attributedstring.java

java源代码 请看看啊 提点宝贵的意见

/*
 * @(#)AttributedString.java	1.33 03/01/23
 *
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package java.text;

import java.util.*;
import java.text.AttributedCharacterIterator.Attribute;

/**
* An AttributedString holds text and related attribute information. It
* may be used as the actual data storage in some cases where a text
* reader wants to access attributed text through the AttributedCharacterIterator
* interface.
*
* @see AttributedCharacterIterator
* @see Annotation
* @since 1.2
*/

public class AttributedString {

    // since there are no vectors of int, we have to use arrays.
    // We allocate them in chunks of 10 elements so we don't have to allocate all the time.
    private static final int ARRAY_SIZE_INCREMENT = 10;

    // field holding the text
    String text;
    
    // fields holding run attribute information
    // run attributes are organized by run
    int runArraySize;               // current size of the arrays
    int runCount;                   // actual number of runs, <= runArraySize
    int runStarts[];                // start index for each run
    Vector runAttributes[];         // vector of attribute keys for each run
    Vector runAttributeValues[];    // parallel vector of attribute values for each run

    /**
     * Constructs an AttributedString instance with the given
     * AttributedCharacterIterators.
     *
     * @param iterators AttributedCharacterIterators to construct
     * AttributedString from.
     * @throws NullPointerException if iterators is null
     */
    AttributedString(AttributedCharacterIterator[] iterators) {
	if (iterators == null) {
            throw new NullPointerException("Iterators must not be null");
	}
        if (iterators.length == 0) {
            text = "";
        }
        else {
            // Build the String contents
            StringBuffer buffer = new StringBuffer();
            for (int counter = 0; counter < iterators.length; counter++) {
                appendContents(buffer, iterators[counter]);
            }

            text = buffer.toString();

            if (text.length() > 0) {
                // Determine the runs, creating a new run when the attributes
                // differ.
                int offset = 0;
                Map last = null;

                for (int counter = 0; counter < iterators.length; counter++) {
                    AttributedCharacterIterator iterator = iterators[counter];
                    int start = iterator.getBeginIndex();
                    int end = iterator.getEndIndex();
                    int index = start;

                    while (index < end) {
                        iterator.setIndex(index);

                        Map attrs = iterator.getAttributes();

                        if (mapsDiffer(last, attrs)) {
                            setAttributes(attrs, index - start + offset);
                        }
                        last = attrs;
                        index = iterator.getRunLimit();
                    }
                    offset += (end - start);
                }
            }
        }
    }

    /**
     * Constructs an AttributedString instance with the given text.
     * @param text The text for this attributed string.
     */
    public AttributedString(String text) {
        if (text == null) {
            throw new NullPointerException();
        }
        this.text = text;
    }
    
    /**
     * Constructs an AttributedString instance with the given text and attributes.
     * @param text The text for this attributed string.
     * @param attributes The attributes that apply to the entire string.
     * @exception IllegalArgumentException if the text has length 0
     * and the attributes parameter is not an empty Map (attributes
     * cannot be applied to a 0-length range).
     */
    public AttributedString(String text, Map attributes) {
        if (text == null || attributes == null) {
            throw new NullPointerException();
        }
        this.text = text;
        
        if (text.length() == 0) {
	    if (attributes.isEmpty())
		return;
            throw new IllegalArgumentException("Can't add attribute to 0-length text");
        }
        
        int attributeCount = attributes.size();
        if (attributeCount > 0) {
            createRunAttributeDataVectors();
            Vector newRunAttributes = new Vector(attributeCount);
            Vector newRunAttributeValues = new Vector(attributeCount);
            runAttributes[0] = newRunAttributes;
            runAttributeValues[0] = newRunAttributeValues;
            Iterator iterator = attributes.entrySet().iterator();
            while (iterator.hasNext()) {
                Map.Entry entry = (Map.Entry) iterator.next();
                newRunAttributes.addElement(entry.getKey());
                newRunAttributeValues.addElement(entry.getValue());
            }
        }
    }
    
    /**
     * Constructs an AttributedString instance with the given attributed
     * text represented by AttributedCharacterIterator.
     * @param text The text for this attributed string.
     */
    public AttributedString(AttributedCharacterIterator text) {
	// If performance is critical, this constructor should be
	// implemented here rather than invoking the constructor for a
	// subrange. We can avoid some range checking in the loops.
	this(text, text.getBeginIndex(), text.getEndIndex(), null);
    }

    /**
     * Constructs an AttributedString instance with the subrange of
     * the given attributed text represented by
     * AttributedCharacterIterator. If the given range produces an
     * empty text, all attributes will be discarded.  Note that any
     * attributes wrapped by an Annotation object are discarded for a
     * subrange of the original attribute range.
     *
     * @param text The text for this attributed string.
     * @param beginIndex Index of the first character of the range.
     * @param endIndex Index of the character following the last character
     * of the range.
     * @exception IllegalArgumentException if the subrange given by
     * beginIndex and endIndex is out of the text range.
     * @see java.text.Annotation
     */
    public AttributedString(AttributedCharacterIterator text,
			    int beginIndex,
			    int endIndex) {
	this(text, beginIndex, endIndex, null);
    }

    /**
     * Constructs an AttributedString instance with the subrange of
     * the given attributed text represented by
     * AttributedCharacterIterator.  Only attributes that match the
     * given attributes will be incorporated into the instance. If the
     * given range produces an empty text, all attributes will be
     * discarded. Note that any attributes wrapped by an Annotation
     * object are discarded for a subrange of the original attribute
     * range.
     *
     * @param text The text for this attributed string.
     * @param beginIndex Index of the first character of the range.
     * @param endIndex Index of the character following the last character
     * of the range.
     * @param attributes Specifies attributes to be extracted
     * from the text. If null is specified, all available attributes will
     * be used.
     * @exception IllegalArgumentException if the subrange given by
     * beginIndex and endIndex is out of the text range.
     * @see java.text.Annotation
     */
    public AttributedString(AttributedCharacterIterator text,
			    int beginIndex,
			    int endIndex,
			    Attribute[] attributes) {
        if (text == null) {
            throw new NullPointerException();
        }

