scuffed-code/icu4c/source/i18n/simtxbd.h

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1999-08-16 21:50:52 +00:00
/*
*****************************************************************************************
* *
* COPYRIGHT: *
* (C) Copyright Taligent, Inc., 1997 *
* (C) Copyright International Business Machines Corporation, 1997-1999 *
* Licensed Material - Program-Property of IBM - All Rights Reserved. *
* US Government Users Restricted Rights - Use, duplication, or disclosure *
* restricted by GSA ADP Schedule Contract with IBM Corp. *
* *
*****************************************************************************************
*
* File SIMTXBD.H
*
* Modification History:
*
* Date Name Description
* 02/18/97 aliu Converted from OpenClass. Changed text() to getText() and
* made return type const &.
* 08/11/98 helena Sync-up JDK1.2.
*****************************************************************************************
*/
#ifndef SIMTXBD_H
#define SIMTXBD_H
#include "utypes.h"
#include "unistr.h"
#include "chariter.h"
#include "brkiter.h"
#include "txtbdat.h"
/**
* SIMPLETEXTBOUNDARY is a concrete implementation of BreakIterator.
* SimpleTextBoundary uses a state machine to compute breaks.
* <P>
* Different state machines are available that compute breaks for
* sentences, words, lines, and characters. They are accessable
* through static functions of BreakIterator.
*/
class SimpleTextBoundary: public BreakIterator {
public:
/**
* Destructor.
*/
virtual ~SimpleTextBoundary();
/**
* Return true if another object is semantically equal to this
* one. The other object should be an instance of a subclass of
* TextBoundary. 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.
*/
virtual bool_t operator==(const BreakIterator&) const;
/**
* Return a polymorphic copy of this object. This is an abstract
* method which subclasses implement.
*/
BreakIterator* clone(void) const;
/**
* Return a polymorphic class ID for this object. Different subclasses
* will return distinct unequal values.
*/
virtual ClassID getDynamicClassID(void) const { return getStaticClassID(); }
/**
* Return a static class ID for this class.
*/
static ClassID getStaticClassID(void) { return (ClassID)&fgClassID; }
/**
* Return the text iterator over which this operates.
* @return the caller of this method owns the returned object.
*/
virtual CharacterIterator* createText(void) const;
/**
* Change the text over which this operates. The text boundary is
* reset to the start.
*/
virtual void setText(const UnicodeString* it);
/**
* Change the text over which this operates. The text boundary is
* reset to the start.
*/
virtual void adoptText(CharacterIterator* it);
/**
* Return the index of the first character in the text being scanned.
*/
virtual UTextOffset first(void);
/**
* Return the index of the last character in the text being scanned.
*/
virtual UTextOffset last(void);
/**
* Return the character index of the previous text boundary, or kDone if all
* boundaries have been returned.
*/
virtual UTextOffset previous(void);
/**
* Return the character index of the next text boundary, or kDone if all
* boundaries have been returned.
*/
virtual UTextOffset next(void);
/**
* Return the character index of the text boundary that was most recently
* returned by next(), previous(), first(), or last().
*/
virtual UTextOffset current(void) const;
/**
* Return the first boundary following the specified offset.
* The value returned is always greater than the offset, or is kDone.
* @param offset the offset to begin scanning.
* @return The first boundary after the specified offset.
*/
virtual UTextOffset following(UTextOffset offset);
/**
* Return the first boundary preceding the specified offset.
* The value returned is always smaller than the offset, or is kDone.
* @param offset the offset to begin scanning.
* @return The first boundary before the specified offset.
*/
virtual UTextOffset preceding(UTextOffset offset);
/**
* Return true if the specfied position is a boundary position.
* @param offset the offset to check.
* @return True if "offset" is a boundary position.
*/
virtual bool_t isBoundary(UTextOffset offset);
/**
* Return the nth boundary from the current boundary.
* @param n the signed number of boundaries to traverse.
* Negative values move to previous boundaries
* and positive values move to later boundaries. A value of 0 does nothing.
* @return The character index of the nth boundary from the current position.
*/
virtual UTextOffset next(int32_t n);
private:
/**
* Construct an SimpleTextBoundary from the provided state table.
* This protected constructor is called from the friend class
* BreakIterator.
*/
SimpleTextBoundary(const TextBoundaryData* data);
/**
* Copy constructor.
*/
SimpleTextBoundary(const SimpleTextBoundary&); // only used by clone
/**
* The assignment operator is required to satisfy the compiler, but never called.
*/
SimpleTextBoundary operator=(const SimpleTextBoundary&) { return *this; } // do not call
/**
* Internal utility used to locate the previous position from which it is safe
* to do a forward scan (state is known).
*/
UTextOffset previousSafePosition(UTextOffset offset);
/**
* Internal utility to get the next position.
*/
UTextOffset nextPosition(UTextOffset offset);
static char fgClassID;
static const UChar kEND_OF_STRING;
const TextBoundaryData* fData;
const WordBreakTable* fForward; // fData->forward()
const WordBreakTable* fBackward; // fData->backward()
const UnicodeClassMapping* fMap; // fData->map()
CharacterIterator* fText;
UTextOffset fPos;
/* Making BreakIterator a friend is somewhat messy. */
friend class BreakIterator;
};
#endif // _SIMTXBD
//eof