BasicStroke 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 BasicStroke.
* The rendering attributes defined by BasicStroke 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 Shape.
* These rendering attributes include:
* Shape
* argument. When a Graphics2D object uses a
* Stroke object to redefine a path during the execution
* of one of its draw methods, the geometry is supplied
* in its original form before the Graphics2D transform
* attribute is applied. Therefore, attributes such as the pen width
* are interpreted in the user space coordinate system of the
* Graphics2D object and are subject to the scaling and
* shearing effects of the user-space-to-device-space transform in that
* particular Graphics2D.
* For example, the width of a rendered shape's outline is determined
* not only by the width attribute of this BasicStroke,
* but also by the transform attribute of the
* Graphics2D object. Consider this code:
* * // sets the Graphics2D object's Tranform attribute * g2d.scale(10, 10); * // sets the Graphics2D object's Stroke attribute * g2d.setStroke(new BasicStroke(1.5f)); ** Assuming there are no other scaling transforms added to the *
Graphics2D 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 Graphics2D 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.
*
* For more information on the user space coordinate system and the
* rendering process, see the Graphics2D class comments.
* @see Graphics2D
* @version 1.42, 01/04/05
* @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 BasicStroke with the specified
* attributes.
* @param width the width of this BasicStroke. 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 BasicStroke
* @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 width is negative
* @throws IllegalArgumentException if cap is not either
* CAP_BUTT, CAP_ROUND or CAP_SQUARE
* @throws IllegalArgumentException if miterlimit is less
* than 1 and join is JOIN_MITER
* @throws IllegalArgumentException if join is not
* either JOIN_ROUND, JOIN_BEVEL, or JOIN_MITER
* @throws IllegalArgumentException if dash_phase
* is negative and dash is not null
* @throws IllegalArgumentException if the length of
* dash is zero
* @throws IllegalArgumentException if dash lengths are all zero.
*/
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 BasicStroke with the specified
* attributes.
* @param width the width of the BasicStroke
* @param cap the decoration of the ends of a BasicStroke
* @param join the decoration applied where path segments meet
* @param miterlimit the limit to trim the miter join
* @throws IllegalArgumentException if width is negative
* @throws IllegalArgumentException if cap is not either
* CAP_BUTT, CAP_ROUND or CAP_SQUARE
* @throws IllegalArgumentException if miterlimit is less
* than 1 and join is JOIN_MITER
* @throws IllegalArgumentException if join 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 BasicStroke with the specified
* attributes. The miterlimit 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 BasicStroke
* @param cap the decoration of the ends of a BasicStroke
* @param join the decoration applied where path segments meet
* @throws IllegalArgumentException if width is negative
* @throws IllegalArgumentException if cap is not either
* CAP_BUTT, CAP_ROUND or CAP_SQUARE
* @throws IllegalArgumentException if join 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 BasicStroke with the specified
* line width and with default values for the cap and join
* styles.
* @param width the width of the BasicStroke
* @throws IllegalArgumentException if width is negative
*/
public BasicStroke(float width) {
this(width, CAP_SQUARE, JOIN_MITER, 10.0f, null, 0.0f);
}
/**
* Constructs a new BasicStroke 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 Shape whose interior defines the
* stroked outline of a specified Shape.
* @param s the Shape boundary be stroked
* @return the Shape of the stroked outline.
