/*
* 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.beans.ConstructorProperties;
/**
* The <code>BasicStroke</code> class defines a basic set of rendering
* attributes for the outlines of graphics primitives, which are rendered
* with a {@link Graphics2D} object that has its Stroke attribute set to
* this <code>BasicStroke</code>.
* The rendering attributes defined by <code>BasicStroke</code> describe
* the shape of the mark made by a pen drawn along the outline of a
* {@link Shape} and the decorations applied at the ends and joins of
* path segments of the <code>Shape</code>.
* These rendering attributes include:
* <dl compact>
* <dt><i>width</i>
* <dd>The pen width, measured perpendicularly to the pen trajectory.
* <dt><i>end caps</i>
* <dd>The decoration applied to the ends of unclosed subpaths and
* dash segments. Subpaths that start and end on the same point are
* still considered unclosed if they do not have a CLOSE segment.
* See {@link java.awt.geom.PathIterator#SEG_CLOSE SEG_CLOSE}
* for more information on the CLOSE segment.
* The three different decorations are: {@link #CAP_BUTT},
* {@link #CAP_ROUND}, and {@link #CAP_SQUARE}.
* <dt><i>line joins</i>
* <dd>The decoration applied at the intersection of two path segments
* and at the intersection of the endpoints of a subpath that is closed
* using {@link java.awt.geom.PathIterator#SEG_CLOSE SEG_CLOSE}.
* The three different decorations are: {@link #JOIN_BEVEL},
* {@link #JOIN_MITER}, and {@link #JOIN_ROUND}.
* <dt><i>miter limit</i>
* <dd>The limit to trim a line join that has a JOIN_MITER decoration.
* A line join is trimmed when the ratio of miter length to stroke
* width is greater than the miterlimit value. The miter length is
* the diagonal length of the miter, which is the distance between
* the inside corner and the outside corner of the intersection.
* The smaller the angle formed by two line segments, the longer
* the miter length and the sharper the angle of intersection. The
* default miterlimit value of 10.0f causes all angles less than
* 11 degrees to be trimmed. Trimming miters converts
* the decoration of the line join to bevel.
* <dt><i>dash attributes</i>
* <dd>The definition of how to make a dash pattern by alternating
* between opaque and transparent sections.
* </dl>
* All attributes that specify measurements and distances controlling
* the shape of the returned outline are measured in the same
* coordinate system as the original unstroked <code>Shape</code>
* argument. When a <code>Graphics2D</code> object uses a
* <code>Stroke</code> object to redefine a path during the execution
* of one of its <code>draw</code> methods, the geometry is supplied
* in its original form before the <code>Graphics2D</code> transform
* attribute is applied. Therefore, attributes such as the pen width
* are interpreted in the user space coordinate system of the
* <code>Graphics2D</code> object and are subject to the scaling and
* shearing effects of the user-space-to-device-space transform in that
* particular <code>Graphics2D</code>.
* For example, the width of a rendered shape's outline is determined
* not only by the width attribute of this <code>BasicStroke</code>,
* but also by the transform attribute of the
* <code>Graphics2D</code> object. Consider this code:
* <blockquote><tt>
* // sets the Graphics2D object's Tranform attribute
* g2d.scale(10, 10);
* // sets the Graphics2D object's Stroke attribute
* g2d.setStroke(new BasicStroke(1.5f));
* </tt></blockquote>
* Assuming there are no other scaling transforms added to the
* <code>Graphics2D</code> object, the resulting line
* will be approximately 15 pixels wide.
* As the example code demonstrates, a floating-point line
* offers better precision, especially when large transforms are
* used with a <code>Graphics2D</code> object.
* When a line is diagonal, the exact width depends on how the
* rendering pipeline chooses which pixels to fill as it traces the
* theoretical widened outline. The choice of which pixels to turn
* on is affected by the antialiasing attribute because the
* antialiasing rendering pipeline can choose to color
* partially-covered pixels.
* <p>
* For more information on the user space coordinate system and the
* rendering process, see the <code>Graphics2D</code> class comments.
* @see Graphics2D
* @author Jim Graham
*/
public class BasicStroke implements Stroke {
/**
* Joins path segments by extending their outside edges until
* they meet.
*/
public final static int JOIN_MITER = 0;
/**
* Joins path segments by rounding off the corner at a radius
* of half the line width.
*/
public final static int JOIN_ROUND = 1;
/**
* Joins path segments by connecting the outer corners of their
* wide outlines with a straight segment.
*/
public final static int JOIN_BEVEL = 2;
/**
* Ends unclosed subpaths and dash segments with no added
* decoration.
*/
public final static int CAP_BUTT = 0;
/**
* Ends unclosed subpaths and dash segments with a round
* decoration that has a radius equal to half of the width
* of the pen.
