Check in the pristine copy of ICU 4.6...

icu46/source/common/unicode/brkiter.h

+/*
+********************************************************************************
+*   Copyright (C) 1997-2010, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+********************************************************************************
+*
+* File brkiter.h
+*
+* Modification History:
+*
+*   Date        Name        Description
+*   02/18/97    aliu        Added typedef for TextCount.  Made DONE const.
+*   05/07/97    aliu        Fixed DLL declaration.
+*   07/09/97    jfitz       Renamed BreakIterator and interface synced with JDK
+*   08/11/98    helena      Sync-up JDK1.2.
+*   01/13/2000  helena      Added UErrorCode parameter to createXXXInstance methods.
+********************************************************************************
+*/
+
+#ifndef BRKITER_H
+#define BRKITER_H
+
+#include "unicode/utypes.h"
+
+/**
+ * \file
+ * \brief C++ API: Break Iterator.
+ */
+
+#if UCONFIG_NO_BREAK_ITERATION
+
+U_NAMESPACE_BEGIN
+
+/*
+ * Allow the declaration of APIs with pointers to BreakIterator
+ * even when break iteration is removed from the build.
+ */
+class BreakIterator;
+
+U_NAMESPACE_END
+
+#else
+
+#include "unicode/uobject.h"
+#include "unicode/unistr.h"
+#include "unicode/chariter.h"
+#include "unicode/locid.h"
+#include "unicode/ubrk.h"
+#include "unicode/strenum.h"
+#include "unicode/utext.h"
+#include "unicode/umisc.h"
+
+U_NAMESPACE_BEGIN
+
+/**
+ * The BreakIterator class implements methods for finding the location
+ * of boundaries in text. 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.
+ * <p>
+ * Line boundary analysis determines where a text string can be broken
+ * when line-wrapping. The mechanism correctly handles punctuation and
+ * hyphenated words.
+ * <p>
+ * Sentence boundary analysis allows selection with correct
+ * interpretation of periods within numbers and abbreviations, and
+ * trailing punctuation marks such as quotation marks and parentheses.
+ * <p>
+ * 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.
+ * <p>
+ * 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.
+ * <p>
+ * The text boundary positions are found according to the rules
+ * described in Unicode Standard Annex #29, Text Boundaries, and
+ * Unicode Standard Annex #14, Line Breaking Properties.  These
+ * are available at http://www.unicode.org/reports/tr14/ and
+ * http://www.unicode.org/reports/tr29/.
+ * <p>
+ * In addition to the C++ API defined in this header file, a
+ * plain C API with equivalent functionality is defined in the
+ * file ubrk.h
+ * <p>
+ * Code snippets illustrating the use of the Break Iterator APIs
+ * are available in the ICU User Guide,
+ * http://icu-project.org/userguide/boundaryAnalysis.html
+ * and in the sample program icu/source/samples/break/break.cpp
+ *
+ */
+class U_COMMON_API BreakIterator : public UObject {
+public:
+    /**
+     *  destructor
+     *  @stable ICU 2.0
+     */
+    virtual ~BreakIterator();
+
+    /**
+     * 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.
+     * <P>
+     * 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.
+     * @stable ICU 2.0
+     */
+    virtual UBool operator==(const BreakIterator&) const = 0;
+
+    /**
+     * Returns the complement of the result of operator==
+     * @param rhs The BreakIterator to be compared for inequality
+     * @return the complement of the result of operator==
+     * @stable ICU 2.0
+     */
+    UBool operator!=(const BreakIterator& rhs) const { return !operator==(rhs); }
+
+    /**
+     * Return a polymorphic copy of this object.  This is an abstract
+     * method which subclasses implement.
+     * @stable ICU 2.0
+     */
+    virtual BreakIterator* clone(void) const = 0;
+
+    /**
+     * Return a polymorphic class ID for this object. Different subclasses
+     * will return distinct unequal values.
+     * @stable ICU 2.0
+     */
+    virtual UClassID getDynamicClassID(void) const = 0;
+
+    /**
+     * Return a CharacterIterator over the text being analyzed.
