or {@code REPEAT} |
| * |
| * @throws NullPointerException |
| * if {@code fractions} array is null, |
| * or {@code colors} array is null, |
| * or {@code cycleMethod} is null |
| * @throws IllegalArgumentException |
| * if {@code radius} is non-positive, |
| * or {@code fractions.length != colors.length}, |
| * or {@code colors} is less than 2 in size, |
| * or a {@code fractions} value is less than 0.0 or greater than 1.0, |
| * or the {@code fractions} are not provided in strictly increasing order |
| */ |
| public RadialGradientPaint(float cx, float cy, float radius, |
| float[] fractions, Color[] colors, |
| CycleMethod cycleMethod) |
| { |
| this(cx, cy, |
| radius, |
| cx, cy, |
| fractions, |
| colors, |
| cycleMethod); |
| } |
| |
| /** |
| * Constructs a {@code RadialGradientPaint} with a default |
| * {@code SRGB} color space, using the center as the focus point. |
| * |
| * @param center the center point, in user space, of the circle defining |
| * the gradient |
| * @param radius the radius of the circle defining the extents of the |
| * color gradient |
| * @param fractions numbers ranging from 0.0 to 1.0 specifying the |
| * distribution of colors along the gradient |
| * @param colors array of colors to use in the gradient. The first color |
| * is used at the focus point, the last color around the |
| * perimeter of the circle. |
| * @param cycleMethod either {@code NO_CYCLE}, {@code REFLECT}, |
| * or {@code REPEAT} |
| * |
| * @throws NullPointerException |
| * if {@code center} point is null, |
| * or {@code fractions} array is null, |
| * or {@code colors} array is null, |
| * or {@code cycleMethod} is null |
| * @throws IllegalArgumentException |
| * if {@code radius} is non-positive, |
| * or {@code fractions.length != colors.length}, |
| * or {@code colors} is less than 2 in size, |
| * or a {@code fractions} value is less than 0.0 or greater than 1.0, |
| * or the {@code fractions} are not provided in strictly increasing order |
| */ |
| public RadialGradientPaint(Point2D center, float radius, |
| float[] fractions, Color[] colors, |
| CycleMethod cycleMethod) |
| { |
| this(center, |
| radius, |
| center, |
| fractions, |
| colors, |
| cycleMethod); |
| } |
| |
| /** |
| * Constructs a {@code RadialGradientPaint} with a default |
| * {@code SRGB} color space. |
| * |
| * @param cx the X coordinate in user space of the center point of the |
| * circle defining the gradient. The last color of the |
| * gradient is mapped to the perimeter of this circle. |
| * @param cy the Y coordinate in user space of the center point of the |
| * circle defining the gradient. The last color of the |
| * gradient is mapped to the perimeter of this circle. |
| * @param radius the radius of the circle defining the extents of the |
| * color gradient |
| * @param fx the X coordinate of the point in user space to which the |
| * first color is mapped |
| * @param fy the Y coordinate of the point in user space to which the |
| * first color is mapped |
| * @param fractions numbers ranging from 0.0 to 1.0 specifying the |
| * distribution of colors along the gradient |
| * @param colors array of colors to use in the gradient. The first color |
| * is used at the focus point, the last color around the |
| * perimeter of the circle. |
| * @param cycleMethod either {@code NO_CYCLE}, {@code REFLECT}, |
| * or {@code REPEAT} |
| * |
| * @throws NullPointerException |
| * if {@code fractions} array is null, |
| * or {@code colors} array is null, |
| * or {@code cycleMethod} is null |
| * @throws IllegalArgumentException |
| * if {@code radius} is non-positive, |
| * or {@code fractions.length != colors.length}, |
| * or {@code colors} is less than 2 in size, |
| * or a {@code fractions} value is less than 0.0 or greater than 1.0, |
| * or the {@code fractions} are not provided in strictly increasing order |
| */ |
| public RadialGradientPaint(float cx, float cy, float radius, |
| float fx, float fy, |
| float[] fractions, Color[] colors, |
| CycleMethod cycleMethod) |
| { |
| this(new Point2D.Float(cx, cy), |
| radius, |
| new Point2D.Float(fx, fy), |
| fractions, |
| colors, |
| cycleMethod); |
| } |
| |
| /** |
| * Constructs a {@code RadialGradientPaint} with a default |
| * {@code SRGB} color space. |
| * |
| * @param center the center point, in user space, of the circle defining |
| * the gradient. The last color of the gradient is mapped |
| * to the perimeter of this circle. |
| * @param radius the radius of the circle defining the extents of the color |
| * gradient |
| * @param focus the point in user space to which the first color is mapped |
