org.eclipse.swt.graphics
Class Region
java.lang.Object
org.eclipse.swt.graphics.Resource
org.eclipse.swt.graphics.Region
-
public final class Region
- extends
Resource
Instances of this class represent areas of an x-y coordinate
system that are aggregates of the areas covered by a number
of polygons.
Application code must explicitly invoke the Region.dispose()
method to release the operating system resources managed by each instance
when those instances are no longer required.
-
See Also:
-
SWT Example: GraphicsExample,
Sample code and further information
Field Summary
|
int
|
handle
the OS resource for the region
(Warning: This field is platform dependent)
IMPORTANT: This field is not part of the SWT
public API. |
Constructor Summary
|
Region
()
Constructs a new empty region. |
Region
(
Device device)
Constructs a new empty region. |
Method Summary
|
void
|
add
(int[] pointArray)
Adds the given polygon to the collection of polygons
the receiver maintains to describe its area. |
void
|
add
(int x,
int y,
int width,
int height)
Adds the given rectangle to the collection of polygons
the receiver maintains to describe its area. |
void
|
add
(
Rectangle rect)
Adds the given rectangle to the collection of polygons
the receiver maintains to describe its area. |
void
|
add
(
Region region)
Adds all of the polygons which make up the area covered
by the argument to the collection of polygons the receiver
maintains to describe its area. |
boolean
|
contains
(int x,
int y)
Returns true if the point specified by the
arguments is inside the area specified by the receiver,
and false otherwise. |
boolean
|
contains
(
Point pt)
Returns true if the given point is inside the
area specified by the receiver, and false
otherwise. |
boolean
|
equals
(
Object object)
Compares the argument to the receiver, and returns true
if they represent the same object using a class
specific comparison. |
Rectangle
|
getBounds
()
Returns a rectangle which represents the rectangular
union of the collection of polygons the receiver
maintains to describe its area. |
int
|
hashCode
()
Returns an integer hash code for the receiver. |
void
|
intersect
(int x,
int y,
int width,
int height)
Intersects the given rectangle to the collection of polygons
the receiver maintains to describe its area. |
void
|
intersect
(
Rectangle rect)
Intersects the given rectangle to the collection of polygons
the receiver maintains to describe its area. |
void
|
intersect
(
Region region)
Intersects all of the polygons which make up the area covered
by the argument to the collection of polygons the receiver
maintains to describe its area. |
boolean
|
intersects
(int x,
int y,
int width,
int height)
Returns true if the rectangle described by the
arguments intersects with any of the polygons the receiver
maintains to describe its area, and false otherwise. |
boolean
|
intersects
(
Rectangle rect)
Returns true if the given rectangle intersects
with any of the polygons the receiver maintains to describe
its area and false otherwise. |
boolean
|
isDisposed
()
Returns true if the region has been disposed,
and false otherwise. |
boolean
|
isEmpty
()
Returns true if the receiver does not cover any
area in the (x, y) coordinate plane, and false if
the receiver does cover some area in the plane. |
void
|
subtract
(int[] pointArray)
Subtracts the given polygon from the collection of polygons
the receiver maintains to describe its area. |
void
|
subtract
(int x,
int y,
int width,
int height)
Subtracts the given rectangle from the collection of polygons
the receiver maintains to describe its area. |
void
|
subtract
(
Rectangle rect)
Subtracts the given rectangle from the collection of polygons
the receiver maintains to describe its area. |
void
|
subtract
(
Region region)
Subtracts all of the polygons which make up the area covered
by the argument from the collection of polygons the receiver
maintains to describe its area. |
String
|
toString
()
Returns a string containing a concise, human-readable
description of the receiver. |
void
|
translate
(int x,
int y)
Translate all of the polygons the receiver maintains to describe
its area by the specified point. |
void
|
translate
(
Point pt)
Translate all of the polygons the receiver maintains to describe
its area by the specified point. |
static
Region
|
win32_new
(
Device device,
int handle)
Invokes platform specific functionality to allocate a new region. |
handle
public int handle
- the OS resource for the region
(Warning: This field is platform dependent)
IMPORTANT: This field is not part of the SWT
public API. It is marked public only so that it can be shared
within the packages provided by SWT. It is not available on all
platforms and should never be accessed from application code.
Region
public Region()
- Constructs a new empty region.
-
Throws:
-
SWTError
-
- ERROR_NO_HANDLES if a handle could not be obtained for region creation
Region
public Region(
Device device)
- Constructs a new empty region.
You must dispose the region when it is no longer required.