*/
public final static int CAP_ROUND = 1;
/**
* Ends unclosed subpaths and dash segments with a square
* projection that extends beyond the end of the segment
* to a distance equal to half of the line width.
*/
public final static int CAP_SQUARE = 2;
float width;
int join;
int cap;
float miterlimit;
float dash[];
float dash_phase;
/**
* Constructs a new <code>BasicStroke</code> with the specified
* attributes.
* @param width the width of this <code>BasicStroke</code>. The
* width must be greater than or equal to 0.0f. If width is
* set to 0.0f, the stroke is rendered as the thinnest
* possible line for the target device and the antialias
* hint setting.
* @param cap the decoration of the ends of a <code>BasicStroke</code>
* @param join the decoration applied where path segments meet
* @param miterlimit the limit to trim the miter join. The miterlimit
* must be greater than or equal to 1.0f.
* @param dash the array representing the dashing pattern
* @param dash_phase the offset to start the dashing pattern
* @throws IllegalArgumentException if <code>width</code> is negative
* @throws IllegalArgumentException if <code>cap</code> is not either
* CAP_BUTT, CAP_ROUND or CAP_SQUARE
* @throws IllegalArgumentException if <code>miterlimit</code> is less
* than 1 and <code>join</code> is JOIN_MITER
* @throws IllegalArgumentException if <code>join</code> is not
* either JOIN_ROUND, JOIN_BEVEL, or JOIN_MITER
* @throws IllegalArgumentException if <code>dash_phase</code>
* is negative and <code>dash</code> is not <code>null</code>
* @throws IllegalArgumentException if the length of
* <code>dash</code> is zero
* @throws IllegalArgumentException if dash lengths are all zero.
*/
@ConstructorProperties({ "lineWidth", "endCap", "lineJoin", "miterLimit", "dashArray", "dashPhase" })
public BasicStroke(float width, int cap, int join, float miterlimit,
float dash[], float dash_phase) {
if (width < 0.0f) {
throw new IllegalArgumentException("negative width");
}
if (cap != CAP_BUTT && cap != CAP_ROUND && cap != CAP_SQUARE) {
throw new IllegalArgumentException("illegal end cap value");
}
if (join == JOIN_MITER) {
if (miterlimit < 1.0f) {
throw new IllegalArgumentException("miter limit < 1");
}
} else if (join != JOIN_ROUND && join != JOIN_BEVEL) {
throw new IllegalArgumentException("illegal line join value");
}
if (dash != null) {
if (dash_phase < 0.0f) {
throw new IllegalArgumentException("negative dash phase");
}
boolean allzero = true;
for (int i = 0; i < dash.length; i++) {
float d = dash[i];
if (d > 0.0) {
allzero = false;
} else if (d < 0.0) {
throw new IllegalArgumentException("negative dash length");
}
}
if (allzero) {
throw new IllegalArgumentException("dash lengths all zero");
}
}
this.width = width;
this.cap = cap;
this.join = join;
this.miterlimit = miterlimit;
if (dash != null) {
this.dash = (float []) dash.clone();
}
this.dash_phase = dash_phase;
}
/**
* Constructs a solid <code>BasicStroke</code> with the specified
* attributes.
* @param width the width of the <code>BasicStroke</code>
* @param cap the decoration of the ends of a <code>BasicStroke</code>
* @param join the decoration applied where path segments meet
* @param miterlimit the limit to trim the miter join
* @throws IllegalArgumentException if <code>width</code> is negative
* @throws IllegalArgumentException if <code>cap</code> is not either
* CAP_BUTT, CAP_ROUND or CAP_SQUARE
* @throws IllegalArgumentException if <code>miterlimit</code> is less
* than 1 and <code>join</code> is JOIN_MITER
* @throws IllegalArgumentException if <code>join</code> is not
* either JOIN_ROUND, JOIN_BEVEL, or JOIN_MITER
*/
public BasicStroke(float width, int cap, int join, float miterlimit) {
this(width, cap, join, miterlimit, null, 0.0f);
}
/**
* Constructs a solid <code>BasicStroke</code> with the specified
* attributes. The <code>miterlimit</code> parameter is
* unnecessary in cases where the default is allowable or the
* line joins are not specified as JOIN_MITER.
* @param width the width of the <code>BasicStroke</code>
* @param cap the decoration of the ends of a <code>BasicStroke</code>
* @param join the decoration applied where path segments meet
* @throws IllegalArgumentException if <code>width</code> is negative
* @throws IllegalArgumentException if <code>cap</code> is not either
* CAP_BUTT, CAP_ROUND or CAP_SQUARE
* @throws IllegalArgumentException if <code>join</code> is not
* either JOIN_ROUND, JOIN_BEVEL, or JOIN_MITER
*/
public BasicStroke(float width, int cap, int join) {
this(width, cap, join, 10.0f, null, 0.0f);
}
/**
* Constructs a solid <code>BasicStroke</code> with the specified
* line width and with default values for the cap and join
* styles.