	// Validate the given subrange
	int textBeginIndex = text.getBeginIndex();
	int textEndIndex = text.getEndIndex();
	if (beginIndex < textBeginIndex || endIndex > textEndIndex || beginIndex > endIndex)
	    throw new IllegalArgumentException("Invalid substring range");

	// Copy the given string
	StringBuffer textBuffer = new StringBuffer();
	text.setIndex(beginIndex);
	for (char c = text.current(); text.getIndex() < endIndex; c = text.next())
	    textBuffer.append(c);
	this.text = textBuffer.toString();

	if (beginIndex == endIndex)
	    return;

	// Select attribute keys to be taken care of
	HashSet keys = new HashSet();
	if (attributes == null) {
	    keys.addAll(text.getAllAttributeKeys());
	} else {
	    for (int i = 0; i < attributes.length; i++)
		keys.add(attributes[i]);
	    keys.retainAll(text.getAllAttributeKeys());
	}
	if (keys.isEmpty())
	    return;

	// Get and set attribute runs for each attribute name. Need to
	// scan from the top of the text so that we can discard any
	// Annotation that is no longer applied to a subset text segment.
	Iterator itr = keys.iterator();
	while (itr.hasNext()) {
	    Attribute attributeKey = (Attribute)itr.next();
	    text.setIndex(textBeginIndex);
	    while (text.getIndex() < endIndex) {
		int start = text.getRunStart(attributeKey);
		int limit = text.getRunLimit(attributeKey);
		Object value = text.getAttribute(attributeKey);

		if (value != null) {
		    if (value instanceof Annotation) {
			if (start >= beginIndex && limit <= endIndex) {
			    addAttribute(attributeKey, value, start - beginIndex, limit - beginIndex);
			} else {
			    if (limit > endIndex)
				break;
			}
		    } else {
			// if the run is beyond the given (subset) range, we
			// don't need to process further.
			if (start >= endIndex)
			    break;
			if (limit > beginIndex) {
			    // attribute is applied to any subrange
			    if (start < beginIndex)
				start = beginIndex;
			    if (limit > endIndex)
				limit = endIndex;
			    if (start != limit) {
				addAttribute(attributeKey, value, start - beginIndex, limit - beginIndex);
			    }
			}
		    }
		}
		text.setIndex(limit);
	    }
	}
    }

    /**
     * Adds an attribute to the entire string.
     * @param attribute the attribute key
     * @param value the value of the attribute; may be null
     * @exception IllegalArgumentException if the AttributedString has length 0
     * (attributes cannot be applied to a 0-length range).
     */
    public void addAttribute(Attribute attribute, Object value) {
        
        if (attribute == null) {
            throw new NullPointerException();
        }

        int len = length();
        if (len == 0) {
            throw new IllegalArgumentException("Can't add attribute to 0-length text");
        }
        
        addAttributeImpl(attribute, value, 0, len);
    }

    /**
     * Adds an attribute to a subrange of the string.
     * @param attribute the attribute key
     * @param value The value of the attribute. May be null.
     * @param beginIndex Index of the first character of the range.
     * @param endIndex Index of the character following the last character of the range.
     * @exception IllegalArgumentException if beginIndex is less then 0, endIndex is
     * greater than the length of the string, or beginIndex and endIndex together don't
     * define a non-empty subrange of the string.
     */
    public void addAttribute(Attribute attribute, Object value,
            int beginIndex, int endIndex) {
        
        if (attribute == null) {
            throw new NullPointerException();
        }

        if (beginIndex < 0 || endIndex > length() || beginIndex >= endIndex) {
            throw new IllegalArgumentException("Invalid substring range");
        }
        
        addAttributeImpl(attribute, value, beginIndex, endIndex);
    }
    
    /**
     * Adds a set of attributes to a subrange of the string.
     * @param attributes The attributes to be added to the string.
     * @param beginIndex Index of the first character of the range.
     * @param endIndex Index of the character following the last
     * character of the range.
     * @exception IllegalArgumentException if beginIndex is less then
     * 0, endIndex is greater than the length of the string, or
     * beginIndex and endIndex together don't define a non-empty
     * subrange of the string and the attributes parameter is not an
     * empty Map.
     */
    public void addAttributes(Map attributes, int beginIndex, int endIndex) {
        if (attributes == null) {
            throw new NullPointerException();
        }

        if (beginIndex < 0 || endIndex > length() || beginIndex > endIndex) {
            throw new IllegalArgumentException("Invalid substring range");
        }
	if (beginIndex == endIndex) {
	    if (attributes.isEmpty())
		return;
            throw new IllegalArgumentException("Can't add attribute to 0-length text");
        }

        // make sure we have run attribute data vectors
        if (runCount == 0) {
            createRunAttributeDataVectors();
        }
        
        // break up runs if necessary
        int beginRunIndex = ensureRunBreak(beginIndex);
        int endRunIndex = ensureRunBreak(endIndex);
        
        Iterator iterator = attributes.entrySet().iterator();
        while (iterator.hasNext()) {
            Map.Entry entry = (Map.Entry) iterator.next();
            addAttributeRunData((Attribute) entry.getKey(), entry.getValue(), beginRunIndex, endRunIndex);
        }
    }

    private synchronized void addAttributeImpl(Attribute attribute, Object value,