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Diffstat (limited to 'libjava/classpath/java/text/BreakIterator.java')
| -rw-r--r-- | libjava/classpath/java/text/BreakIterator.java | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/libjava/classpath/java/text/BreakIterator.java b/libjava/classpath/java/text/BreakIterator.java new file mode 100644 index 00000000000..d021dceba73 --- /dev/null +++ b/libjava/classpath/java/text/BreakIterator.java @@ -0,0 +1,374 @@ +/* BreakIterator.java -- Breaks text into elements + Copyright (C) 1998, 1999, 2001, 2004, 2005 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package java.text; + +import java.util.Locale; +import java.util.MissingResourceException; +import java.util.ResourceBundle; + +/** + * This class iterates over text elements such as words, lines, sentences, + * and characters. It can only iterate over one of these text elements at + * a time. An instance of this class configured for the desired iteration + * type is created by calling one of the static factory methods, not + * by directly calling a constructor. + * + * The standard iterators created by the factory methods in this + * class will be valid upon creation. That is, their methods will + * not cause exceptions if called before you call setText(). + * + * @author Tom Tromey (tromey@cygnus.com) + * @author Aaron M. Renn (arenn@urbanophile.com) + * @date March 19, 1999 + */ +/* Written using "Java Class Libraries", 2nd edition, plus online + * API docs for JDK 1.2 beta from http://www.javasoft.com. + * Status: Believed complete and correct to 1.1. + */ +public abstract class BreakIterator implements Cloneable +{ + /** + * This value is returned by the <code>next()</code> and + * <code>previous</code> in order to indicate that the end of the + * text has been reached. + */ + // The value was discovered by writing a test program. + public static final int DONE = -1; + + /** + * This method initializes a new instance of <code>BreakIterator</code>. + * This protected constructor is available to subclasses as a default + * no-arg superclass constructor. + */ + protected BreakIterator () + { + } + + /** + * Create a clone of this object. + */ + public Object clone () + { + try + { + return super.clone(); + } + catch (CloneNotSupportedException e) + { + return null; + } + } + + /** + * This method returns the index of the current text element boundary. + * + * @return The current text boundary. + */ + public abstract int current (); + + /** + * This method returns the first text element boundary in the text being + * iterated over. + * + * @return The first text boundary. + */ + public abstract int first (); + + /** + * This methdod returns the offset of the text element boundary following + * the specified offset. + * + * @param offset The text index from which to find the next text boundary. + * + * @param The next text boundary following the specified index. + */ + public abstract int following (int pos); + + /** + * This method returns a list of locales for which instances of + * <code>BreakIterator</code> are available. + * + * @return A list of available locales + */ + public static synchronized Locale[] getAvailableLocales () + { + Locale[] l = new Locale[1]; + l[0] = Locale.US; + return l; + } + + private static BreakIterator getInstance (String type, Locale loc) + { + String className; + try + { + ResourceBundle res + = ResourceBundle.getBundle("gnu.java.locale.LocaleInformation", + loc, ClassLoader.getSystemClassLoader()); + className = res.getString(type); + } + catch (MissingResourceException x) + { + return null; + } + try + { + Class k = Class.forName(className); + return (BreakIterator) k.newInstance(); + } + catch (ClassNotFoundException x1) + { + return null; + } + catch (InstantiationException x2) + { + return null; + } + catch (IllegalAccessException x3) + { + return null; + } + } + + /** + * This method returns an instance of <code>BreakIterator</code> that will + * iterate over characters as defined in the default locale. + * + * @return A <code>BreakIterator</code> instance for the default locale. + */ + public static BreakIterator getCharacterInstance () + { + return getCharacterInstance (Locale.getDefault()); + } + + /** + * This method returns an instance of <code>BreakIterator</code> that will + * iterate over characters as defined in the specified locale. If the + * desired locale is not available, the default locale is used. + * + * @param locale The desired locale. + * + * @return A <code>BreakIterator</code> instance for the default locale. + */ + public static BreakIterator getCharacterInstance (Locale loc) + { + BreakIterator r = getInstance ("CharacterIterator", loc); + if (r == null) + r = new gnu.java.text.CharacterBreakIterator (); + return r; + } + + /** + * This method returns an instance