#include <brkiter.h>
Inheritance diagram for BreakIterator:
Public Member Functions | |
virtual UBool | operator== (const BreakIterator &) const=0 |
Return true if another object is semantically equal to this one. | |
UBool | operator!= (const BreakIterator &rhs) const |
Returns the complement of the result of operator== . | |
virtual BreakIterator * | clone (void) const=0 |
Return a polymorphic copy of this object. | |
virtual UClassID | getDynamicClassID (void) const=0 |
Return a polymorphic class ID for this object. | |
virtual const CharacterIterator & | getText (void) const=0 |
Return a CharacterIterator over the text being analyzed. | |
virtual void | setText (const UnicodeString &text)=0 |
Change the text over which this operates. | |
virtual void | adoptText (CharacterIterator *it)=0 |
Change the text over which this operates. | |
virtual int32_t | first (void)=0 |
Return the index of the first character in the text being scanned. | |
virtual int32_t | last (void)=0 |
Return the index immediately BEYOND the last character in the text being scanned. | |
virtual int32_t | previous (void)=0 |
Return the boundary preceding the current boundary. | |
virtual int32_t | next (void)=0 |
Return the boundary following the current boundary. | |
virtual int32_t | current (void) const=0 |
Return character index of the text boundary that was most recently returned by next(), previous(), first(), or last(). | |
virtual int32_t | following (int32_t offset)=0 |
Return the first boundary following the specified offset. | |
virtual int32_t | preceding (int32_t offset)=0 |
Return the first boundary preceding the specified offset. | |
virtual UBool | isBoundary (int32_t offset)=0 |
Return true if the specfied position is a boundary position. | |
virtual int32_t | next (int32_t n)=0 |
Return the nth boundary from the current boundary. | |
virtual BreakIterator * | createBufferClone (void *stackBuffer, int32_t &BufferSize, UErrorCode &status)=0 |
Thread safe client-buffer-based cloning operation Do NOT call delete on a safeclone, since 'new' is not used to create it. | |
UBool | isBufferClone (void) |
Static Public Member Functions | |
BreakIterator * | createWordInstance (const Locale &where, UErrorCode &status) |
Create BreakIterator for word-breaks using the given locale. | |
BreakIterator * | createLineInstance (const Locale &where, UErrorCode &status) |
Create BreakIterator for line-breaks using specified locale. | |
BreakIterator * | createCharacterInstance (const Locale &where, UErrorCode &status) |
Create BreakIterator for character-breaks using specified locale Returns an instance of a BreakIterator implementing character breaks. | |
BreakIterator * | createSentenceInstance (const Locale &where, UErrorCode &status) |
Create BreakIterator for sentence-breaks using specified locale Returns an instance of a BreakIterator implementing sentence breaks. | |
BreakIterator * | createTitleInstance (const Locale &where, UErrorCode &status) |
Create BreakIterator for title-casing breaks using the specified locale Returns an instance of a BreakIterator implementing title breaks. | |
const Locale * | getAvailableLocales (int32_t &count) |
Get the set of Locales for which TextBoundaries are installed. | |
UnicodeString & | getDisplayName (const Locale &objectLocale, const Locale &displayLocale, UnicodeString &name) |
Get name of the object for the desired Locale, in the desired langauge. | |
UnicodeString & | getDisplayName (const Locale &objectLocale, UnicodeString &name) |
Get name of the object for the desired Locale, in the langauge of the default locale. | |
Static Public Attributes | |
const int32_t | DONE |
DONE is returned by previous() and next() after all valid boundaries have been returned. | |
Protected Attributes | |
UBool | fBufferClone |
BreakIterator is an abstract base class. Instances of BreakIterator maintain a current position and scan over text returning the index of characters where boundaries occur.
Line boundary analysis determines where a text string can be broken when line-wrapping. The mechanism correctly handles punctuation and hyphenated words.
Sentence boundary analysis allows selection with correct interpretation of periods within numbers and abbreviations, and trailing punctuation marks such as quotation marks and parentheses.
Word boundary analysis is used by search and replace functions, as well as within text editing applications that allow the user to select words with a double click. Word selection provides correct interpretation of punctuation marks within and following words. Characters that are not part of a word, such as symbols or punctuation marks, have word-breaks on both sides.
Character boundary analysis allows users to interact with characters as they expect to, for example, when moving the cursor through a text string. Character boundary analysis provides correct navigation of through character strings, regardless of how the character is stored. For example, an accented character might be stored as a base character and a diacritical mark. What users consider to be a character can differ between languages.
This is the interface for all text boundaries.
