| /* | |
| * Copyright (c) 1997, 2010, 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.Point2D; | |
| import java.awt.geom.Rectangle2D; | |
| import java.awt.geom.AffineTransform; | |
| import java.awt.image.ColorModel; | |
| import java.beans.ConstructorProperties; | |
| /** | |
| * The {@code GradientPaint} class provides a way to fill | |
| * a {@link Shape} with a linear color gradient pattern. | |
| * If {@link Point} P1 with {@link Color} C1 and {@code Point} P2 with | |
| * {@code Color} C2 are specified in user space, the | |
| * {@code Color} on the P1, P2 connecting line is proportionally | |
| * changed from C1 to C2. Any point P not on the extended P1, P2 | |
| * connecting line has the color of the point P' that is the perpendicular | |
| * projection of P on the extended P1, P2 connecting line. | |
| * Points on the extended line outside of the P1, P2 segment can be colored | |
| * in one of two ways. | |
| * <ul> | |
| * <li> | |
| * If the gradient is cyclic then the points on the extended P1, P2 | |
| * connecting line cycle back and forth between the colors C1 and C2. | |
| * <li> | |
| * If the gradient is acyclic then points on the P1 side of the segment | |
| * have the constant {@code Color} C1 while points on the P2 side | |
| * have the constant {@code Color} C2. | |
| * </ul> | |
| * | |
| * @see Paint | |
| * @see Graphics2D#setPaint | |
| * @version 10 Feb 1997 | |
| */ | |
| public class GradientPaint implements Paint { | |
| Point2D.Float p1; | |
| Point2D.Float p2; | |
| Color color1; | |
| Color color2; | |
| boolean cyclic; | |
| /** | |
| * Constructs a simple acyclic {@code GradientPaint} object. | |
| * @param x1 x coordinate of the first specified | |
| * {@code Point} in user space | |
| * @param y1 y coordinate of the first specified | |
| * {@code Point} in user space | |
| * @param color1 {@code Color} at the first specified | |
| * {@code Point} | |
| * @param x2 x coordinate of the second specified | |
| * {@code Point} in user space | |
| * @param y2 y coordinate of the second specified | |
| * {@code Point} in user space | |
| * @param color2 {@code Color} at the second specified | |
| * {@code Point} | |
| * @throws NullPointerException if either one of colors is null | |
| */ | |
| public GradientPaint(float x1, | |
| float y1, | |
| Color color1, | |
| float x2, | |
| float y2, | |
| Color color2) { | |
| if ((color1 == null) || (color2 == null)) { | |
| throw new NullPointerException("Colors cannot be null"); | |
| } | |
| p1 = new Point2D.Float(x1, y1); | |
| p2 = new Point2D.Float(x2, y2); | |
| this.color1 = color1; | |
| this.color2 = color2; | |
| } | |
| /** | |
| * Constructs a simple acyclic {@code GradientPaint} object. | |
| * @param pt1 the first specified {@code Point} in user space | |
| * @param color1 {@code Color} at the first specified | |
| * {@code Point} | |
| * @param pt2 the second specified {@code Point} in user space | |
| * @param color2 {@code Color} at the second specified | |
| * {@code Point} | |
| * @throws NullPointerException if either one of colors or points | |
| * is null | |
| */ | |
| public GradientPaint(Point2D pt1, | |
| Color color1, | |
| Point2D pt2, | |
| Color color2) { | |
| if ((color1 == null) || (color2 == null) || | |
| (pt1 == null) || (pt2 == null)) { | |
| throw new NullPointerException("Colors and points should be non-null"); | |
| } | |
| p1 = new Point2D.Float((float)pt1.getX(), (float)pt1.getY()); | |
| p2 = new Point2D.Float((float)pt2.getX(), (float)pt2.getY()); | |
| this.color1 = color1; | |
| this.color2 = color2; | |
| } | |
| /** | |
| * Constructs either a cyclic or acyclic {@code GradientPaint} | |
| * object depending on the {@code boolean} parameter. | |
| * @param x1 x coordinate of the first specified | |
| * {@code Point} in user space | |
| * @param y1 y coordinate of the first specified | |
| * {@code Point} in user space | |
