jdk/src/share/classes/sun/text/normalizer/UCharacterIterator.java
changeset 2 90ce3da70b43
child 5506 202f599c92aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/sun/text/normalizer/UCharacterIterator.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,292 @@
+/*
+ * Portions Copyright 2003-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/*
+ *******************************************************************************
+ * (C) Copyright IBM Corp. 1996-2005 - All Rights Reserved                     *
+ *                                                                             *
+ * The original version of this source code and documentation is copyrighted   *
+ * and owned by IBM, These materials are provided under terms of a License     *
+ * Agreement between IBM and Sun. This technology is protected by multiple     *
+ * US and International patents. This notice and attribution to IBM may not    *
+ * to removed.                                                                 *
+ *******************************************************************************
+ */
+
+package sun.text.normalizer;
+
+import java.text.CharacterIterator;
+
+/**
+ * Abstract class that defines an API for iteration on text objects.This is an
+ * interface for forward and backward iteration and random access into a text
+ * object. Forward iteration is done with post-increment and backward iteration
+ * is done with pre-decrement semantics, while the
+ * <code>java.text.CharacterIterator</code> interface methods provided forward
+ * iteration with "pre-increment" and backward iteration with pre-decrement
+ * semantics. This API is more efficient for forward iteration over code points.
+ * The other major difference is that this API can do both code unit and code point
+ * iteration, <code>java.text.CharacterIterator</code> can only iterate over
+ * code units and is limited to BMP (0 - 0xFFFF)
+ * @author Ram
+ * @stable ICU 2.4
+ */
+public abstract class UCharacterIterator
+                      implements Cloneable {
+
+    /**
+     * Protected default constructor for the subclasses
+     * @stable ICU 2.4
+     */
+    protected UCharacterIterator(){
+    }
+
+    /**
+     * Indicator that we have reached the ends of the UTF16 text.
+     * Moved from UForwardCharacterIterator.java
+     * @stable ICU 2.4
+     */
+    public static final int DONE = -1;
+
+    // static final methods ----------------------------------------------------
+
+    /**
+     * Returns a <code>UCharacterIterator</code> object given a
+     * source string.
+     * @param source a string
+     * @return UCharacterIterator object
+     * @exception IllegalArgumentException if the argument is null
+     * @stable ICU 2.4
+     */
+    public static final UCharacterIterator getInstance(String source){
+        return new ReplaceableUCharacterIterator(source);
+    }
+
+    //// for StringPrep
+    /**
+     * Returns a <code>UCharacterIterator</code> object given a
+     * source StringBuffer.
+     * @param source an string buffer of UTF-16 code units
+     * @return UCharacterIterator object
+     * @exception IllegalArgumentException if the argument is null
+     * @stable ICU 2.4
+     */
+    public static final UCharacterIterator getInstance(StringBuffer source){
+        return new ReplaceableUCharacterIterator(source);
+    }
+
+    /**
+     * Returns a <code>UCharacterIterator</code> object given a
+     * CharacterIterator.
+     * @param source a valid CharacterIterator object.
+     * @return UCharacterIterator object
+     * @exception IllegalArgumentException if the argument is null
+     * @stable ICU 2.4
+     */
+    public static final UCharacterIterator getInstance(CharacterIterator source){
+        return new CharacterIteratorWrapper(source);
+    }
+
+    // public methods ----------------------------------------------------------
+
+    /**
+     * Returns the code unit at the current index.  If index is out
+     * of range, returns DONE.  Index is not changed.
+     * @return current code unit
+     * @stable ICU 2.4
+     */
+    public abstract int current();
+
+    /**
+     * Returns the length of the text
+     * @return length of the text
+     * @stable ICU 2.4
+     */
+    public abstract int getLength();
+
+
+    /**
+     * Gets the current index in text.
+     * @return current index in text.
+     * @stable ICU 2.4
+     */
+    public abstract int getIndex();
+
+
+    /**
+     * Returns the UTF16 code unit at index, and increments to the next
+     * code unit (post-increment semantics).  If index is out of
+     * range, DONE is returned, and the iterator is reset to the limit
+     * of the text.
+     * @return the next UTF16 code unit, or DONE if the index is at the limit
+     *         of the text.
+     * @stable ICU 2.4
+     */
+    public abstract int next();
+
+    /**
+     * Returns the code point at index, and increments to the next code
+     * point (post-increment semantics).  If index does not point to a
+     * valid surrogate pair, the behavior is the same as
+     * <code>next()</code>.  Otherwise the iterator is incremented past
+     * the surrogate pair, and the code point represented by the pair
+     * is returned.