+     * @stable ICU 2.0
+     */
+    virtual CharacterIterator& getText(void) const = 0;
+
+
+    /**
+      *  Get a UText for the text being analyzed.
+      *  The returned UText is a shallow clone of the UText used internally
+      *  by the break iterator implementation.  It can safely be used to
+      *  access the text without impacting any break iterator operations,
+      *  but the underlying text itself must not be altered.
+      *
+      * @param fillIn A UText to be filled in.  If NULL, a new UText will be
+      *           allocated to hold the result.
+      * @param status receives any error codes.
+      * @return   The current UText for this break iterator.  If an input
+      *           UText was provided, it will always be returned.
+      * @stable ICU 3.4
+      */
+     virtual UText *getUText(UText *fillIn, UErrorCode &status) const = 0;
+
+    /**
+     * Change the text over which this operates. The text boundary is
+     * reset to the start.
+     * @param text The UnicodeString used to change the text.
+     * @stable ICU 2.0
+     */
+    virtual void  setText(const UnicodeString &text) = 0;
+
+    /**
+     * Reset the break iterator to operate over the text represented by
+     * the UText.  The iterator position is reset to the start.
+     *
+     * This function makes a shallow clone of the supplied UText.  This means
+     * that the caller is free to immediately close or otherwise reuse the
+     * Utext that was passed as a parameter, but that the underlying text itself
+     * must not be altered while being referenced by the break iterator.
+     *
+     * @param text The UText used to change the text.
+     * @param status receives any error codes.
+     * @stable ICU 3.4
+     */
+    virtual void  setText(UText *text, UErrorCode &status) = 0;
+
+    /**
+     * Change the text over which this operates. The text boundary is
+     * reset to the start.
+     * Note that setText(UText *) provides similar functionality to this function,
+     * and is more efficient.
+     * @param it The CharacterIterator used to change the text.
+     * @stable ICU 2.0
+     */
+    virtual void  adoptText(CharacterIterator* it) = 0;
+
+    enum {
+        /**
+         * DONE is returned by previous() and next() after all valid
+         * boundaries have been returned.
+         * @stable ICU 2.0
+         */
+        DONE = (int32_t)-1
+    };
+
+    /**
+     * Return the index of the first character in the text being scanned.
+     * @stable ICU 2.0
+     */
+    virtual int32_t first(void) = 0;
+
+    /**
+     * Return the index immediately BEYOND the last character in the text being scanned.
+     * @stable ICU 2.0
+     */
+    virtual int32_t last(void) = 0;
+
+    /**
+     * Return the boundary preceding the current boundary.
+     * @return The character index of the previous text boundary or DONE if all
+     * boundaries have been returned.
+     * @stable ICU 2.0
+     */
+    virtual int32_t previous(void) = 0;
+
+    /**
+     * Return the boundary following the current boundary.
+     * @return The character index of the next text boundary or DONE if all
+     * boundaries have been returned.
+     * @stable ICU 2.0
+     */
+    virtual int32_t next(void) = 0;
+
+    /**
+     * Return character index of the current interator position within the text.
+     * @return The boundary most recently returned.
+     * @stable ICU 2.0
+     */
+    virtual int32_t current(void) const = 0;
+
+    /**
+     * Return the first boundary following the specified offset.
+     * The value returned is always greater than the offset or
+     * the value BreakIterator.DONE
+     * @param offset the offset to begin scanning.
+     * @return The first boundary after the specified offset.
+     * @stable ICU 2.0
+     */
+    virtual int32_t following(int32_t offset) = 0;
+
+    /**
+     * Return the first boundary preceding the specified offset.
+     * The value returned is always smaller than the offset or
+     * the value BreakIterator.DONE
+     * @param offset the offset to begin scanning.
+     * @return The first boundary before the specified offset.
+     * @stable ICU 2.0
+     */
+    virtual int32_t preceding(int32_t offset) = 0;
+
+    /**
+     * Return true if the specfied position is a boundary position.
