java.text.BreakIterator#previous ( )源码实例Demo

/**
 * Needed to unify forward and backward searching.
 * The method assumes that s is the text assigned to words.
 */
private int findWordLimit(int index, BreakIterator words, boolean direction,
                                 String s) {
    // Fix for 4256660 and 4256661.
    // Words iterator is different from character and sentence iterators
    // in that end of one word is not necessarily start of another word.
    // Please see java.text.BreakIterator JavaDoc. The code below is
    // based on nextWordStartAfter example from BreakIterator.java.
    int last = (direction == NEXT) ? words.following(index)
                                   : words.preceding(index);
    int current = (direction == NEXT) ? words.next()
                                      : words.previous();
    while (current != BreakIterator.DONE) {
        for (int p = Math.min(last, current); p < Math.max(last, current); p++) {
            if (Character.isLetter(s.charAt(p))) {
                return last;
            }
        }
        last = current;
        current = (direction == NEXT) ? words.next()
                                      : words.previous();
    }
    return BreakIterator.DONE;
}
 

/**
 * Needed to unify forward and backward searching.
 * The method assumes that s is the text assigned to words.
 */
private int findWordLimit(int index, BreakIterator words, boolean direction,
                                 String s) {
    // Fix for 4256660 and 4256661.
    // Words iterator is different from character and sentence iterators
    // in that end of one word is not necessarily start of another word.
    // Please see java.text.BreakIterator JavaDoc. The code below is
    // based on nextWordStartAfter example from BreakIterator.java.
    int last = (direction == NEXT) ? words.following(index)
                                   : words.preceding(index);
    int current = (direction == NEXT) ? words.next()
                                      : words.previous();
    while (current != BreakIterator.DONE) {
        for (int p = Math.min(last, current); p < Math.max(last, current); p++) {
            if (Character.isLetter(s.charAt(p))) {
                return last;
            }
        }
        last = current;
        current = (direction == NEXT) ? words.next()
                                      : words.previous();
    }
    return BreakIterator.DONE;
}
 

/**
 * Needed to unify forward and backward searching.
 * The method assumes that s is the text assigned to words.
 */
private int findWordLimit(int index, BreakIterator words, boolean direction,
                                 String s) {
    // Fix for 4256660 and 4256661.
    // Words iterator is different from character and sentence iterators
    // in that end of one word is not necessarily start of another word.
    // Please see java.text.BreakIterator JavaDoc. The code below is
    // based on nextWordStartAfter example from BreakIterator.java.
    int last = (direction == NEXT) ? words.following(index)
                                   : words.preceding(index);
    int current = (direction == NEXT) ? words.next()
                                      : words.previous();
    while (current != BreakIterator.DONE) {
        for (int p = Math.min(last, current); p < Math.max(last, current); p++) {
            if (Character.isLetter(s.charAt(p))) {
                return last;
            }
        }
        last = current;
        current = (direction == NEXT) ? words.next()
                                      : words.previous();
    }
    return BreakIterator.DONE;
}
 

/**
 * Needed to unify forward and backward searching.
 * The method assumes that s is the text assigned to words.
 */
private int findWordLimit(int index, BreakIterator words, boolean direction,
                                 String s) {
    // Fix for 4256660 and 4256661.
    // Words iterator is different from character and sentence iterators
    // in that end of one word is not necessarily start of another word.
    // Please see java.text.BreakIterator JavaDoc. The code below is
    // based on nextWordStartAfter example from BreakIterator.java.
    int last = (direction == NEXT) ? words.following(index)
                                   : words.preceding(index);
    int current = (direction == NEXT) ? words.next()
                                      : words.previous();
    while (current != BreakIterator.DONE) {
        for (int p = Math.min(last, current); p < Math.max(last, current); p++) {
            if (Character.isLetter(s.charAt(p))) {
                return last;
            }
        }
        last = current;
        current = (direction == NEXT) ? words.next()
                                      : words.previous();
    }
    return BreakIterator.DONE;
}
 