-
Parameters:
-
device
- the device on which to allocate the region
-
Throws:
-
IllegalArgumentException
-
- ERROR_NULL_ARGUMENT - if device is null and there is no current device
-
SWTError
-
- ERROR_NO_HANDLES if a handle could not be obtained for region creation
-
Since:
- 3.0
-
See Also:
-
Resource.dispose()
add
public void add(int[] pointArray)
- Adds the given polygon to the collection of polygons
the receiver maintains to describe its area.
-
-
Parameters:
-
pointArray
- points that describe the polygon to merge with the receiver
-
Throws:
-
IllegalArgumentException
-
- ERROR_NULL_ARGUMENT - if the argument is null
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
-
Since:
- 3.0
add
public void add(
Rectangle rect)
- Adds the given rectangle to the collection of polygons
the receiver maintains to describe its area.
-
-
Parameters:
-
rect
- the rectangle to merge with the receiver
-
Throws:
-
IllegalArgumentException
-
- ERROR_NULL_ARGUMENT - if the argument is null
- ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
add
public void add(int x,
int y,
int width,
int height)
- Adds the given rectangle to the collection of polygons
the receiver maintains to describe its area.
-
-
Parameters:
-
x
- the x coordinate of the rectangle -
y
- the y coordinate of the rectangle -
width
- the width coordinate of the rectangle -
height
- the height coordinate of the rectangle
-
Throws:
-
IllegalArgumentException
-
- ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
-
Since:
- 3.1
add
public void add(
Region region)
- Adds all of the polygons which make up the area covered
by the argument to the collection of polygons the receiver
maintains to describe its area.
-
-
Parameters:
-
region
- the region to merge
-
Throws:
-
IllegalArgumentException
-
- ERROR_NULL_ARGUMENT - if the argument is null
- ERROR_INVALID_ARGUMENT - if the argument has been disposed
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
contains
public boolean contains(int x,
int y)
- Returns
true
if the point specified by the
arguments is inside the area specified by the receiver,
and false
otherwise.
-
-
Parameters:
-
x
- the x coordinate of the point to test for containment -
y
- the y coordinate of the point to test for containment
-
Returns:
-
true
if the region contains the point and false
otherwise
-
Throws:
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
contains
public boolean contains(
Point pt)
- Returns
true
if the given point is inside the
area specified by the receiver, and false
otherwise.
-
-
Parameters:
-
pt
- the point to test for containment
-
Returns:
-
true
if the region contains the point and false
otherwise
-
Throws:
-
IllegalArgumentException
-
- ERROR_NULL_ARGUMENT - if the argument is null
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
equals
public boolean equals(
Object object)
- Compares the argument to the receiver, and returns true
if they represent the same object using a class
specific comparison.
-
-
Overrides:
-
equals
in class
Object
-
-
Parameters:
-
object
- the object to compare with this object
-
Returns:
-
true
if the object is the same as this object and false
otherwise -
See Also:
-
hashCode()
getBounds
public
Rectangle getBounds()
- Returns a rectangle which represents the rectangular
union of the collection of polygons the receiver
maintains to describe its area.
-
-
Returns:
- a bounding rectangle for the region
-
Throws:
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
-
See Also:
-
Rectangle.union(org.eclipse.swt.graphics.Rectangle)
hashCode
public int hashCode()
- Returns an integer hash code for the receiver. Any two
objects that return
true
when passed to
equals
must return the same value for this
method.
-
-
Overrides:
-
hashCode
in class
Object
-
-
Returns:
- the receiver's hash
-
See Also:
-
equals(java.lang.Object)
intersect
public void intersect(
Rectangle rect)
- Intersects the given rectangle to the collection of polygons
the receiver maintains to describe its area.
-
-
Parameters:
-
rect
- the rectangle to intersect with the receiver
-
Throws:
-
IllegalArgumentException
-
- ERROR_NULL_ARGUMENT - if the argument is null
- ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
-
Since:
- 3.0
intersect
public void intersect(int x,
int y,
int width,
int height)
- Intersects the given rectangle to the collection of polygons
the receiver maintains to describe its area.
-
-
Parameters:
-
x
- the x coordinate of the rectangle -
y
- the y coordinate of the rectangle -
width
- the width coordinate of the rectangle -
height
- the height coordinate of the rectangle
-
Throws:
-
IllegalArgumentException
-
- ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
-
Since:
- 3.1
intersect
public void intersect(
Region region)
- Intersects all of the polygons which make up the area covered
by the argument to the collection of polygons the receiver
maintains to describe its area.