+     * As a side effect, the current position of the iterator is set
+     * to the first boundary position at or following the specified offset.
+     * @param offset the offset to check.
+     * @return True if "offset" is a boundary position.
+     * @stable ICU 2.0
+     */
+    virtual UBool isBoundary(int32_t offset) = 0;
+
+    /**
+     * Return the nth boundary from the current boundary
+     * @param n which boundary to return.  A value of 0
+     * does nothing.  Negative values move to previous boundaries
+     * and positive values move to later boundaries.
+     * @return The index of the nth boundary from the current position, or
+     * DONE if there are fewer than |n| boundaries in the specfied direction.
+     * @stable ICU 2.0
+     */
+    virtual int32_t next(int32_t n) = 0;
+
+    /**
+     * 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)
+     * @param where the locale.
+     * @param status the error code
+     * @return A BreakIterator for word-breaks.  The UErrorCode& status
+     * parameter is used to return status information to the user.
+     * To check whether the construction succeeded or not, you should check
+     * the value of U_SUCCESS(err).  If you wish more detailed information, you
+     * can check for informational error results which still indicate success.
+     * U_USING_FALLBACK_WARNING indicates that a fall back locale was used.  For
+     * example, 'de_CH' was requested, but nothing was found there, so 'de' was
+     * used.  U_USING_DEFAULT_WARNING indicates that the default locale data was
+     * used; neither the requested locale nor any of its fall back locales
+     * could be found.
+     * The caller owns the returned object and is responsible for deleting it.
+     * @stable ICU 2.0
+     */
+    static BreakIterator* U_EXPORT2
+    createWordInstance(const Locale& where, UErrorCode& status);
+
+    /**
+     * 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.
+     * @param where the locale.
+     * @param status The error code.
+     * @return A BreakIterator for line-breaks.  The UErrorCode& status
+     * parameter is used to return status information to the user.
+     * To check whether the construction succeeded or not, you should check
+     * the value of U_SUCCESS(err).  If you wish more detailed information, you
+     * can check for informational error results which still indicate success.
+     * U_USING_FALLBACK_WARNING indicates that a fall back locale was used.  For
+     * example, 'de_CH' was requested, but nothing was found there, so 'de' was
+     * used.  U_USING_DEFAULT_WARNING indicates that the default locale data was
+     * used; neither the requested locale nor any of its fall back locales
+     * could be found.
+     * The caller owns the returned object and is responsible for deleting it.
+     * @stable ICU 2.0
+     */
+    static BreakIterator* U_EXPORT2
+    createLineInstance(const Locale& where, UErrorCode& status);
+
+    /**
+     * 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.
+     * @param where the locale.
+     * @param status The error code.
+     * @return A BreakIterator for character-breaks.  The UErrorCode& status
+     * parameter is used to return status information to the user.
+     * To check whether the construction succeeded or not, you should check
+     * the value of U_SUCCESS(err).  If you wish more detailed information, you
+     * can check for informational error results which still indicate success.
+     * U_USING_FALLBACK_WARNING indicates that a fall back locale was used.  For
+     * example, 'de_CH' was requested, but nothing was found there, so 'de' was
+     * used.  U_USING_DEFAULT_WARNING indicates that the default locale data was
+     * used; neither the requested locale nor any of its fall back locales
+     * could be found.
+     * The caller owns the returned object and is responsible for deleting it.
+     * @stable ICU 2.0
+     */
+    static BreakIterator* U_EXPORT2
+    createCharacterInstance(const Locale& where, UErrorCode& status);
+
+    /**
+     * Create BreakIterator for sentence-breaks using specified locale
+     * Returns an instance of a BreakIterator implementing sentence breaks.
+     * @param where the locale.
+     * @param status The error code.
+     * @return A BreakIterator for sentence-breaks.  The UErrorCode& status
+     * parameter is used to return status information to the user.
+     * To check whether the construction succeeded or not, you should check
+     * the value of U_SUCCESS(err).  If you wish more detailed information, you
+     * can check for informational error results which still indicate success.
