Package 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:

  • Constructor Summary

    Constructors
    Constructor
    Description
    Region()
    Constructs a new empty region.
    Region(Device device)
    Constructs a new empty region.

  • Method Summary

    Modifier and Type
    Method
    Description
    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 long
    win32_getHandle(Region region, int zoom)
    IMPORTANT: This method is not part of the public API for Image.

    Methods inherited from class org.eclipse.swt.graphics.Resource

    dispose, getDevice, setNonDisposeHandler

    Methods inherited from class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • Region

      public Region()
      Constructs a new empty region.

      You must dispose the region when it is no longer required.

      Throws:
      SWTError -
      • ERROR_NO_HANDLES if a handle could not be obtained for region creation
      See Also:

    • 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:

  • Method Details

    • 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:

    • 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:

    • 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:

    • 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:

    • 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:

    • 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 (except Resource.dispose()) 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

    • win32_getHandle

      public static long win32_getHandle(Region region, int zoom)
      IMPORTANT: This method is not part of the public API for Image. 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. Gets the handle for the region scaled at required zoom level
      Parameters:
      region - the region to be scaled
      zoom - the zoom level for which the region is needed
      Returns:
      the handle of the region scaled for the zoom level
      Restriction:
      This method is not intended to be referenced by clients.

    • 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