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Diffstat (limited to 'projects/net.wotonomy.foundation/src/main/java/net/wotonomy/foundation/NSRange.java')
| -rw-r--r-- | projects/net.wotonomy.foundation/src/main/java/net/wotonomy/foundation/NSRange.java | 351 |
1 files changed, 351 insertions, 0 deletions
diff --git a/projects/net.wotonomy.foundation/src/main/java/net/wotonomy/foundation/NSRange.java b/projects/net.wotonomy.foundation/src/main/java/net/wotonomy/foundation/NSRange.java new file mode 100644 index 0000000..2de52f5 --- /dev/null +++ b/projects/net.wotonomy.foundation/src/main/java/net/wotonomy/foundation/NSRange.java @@ -0,0 +1,351 @@ +/* +Wotonomy: OpenStep design patterns for pure Java applications. +Copyright (C) 2000 Blacksmith, Inc. + +This library is free software; you can redistribute it and/or +modify it under the terms of the GNU Lesser General Public +License as published by the Free Software Foundation; either +version 2.1 of the License, or (at your option) any later version. + +This library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Lesser General Public License for more details. + +You should have received a copy of the GNU Lesser General Public +License along with this library; if not, see http://www.gnu.org +*/ + +package net.wotonomy.foundation; + +/** +* A pure java implementation of NSRange. +* An NSRange represents a range of numbers +* having a starting location and spanning a +* length. +* +* @author michael@mpowers.net +* @author $Author: cgruber $ +* @version $Revision: 920 $ +*/ +public class NSRange implements Cloneable +{ + /** + * An empty range. + */ + public static final NSRange ZeroRange = new NSRange(); + + protected int loc; + protected int len; + + /** + * Default constructor produces an empty range. + */ + public NSRange () + { + this( 0, 0 ); + } + + /** + * Produces a range with the specified location and length. + */ + public NSRange (int location, int length) + { + loc = location; + len = length; + } + + /** + * Produces a range that has the same location and length as + * the specified range. + */ + public NSRange (NSRange aRange) + { + this( aRange.location(), aRange.length() ); + } + + /** + * Returns the location of this range. + */ + public int location () + { + return loc; + } + + /** + * Returns the length of this range. + */ + public int length () + { + return len; + } + + /** + * Returns the maximum extent of the range. This number is + * one more than the last position in the range. + */ + public int maxRange () + { + return location() + length() -1; + } + + /** + * Returns whether this is an empty range, therefore + * whether the length is zero. + */ + public boolean isEmpty () + { + return ( length() == 0 ); + } + + /** + * Returns whether the specified location is contained + * within this range. + */ + public boolean locationInRange (int location) + { + if ( location < location() ) return false; + if ( location >= maxRange() ) return false; + return true; + } + + /** + * Returns whether the specified range is equal to this range. + */ + public boolean isEqualToRange (NSRange aRange) + { + if ( aRange == null ) return false; + return ( ( aRange.location() == location() ) + && ( aRange.length() == length() ) ); + } + + /** + * Returns whether the specified object is equal to this range. + */ + public boolean equals (Object anObject) + { + if ( anObject instanceof NSRange ) + return isEqualToRange( (NSRange) anObject ); + return false; + } + + /** + * Returns a hashCode. + */ + public int hashCode () + { + // TODO: Test this logic. + return ( location() << 2 ) & length(); // bitwise ops never my forte + } + + /** + * Returns a string representation of this range. + */ + public String toString () + { + return "[NSRange: location = " + location() + + "; length = " + length() + "]"; + } + + /** + * Returns the union of this range and the specified range, if any. + * Gaps are filled, so the result is the smallest starting position + * and the largest ending position. + */ + public NSRange rangeByUnioningRange (NSRange aRange) + { + if ( aRange == null ) return this; + + // TODO: Test this logic. + int resultLoc = Math.min( this.location(), aRange.location() ); + int resultLen = Math.max( this.location() + this.length(), + aRange.location() + aRange.length() ) - resultLoc; + return new NSRange( resultLoc, resultLen ); + } + + /** + * Returns the intersection of this range and the specified range, + * if any. If no intersection, returns an empty range. + */ + public NSRange rangeByIntersectingRange (NSRange aRange) + { + // TODO: Test this logic. + if ( ! intersectsRange( aRange ) ) return ZeroRange; + int start = Math.max( this.location(), aRange.location() ); + int end = Math.min( this.location() + this.length(), + aRange.location() + aRange.length() ); + return new NSRange( start, end - start ); + } + + /** + * Returns whether the specified range overlaps + * at any point with this range. + */ + public boolean intersectsRange (NSRange aRange) + { + // TODO: Test this logic. + if ( aRange == null ) return false; + if ( ( this.location() >= aRange.location() ) + && ( this.location() < aRange.location() + aRange.length() ) ) + return true; + if ( ( aRange.location() >= this.location() ) + && ( aRange.location() < this.location() + this.length() ) ) + return true; + return false; + } + + /** + * Returns whether this range is completely + * contained within the specified range. + */ + public boolean isSubrangeOfRange (NSRange aRange) + { + // TODO: Test this logic. + if ( aRange == null ) return false; + if ( ( this.location() >= aRange.location() ) + && ( this.maxRange() <= aRange.maxRange() ) ) + return true; + return false; + } + + /** + * Eliminates any intersections between this range and the specified + * range. This produces two ranges, either of which may be empty. + * These two ranges are returned by modifying the supplied second + * and third parameters. + */ + public void subtractRange (NSRange aRange, + NSMutableRange firstResult, NSMutableRange secondResult) + { + if ( aRange == null ) return; + + // TODO: Test this logic. + // no intersection: return this and aRange without calculation + if ( ! intersectsRange( aRange ) ) + { + if ( firstResult != null ) + { + firstResult.setLocation( this.location() ); + firstResult.setLength( this.length() ); + } + if ( secondResult != null ) + { + secondResult.setLocation( aRange.location() ); + secondResult.setLength( aRange.location() ); + } + return; + } + + // TODO: Test this logic. + // this range is completely contained by other range + if ( isSubrangeOfRange( aRange ) ) + { + if ( firstResult != null ) + { + firstResult.setLocation( aRange.location() ); + firstResult.setLength( this.location() - aRange.location() ); + } + if ( secondResult != null ) + { + secondResult.setLocation( this.maxRange() ); + secondResult.setLength( + aRange.maxRange() - this.maxRange() - 1 ); // test this + } + return; + } + + // TODO: Test this logic. + // other range is completely contained by this range + if ( aRange.isSubrangeOfRange( this ) ) + { + if ( firstResult != null ) + { + firstResult.setLocation( this.location() ); + firstResult.setLength( aRange.location() - this.location() ); + } + if ( secondResult != null ) + { + secondResult.setLocation( aRange.maxRange() ); + secondResult.setLength( + this.maxRange() - aRange.maxRange() - 1 ); // test this + } + return; + } + + // TODO: Test this logic. + // ranges intersect: remove only the intersection + + NSRange firstRange, secondRange; + if ( this.location() <= aRange.location() ) + { + firstRange = this; + secondRange = aRange; + } + else + { + firstRange = aRange; + secondRange = this; + } + + if ( firstResult != null ) + { + firstResult.setLocation( firstRange.location() ); + firstResult.setLength( + secondRange.location() - firstRange.location() ); + } + if ( secondResult != null ) + { + secondResult.setLocation( firstRange.maxRange() ); + secondResult.setLength( + secondRange.maxRange() - aRange.maxRange() - 1 ); // test this + } + return; + + } + + /** + * Returns a copy of this range. + */ + public Object clone () + { + return new NSRange( location(), length() ); + } + + /** + * Parses a range from a string of the form "{x,y}" where + * x is the location and y is the length. If not parsable, + * an IllegalArgumentException is thrown. + */ + public static NSRange fromString (String aString) + { + // TODO: Test this logic. + try + { + java.util.StringTokenizer tokens = + new java.util.StringTokenizer( aString, "{,}" ); + int loc = Integer.parseInt( tokens.nextToken() ); + int len = Integer.parseInt( tokens.nextToken() ); + return new NSRange( loc, len ); + } + catch ( Exception exc ) + { + throw new IllegalArgumentException( exc.toString() ); + } + } + +} + +/* + * $Log$ + * Revision 1.2 2006/02/16 13:15:00 cgruber + * Check in all sources in eclipse-friendly maven-enabled packages. + * + * Revision 1.1.1.1 2000/12/21 15:47:42 mpowers + * Contributing wotonomy. + * + * Revision 1.3 2000/12/20 16:25:38 michael + * Added log to all files. + * + * + */ + |