+     * @return the next codepoint in text, or DONE if the index is at
+     *         the limit of the text.
+     * @stable ICU 2.4
+     */
+    public int nextCodePoint(){
+        int ch1 = next();
+        if(UTF16.isLeadSurrogate((char)ch1)){
+            int ch2 = next();
+            if(UTF16.isTrailSurrogate((char)ch2)){
+                return UCharacterProperty.getRawSupplementary((char)ch1,
+                                                              (char)ch2);
+            }else if (ch2 != DONE) {
+                // unmatched surrogate so back out
+                previous();
+            }
+        }
+        return ch1;
+    }
+
+    /**
+     * Decrement to the position of the previous code unit in the
+     * text, and return it (pre-decrement semantics).  If the
+     * resulting index is less than 0, the index is reset to 0 and
+     * DONE is returned.
+     * @return the previous code unit in the text, or DONE if the new
+     *         index is before the start of the text.
+     * @stable ICU 2.4
+     */
+    public abstract int previous();
+
+    /**
+     * Sets the index to the specified index in the text.
+     * @param index the index within the text.
+     * @exception IndexOutOfBoundsException is thrown if an invalid index is
+     *            supplied
+     * @stable ICU 2.4
+     */
+    public abstract void setIndex(int index);
+
+    //// for StringPrep
+    /**
+     * Fills the buffer with the underlying text storage of the iterator
+     * If the buffer capacity is not enough a exception is thrown. The capacity
+     * of the fill in buffer should at least be equal to length of text in the
+     * iterator obtained by calling <code>getLength()</code>.
+     * <b>Usage:</b>
+     *
+     * <code>
+     * <pre>
+     *         UChacterIterator iter = new UCharacterIterator.getInstance(text);
+     *         char[] buf = new char[iter.getLength()];
+     *         iter.getText(buf);
+     *
+     *         OR
+     *         char[] buf= new char[1];
+     *         int len = 0;
+     *         for(;;){
+     *             try{
+     *                 len = iter.getText(buf);
+     *                 break;
+     *             }catch(IndexOutOfBoundsException e){
+     *                 buf = new char[iter.getLength()];
+     *             }
+     *         }
+     * </pre>
+     * </code>
+     *
+     * @param fillIn an array of chars to fill with the underlying UTF-16 code
+     *         units.
+     * @param offset the position within the array to start putting the data.
+     * @return the number of code units added to fillIn, as a convenience
+     * @exception IndexOutOfBounds exception if there is not enough
+     *            room after offset in the array, or if offset < 0.
+     * @stable ICU 2.4
+     */
+    public abstract int getText(char[] fillIn, int offset);
+
+    //// for StringPrep
+    /**
+     * Convenience override for <code>getText(char[], int)</code> that provides
+     * an offset of 0.
+     * @param fillIn an array of chars to fill with the underlying UTF-16 code
+     *         units.
+     * @return the number of code units added to fillIn, as a convenience
+     * @exception IndexOutOfBounds exception if there is not enough
+     *            room in the array.
+     * @stable ICU 2.4
+     */
+    public final int getText(char[] fillIn) {
+        return getText(fillIn, 0);
+    }
+
+    //// for StringPrep
+    /**
+     * Convenience method for returning the underlying text storage as as string
+     * @return the underlying text storage in the iterator as a string
+     * @stable ICU 2.4
+     */
+    public String getText() {
+        char[] text = new char[getLength()];
+        getText(text);
+        return new String(text);
+    }
+
+    /**
+     * Moves the current position by the number of code units
+     * specified, either forward or backward depending on the sign
+     * of delta (positive or negative respectively).  If the resulting
+     * index would be less than zero, the index is set to zero, and if
+     * the resulting index would be greater than limit, the index is
+     * set to limit.
+     *
+     * @param delta the number of code units to move the current
+     *              index.
+     * @return the new index.
+     * @exception IndexOutOfBoundsException is thrown if an invalid index is
+     *            supplied
+     * @stable ICU 2.4
+     *
+     */
+    public int moveIndex(int delta) {
+        int x = Math.max(0, Math.min(getIndex() + delta, getLength()));
+        setIndex(x);
+        return x;
+    }
+
+    /**
+     * Creates a copy of this iterator, independent from other iterators.
+     * If it is not possible to clone the iterator, returns null.
+     * @return copy of this iterator
+     * @stable ICU 2.4
+     */
+    public Object clone() throws CloneNotSupportedException{
+        return super.clone();
+    }
+
+}