/**
 * Needed to unify forward and backward searching.
 * The method assumes that s is the text assigned to words.
 */
private int findWordLimit(int index, BreakIterator words, boolean direction,
                                 String s) {
    // Fix for 4256660 and 4256661.
    // Words iterator is different from character and sentence iterators
    // in that end of one word is not necessarily start of another word.
    // Please see java.text.BreakIterator JavaDoc. The code below is
    // based on nextWordStartAfter example from BreakIterator.java.
    int last = (direction == NEXT) ? words.following(index)
                                   : words.preceding(index);
    int current = (direction == NEXT) ? words.next()
                                      : words.previous();
    while (current != BreakIterator.DONE) {
        for (int p = Math.min(last, current); p < Math.max(last, current); p++) {
            if (Character.isLetter(s.charAt(p))) {
                return last;
            }
        }
        last = current;
        current = (direction == NEXT) ? words.next()
                                      : words.previous();
    }
    return BreakIterator.DONE;
}
 

/**
 * Needed to unify forward and backward searching.
 * The method assumes that s is the text assigned to words.
 */
private int findWordLimit(int index, BreakIterator words, boolean direction,
                                 String s) {
    // Fix for 4256660 and 4256661.
    // Words iterator is different from character and sentence iterators
    // in that end of one word is not necessarily start of another word.
    // Please see java.text.BreakIterator JavaDoc. The code below is
    // based on nextWordStartAfter example from BreakIterator.java.
    int last = (direction == NEXT) ? words.following(index)
                                   : words.preceding(index);
    int current = (direction == NEXT) ? words.next()
                                      : words.previous();
    while (current != BreakIterator.DONE) {
        for (int p = Math.min(last, current); p < Math.max(last, current); p++) {
            if (Character.isLetter(s.charAt(p))) {
                return last;
            }
        }
        last = current;
        current = (direction == NEXT) ? words.next()
                                      : words.previous();
    }
    return BreakIterator.DONE;
}
 

/**
 * Needed to unify forward and backward searching.
 * The method assumes that s is the text assigned to words.
 */
private int findWordLimit(int index, BreakIterator words, boolean direction,
                                 String s) {
    // Fix for 4256660 and 4256661.
    // Words iterator is different from character and sentence iterators
    // in that end of one word is not necessarily start of another word.
    // Please see java.text.BreakIterator JavaDoc. The code below is
    // based on nextWordStartAfter example from BreakIterator.java.
    int last = (direction == NEXT) ? words.following(index)
                                   : words.preceding(index);
    int current = (direction == NEXT) ? words.next()
                                      : words.previous();
    while (current != BreakIterator.DONE) {
        for (int p = Math.min(last, current); p < Math.max(last, current); p++) {
            if (Character.isLetter(s.charAt(p))) {
                return last;
            }
        }
        last = current;
        current = (direction == NEXT) ? words.next()
                                      : words.previous();
    }
    return BreakIterator.DONE;
}
 

/**
 * Needed to unify forward and backward searching.
 * The method assumes that s is the text assigned to words.
 */
private int findWordLimit(int index, BreakIterator words, boolean direction,
                                 String s) {
    // Fix for 4256660 and 4256661.
    // Words iterator is different from character and sentence iterators
    // in that end of one word is not necessarily start of another word.
    // Please see java.text.BreakIterator JavaDoc. The code below is
    // based on nextWordStartAfter example from BreakIterator.java.
    int last = (direction == NEXT) ? words.following(index)
                                   : words.preceding(index);
    int current = (direction == NEXT) ? words.next()
                                      : words.previous();
    while (current != BreakIterator.DONE) {
        for (int p = Math.min(last, current); p < Math.max(last, current); p++) {
            if (Character.isLetter(s.charAt(p))) {
                return last;
            }
        }
        last = current;
        current = (direction == NEXT) ? words.next()
                                      : words.previous();
    }
    return BreakIterator.DONE;
}
 