| * @param fractions numbers ranging from 0.0 to 1.0 specifying the |
| * distribution of colors along the gradient |
| * @param colors array of colors to use in the gradient. The first color |
| * is used at the focus point, the last color around the |
| * perimeter of the circle. |
| * @param cycleMethod either {@code NO_CYCLE}, {@code REFLECT}, |
| * or {@code REPEAT} |
| * |
| * @throws NullPointerException |
| * if one of the points is null, |
| * or {@code fractions} array is null, |
| * or {@code colors} array is null, |
| * or {@code cycleMethod} is null |
| * @throws IllegalArgumentException |
| * if {@code radius} is non-positive, |
| * or {@code fractions.length != colors.length}, |
| * or {@code colors} is less than 2 in size, |
| * or a {@code fractions} value is less than 0.0 or greater than 1.0, |
| * or the {@code fractions} are not provided in strictly increasing order |
| */ |
| public RadialGradientPaint(Point2D center, float radius, |
| Point2D focus, |
| float[] fractions, Color[] colors, |
| CycleMethod cycleMethod) |
| { |
| this(center, |
| radius, |
| focus, |
| fractions, |
| colors, |
| cycleMethod, |
| ColorSpaceType.SRGB, |
| new AffineTransform()); |
| } |
| |
| /** |
| * Constructs a {@code RadialGradientPaint}. |
| * |
| * @param center the center point in user space of the circle defining the |
| * gradient. The last color of the gradient is mapped to |
| * the perimeter of this circle. |
| * @param radius the radius of the circle defining the extents of the |
| * color gradient |
| * @param focus the point in user space to which the first color is mapped |
| * @param fractions numbers ranging from 0.0 to 1.0 specifying the |
| * distribution of colors along the gradient |
| * @param colors array of colors to use in the gradient. The first color |
| * is used at the focus point, the last color around the |
| * perimeter of the circle. |
| * @param cycleMethod either {@code NO_CYCLE}, {@code REFLECT}, |
| * or {@code REPEAT} |
| * @param colorSpace which color space to use for interpolation, |
| * either {@code SRGB} or {@code LINEAR_RGB} |
| * @param gradientTransform transform to apply to the gradient |
| * |
| * @throws NullPointerException |
| * if one of the points is null, |
| * or {@code fractions} array is null, |
| * or {@code colors} array is null, |
| * or {@code cycleMethod} is null, |
| * or {@code colorSpace} is null, |
| * or {@code gradientTransform} is null |
| * @throws IllegalArgumentException |
| * if {@code radius} is non-positive, |
| * or {@code fractions.length != colors.length}, |
| * or {@code colors} is less than 2 in size, |
| * or a {@code fractions} value is less than 0.0 or greater than 1.0, |
| * or the {@code fractions} are not provided in strictly increasing order |
| */ |
| public RadialGradientPaint(Point2D center, |
| float radius, |
| Point2D focus, |
| float[] fractions, Color[] colors, |
| CycleMethod cycleMethod, |
| ColorSpaceType colorSpace, |
| AffineTransform gradientTransform) |
| { |
| super(fractions, colors, cycleMethod, colorSpace, gradientTransform); |
| |
| // check input arguments |
| if (center == null) { |
| throw new NullPointerException("Center point must be non-null"); |
| } |
| |
| if (focus == null) { |
| throw new NullPointerException("Focus point must be non-null"); |
| } |
| |
| if (radius <= 0) { |
| throw new IllegalArgumentException("Radius must be greater " + |
| "than zero"); |
| } |
| |
| // copy parameters |
| this.center = new Point2D.Double(center.getX(), center.getY()); |
| this.focus = new Point2D.Double(focus.getX(), focus.getY()); |
| this.radius = radius; |
| } |
| |
| /** |
| * Constructs a {@code RadialGradientPaint} with a default |
| * {@code SRGB} color space. |
| * The gradient circle of the {@code RadialGradientPaint} is defined |
| * by the given bounding box. |
| * <p> |
| * This constructor is a more convenient way to express the |
| * following (equivalent) code:<br> |
| * |
| * <pre> |
| * double gw = gradientBounds.getWidth(); |
| * double gh = gradientBounds.getHeight(); |
| * double cx = gradientBounds.getCenterX(); |
| * double cy = gradientBounds.getCenterY(); |
| * Point2D center = new Point2D.Double(cx, cy); |
| * |
| * AffineTransform gradientTransform = new AffineTransform(); |
| * gradientTransform.translate(cx, cy); |
| * gradientTransform.scale(gw / 2, gh / 2); |
| * gradientTransform.translate(-cx, -cy); |
| * |
| * RadialGradientPaint gp = |
| * new RadialGradientPaint(center, 1.0f, center, |
| * fractions, colors, |
| * cycleMethod, |
| * ColorSpaceType.SRGB, |
| * gradientTransform); |
| * </pre> |
| * |
