public class Circle extends Object
| 构造器 | 说明 |
|---|---|
Circle(float x,
float y,
float radius) |
A constructor used to create a
Circle instance with specified center coordinates and radius. |
| 限定符和类型 | 方法 | 说明 |
|---|---|---|
boolean |
equals(Object object) |
Indicates whether some other object is "equal to" this one.
|
double |
getArea() |
Obtains the area of this circle.
|
Point |
getCenter() |
Obtains the center of this circle.
|
float |
getCenterX() |
Obtains the x-coordinate of the circle's center.
|
float |
getCenterY() |
Obtains the y-coordinate of the circle's center.
|
float |
getRadius() |
Obtains the radius of this circle.
|
int |
hashCode() |
Returns a hash code value for the object.
|
boolean |
isEmpty() |
Checks whether the radius of this circle is less than zero.
|
boolean |
isInclude(float x,
float y) |
Checks whether a specified point (x, y) is included in this circle.
|
boolean |
isInclude(float x1,
float y1,
float r1) |
Checks whether a circle with specified center coordinates and radius is included in this circle.
|
boolean |
isInclude(Circle circle) |
Checks whether a specified circle is included in this circle.
|
boolean |
isInclude(Point point) |
Checks whether a specified
Point instance is included in this circle. |
boolean |
isIntersect(float x1,
float y1,
float r1) |
Checks whether a circle, with specified center coordinates and radius, intersects this circle.
|
boolean |
isIntersect(Circle circle) |
Checks whether a specified circle intersects this circle.
|
void |
set(float x,
float y,
float radius) |
Sets attributes of this circle based on the specified center coordinates and radius.
|
void |
set(Circle circle) |
Sets attributes of this circle based on a specified circle.
|
void |
set(Point point,
float radius) |
Sets attributes of this circle based on a specified
Point instance and radius. |
void |
setCenter(float x,
float y) |
Sets the center of this circle based on specified coordinates.
|
void |
setCenter(Point point) |
Sets the center of this circle.
|
void |
setCenterX(float x) |
Sets the x-coordinate for the circle's center.
|
void |
setCenterY(float y) |
Sets the y-coordinate for the circle's center.
|
void |
setEmpty() |
Sets the circle's center coordinates to (0, 0) and the radius to zero.
|
void |
setRadius(float radius) |
Sets the radius for this circle.
|
void |
shrink(float size) |
Shrinks the radius of this circle.
|
void |
stretch(float size) |
Stretches the radius of this circle.
|
String |
toString() |
Returns a string representation of the object.
|
void |
translate(float dx,
float dy) |
Translates this circle by a specified distance.
|
void |
translate(Point point) |
Translates this circle, whose offsets on x- and y-axes are specified by a point.
|
void |
zoom(float factor) |
Zooms in or out this circle.
|
public Circle(float x,
float y,
float radius)
Circle instance with specified center coordinates and radius.x - Indicates the specified x-coordinate of the circle's center.y - Indicates the specified y-coordinate of the circle's center.radius - Indicates the specified radius of the circle.public boolean isEmpty()
true if the circle's radius is less than zero; returns false otherwise.public void set(float x,
float y,
float radius)
x - Indicates the specified x-coordinate of the circle's center.y - Indicates the specified y-coordinate of the circle's center.radius - Indicates the specified radius.public void setEmpty()
public boolean equals(Object object)
Object
The equals method implements an equivalence relation
on non-null object references:
x, x.equals(x) should return
true.
x and y, x.equals(y)
should return true if and only if
y.equals(x) returns true.
x, y, and z, if
x.equals(y) returns true and
y.equals(z) returns true, then
x.equals(z) should return true.
x and y, multiple invocations of
x.equals(y) consistently return true
or consistently return false, provided no
information used in equals comparisons on the
objects is modified.
x,
x.equals(null) should return false.
The equals method for class Object implements
the most discriminating possible equivalence relation on objects;
that is, for any non-null reference values x and
y, this method returns true if and only
if x and y refer to the same object
(x == y has the value true).
