| /* Segment.java -- |
| Copyright (C) 2002, 2004, 2006 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 javax.swing.text; |
| |
| import java.text.CharacterIterator; |
| |
| /** |
| * A text fragment represented by a sequence of characters stored in an array. |
| */ |
| public class Segment implements Cloneable, CharacterIterator |
| { |
| private boolean partialReturn; |
| |
| /** The current index. */ |
| private int current; |
| |
| /** Storage for the characters (may contain additional characters). */ |
| public char[] array; |
| |
| /** The number of characters in the segment. */ |
| public int count; |
| |
| /** The offset of the first character in the segment. */ |
| public int offset; |
| |
| /** |
| * Creates a new <code>Segment</code>. |
| */ |
| public Segment() |
| { |
| // Nothing to do here. |
| } |
| |
| /** |
| * Creates a new <code>Segment</code>. |
| * |
| * @param array the underlying character data. |
| * @param offset the offset of the first character in the segment. |
| * @param count the number of characters in the segment. |
| */ |
| public Segment(char[] array, int offset, int count) |
| { |
| this.array = array; |
| this.offset = offset; |
| this.count = count; |
| } |
| |
| /** |
| * Clones the segment (note that the underlying character array is not cloned, |
| * just the reference to it). |
| * |
| * @return A clone of the segment. |
| */ |
| public Object clone() |
| { |
| try |
| { |
| return super.clone(); |
| } |
| catch (CloneNotSupportedException e) |
| { |
| return null; |
| } |
| } |
| |
| /** |
| * Returns the character at the current index. If the segment consists of |
| * zero characters, or the current index has passed the end of the |
| * characters in the segment, this method returns {@link #DONE}. |
| * |
| * @return The character at the current index. |
| */ |
| public char current() |
| { |
| if (count == 0 |
| || current >= getEndIndex()) |
| return DONE; |
| |
| return array[current]; |
| } |
| |
| /** |
| * Sets the current index to the first character in the segment and returns |
| * that character. If the segment contains zero characters, this method |
| * returns {@link #DONE}. |
| * |
| * @return The first character in the segment, or {@link #DONE} if the |
| * segment contains zero characters. |
| */ |
| public char first() |
| { |
| if (count == 0) |
| return DONE; |
| |
| current = getBeginIndex(); |
| return array[current]; |
| } |
| |
| /** |
| * Returns the index of the first character in the segment. |
| * |
| * @return The index of the first character. |
| */ |
| public int getBeginIndex() |
| { |
| return offset; |
| } |
| |
| /** |
| * Returns the end index for the segment (one position beyond the last |
| * character in the segment - note that this can be outside the range of the |
| * underlying character array). |
| * |
| * @return The end index for the segment. |
| */ |
| public int getEndIndex() |
| { |
| return offset + count; |
| } |
| |
| /** |
| * Returns the index of the current character in the segment. |
| * |
| * @return The index of the current character. |
| */ |
| public int getIndex() |
| { |
| return current; |
| } |
| |
| /** |
| * Sets the current index to point to the last character in the segment and |
| * returns that character. If the segment contains zero characters, the |
| * current index is set to {@link #getEndIndex()} and this method returns |
| * {@link #DONE}. |
| * |
| * @return The last character in the segment, or {@link #DONE} if the |
| * segment contains zero characters. |
| */ |
| public char last() |
| { |
| if (count == 0) |
| { |
| current = getEndIndex(); |
| return DONE; |
| } |
| |
| current = getEndIndex() - 1; |
| return array[current]; |
| } |
| |
| /** |
| * Sets the current index to point to the next character in the segment and |
| * returns that character. If the next character position is past the end of |
| * the segment, the index is set to {@link #getEndIndex()} and the method |
| * returns {@link #DONE}. If the segment contains zero characters, this |
| * method returns {@link #DONE}. |
| * |
| * @return The next character in the segment or {@link #DONE} (if the next |
| * character position is past the end of the segment or if the |
| * segment contains zero characters). |
| */ |
| public char next() |
| { |
| if (count == 0) |
| return DONE; |
| |
| if ((current + 1) >= getEndIndex()) |
| { |
| current = getEndIndex(); |
| return DONE; |
| } |
| |
| current++; |
| return array[current]; |
| } |
| |
| /** |
| * Sets the current index to point to the previous character in the segment |
| * and returns that character. If the current index is equal to |
| * {@link #getBeginIndex()}, or if the segment contains zero characters, this |
| * method returns {@link #DONE}. |
| * |
| * @return The previous character in the segment or {@link #DONE} (if the |
| * current character position is at the beginning of the segment or |
| * if the segment contains zero characters). |
| */ |
| public char previous() |
| { |
| if (count == 0 |
| || current == getBeginIndex()) |
| return DONE; |
| |
| current--; |
| return array[current]; |
| } |
| |
| /** |
| * Sets the current index and returns the character at that position (or |
| * {@link #DONE} if the index is equal to {@link #getEndIndex()}. |
| * |
| * @param position the current position. |
| * |
| * @return The character at the specified <code>position</code>, or |
| * {@link #DONE} if <code>position</code> is equal to |
| * {@link #getEndIndex()}. |
| * |
| * @throws IllegalArgumentException if <code>position</code> is not in the |
| * range {@link #getBeginIndex()} to {@link #getEndIndex()}. |
| */ |
| public char setIndex(int position) |
| { |
| if (position < getBeginIndex() |
| || position > getEndIndex()) |
| throw new IllegalArgumentException("position: " + position |
| + ", beginIndex: " + getBeginIndex() |
| + ", endIndex: " + getEndIndex() |
| + ", text: " + toString()); |
| |
| current = position; |
| |
| if (position == getEndIndex()) |
| return DONE; |
| |
| return array[current]; |
| } |
| |
| /** |
| * Returns a <code>String</code> containing the same characters as this |
| * <code>Segment</code>. |
| * |
| * @return A <code>String</code> containing the same characters as this |
| * <code>Segment</code>. |
| */ |
| public String toString() |
| { |
| return (array != null) ? new String(array, offset, count) : ""; |
| } |
| |
| /** |
| * Sets the partial return flag. |
| * |
| * @param p the new value of the flag. |
| * |
| * @since 1.4 |
| */ |
| public void setPartialReturn(boolean p) |
| { |
| partialReturn = p; |
| } |
| |
| /** |
| * Returns the partial return flag. |
| * |
| * @return The partial return flag. |
| * @since 1.4 |
| */ |
| public boolean isPartialReturn() |
| { |
| return partialReturn; |
| } |
| } |