+     * U_USING_FALLBACK_WARNING indicates that a fall back locale was used.  For
+     * example, 'de_CH' was requested, but nothing was found there, so 'de' was
+     * used.  U_USING_DEFAULT_WARNING indicates that the default locale data was
+     * used; neither the requested locale nor any of its fall back locales
+     * could be found.
+     * The caller owns the returned object and is responsible for deleting it.
+     * @stable ICU 2.0
+     */
+    static BreakIterator* U_EXPORT2
+    createSentenceInstance(const Locale& where, UErrorCode& status);
+
+    /**
+     * Create BreakIterator for title-casing breaks using the specified locale
+     * Returns an instance of a BreakIterator implementing title breaks.
+     * The iterator returned locates title boundaries as described for
+     * Unicode 3.2 only. For Unicode 4.0 and above title boundary iteration,
+     * please use Word Boundary iterator.{@link #createWordInstance }
+     *
+     * @param where the locale.
+     * @param status The error code.
+     * @return A BreakIterator for title-breaks.  The UErrorCode& status
+     * parameter is used to return status information to the user.
+     * To check whether the construction succeeded or not, you should check
+     * the value of U_SUCCESS(err).  If you wish more detailed information, you
+     * can check for informational error results which still indicate success.
+     * U_USING_FALLBACK_WARNING indicates that a fall back locale was used.  For
+     * example, 'de_CH' was requested, but nothing was found there, so 'de' was
+     * used.  U_USING_DEFAULT_WARNING indicates that the default locale data was
+     * used; neither the requested locale nor any of its fall back locales
+     * could be found.
+     * The caller owns the returned object and is responsible for deleting it.
+     * @stable ICU 2.1
+     */
+    static BreakIterator* U_EXPORT2
+    createTitleInstance(const Locale& where, UErrorCode& status);
+
+    /**
+     * Get the set of Locales for which TextBoundaries are installed.
+     * <p><b>Note:</b> this will not return locales added through the register
+     * call. To see the registered locales too, use the getAvailableLocales
+     * function that returns a StringEnumeration object </p>
+     * @param count the output parameter of number of elements in the locale list
+     * @return available locales
+     * @stable ICU 2.0
+     */
+    static const Locale* U_EXPORT2 getAvailableLocales(int32_t& count);
+
+    /**
+     * Get name of the object for the desired Locale, in the desired langauge.
+     * @param objectLocale must be from getAvailableLocales.
+     * @param displayLocale specifies the desired locale for output.
+     * @param name the fill-in parameter of the return value
+     * Uses best match.
+     * @return user-displayable name
+     * @stable ICU 2.0
+     */
+    static UnicodeString& U_EXPORT2 getDisplayName(const Locale& objectLocale,
+                                         const Locale& displayLocale,
+                                         UnicodeString& name);
+
+    /**
+     * Get name of the object for the desired Locale, in the langauge of the
+     * default locale.
+     * @param objectLocale must be from getMatchingLocales
+     * @param name the fill-in parameter of the return value
+     * @return user-displayable name
+     * @stable ICU 2.0
+     */
+    static UnicodeString& U_EXPORT2 getDisplayName(const Locale& objectLocale,
+                                         UnicodeString& name);
+
+    /**
+     * Thread safe client-buffer-based cloning operation
+     *    Do NOT call delete on a safeclone, since 'new' is not used to create it.
+     * @param stackBuffer user allocated space for the new clone. If NULL new memory will be allocated.
+     * If buffer is not large enough, new memory will be allocated.
+     * @param BufferSize reference to size of allocated space.
+     * If BufferSize == 0, a sufficient size for use in cloning will
+     * be returned ('pre-flighting')
+     * If BufferSize is not enough for a stack-based safe clone,
+     * new memory will be allocated.
+     * @param status to indicate whether the operation went on smoothly or there were errors
+     *  An informational status value, U_SAFECLONE_ALLOCATED_ERROR, is used if any allocations were
+     *  necessary.