/**
 * Needed to unify forward and backward searching.
 * The method assumes that s is the text assigned to words.
 */
private int findWordLimit(int index, BreakIterator words, boolean direction,
                                 String s) {
    // Fix for 4256660 and 4256661.
    // Words iterator is different from character and sentence iterators
    // in that end of one word is not necessarily start of another word.
    // Please see java.text.BreakIterator JavaDoc. The code below is
    // based on nextWordStartAfter example from BreakIterator.java.
    int last = (direction == NEXT) ? words.following(index)
                                   : words.preceding(index);
    int current = (direction == NEXT) ? words.next()
                                      : words.previous();
    while (current != BreakIterator.DONE) {
        for (int p = Math.min(last, current); p < Math.max(last, current); p++) {
            if (Character.isLetter(s.charAt(p))) {
                return last;
            }
        }
        last = current;
        current = (direction == NEXT) ? words.next()
                                      : words.previous();
    }
    return BreakIterator.DONE;
}
 

private Vector testLastAndPrevious(BreakIterator bi, String text) {
    int p = bi.last();
    int lastP = p;
    Vector<String> result = new Vector<String>();

    if (p != text.length())
        errln("last() returned " + p + " instead of " + text.length());
    while (p != BreakIterator.DONE) {
        p = bi.previous();
        if (p != BreakIterator.DONE) {
            if (p >= lastP)
                errln("previous() failed to move backward: previous() on position "
                                + lastP + " yielded " + p);

            result.insertElementAt(text.substring(p, lastP), 0);
        }
        else {
            if (lastP != 0)
                errln("previous() returned DONE prematurely: offset was "
                                + lastP + " instead of 0");
        }
        lastP = p;
    }
    return result;
}
 

/**
 * Needed to unify forward and backward searching.
 * The method assumes that s is the text assigned to words.
 */
private int findWordLimit(int index, BreakIterator words, boolean direction,
                                 String s) {
    // Fix for 4256660 and 4256661.
    // Words iterator is different from character and sentence iterators
    // in that end of one word is not necessarily start of another word.
    // Please see java.text.BreakIterator JavaDoc. The code below is
    // based on nextWordStartAfter example from BreakIterator.java.
    int last = (direction == NEXT) ? words.following(index)
                                   : words.preceding(index);
    int current = (direction == NEXT) ? words.next()
                                      : words.previous();
    while (current != BreakIterator.DONE) {
        for (int p = Math.min(last, current); p < Math.max(last, current); p++) {
            if (Character.isLetter(s.charAt(p))) {
                return last;
            }
        }
        last = current;
        current = (direction == NEXT) ? words.next()
                                      : words.previous();
    }
    return BreakIterator.DONE;
}
 

/**
 * Returns the Segment at <code>index</code> representing either
 * the paragraph or sentence as identified by <code>part</code>, or
 * null if a valid paragraph/sentence can't be found. The offset
 * will point to the start of the word/sentence in the array, and
 * the modelOffset will point to the location of the word/sentence
 * in the model.
 */
private IndexedSegment getSegmentAt(int part, int index)
    throws BadLocationException {

    IndexedSegment seg = getParagraphElementText(index);
    if (seg == null) {
        return null;
    }
    BreakIterator iterator;
    switch (part) {
    case AccessibleText.WORD:
        iterator = BreakIterator.getWordInstance(getLocale());
        break;
    case AccessibleText.SENTENCE:
        iterator = BreakIterator.getSentenceInstance(getLocale());
        break;
    default:
        return null;
    }
    seg.first();
    iterator.setText(seg);
    int end = iterator.following(index - seg.modelOffset + seg.offset);
    if (end == BreakIterator.DONE) {
        return null;
    }
    if (end > seg.offset + seg.count) {
        return null;
    }
    int begin = iterator.previous();
    if (begin == BreakIterator.DONE ||
        begin >= seg.offset + seg.count) {
        return null;
    }
    seg.modelOffset = seg.modelOffset + begin - seg.offset;
    seg.offset = begin;
    seg.count = end - begin;
    return seg;
}
 

/**
 * Skips n number of word boundaries backwards.
 */
default void wordBreaksBackwards(int n, SelectionPolicy selectionPolicy) {
    if(getLength() == 0) {
        return;
    }

