com.goldencode.p2j.ui.client

Class Region

java.lang.Object

com.goldencode.p2j.ui.client.Region

public class Region
extends java.lang.Object

The Region class provides means to define, modify and iterate regions which are collections of rectangles. An important feature of regions is their ability to represent the set of rectangles in various ways having the same effect - they all should answer the question - whether a particular point belongs to the set or not - identically.

The current implementation is optimized to a level where there is no intersecting rectangles in the set and adjacent rectangles sharing a side are merged into a single one.

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	allInvalidated tracks the null rectangle case
private java.util.ArrayList<Rectangle>	rct array of individual non-nesting rectangles

Constructor Summary

Constructors

Constructor and Description
Region() Constructor.
Region(Rectangle rect) Constructor taking an initial rectangle.

Method Summary

Modifier and Type	Method and Description
void	addRectangle(Rectangle rect) Adds a rectangle to this region.
int	contains(double x, double y) Checks whether the region contains the given point.
int	contains(Point p) Checks whether the region contains the given point.
boolean	isEmpty() Checks whether the region is empty.
java.util.Iterator<Rectangle>	iterator() Gets an iterator for the region.
void	resetRegion() Clears this region entirely.
java.lang.String	toString() Gets a string representation of this region.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

rct

private java.util.ArrayList<Rectangle> rct

array of individual non-nesting rectangles

allInvalidated

private boolean allInvalidated

tracks the null rectangle case

Constructor Detail

Region

public Region()

Constructor.

Region

public Region(Rectangle rect)

Constructor taking an initial rectangle.

Parameters:

rect - rectangle that is added initially to the region

Method Detail

addRectangle

public void addRectangle(Rectangle rect)

Adds a rectangle to this region. The region is newly optimized as soon as the rectangle is added

Parameters:

rect - rectangle that is to be added to the region

resetRegion

public void resetRegion()

Clears this region entirely.

isEmpty

public boolean isEmpty()

Checks whether the region is empty.

Returns:

true when region has no rectangles

contains

public int contains(Point p)

Checks whether the region contains the given point.

Parameters:

p - point to check

Returns:

index of the rectangle that contains the point or -1 if none

contains

public int contains(double x,
                    double y)

Checks whether the region contains the given point.

Parameters:

x - x-coordinate of the point to check

y - y-coordinate of the point to check

Returns:

index of the rectangle that contains the point or -1 if none

iterator

public java.util.Iterator<Rectangle> iterator()

Gets an iterator for the region.

Returns:

an iterator that can be used to traverse all rectangles of the region

toString

public java.lang.String toString()

Gets a string representation of this region.

Overrides:

toString in class java.lang.Object

Returns:

a string describing the region