scuffed-code/icu4c/source/common/unicode/rep.h
2001-02-14 18:02:44 +00:00

209 lines
7.6 KiB
C++

/*
**********************************************************************
* Copyright (C) 1999, International Business Machines Corporation and
* others. All Rights Reserved.
**********************************************************************
* Date Name Description
* 11/17/99 aliu Creation. Ported from java. Modified to
* match current UnicodeString API. Forced
* to use name "handleReplaceBetween" because
* of existing methods in UnicodeString.
**********************************************************************
*/
#ifndef REP_H
#define REP_H
#include "unicode/utypes.h"
class UnicodeString;
/**
* <code>Replaceable</code> is an abstract base class representing a
* string of characters that supports the replacement of a range of
* itself with a new string of characters. It is used by APIs that
* change a piece of text while retaining style attributes. In other
* words, an implicit aspect of the <code>Replaceable</code> API is
* that during a replace operation, new characters take on the
* attributes, if any, of the old characters. For example, if the
* string "the <b>bold</b> font" has range (4, 8) replaced with
* "strong", then it becomes "the <b>strong</b> font".
*
* <p><code>Replaceable</code> specifies ranges using an initial
* offset and a limit offset. The range of characters thus specified
* includes the characters at offset initial..limit-1. That is, the
* start offset is inclusive, and the limit offset is exclusive.
*
* <p><code>Replaceable</code> also includes API to access characters
* in the string: <code>length()</code>, <code>charAt()</code>, and
* <code>extractBetween()</code>.
*
* @author Alan Liu
* @draft
*/
class U_COMMON_API Replaceable {
public:
/**
* Destructor.
* @draft
*/
virtual ~Replaceable();
/**
* Return the number of characters in the text.
* @return number of characters in text
* @draft ICU 1.8
*/
inline int32_t length() const;
/**
* Return the Unicode code unit at the given offset into the text.
* @param offset an integer between 0 and <code>length()</code>-1
* inclusive
* @return code unit of text at given offset
* @draft ICU 1.8
*/
inline UChar charAt(UTextOffset offset) const;
/**
* Return the Unicode code point that contains the code unit
* at the given offset into the text.
* @param offset an integer between 0 and <code>length()</code>-1
* inclusive that indicates the text offset of any of the code units
* that will be assembled into a code point (21-bit value) and returned
* @return code point of text at given offset
* @draft ICU 1.8
*/
inline UChar32 char32At(UTextOffset offset) const;
/**
* Copy characters from this object into the destination character
* array. The first character to be copied is at index
* <code>srcStart</code>; the last character to be copied is at
* index <code>srcLimit-1</code> (thus the total number of
* characters to be copied is <code>srcLimit-srcStart</code>). The
* characters are copied into the subarray of <code>dst</code>
* starting at index <code>dstStart</code> and ending at index
* <code>dstStart + (srcLimit-srcStart) - 1</code>.
*
* @param srcStart the beginning index to copy, inclusive; <code>0
* <= srcStart <= srcLimit</code>.
* @param srcLimit the ending index to copy, exclusive;
* <code>srcStart <= srcLimit <= length()</code>.
* @param dst the destination array.
* @param dstStart the start offset in the destination array.
* @draft
*/
/* THIS API IS NOT NEEDED, BUT KEPT HERE AS A COMMENT IN
CASE OF FUTURE NEED. CURRENTLY INDIVIDUAL CHARACTER
ACCESS SUFFICES. */
/* virtual void extractBetween(UTextOffset srcStart,
UTextOffset srcLimit,
UChar* dst,
UTextOffset dstStart = 0) const = 0; */
/**
* Replace a substring of this object with the given text. If the
* characters being replaced have attributes, the new characters
* that replace them should be given the same attributes.
*
* @param start the beginning index, inclusive; <code>0 <= start
* <= limit</code>.
* @param limit the ending index, exclusive; <code>start <= limit
* <= length()</code>.
* @param text the text to replace characters <code>start</code>
* to <code>limit - 1</code>
* @draft
*/
virtual void handleReplaceBetween(UTextOffset start,
UTextOffset limit,
const UnicodeString& text) = 0;
// Note: All other methods in this class take the names of
// existing UnicodeString methods. This method is the exception.
// It is named differently because all replace methods of
// UnicodeString return a UnicodeString&. The 'between' is
// required in order to conform to the UnicodeString naming
// convention; API taking start/length are named <operation>, and
// those taking start/limit are named <operationBetween>. The
// 'handle' is added because 'replaceBetween' and
// 'doReplaceBetween' are already taken.
/**
* Copy a substring of this object, retaining attribute (out-of-band)
* information. This method is used to duplicate or reorder substrings.
* The destination index must not overlap the source range.
* Implementations that do not care about maintaining out-of-band
* information during copying may use the naive implementation:
*
* <pre> char[] text = new char[limit - start];
* getChars(start, limit, text, 0);
* replace(dest, dest, text, 0, limit - start);</pre>
*
* @param start the beginning index, inclusive; <code>0 <= start <=
* limit</code>.
* @param limit the ending index, exclusive; <code>start <= limit <=
* length()</code>.
* @param dest the destination index. The characters from
* <code>start..limit-1</code> will be copied to <code>dest</code>.
* Implementations of this method may assume that <code>dest <= start ||
* dest >= limit</code>.
*/
virtual void copy(int32_t start, int32_t limit, int32_t dest) = 0;
protected:
/**
* Default constructor.
*/
Replaceable();
/**
* Constructor with initial length.
*/
Replaceable(int32_t initialLength);
/**
* Virtual version of charAt().
* This allows UnicodeString::charAt() to be inline again (see jitterbug 709).
*/
virtual UChar getCharAt(UTextOffset offset) const = 0;
/**
* Virtual version of char32At().
* This allows UnicodeString::char32At() to be inline again (see jitterbug 709).
*/
virtual UChar32 getChar32At(UTextOffset offset) const = 0;
/**
* This field must always reflect the number of UChars in the text
* object. A subclass must keep this up to date.
* Moved here from UnicodeString so that length() can be inline (see jitterbug 709).
*/
int32_t fLength; // number characters in fArray
};
inline Replaceable::Replaceable() : fLength(0) {}
inline Replaceable::Replaceable(int32_t initialLength) : fLength(initialLength) {}
inline Replaceable::~Replaceable() {}
inline int32_t
Replaceable::length() const {
return fLength;
}
inline UChar
Replaceable::charAt(UTextOffset offset) const {
return getCharAt(offset);
}
inline UChar32
Replaceable::char32At(UTextOffset offset) const {
return getChar32At(offset);
}
#endif