    BreakIterator wordBreakIterator = BreakIterator.getWordInstance( getLocale() );
    wordBreakIterator.setText(getText());
    wordBreakIterator.preceding(getCaretPosition());
    for (int i = 1; i < n; i++) {
        wordBreakIterator.previous();
    }

    moveTo(wordBreakIterator.current(), selectionPolicy);
}
 

private static void fillBreaks(@NonNull String text, @NonNull byte[] breaks, byte type) {
    BreakIterator iterator;

    switch (type) {
    case CHARACTER:
        iterator = BreakIterator.getCharacterInstance();
        break;

    default:
        iterator = BreakIterator.getLineInstance();
        break;
    }

    iterator.setText(text);
    iterator.first();

    byte forwardType = typeMode(type, true);
    int charNext;

    while ((charNext = iterator.next()) != BreakIterator.DONE) {
        breaks[charNext - 1] |= forwardType;
    }

    iterator.last();
    byte backwardType = typeMode(type, false);
    int charIndex;

    while ((charIndex = iterator.previous()) != BreakIterator.DONE) {
        breaks[charIndex] |= backwardType;
    }
}
 

/**
 * Returns the Segment at <code>index</code> representing either
 * the paragraph or sentence as identified by <code>part</code>, or
 * null if a valid paragraph/sentence can't be found. The offset
 * will point to the start of the word/sentence in the array, and
 * the modelOffset will point to the location of the word/sentence
 * in the model.
 */
private IndexedSegment getSegmentAt(int part, int index)
    throws BadLocationException {

    IndexedSegment seg = getParagraphElementText(index);
    if (seg == null) {
        return null;
    }
    BreakIterator iterator;
    switch (part) {
    case AccessibleText.WORD:
        iterator = BreakIterator.getWordInstance(getLocale());
        break;
    case AccessibleText.SENTENCE:
        iterator = BreakIterator.getSentenceInstance(getLocale());
        break;
    default:
        return null;
    }
    seg.first();
    iterator.setText(seg);
    int end = iterator.following(index - seg.modelOffset + seg.offset);
    if (end == BreakIterator.DONE) {
        return null;
    }
    if (end > seg.offset + seg.count) {
        return null;
    }
    int begin = iterator.previous();
    if (begin == BreakIterator.DONE ||
        begin >= seg.offset + seg.count) {
        return null;
    }
    seg.modelOffset = seg.modelOffset + begin - seg.offset;
    seg.offset = begin;
    seg.count = end - begin;
    return seg;
}
 

/**
 * Returns the Segment at <code>index</code> representing either
 * the paragraph or sentence as identified by <code>part</code>, or
 * null if a valid paragraph/sentence can't be found. The offset
 * will point to the start of the word/sentence in the array, and
 * the modelOffset will point to the location of the word/sentence
 * in the model.
 */
private IndexedSegment getSegmentAt(int part, int index)
    throws BadLocationException {

    IndexedSegment seg = getParagraphElementText(index);
    if (seg == null) {
        return null;
    }
    BreakIterator iterator;
    switch (part) {
    case AccessibleText.WORD:
        iterator = BreakIterator.getWordInstance(getLocale());
        break;
    case AccessibleText.SENTENCE:
        iterator = BreakIterator.getSentenceInstance(getLocale());
        break;
    default:
        return null;
    }
    seg.first();
    iterator.setText(seg);
    int end = iterator.following(index - seg.modelOffset + seg.offset);
    if (end == BreakIterator.DONE) {
        return null;
    }
    if (end > seg.offset + seg.count) {
        return null;
    }
    int begin = iterator.previous();
    if (begin == BreakIterator.DONE ||
        begin >= seg.offset + seg.count) {
        return null;
    }
    seg.modelOffset = seg.modelOffset + begin - seg.offset;
    seg.offset = begin;
    seg.count = end - begin;
    return seg;
}
 

/** Assumes that {@code getArea().getLength != 0} is true and {@link BreakIterator#setText(String)} has been called */
private int calculatePositionViaBreakingBackwards(int numOfBreaks, BreakIterator breakIterator, int position) {
    breakIterator.preceding(position);
    for (int i = 1; i < numOfBreaks; i++) {
        breakIterator.previous();
    }
    return breakIterator.current();
}
 

