edu.rit.draw.item

Class Arc

java.lang.Object

edu.rit.draw.item.DrawingItem

edu.rit.draw.item.OutlinedItem

edu.rit.draw.item.Arc

All Implemented Interfaces:

java.io.Externalizable, java.io.Serializable

public class Arc
extends OutlinedItem
implements java.io.Externalizable

Class Arc provides a DrawingItem that is a circular arc. The arc has an outline but no filled interior. The arc is defined by the following attributes:

• center() -- The arc's center point. The default is (0,0).
  
• radius() -- The arc's radius. The default is 1.
  
• start() -- The arc's starting angle in radians. This is the angle from the positive X axis to the arc's starting point. The default is 0.
  
• extent() -- The arc's angular extent in radians. This is the angle from the arc's starting point to the arc's ending point. The default is π/2.

Angles increase from the positive X axis towards the positive Y axis. Since the positive X axis points to the right and the positive Y axis points down, angles increase in the clockwise direction. (This is the opposite of the usual mathematical convention, where the positive Y axis points upwards.)

The static defaultCenter(), defaultRadius(), defaultStart(), and defaultExtent() methods are provided to set the default center point, radius, starting angle, and angular extent. If the center point, radius, starting angle, or angular extent is not specified, the current default center point, radius, starting angle, or angular extent is used.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static Point	NORMAL_CENTER The normal center point: (0,0).
static double	NORMAL_EXTENT The normal angular extent: π/2.
static double	NORMAL_RADIUS The normal radius: 1.
static double	NORMAL_START The normal starting angle: 0.

Fields inherited from class edu.rit.draw.item.OutlinedItem

NORMAL_OUTLINE

Constructor Summary

Constructors

Constructor and Description
Arc() Construct a new arc.
Arc(Arc theArc) Construct a new arc with the same center point, radius, starting angle, and angular extent as the given arc.

Method Summary

Modifier and Type	Method and Description
Arc	add() Add this arc to the end of the default drawing's sequence of drawing items.
Arc	add(Drawing theDrawing) Add this arc to the end of the given drawing's sequence of drawing items.
Arc	addFirst() Add this arc to the beginning of the default drawing's sequence of drawing items.
Arc	addFirst(Drawing theDrawing) Add this arc to the beginning of the given drawing's sequence of drawing items.
Point	center() Returns this arc's center point.
Arc	center(Point theCenter) Set this arc's center point.
static Point	defaultCenter() Returns the default center point.
static void	defaultCenter(Point theCenter) Set the default center point.
static double	defaultExtent() Returns the default angular extent.
static void	defaultExtent(double theExtent) Set the default angular extent.
static double	defaultRadius() Returns the default radius.
static void	defaultRadius(double theRadius) Set the default radius.
static double	defaultStart() Returns the default starting angle.
static void	defaultStart(double theStart) Set the default starting angle.
void	draw(java.awt.Graphics2D g2d) Draw this drawing item in the given graphics context.
double	extent() Returns this arc's angular extent.
Arc	extent(double theExtent) Set this arc's angular extent.
double	height() Returns the height of this drawing item's bounding box.
Point	nw() Returns the northwest corner point of this drawing item's bounding box.
Arc	outline(Outline theOutline) Set this arc's outline.
double	radius() Returns this arc's radius.
Arc	radius(double theRadius) Set this arc's radius.
void	readExternal(java.io.ObjectInput in) Read this arc from the given object input stream.
Size	size() Returns the size of this drawing item's bounding box.
double	start() Returns this arc's starting angle.
Arc	start(double theStart) Set this arc's starting angle.
double	width() Returns the width of this drawing item's bounding box.
void	writeExternal(java.io.ObjectOutput out) Write this arc to the given object output stream.

Methods inherited from class edu.rit.draw.item.OutlinedItem

defaultOutline, defaultOutline, outline

Methods inherited from class edu.rit.draw.item.DrawingItem

boundingBox, c, e, n, ne, s, se, sw, w

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NORMAL_CENTER

public static final Point NORMAL_CENTER

The normal center point: (0,0).

NORMAL_RADIUS

public static final double NORMAL_RADIUS

The normal radius: 1.

See Also:

Constant Field Values

NORMAL_START

public static final double NORMAL_START

The normal starting angle: 0.

See Also:

Constant Field Values

NORMAL_EXTENT

public static final double NORMAL_EXTENT

The normal angular extent: π/2.

See Also:

Constant Field Values

Constructor Detail

Arc

public Arc()

Construct a new arc. The default center point, radius, starting angle, and angular extent are used.

Arc

public Arc(Arc theArc)

Construct a new arc with the same center point, radius, starting angle, and angular extent as the given arc.

Parameters:

theArc - Arc.

Throws:

java.lang.NullPointerException - (unchecked exception) Thrown if theArc is null.

Method Detail

defaultCenter

public static Point defaultCenter()

Returns the default center point.

Returns:

Default center point.

defaultCenter

public static void defaultCenter(Point theCenter)

Set the default center point. Before calling this method the first time, the default center point is (0,0).

Parameters:

theCenter - Default center point.