* @param width the width of the <code>BasicStroke</code>
* @throws IllegalArgumentException if <code>width</code> is negative
*/
public BasicStroke(float width) {
this(width, CAP_SQUARE, JOIN_MITER, 10.0f, null, 0.0f);
}
/**
* Constructs a new <code>BasicStroke</code> with defaults for all
* attributes.
* The default attributes are a solid line of width 1.0, CAP_SQUARE,
* JOIN_MITER, a miter limit of 10.0.
*/
public BasicStroke() {
this(1.0f, CAP_SQUARE, JOIN_MITER, 10.0f, null, 0.0f);
}
/**
* Returns a <code>Shape</code> whose interior defines the
* stroked outline of a specified <code>Shape</code>.
* @param s the <code>Shape</code> boundary be stroked
* @return the <code>Shape</code> of the stroked outline.
*/
public Shape createStrokedShape(Shape s) {
sun.java2d.pipe.RenderingEngine re =
sun.java2d.pipe.RenderingEngine.getInstance();
return re.createStrokedShape(s, width, cap, join, miterlimit,
dash, dash_phase);
}
/**
* Returns the line width. Line width is represented in user space,
* which is the default-coordinate space used by Java 2D. See the
* <code>Graphics2D</code> class comments for more information on
* the user space coordinate system.
* @return the line width of this <code>BasicStroke</code>.
* @see Graphics2D
*/
public float getLineWidth() {
return width;
}
/**
* Returns the end cap style.
* @return the end cap style of this <code>BasicStroke</code> as one
* of the static <code>int</code> values that define possible end cap
* styles.
*/
public int getEndCap() {
return cap;
}
/**
* Returns the line join style.
* @return the line join style of the <code>BasicStroke</code> as one
* of the static <code>int</code> values that define possible line
* join styles.
*/
public int getLineJoin() {
return join;
}
/**
* Returns the limit of miter joins.
* @return the limit of miter joins of the <code>BasicStroke</code>.
*/
public float getMiterLimit() {
return miterlimit;
}
/**
* Returns the array representing the lengths of the dash segments.
* Alternate entries in the array represent the user space lengths
* of the opaque and transparent segments of the dashes.
* As the pen moves along the outline of the <code>Shape</code>
* to be stroked, the user space
* distance that the pen travels is accumulated. The distance
* value is used to index into the dash array.
* The pen is opaque when its current cumulative distance maps
* to an even element of the dash array and transparent otherwise.
* @return the dash array.
*/
public float[] getDashArray() {
if (dash == null) {
return null;
}
return (float[]) dash.clone();
}
/**
* Returns the current dash phase.
* The dash phase is a distance specified in user coordinates that
* represents an offset into the dashing pattern. In other words, the dash
* phase defines the point in the dashing pattern that will correspond to
* the beginning of the stroke.
* @return the dash phase as a <code>float</code> value.
*/
public float getDashPhase() {
return dash_phase;
}
/**
* Returns the hashcode for this stroke.
* @return a hash code for this stroke.
*/
public int hashCode() {
int hash = Float.floatToIntBits(width);
hash = hash * 31 + join;
hash = hash * 31 + cap;
hash = hash * 31 + Float.floatToIntBits(miterlimit);
if (dash != null) {
hash = hash * 31 + Float.floatToIntBits(dash_phase);
for (int i = 0; i < dash.length; i++) {
hash = hash * 31 + Float.floatToIntBits(dash[i]);
}
}
return hash;
}
/**
* Returns true if this BasicStroke represents the same
* stroking operation as the given argument.
*/
/**
* Tests if a specified object is equal to this <code>BasicStroke</code>
* by first testing if it is a <code>BasicStroke</code> and then comparing
* its width, join, cap, miter limit, dash, and dash phase attributes with
* those of this <code>BasicStroke</code>.
* @param obj the specified object to compare to this
* <code>BasicStroke</code>
* @return <code>true</code> if the width, join, cap, miter limit, dash, and
* dash phase are the same for both objects;
* <code>false</code> otherwise.
*/
public boolean equals(Object obj) {
if (!(obj instanceof BasicStroke)) {
return false;
}
BasicStroke bs = (BasicStroke) obj;
if (width != bs.width) {
return false;
}
if (join != bs.join) {
return false;
}
if (cap != bs.cap) {
return false;
}
if (miterlimit != bs.miterlimit) {
return false;
}
if (dash != null) {
if (dash_phase != bs.dash_phase) {
return false;
}
if (!java.util.Arrays.equals(dash, bs.dash)) {
return false;
}
}
else if (bs.dash != null) {
return false;
}
return true;
}
}