Note that it is generally necessary to override the hashCode
method whenever this method is overridden, so as to maintain the
general contract for the hashCode method, which states
that equal objects must have equal hash codes.
equals 在类中 Objectobject - the reference object with which to compare.true if this object is the same as the obj
argument; false otherwise.Object.hashCode(),
HashMappublic int hashCode()
ObjectHashMap.
The general contract of hashCode is:
hashCode method
must consistently return the same integer, provided no information
used in equals comparisons on the object is modified.
This integer need not remain consistent from one execution of an
application to another execution of the same application.
equals(Object)
method, then calling the hashCode method on each of
the two objects must produce the same integer result.
Object.equals(java.lang.Object)
method, then calling the hashCode method on each of the
two objects must produce distinct integer results. However, the
programmer should be aware that producing distinct integer results
for unequal objects may improve the performance of hash tables.
As much as is reasonably practical, the hashCode method defined by
class Object does return distinct integers for distinct
objects. (This is typically implemented by converting the internal
address of the object into an integer, but this implementation
technique is not required by the
Java™ programming language.)
hashCode 在类中 ObjectObject.equals(java.lang.Object),
System.identityHashCode(java.lang.Object)public String toString()
ObjecttoString method returns a string that
"textually represents" this object. The result should
be a concise but informative representation that is easy for a
person to read.
It is recommended that all subclasses override this method.
The toString method for class Object
returns a string consisting of the name of the class of which the
object is an instance, the at-sign character `@', and
the unsigned hexadecimal representation of the hash code of the
object. In other words, this method returns a string equal to the
value of:
getClass().getName() + '@' + Integer.toHexString(hashCode())
public void set(Point point, float radius)
Point instance and radius.point - Indicates the circle's center to set.radius - Indicates the circle's radius to set.public void set(Circle circle)
circle - Indicates the specified circle.public float getRadius()
public void setRadius(float radius)
radius - Indicates the radius to set.public Point getCenter()
public float getCenterX()
public float getCenterY()
public void setCenter(float x,
float y)
x - Indicates the x-coordinate of the center to set.y - Indicates the y-coordinate of the center to set.public void setCenter(Point point)
point - Indicates the center to set.public void setCenterX(float x)
x - Indicates the x-coordinate to set.public void setCenterY(float y)
y - Indicates the y-coordinate to set.public boolean isInclude(float x,
float y)
x - Indicates the x-coordinate of the specified point.y - Indicates the y-coordinate of the specified point.true if the specified point is included in the circle; returns false otherwise.public boolean isInclude(Point point)
Point instance is included in this circle.point - Indicates the specified Point instance.true if the specified Point instance is included in this circle;
returns false otherwise.public boolean isInclude(float x1,
float y1,
float r1)
x1 - Indicates the x-coordinate of the specified circle's center.y1 - Indicates the y-coordinate of the specified circle's center.r1 - Indicates the radius of the specified circle.true if the specified circle is included in this circle; returns false otherwise.public boolean isInclude(Circle circle)
circle - Indicates the specified circle.true if the specified circle is included in this circle; returns false otherwise.public boolean isIntersect(float x1,
float y1,
float r1)
x1 - Indicates the x-coordinate of the specified circle's center.y1 - Indicates the y-coordinate of the specified circle's center.r1 - Indicates the radius of the specified circle.true if the specified circle intersects this circle; returns false otherwise.public boolean isIntersect(Circle circle)
circle - Indicates the specified circle.true if the specified circle intersects this circle; returns false otherwise.public void zoom(float factor)
factor - Indicates the zoom factor.public void stretch(float size)
size - Indicates the length to extend the radius.public void shrink(float size)
size - Indicates the length to chop from the original radius.public void translate(float dx,
float dy)
dx - Indicates the offset of the circle on the x-axis.dy - Indicates the offset of the circle on the y-axis.public void translate(Point point)
point - Indicates the point that specifies the circle's offsets on x- and y-axes.public double getArea()