| * @param gradientBounds the bounding box, in user space, of the circle |
| * defining the outermost extent of the gradient |
| * @param fractions numbers ranging from 0.0 to 1.0 specifying the |
| * distribution of colors along the gradient |
| * @param colors array of colors to use in the gradient. The first color |
| * is used at the focus point, the last color around the |
| * perimeter of the circle. |
| * @param cycleMethod either {@code NO_CYCLE}, {@code REFLECT}, |
| * or {@code REPEAT} |
| * |
| * @throws NullPointerException |
| * if {@code gradientBounds} is null, |
| * or {@code fractions} array is null, |
| * or {@code colors} array is null, |
| * or {@code cycleMethod} is null |
| * @throws IllegalArgumentException |
| * if {@code gradientBounds} is empty, |
| * or {@code fractions.length != colors.length}, |
| * or {@code colors} is less than 2 in size, |
| * or a {@code fractions} value is less than 0.0 or greater than 1.0, |
| * or the {@code fractions} are not provided in strictly increasing order |
| */ |
| public RadialGradientPaint(Rectangle2D gradientBounds, |
| float[] fractions, Color[] colors, |
| CycleMethod cycleMethod) |
| { |
| // gradient center/focal point is the center of the bounding box, |
| // radius is set to 1.0, and then we set a scale transform |
| // to achieve an elliptical gradient defined by the bounding box |
| this(new Point2D.Double(gradientBounds.getCenterX(), |
| gradientBounds.getCenterY()), |
| 1.0f, |
| new Point2D.Double(gradientBounds.getCenterX(), |
| gradientBounds.getCenterY()), |
| fractions, |
| colors, |
| cycleMethod, |
| ColorSpaceType.SRGB, |
| createGradientTransform(gradientBounds)); |
| |
| if (gradientBounds.isEmpty()) { |
| throw new IllegalArgumentException("Gradient bounds must be " + |
| "non-empty"); |
| } |
| } |
| |
| private static AffineTransform createGradientTransform(Rectangle2D r) { |
| double cx = r.getCenterX(); |
| double cy = r.getCenterY(); |
| AffineTransform xform = AffineTransform.getTranslateInstance(cx, cy); |
| xform.scale(r.getWidth()/2, r.getHeight()/2); |
| xform.translate(-cx, -cy); |
| return xform; |
| } |
| |
| /** |
| * Creates and returns a {@link PaintContext} used to |
| * generate a circular radial color gradient pattern. |
| * See the description of the {@link Paint#createContext createContext} method |
| * for information on null parameter handling. |
| * |
| * @param cm the preferred {@link ColorModel} which represents the most convenient |
| * format for the caller to receive the pixel data, or {@code null} |
| * if there is no preference. |
| * @param deviceBounds the device space bounding box |
| * of the graphics primitive being rendered. |
| * @param userBounds the user space bounding box |
| * of the graphics primitive being rendered. |
| * @param transform the {@link AffineTransform} from user |
| * space into device space. |
| * @param hints the set of hints that the context object can use to |
| * choose between rendering alternatives. |
| * @return the {@code PaintContext} for |
| * generating color patterns. |
| * @see Paint |
| * @see PaintContext |
| * @see ColorModel |
| * @see Rectangle |
| * @see Rectangle2D |
| * @see AffineTransform |
| * @see RenderingHints |
| */ |
| public PaintContext createContext(ColorModel cm, |
| Rectangle deviceBounds, |
| Rectangle2D userBounds, |
| AffineTransform transform, |
| RenderingHints hints) |
| { |
| // avoid modifying the user's transform... |
| transform = new AffineTransform(transform); |
| // incorporate the gradient transform |
| transform.concatenate(gradientTransform); |
| |
| return new RadialGradientPaintContext(this, cm, |
| deviceBounds, userBounds, |
| transform, hints, |
| (float)center.getX(), |
| (float)center.getY(), |
| radius, |
| (float)focus.getX(), |
| (float)focus.getY(), |
| fractions, colors, |
| cycleMethod, colorSpace); |
| } |
| |
| /** |
| * Returns a copy of the center point of the radial gradient. |
| * |
| * @return a {@code Point2D} object that is a copy of the center point |
| */ |
| public Point2D getCenterPoint() { |
| return new Point2D.Double(center.getX(), center.getY()); |
| } |
| |
| /** |
| * Returns a copy of the end point of the gradient axis. |
| * |
| * @return a {@code Point2D} object that is a copy of the focus point |
| */ |
| public Point2D getFocusPoint() { |
| return new Point2D.Double(focus.getX(), focus.getY()); |
| } |
| |
| /** |
| * Returns the radius of the circle defining the radial gradient. |
| * |
| * @return the radius of the circle defining the radial gradient |
| */ |
| public float getRadius() { |
| return radius; |
| } |
| } |