-
-
Parameters:
-
region
- the region to intersect
-
Throws:
-
IllegalArgumentException
-
- ERROR_NULL_ARGUMENT - if the argument is null
- ERROR_INVALID_ARGUMENT - if the argument has been disposed
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
-
Since:
- 3.0
intersects
public boolean intersects(int x,
int y,
int width,
int height)
- Returns
true
if the rectangle described by the
arguments intersects with any of the polygons the receiver
maintains to describe its area, and false
otherwise.
-
-
Parameters:
-
x
- the x coordinate of the origin of the rectangle -
y
- the y coordinate of the origin of the rectangle -
width
- the width of the rectangle -
height
- the height of the rectangle
-
Returns:
-
true
if the rectangle intersects with the receiver, and false
otherwise
-
Throws:
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
-
See Also:
-
Rectangle.intersects(Rectangle)
intersects
public boolean intersects(
Rectangle rect)
- Returns
true
if the given rectangle intersects
with any of the polygons the receiver maintains to describe
its area and false
otherwise.
-
-
Parameters:
-
rect
- the rectangle to test for intersection
-
Returns:
-
true
if the rectangle intersects with the receiver, and false
otherwise
-
Throws:
-
IllegalArgumentException
-
- ERROR_NULL_ARGUMENT - if the argument is null
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
-
See Also:
-
Rectangle.intersects(Rectangle)
isDisposed
public boolean isDisposed()
- Returns
true
if the region has been disposed,
and false
otherwise.
This method gets the dispose state for the region.
When a region has been disposed, it is an error to
invoke any other method using the region.
-
-
Specified by:
-
isDisposed
in class
Resource
-
-
Returns:
-
true
when the region is disposed, and false
otherwise
isEmpty
public boolean isEmpty()
- Returns
true
if the receiver does not cover any
area in the (x, y) coordinate plane, and false
if
the receiver does cover some area in the plane.
-
-
Returns:
-
true
if the receiver is empty, and false
otherwise
-
Throws:
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
subtract
public void subtract(int[] pointArray)
- Subtracts the given polygon from the collection of polygons
the receiver maintains to describe its area.
-
-
Parameters:
-
pointArray
- points that describe the polygon to merge with the receiver
-
Throws:
-
IllegalArgumentException
-
- ERROR_NULL_ARGUMENT - if the argument is null
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
-
Since:
- 3.0
subtract
public void subtract(
Rectangle rect)
- Subtracts the given rectangle from the collection of polygons
the receiver maintains to describe its area.
-
-
Parameters:
-
rect
- the rectangle to subtract from the receiver
-
Throws:
-
IllegalArgumentException
-
- ERROR_NULL_ARGUMENT - if the argument is null
- ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
-
Since:
- 3.0
subtract
public void subtract(int x,
int y,
int width,
int height)
- Subtracts the given rectangle from the collection of polygons
the receiver maintains to describe its area.
-
-
Parameters:
-
x
- the x coordinate of the rectangle -
y
- the y coordinate of the rectangle -
width
- the width coordinate of the rectangle -
height
- the height coordinate of the rectangle
-
Throws:
-
IllegalArgumentException
-
- ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
-
Since:
- 3.1
subtract
public void subtract(
Region region)
- Subtracts all of the polygons which make up the area covered
by the argument from the collection of polygons the receiver
maintains to describe its area.
-
-
Parameters:
-
region
- the region to subtract
-
Throws:
-
IllegalArgumentException
-
- ERROR_NULL_ARGUMENT - if the argument is null
- ERROR_INVALID_ARGUMENT - if the argument has been disposed
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
-
Since:
- 3.0
translate
public void translate(int x,
int y)
- Translate all of the polygons the receiver maintains to describe
its area by the specified point.
-
-
Parameters:
-
x
- the x coordinate of the point to translate -
y
- the y coordinate of the point to translate
-
Throws:
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
-
Since:
- 3.1
translate
public void translate(
Point pt)
- Translate all of the polygons the receiver maintains to describe
its area by the specified point.
-
-
Parameters:
-
pt
- the point to translate
-
Throws:
-
IllegalArgumentException
-
- ERROR_NULL_ARGUMENT - if the argument is null
-
SWTException
-
- ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
-
Since:
- 3.1
toString
public
String toString()
- Returns a string containing a concise, human-readable
description of the receiver.
-
-
Overrides:
-
toString
in class
Object
-
-
Returns:
- a string representation of the receiver
win32_new
public static
Region win32_new(
Device device,
int handle)
- Invokes platform specific functionality to allocate a new region.
IMPORTANT: This method is not part of the public
API for Region
. It is marked public only so that it
can be shared within the packages provided by SWT. It is not
available on all platforms, and should never be called from
application code.
-
-
Parameters:
-
device
- the device on which to allocate the region -
handle
- the handle for the region
-
Returns:
- a new region object containing the specified device and handle
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