/*
* Copyright 2006-2017 ICEsoft Technologies Canada Corp.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an "AS
* IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language
* governing permissions and limitations under the License.
*/
package org.icepdf.core.pobjects.graphics.batik.ext.awt;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.geom.NoninvertibleTransformException;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.awt.image.ColorModel;
/**
* The <code>LinearGradientPaint</code> class provides a way to fill
* a {@link java.awt.Shape} with a linear color gradient pattern. The user may
* specify 2 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.
* <br>
* 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).
* <br>
* For example:
* <br>
* <code>
* <br>
* Point2D start = new Point2D.Float(0, 0);<br>
* Point2D end = new Point2D.Float(100,100);<br>
* float[] dist = {0.0, 0.2, 1.0};<br>
* Color[] colors = {Color.red, Color.white, Color.blue};<br>
* LinearGradientPaint p = new LinearGradientPaint(start, end, dist, colors);
* </code>
* <br>
* 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%.
* <br>
* <p> In the event that the user does not set the first keyframe value equal
* to 0 and 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>
* {Color.blue, Color.red}, {.3, .7}<br>
* this will be converted to a gradient with the following keyframes:
* {Color.blue, Color.blue, Color.red, Color.red}, {0, .3, .7, 1}
* <br>
* <br>
* 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, so the endpoint colors
* will be used to fill the remaining area.
* <br>
* <p> The following image demonstrates the options NO_CYCLE and REFLECT.
* <br>
* <br>
* <img src = "cyclic.jpg" alt="" >
* <br>
* <p> The colorSpace parameter allows the user to specify in which colorspace
* the interpolation should be performed, default sRGB or linearized RGB.
*
* @author Nicholas Talian, Vincent Hardy, Jim Graham, Jerry Evans
* @author <a href="mailto:vincent.hardy@eng.sun.com">Vincent Hardy</a>
* @version $Id: LinearGradientPaint.java,v 1.1 2008/09/30 20:44:16 patrickc Exp $
* @see java.awt.Paint
* @see java.awt.Graphics2D#setPaint
*/
public final class LinearGradientPaint extends MultipleGradientPaint {
/**
* Gradient start and end points.
*/
private Point2D start, end;
/**
* Constructs an <code>LinearGradientPaint</code> with the default
* NO_CYCLE repeating method and SRGB colorspace.
*
* @param startX the x coordinate of the gradient axis start point
* in user space
* @param startY the y coordinate of the gradient axis start point
* in user space
* @param endX the x coordinate of the gradient axis end point
* in user space
* @param endY the y coordinate of the gradient axis end point
* in user space
* @param fractions numbers ranging from 0.0 to 1.0 specifying the
* distribution of colors along the gradient
* @param colors array of colors corresponding to each fractional value
* @throws IllegalArgumentException if start and end points are the
* same points, or if fractions.length != colors.length, or if colors
* is less than 2 in size.
*/
public LinearGradientPaint(float startX, float startY,
float endX, float endY,
float[] fractions, Color[] colors) {
this(new Point2D.Float(startX, startY),
new Point2D.Float(endX, endY),
fractions,
colors,
NO_CYCLE,
SRGB);
}
/**
* Constructs an <code>LinearGradientPaint</code> with default SRGB
* colorspace.
*
* @param startX the x coordinate of the gradient axis start point
* in user space
* @param startY the y coordinate of the gradient axis start point
* in user space
* @param endX the x coordinate of the gradient axis end point
* in user space
* @param endY the y coordinate of the gradient axis end point
* in user space
* @param fractions numbers ranging from 0.0 to 1.0 specifying the
* distribution of colors along the gradient
* @param colors array of colors corresponding to each fractional value
* @param cycleMethod either NO_CYCLE, REFLECT, or REPEAT
* @throws IllegalArgumentException if start and end points are the
* same points, or if fractions.length != colors.length, or if colors
* is less than 2 in size.
*/
public LinearGradientPaint(float startX, float startY,
float endX, float endY,
float[] fractions, Color[] colors,
CycleMethodEnum cycleMethod) {
this(new Point2D.Float(startX, startY),
new Point2D.Float(endX, endY),
fractions,
colors,
cycleMethod,
SRGB);
}
/**
* Constructs a <code>LinearGradientPaint</code> with the default
* NO_CYCLE repeating method and SRGB colorspace.