/**
 * Returns the Segment at <code>index</code> representing either
 * the paragraph or sentence as identified by <code>part</code>, or
 * null if a valid paragraph/sentence can't be found. The offset
 * will point to the start of the word/sentence in the array, and
 * the modelOffset will point to the location of the word/sentence
 * in the model.
 */
private IndexedSegment getSegmentAt(int part, int index)
    throws BadLocationException {

    IndexedSegment seg = getParagraphElementText(index);
    if (seg == null) {
        return null;
    }
    BreakIterator iterator;
    switch (part) {
    case AccessibleText.WORD:
        iterator = BreakIterator.getWordInstance(getLocale());
        break;
    case AccessibleText.SENTENCE:
        iterator = BreakIterator.getSentenceInstance(getLocale());
        break;
    default:
        return null;
    }
    seg.first();
    iterator.setText(seg);
    int end = iterator.following(index - seg.modelOffset + seg.offset);
    if (end == BreakIterator.DONE) {
        return null;
    }
    if (end > seg.offset + seg.count) {
        return null;
    }
    int begin = iterator.previous();
    if (begin == BreakIterator.DONE ||
        begin >= seg.offset + seg.count) {
        return null;
    }
    seg.modelOffset = seg.modelOffset + begin - seg.offset;
    seg.offset = begin;
    seg.count = end - begin;
    return seg;
}
 

private void doMultipleSelectionTest(BreakIterator iterator, String testText)
{
    logln("Multiple selection test...");
    BreakIterator testIterator = (BreakIterator)iterator.clone();
    int offset = iterator.first();
    int testOffset;
    int count = 0;

    do {
        testOffset = testIterator.first();
        testOffset = testIterator.next(count);
        logln("next(" + count + ") -> " + testOffset);
        if (offset != testOffset)
            errln("next(n) and next() not returning consistent results: for step " + count + ", next(n) returned " + testOffset + " and next() had " + offset);

        if (offset != BreakIterator.DONE) {
            count++;
            offset = iterator.next();
        }
    } while (offset != BreakIterator.DONE);

    // now do it backwards...
    offset = iterator.last();
    count = 0;

    do {
        testOffset = testIterator.last();
        testOffset = testIterator.next(count);
        logln("next(" + count + ") -> " + testOffset);
        if (offset != testOffset)
            errln("next(n) and next() not returning consistent results: for step " + count + ", next(n) returned " + testOffset + " and next() had " + offset);

        if (offset != BreakIterator.DONE) {
            count--;
            offset = iterator.previous();
        }
    } while (offset != BreakIterator.DONE);
}
 

/**
 * Returns the Segment at <code>index</code> representing either
 * the paragraph or sentence as identified by <code>part</code>, or
 * null if a valid paragraph/sentence can't be found. The offset
 * will point to the start of the word/sentence in the array, and
 * the modelOffset will point to the location of the word/sentence
 * in the model.
 */
private IndexedSegment getSegmentAt(int part, int index)
    throws BadLocationException {

    IndexedSegment seg = getParagraphElementText(index);
    if (seg == null) {
        return null;
    }
    BreakIterator iterator;
    switch (part) {
    case AccessibleText.WORD:
        iterator = BreakIterator.getWordInstance(getLocale());
        break;
    case AccessibleText.SENTENCE:
        iterator = BreakIterator.getSentenceInstance(getLocale());
        break;
    default:
        return null;
    }
    seg.first();
    iterator.setText(seg);
    int end = iterator.following(index - seg.modelOffset + seg.offset);
    if (end == BreakIterator.DONE) {
        return null;
    }
    if (end > seg.offset + seg.count) {
        return null;
    }
    int begin = iterator.previous();
    if (begin == BreakIterator.DONE ||
        begin >= seg.offset + seg.count) {
        return null;
    }
    seg.modelOffset = seg.modelOffset + begin - seg.offset;
    seg.offset = begin;
    seg.count = end - begin;
    return seg;
}