Examples:
Helper function to output text
Print each element in order:void printTextRange( BreakIterator& iterator, int32_t start, int32_t end ) { UnicodeString textBuffer, temp; CharacterIterator *strIter = iterator.createText(); strIter->getText(temp); cout << " " << start << " " << end << " |" << temp.extractBetween(start, end, textBuffer) << "|" << endl; delete strIter; }
Print first elementvoid printEachForward( BreakIterator& boundary) { int32_t start = boundary.first(); for (int32_t end = boundary.next(); end != BreakIterator::DONE; start = end, end = boundary.next()) { printTextRange( boundary, start, end ); } } \code </PRE> Print each element in reverse order: <PRE> \code void printEachBackward( BreakIterator& boundary) { int32_t end = boundary.last(); for (int32_t start = boundary.previous(); start != BreakIterator::DONE; end = start, start = boundary.previous()) { printTextRange( boundary, start, end ); } }
Print last elementvoid printFirst(BreakIterator& boundary) { int32_t start = boundary.first(); int32_t end = boundary.next(); printTextRange( boundary, start, end ); }
Print the element at a specified positionvoid printLast(BreakIterator& boundary) { int32_t end = boundary.last(); int32_t start = boundary.previous(); printTextRange( boundary, start, end ); }
Creating and using text boundariesvoid printAt(BreakIterator &boundary, int32_t pos ) { int32_t end = boundary.following(pos); int32_t start = boundary.previous(); printTextRange( boundary, start, end ); }
void BreakIterator_Example( void ) { BreakIterator* boundary; UnicodeString stringToExamine("Aaa bbb ccc. Ddd eee fff."); cout << "Examining: " << stringToExamine << endl; //print each sentence in forward and reverse order boundary = BreakIterator::createSentenceInstance( Locale::US ); boundary->setText(stringToExamine); cout << "----- forward: -----------" << endl; printEachForward(*boundary); cout << "----- backward: ----------" << endl; printEachBackward(*boundary); delete boundary; //print each word in order boundary = BreakIterator::createWordInstance(); boundary->setText(stringToExamine); cout << "----- forward: -----------" << endl; printEachForward(*boundary); //print first element cout << "----- first: -------------" << endl; printFirst(*boundary); //print last element cout << "----- last: --------------" << endl; printLast(*boundary); //print word at charpos 10 cout << "----- at pos 10: ---------" << endl; printAt(*boundary, 10 ); delete boundary; }
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Change the text over which this operates. The text boundary is reset to the start. Implemented in RuleBasedBreakIterator. |
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Return a polymorphic copy of this object. This is an abstract method which subclasses implement. Implemented in DictionaryBasedBreakIterator, and RuleBasedBreakIterator. |
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Thread safe client-buffer-based cloning operation Do NOT call delete on a safeclone, since 'new' is not used to create it.
Implemented in DictionaryBasedBreakIterator, and RuleBasedBreakIterator. |
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Create BreakIterator for character-breaks using specified locale Returns an instance of a BreakIterator implementing character breaks. Character breaks are boundaries of combining character sequences.
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Create BreakIterator for line-breaks using specified locale. Returns an instance of a BreakIterator implementing line breaks. Line breaks are logically possible line breaks, actual line breaks are usually determined based on display width. LineBreak is useful for word wrapping text.
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Create BreakIterator for sentence-breaks using specified locale Returns an instance of a BreakIterator implementing sentence breaks.
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Create BreakIterator for title-casing breaks using the specified locale Returns an instance of a BreakIterator implementing title breaks.
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Create BreakIterator for word-breaks using the given locale. Returns an instance of a BreakIterator implementing word breaks. WordBreak is useful for word selection (ex. double click)
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Return character index of the text boundary that was most recently returned by next(), previous(), first(), or last().
Implemented in RuleBasedBreakIterator. |
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Return the index of the first character in the text being scanned.
Implemented in RuleBasedBreakIterator. |
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Return the first boundary following the specified offset. The value returned is always greater than the offset or the value BreakIterator.DONE
Implemented in DictionaryBasedBreakIterator, and RuleBasedBreakIterator. |
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Get the set of Locales for which TextBoundaries are installed.
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Get name of the object for the desired Locale, in the langauge of the default locale.
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Get name of the object for the desired Locale, in the desired langauge.
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Return a polymorphic class ID for this object. Different subclasses will return distinct unequal values. Implemented in DictionaryBasedBreakIterator, and RuleBasedBreakIterator. |
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Return a CharacterIterator over the text being analyzed.
Implemented in RuleBasedBreakIterator. |
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Return true if the specfied position is a boundary position.
Implemented in RuleBasedBreakIterator. |
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Return the index immediately BEYOND the last character in the text being scanned.
Implemented in RuleBasedBreakIterator. |
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Return the nth boundary from the current boundary.
Implemented in RuleBasedBreakIterator. |
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Return the boundary following the current boundary.
Implemented in RuleBasedBreakIterator. |
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Return true if another object is semantically equal to this one. The other object should be an instance of the same subclass of BreakIterator. Objects of different subclasses are considered unequal. Return true if this BreakIterator is at the same position in the same text, and is the same class and type (word, line, etc.) of BreakIterator, as the argument. Text is considered the same if it contains the same characters, it need not be the same object, and styles are not considered. Implemented in RuleBasedBreakIterator. |
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Return the first boundary preceding the specified offset. The value returned is always smaller than the offset or the value BreakIterator.DONE
Implemented in DictionaryBasedBreakIterator, and RuleBasedBreakIterator. |
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Return the boundary preceding the current boundary.
Implemented in DictionaryBasedBreakIterator, and RuleBasedBreakIterator. |
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Change the text over which this operates. The text boundary is reset to the start. Implemented in RuleBasedBreakIterator. |
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DONE is returned by previous() and next() after all valid boundaries have been returned.
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