of <code>BreakIterator</code> that will + * iterate over line breaks as defined in the default locale. + * + * @return A <code>BreakIterator</code> instance for the default locale. + */ + public static BreakIterator getLineInstance () + { + return getLineInstance (Locale.getDefault()); + } + + /** + * This method returns an instance of <code>BreakIterator</code> that will + * iterate over line breaks as defined in the specified locale. If the + * desired locale is not available, the default locale is used. + * + * @param locale The desired locale. + * + * @return A <code>BreakIterator</code> instance for the default locale. + */ + public static BreakIterator getLineInstance (Locale loc) + { + BreakIterator r = getInstance ("LineIterator", loc); + if (r == null) + r = new gnu.java.text.LineBreakIterator (); + return r; + } + + /** + * This method returns an instance of <code>BreakIterator</code> that will + * iterate over sentences as defined in the default locale. + * + * @return A <code>BreakIterator</code> instance for the default locale. + */ + public static BreakIterator getSentenceInstance () + { + return getSentenceInstance (Locale.getDefault()); + } + + /** + * This method returns an instance of <code>BreakIterator</code> that will + * iterate over sentences as defined in the specified locale. If the + * desired locale is not available, the default locale is used. + * + * @param locale The desired locale. + * + * @return A <code>BreakIterator</code> instance for the default locale. + */ + public static BreakIterator getSentenceInstance (Locale loc) + { + BreakIterator r = getInstance ("SentenceIterator", loc); + if (r == null) + r = new gnu.java.text.SentenceBreakIterator (); + return r; + } + + /** + * This method returns the text this object is iterating over as a + * <code>CharacterIterator</code>. + * + * @param The text being iterated over. + */ + public abstract CharacterIterator getText (); + + /** + * This method returns an instance of <code>BreakIterator</code> that will + * iterate over words as defined in the default locale. + * + * @return A <code>BreakIterator</code> instance for the default locale. + */ + public static BreakIterator getWordInstance () + { + return getWordInstance (Locale.getDefault()); + } + + /** + * This method returns an instance of <code>BreakIterator</code> that will + * iterate over words as defined in the specified locale. If the + * desired locale is not available, the default locale is used. + * + * @param locale The desired locale. + * + * @return A <code>BreakIterator</code> instance for the default locale. + */ + public static BreakIterator getWordInstance (Locale loc) + { + BreakIterator r = getInstance ("WordIterator", loc); + if (r == null) + r = new gnu.java.text.WordBreakIterator (); + return r; + } + + /** + * This method tests whether or not the specified position is a text + * element boundary. + * + * @param offset The text position to test. + * + * @return <code>true</code> if the position is a boundary, + * <code>false</code> otherwise. + */ + public boolean isBoundary (int pos) + { + if (pos == 0) + return true; + return following (pos - 1) == pos; + } + + /** + * This method returns the last text element boundary in the text being + * iterated over. + * + * @return The last text boundary. + */ + public abstract int last (); + + /** + * This method returns the text element boundary following the current + * text position. + * + * @return The next text boundary. + */ + public abstract int next (); + + /** + * This method returns the n'th text element boundary following the current + * text position. + * + * @param n The number of text element boundaries to skip. + * + * @return The next text boundary. + */ + public abstract int next (int n); + + /** + * This methdod returns the offset of the text element boundary preceding + * the specified offset. + * + * @param offset The text index from which to find the preceding + * text boundary. + * + * @returns The next text boundary preceding the specified index. + */ + public int preceding (int pos) + { + if (following (pos) == DONE) + last (); + while (previous () >= pos) + ; + return current (); + } + + /** + * This method returns the text element boundary preceding the current + * text position. + * + * @return The previous text boundary. + */ + public abstract int previous (); + + /** + * This method sets the text string to iterate over. + * + * @param str The <code>String</code> to iterate over. + */ + public void setText (String newText) + { + setText (new StringCharacterIterator (newText)); + } + + /** + * This method sets the text to iterate over from the specified + * <code>CharacterIterator</code>. + * + * @param ci The desired <code>CharacterIterator</code>. + */ + public abstract void setText (CharacterIterator newText); +} |