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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* 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).
*
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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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
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