| * @param color1 {@code Color} at the first specified | |
| * {@code Point} | |
| * @param x2 x coordinate of the second specified | |
| * {@code Point} in user space | |
| * @param y2 y coordinate of the second specified | |
| * {@code Point} in user space | |
| * @param color2 {@code Color} at the second specified | |
| * {@code Point} | |
| * @param cyclic {@code true} if the gradient pattern should cycle | |
| * repeatedly between the two colors; {@code false} otherwise | |
| */ | |
| public GradientPaint(float x1, | |
| float y1, | |
| Color color1, | |
| float x2, | |
| float y2, | |
| Color color2, | |
| boolean cyclic) { | |
| this (x1, y1, color1, x2, y2, color2); | |
| this.cyclic = cyclic; | |
| } | |
| /** | |
| * Constructs either a cyclic or acyclic {@code GradientPaint} | |
| * object depending on the {@code boolean} parameter. | |
| * @param pt1 the first specified {@code Point} | |
| * in user space | |
| * @param color1 {@code Color} at the first specified | |
| * {@code Point} | |
| * @param pt2 the second specified {@code Point} | |
| * in user space | |
| * @param color2 {@code Color} at the second specified | |
| * {@code Point} | |
| * @param cyclic {@code true} if the gradient pattern should cycle | |
| * repeatedly between the two colors; {@code false} otherwise | |
| * @throws NullPointerException if either one of colors or points | |
| * is null | |
| */ | |
| @ConstructorProperties({ "point1", "color1", "point2", "color2", "cyclic" }) | |
| public GradientPaint(Point2D pt1, | |
| Color color1, | |
| Point2D pt2, | |
| Color color2, | |
| boolean cyclic) { | |
| this (pt1, color1, pt2, color2); | |
| this.cyclic = cyclic; | |
| } | |
| /** | |
| * Returns a copy of the point P1 that anchors the first color. | |
| * @return a {@link Point2D} object that is a copy of the point | |
| * that anchors the first color of this | |
| * {@code GradientPaint}. | |
| */ | |
| public Point2D getPoint1() { | |
| return new Point2D.Float(p1.x, p1.y); | |
| } | |
| /** | |
| * Returns the color C1 anchored by the point P1. | |
| * @return a {@code Color} object that is the color | |
| * anchored by P1. | |
| */ | |
| public Color getColor1() { | |
| return color1; | |
| } | |
| /** | |
| * Returns a copy of the point P2 which anchors the second color. | |
| * @return a {@link Point2D} object that is a copy of the point | |
| * that anchors the second color of this | |
| * {@code GradientPaint}. | |
| */ | |
| public Point2D getPoint2() { | |
| return new Point2D.Float(p2.x, p2.y); | |
| } | |
| /** | |
| * Returns the color C2 anchored by the point P2. | |
| * @return a {@code Color} object that is the color | |
| * anchored by P2. | |
| */ | |
| public Color getColor2() { | |
| return color2; | |
| } | |
| /** | |
| * Returns {@code true} if the gradient cycles repeatedly | |
| * between the two colors C1 and C2. | |
| * @return {@code true} if the gradient cycles repeatedly | |
| * between the two colors; {@code false} otherwise. | |
| */ | |
| public boolean isCyclic() { | |
| return cyclic; | |
| } | |
| /** | |
| * Creates and returns a {@link PaintContext} used to | |
| * generate a linear color gradient pattern. | |
| * See the {@link Paint#createContext specification} of the | |
| * method in the {@link Paint} interface 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 xform 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 xform, | |
| RenderingHints hints) { | |
| return new GradientPaintContext(cm, p1, p2, xform, | |
| color1, color2, cyclic); | |
| } | |
| /** | |
| * Returns the transparency mode for this {@code GradientPaint}. | |
| * @return an integer value representing this {@code GradientPaint} | |
| * object's transparency mode. | |
| * @see Transparency | |
| */ | |
| public int getTransparency() { | |
| int a1 = color1.getAlpha(); | |
| int a2 = color2.getAlpha(); | |
| return (((a1 & a2) == 0xff) ? OPAQUE : TRANSLUCENT); | |
| } | |
| } |