Throws:

java.lang.NullPointerException - (unchecked exception) Thrown if theCenter is null.

defaultRadius

public static double defaultRadius()

Returns the default radius.

Returns:

Default radius.

defaultRadius

public static void defaultRadius(double theRadius)

Set the default radius. Before calling this method the first time, the default radius is 1.

Parameters:

theRadius - Default radius.

Throws:

java.lang.IllegalArgumentException - (unchecked exception) Thrown if theRadius <= 0.

defaultStart

public static double defaultStart()

Returns the default starting angle.

Returns:

Default starting angle (radians).

defaultStart

public static void defaultStart(double theStart)

Set the default starting angle. Before calling this method the first time, the default starting angle is 0.

Parameters:

theStart - Default starting angle (radians).

defaultExtent

public static double defaultExtent()

Returns the default angular extent.

Returns:

Default angular extent (radians).

defaultExtent

public static void defaultExtent(double theExtent)

Set the default angular extent. Before calling this method the first time, the default angular extent is π/2.

Parameters:

theExtent - Default angular extent (radians).

size

public Size size()

Returns the size of this drawing item's bounding box.

Overrides:

size in class DrawingItem

Returns:

Size.

width

public double width()

Returns the width of this drawing item's bounding box.

Specified by:

width in class DrawingItem

Returns:

Width.

height

public double height()

Returns the height of this drawing item's bounding box.

Specified by:

height in class DrawingItem

Returns:

Height.

nw

public Point nw()

Returns the northwest corner point of this drawing item's bounding box.

Specified by:

nw in class DrawingItem

Returns:

Northwest corner point.

outline

public Arc outline(Outline theOutline)

Set this arc's outline.

Overrides:

outline in class OutlinedItem

Parameters:

theOutline - Outline, or Outline.NONE.

Returns:

This arc.

center

public Point center()

Returns this arc's center point.

Returns:

Center point.

center

public Arc center(Point theCenter)

Set this arc's center point.

Parameters:

theCenter - Center point.

Returns:

This arc.

Throws:

java.lang.NullPointerException - (unchecked exception) Thrown if theCenter is null.

radius

public double radius()

Returns this arc's radius.

Returns:

Radius.

radius

public Arc radius(double theRadius)

Set this arc's radius.

Parameters:

theRadius - Radius.

Returns:

This arc.

Throws:

java.lang.IllegalArgumentException - (unchecked exception) Thrown if theRadius <= 0.

start

public double start()

Returns this arc's starting angle.

Returns:

Starting angle (radians).

start

public Arc start(double theStart)

Set this arc's starting angle.

Parameters:

theStart - Starting angle (radians).

Returns:

This arc.

extent

public double extent()

Returns this arc's angular extent.

Returns:

Angular extent (radians).

extent

public Arc extent(double theExtent)

Set this arc's angular extent.

Parameters:

theExtent - Angular extent (radians).

Returns:

This arc.

add

public Arc add()

Add this arc to the end of the default drawing's sequence of drawing items.

Overrides:

add in class OutlinedItem

Returns:

This arc.

Throws:

java.lang.NullPointerException - (unchecked exception) Thrown if there is no default drawing.

See Also:

Drawing.defaultDrawing()

add

public Arc add(Drawing theDrawing)

Add this arc to the end of the given drawing's sequence of drawing items.

Overrides:

add in class OutlinedItem

Parameters:

theDrawing - Drawing.

Returns:

This arc.

Throws:

java.lang.NullPointerException - (unchecked exception) Thrown if theDrawing is null.

addFirst

public Arc addFirst()

Add this arc to the beginning of the default drawing's sequence of drawing items.

Overrides:

addFirst in class OutlinedItem

Returns:

This arc.

Throws:

java.lang.NullPointerException - (unchecked exception) Thrown if there is no default drawing.

See Also:

Drawing.defaultDrawing()

addFirst

public Arc addFirst(Drawing theDrawing)

Add this arc to the beginning of the given drawing's sequence of drawing items.

Overrides:

addFirst in class OutlinedItem

Parameters:

theDrawing - Drawing.

Returns:

This arc.

Throws:

java.lang.NullPointerException - (unchecked exception) Thrown if theDrawing is null.

writeExternal

public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException

Write this arc to the given object output stream.

Specified by:

writeExternal in interface java.io.Externalizable

Overrides:

writeExternal in class OutlinedItem

Parameters:

out - Object output stream.

Throws:

java.io.IOException - Thrown if an I/O error occurred.

readExternal

public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException

Read this arc from the given object input stream.

Specified by:

readExternal in interface java.io.Externalizable

Overrides:

readExternal in class OutlinedItem

Parameters:

in - Object input stream.

Throws:

java.io.IOException - Thrown if an I/O error occurred.

java.lang.ClassNotFoundException - Thrown if any class needed to deserialize this line cannot be found.

draw

public void draw(java.awt.Graphics2D g2d)

Draw this drawing item in the given graphics context. This method is allowed to change the graphics context's paint, stroke, and transform, and it doesn't have to change them back.

Overrides:

draw in class DrawingItem

Parameters:

g2d - 2-D graphics context.