*
* @param start the gradient axis start <code>Point</code> in user space
* @param end the gradient axis end <code>Point</code> in user space
* @param fractions numbers ranging from 0.0 to 1.0 specifying the
* distribution of colors along the gradient
* @param colors array of colors corresponding to each fractional value
* @throws NullPointerException if one of the points is null
* @throws IllegalArgumentException if start and end points are the
* same points, or if fractions.length != colors.length, or if colors
* is less than 2 in size.
*/
public LinearGradientPaint(Point2D start, Point2D end, float[] fractions,
Color[] colors) {
this(start, end, fractions, colors, NO_CYCLE, SRGB);
}
/**
* Constructs a <code>LinearGradientPaint</code>.
*
* @param start the gradient axis start <code>Point</code> in user space
* @param end the gradient axis end <code>Point</code> in user space
* @param fractions numbers ranging from 0.0 to 1.0 specifying the
* distribution of colors along the gradient
* @param colors array of colors corresponding to each fractional value
* @param cycleMethod either NO_CYCLE, REFLECT, or REPEAT
* @param colorSpace which colorspace to use for interpolation,
* either SRGB or LINEAR_RGB
* @throws NullPointerException if one of the points is null
* @throws IllegalArgumentException if start and end points are the
* same points, or if fractions.length != colors.length, or if colors
* is less than 2 in size.
*/
public LinearGradientPaint(Point2D start, Point2D end, float[] fractions,
Color[] colors,
CycleMethodEnum cycleMethod,
ColorSpaceEnum colorSpace) {
this(start, end, fractions, colors, cycleMethod, colorSpace,
new AffineTransform());
}
/**
* Constructs a <code>LinearGradientPaint</code>.
*
* @param start the gradient axis start <code>Point</code> in user space
* @param end the gradient axis end <code>Point</code> in user space
* @param fractions numbers ranging from 0.0 to 1.0 specifying the
* distribution of colors along the gradient
* @param colors array of colors corresponding to each fractional value
* @param cycleMethod either NO_CYCLE, REFLECT, or REPEAT
* @param colorSpace which colorspace to use for interpolation,
* either SRGB or LINEAR_RGB
* @param gradientTransform transform to apply to the gradient
* @throws NullPointerException if one of the points is null,
* or gradientTransform is null
* @throws IllegalArgumentException if start and end points are the
* same points, or if fractions.length != colors.length, or if colors
* is less than 2 in size.
*/
public LinearGradientPaint(Point2D start, Point2D end, float[] fractions,
Color[] colors,
CycleMethodEnum cycleMethod,
ColorSpaceEnum colorSpace,
AffineTransform gradientTransform) {
super(fractions, colors, cycleMethod, colorSpace, gradientTransform);
//
// Check input parameters
//
if (start == null || end == null) {
throw new NullPointerException("Start and end points must be" +
"non-null");
}
if (start.equals(end)) {
throw new IllegalArgumentException("Start point cannot equal" +
"endpoint");
}
//copy the points...
this.start = (Point2D) start.clone();
this.end = (Point2D) end.clone();
}
/**
* Creates and returns a PaintContext used to generate the color pattern,
* for use by the internal rendering engine.
*
* @param cm {@link ColorModel} that receives
* the <code>Paint</code> data. This is used only as a hint.
* @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 hints that the context object uses to choose
* between rendering alternatives
* @return the {@link PaintContext} that generates color patterns.
* @see PaintContext
*/
public PaintContext createContext(ColorModel cm,
Rectangle deviceBounds,
Rectangle2D userBounds,
AffineTransform transform,
RenderingHints hints) {
// Can't modify the transform passed in...
transform = new AffineTransform(transform);
//incorporate the gradient transform
transform.concatenate(gradientTransform);
try {
return new LinearGradientPaintContext(cm,
deviceBounds,
userBounds,
transform,
hints,
start,
end,
fractions,
this.getColors(),
cycleMethod,
colorSpace);
} catch (NoninvertibleTransformException e) {
throw new IllegalArgumentException("transform should be" +
"invertible");
}
}
/**
* Returns a copy of the start point of the gradient axis
*
* @return a {@link Point2D} object that is a copy of the point
* that anchors the first color of this
* <code>LinearGradientPaint</code>.
*/
public Point2D getStartPoint() {
return new Point2D.Double(start.getX(), start.getY());
}
/**
* Returns a copy of the end point of the gradient axis
*
* @return a {@link Point2D} object that is a copy of the point
* that anchors the last color of this
* <code>LinearGradientPaint</code>.
*/
public Point2D getEndPoint() {
return new Point2D.Double(end.getX(), end.getY());
}
}