java.awt

Class BasicStroke

java.lang.Object

java.awt.BasicStroke

All Implemented Interfaces:

Stroke

public class BasicStroke
extends Object
implements Stroke

The BasicStroke class defines a basic set of rendering attributes for the outlines of graphics primitives, which are rendered with a 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 Shape and the decorations applied at the ends and joins of path segments of the Shape. These rendering attributes include:

width

The pen width, measured perpendicularly to the pen trajectory.

end caps

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 SEG_CLOSE for more information on the CLOSE segment. The three different decorations are: CAP_BUTT, CAP_ROUND, and CAP_SQUARE.

line joins

The decoration applied at the intersection of two path segments and at the intersection of the endpoints of a subpath that is closed using SEG_CLOSE. The three different decorations are: JOIN_BEVEL, JOIN_MITER, and JOIN_ROUND.

miter limit

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.

dash attributes

The definition of how to make a dash pattern by alternating between opaque and transparent sections.

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 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 Also:

Graphics2D

Field Summary

Fields

Modifier and Type	Field and Description
static int	CAP_BUTT Ends unclosed subpaths and dash segments with no added decoration.
static int	CAP_ROUND Ends unclosed subpaths and dash segments with a round decoration that has a radius equal to half of the width of the pen.
static int	CAP_SQUARE 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.
static int	JOIN_BEVEL Joins path segments by connecting the outer corners of their wide outlines with a straight segment.
static int	JOIN_MITER Joins path segments by extending their outside edges until they meet.
static int	JOIN_ROUND Joins path segments by rounding off the corner at a radius of half the line width.

Constructor Summary

Constructors

Constructor and Description
BasicStroke() Constructs a new BasicStroke with defaults for all attributes.
BasicStroke(float width) Constructs a solid BasicStroke with the specified line width and with default values for the cap and join styles.
BasicStroke(float width, int cap, int join) Constructs a solid BasicStroke with the specified attributes.
BasicStroke(float width, int cap, int join, float miterlimit) Constructs a solid BasicStroke with the specified attributes.
BasicStroke(float width, int cap, int join, float miterlimit, float[] dash, float dash_phase) Constructs a new BasicStroke with the specified attributes.

Method Summary

Methods

Modifier and Type	Method and Description
Shape	createStrokedShape(Shape s) Returns a Shape whose interior defines the stroked outline of a specified Shape.
boolean	equals(Object obj) 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.
float[]	getDashArray() Returns the array representing the lengths of the dash segments.
float	getDashPhase() Returns the current dash phase.
int	getEndCap() Returns the end cap style.
int	getLineJoin() Returns the line join style.
float	getLineWidth() Returns the line width.
float