*/
public Shape createStrokedShape(Shape s) {
FillAdapter filler = new FillAdapter();
PathStroker stroker = new PathStroker(filler);
PathDasher dasher = null;
try {
PathConsumer consumer;
stroker.setPenDiameter(width);
stroker.setPenT4(null);
stroker.setCaps(RasterizerCaps[cap]);
stroker.setCorners(RasterizerCorners[join], miterlimit);
if (dash != null) {
dasher = new PathDasher(stroker);
dasher.setDash(dash, dash_phase);
dasher.setDashT4(null);
consumer = dasher;
} else {
consumer = stroker;
}
feedConsumer(consumer, s.getPathIterator(null));
} finally {
stroker.dispose();
if (dasher != null) {
dasher.dispose();
}
}
return filler.getShape();
}
private void feedConsumer(PathConsumer consumer, PathIterator pi) {
try {
consumer.beginPath();
boolean pathClosed = false;
float mx = 0.0f;
float my = 0.0f;
float point[] = new float[6];
while (!pi.isDone()) {
int type = pi.currentSegment(point);
if (pathClosed == true) {
pathClosed = false;
if (type != PathIterator.SEG_MOVETO) {
// Force current point back to last moveto point
consumer.beginSubpath(mx, my);
}
}
switch (type) {
case PathIterator.SEG_MOVETO:
mx = point[0];
my = point[1];
consumer.beginSubpath(point[0], point[1]);
break;
case PathIterator.SEG_LINETO:
consumer.appendLine(point[0], point[1]);
break;
case PathIterator.SEG_QUADTO:
// Quadratic curves take two points
consumer.appendQuadratic(point[0], point[1],
point[2], point[3]);
break;
case PathIterator.SEG_CUBICTO:
// Cubic curves take three points
consumer.appendCubic(point[0], point[1],
point[2], point[3],
point[4], point[5]);
break;
case PathIterator.SEG_CLOSE:
consumer.closedSubpath();
pathClosed = true;
break;
}
pi.next();
}
consumer.endPath();
} catch (PathException e) {
throw new InternalError("Unable to Stroke shape ("+
e.getMessage()+")");
}
}
/**
* Returns the line width. Line width is represented in user space,
* which is the default-coordinate space used by Java 2D. See the
* Graphics2D class comments for more information on
* the user space coordinate system.
* @return the line width of this BasicStroke.
* @see Graphics2D
*/
public float getLineWidth() {
return width;
}
/**
* Returns the end cap style.
* @return the end cap style of this BasicStroke as one
* of the static int values that define possible end cap
* styles.
*/
public int getEndCap() {
return cap;
}
/**
* Returns the line join style.
* @return the line join style of the BasicStroke as one
* of the static int 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 BasicStroke.
*/
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 Shape
* 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 float 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 BasicStroke
* by first testing if it is a BasicStroke and then comparing
* its width, join, cap, miter limit, dash, and dash phase attributes with
* those of this BasicStroke.
* @param obj the specified object to compare to this
* BasicStroke
* @return true if the width, join, cap, miter limit, dash, and
* dash phase are the same for both objects;
* false 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;
}
private static final int RasterizerCaps[] = {
Rasterizer.BUTT, Rasterizer.ROUND, Rasterizer.SQUARE
};
private static final int RasterizerCorners[] = {
Rasterizer.MITER, Rasterizer.ROUND, Rasterizer.BEVEL
};
private class FillAdapter implements PathConsumer {
boolean closed;
GeneralPath path;
public FillAdapter() {
path = new GeneralPath(GeneralPath.WIND_NON_ZERO);
}
public Shape getShape() {
return path;
}
public void dispose() {
}
public PathConsumer getConsumer() {
return null;
}
public void beginPath() {}
public void beginSubpath(float x0, float y0) {
if (closed) {
path.closePath();
closed = false;
}
path.moveTo(x0, y0);
}
public void appendLine(float x1, float y1) {
path.lineTo(x1, y1);
}
public void appendQuadratic(float xm, float ym, float x1, float y1) {
path.quadTo(xm, ym, x1, y1);
}
public void appendCubic(float xm, float ym,
float xn, float yn,
float x1, float y1) {
path.curveTo(xm, ym, xn, yn, x1, y1);
}
public void closedSubpath() {
closed = true;
}
public void endPath() {
if (closed) {
path.closePath();
closed = false;
}
}
public void useProxy(FastPathProducer proxy)
throws PathException
{
proxy.sendTo(this);
}
public long getCPathConsumer() {
return 0;
}
}
}