+     * @return pointer to the new clone
+     *
+     * @stable ICU 2.0
+     */
+    virtual BreakIterator *  createBufferClone(void *stackBuffer,
+                                               int32_t &BufferSize,
+                                               UErrorCode &status) = 0;
+
+    /**
+     *   Determine whether the BreakIterator was created in user memory by
+     *   createBufferClone(), and thus should not be deleted.  Such objects
+     *   must be closed by an explicit call to the destructor (not delete).
+     *  @stable ICU 2.0
+     */
+    inline UBool isBufferClone(void);
+
+#if !UCONFIG_NO_SERVICE
+    /**
+     * Register a new break iterator of the indicated kind, to use in the given locale.
+     * The break iterator will be adopted.  Clones of the iterator will be returned
+     * if a request for a break iterator of the given kind matches or falls back to
+     * this locale.
+     * @param toAdopt the BreakIterator instance to be adopted
+     * @param locale the Locale for which this instance is to be registered
+     * @param kind the type of iterator for which this instance is to be registered
+     * @param status the in/out status code, no special meanings are assigned
+     * @return a registry key that can be used to unregister this instance
+     * @stable ICU 2.4
+     */
+    static URegistryKey U_EXPORT2 registerInstance(BreakIterator* toAdopt,
+                                        const Locale& locale,
+                                        UBreakIteratorType kind,
+                                        UErrorCode& status);
+
+    /**
+     * Unregister a previously-registered BreakIterator using the key returned from the
+     * register call.  Key becomes invalid after a successful call and should not be used again.
+     * The BreakIterator corresponding to the key will be deleted.
+     * @param key the registry key returned by a previous call to registerInstance
+     * @param status the in/out status code, no special meanings are assigned
+     * @return TRUE if the iterator for the key was successfully unregistered
+     * @stable ICU 2.4
+     */
+    static UBool U_EXPORT2 unregister(URegistryKey key, UErrorCode& status);
+
+    /**
+     * Return a StringEnumeration over the locales available at the time of the call,
+     * including registered locales.
+     * @return a StringEnumeration over the locales available at the time of the call
+     * @stable ICU 2.4
+     */
+    static StringEnumeration* U_EXPORT2 getAvailableLocales(void);
+#endif
+
+    /**
+     * Returns the locale for this break iterator. Two flavors are available: valid and
+     * actual locale.
+     * @stable ICU 2.8
+     */
+    Locale getLocale(ULocDataLocaleType type, UErrorCode& status) const;
+
+    /** Get the locale for this break iterator object. You can choose between valid and actual locale.
+     *  @param type type of the locale we're looking for (valid or actual)
+     *  @param status error code for the operation
+     *  @return the locale
+     *  @internal
+     */
+    const char *getLocaleID(ULocDataLocaleType type, UErrorCode& status) const;
+
+ private:
+    static BreakIterator* buildInstance(const Locale& loc, const char *type, int32_t kind, UErrorCode& status);
+    static BreakIterator* createInstance(const Locale& loc, int32_t kind, UErrorCode& status);
+    static BreakIterator* makeInstance(const Locale& loc, int32_t kind, UErrorCode& status);
+
+    friend class ICUBreakIteratorFactory;
+    friend class ICUBreakIteratorService;
+
+protected:
+    /** @internal */
+    BreakIterator();
+    /** @internal */
+    UBool fBufferClone;
+    /** @internal */
+    BreakIterator (const BreakIterator &other) : UObject(other), fBufferClone(FALSE) {}
+
+private:
+
+    /** @internal */
+    char actualLocale[ULOC_FULLNAME_CAPACITY];
+    char validLocale[ULOC_FULLNAME_CAPACITY];
+
+    /**
+     * The assignment operator has no real implementation.
+     * It's provided to make the compiler happy. Do not call.
+     */
+    BreakIterator& operator=(const BreakIterator&);
+};
+
+inline UBool BreakIterator::isBufferClone()
+{
+    return fBufferClone;
+}
+
+U_NAMESPACE_END
+
+#endif /* #if !UCONFIG_NO_BREAK_ITERATION */
+
+#endif // _BRKITER
+//eof
+