| /* |
| ************************************************************************** |
| * Copyright (C) 1999-2012, 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/uobject.h" |
| |
| /** |
| * \file |
| * \brief C++ API: Replaceable String |
| */ |
| |
| U_NAMESPACE_BEGIN |
| |
| 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 metadata. Metadata is data |
| * other than the Unicode characters returned by char32At(). One |
| * example of metadata is style attributes; another is an edit |
| * history, marking each character with an author and revision number. |
| * |
| * <p>An implicit aspect of the <code>Replaceable</code> API is that |
| * during a replace operation, new characters take on the metadata 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 a start |
| * offset and a limit offset. The range of characters thus specified |
| * includes the characters at offset start..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>, |
| * <code>char32At()</code>, and <code>extractBetween()</code>. |
| * |
| * <p>For a subclass to support metadata, typical behavior of |
| * <code>replace()</code> is the following: |
| * <ul> |
| * <li>Set the metadata of the new text to the metadata of the first |
| * character replaced</li> |
| * <li>If no characters are replaced, use the metadata of the |
| * previous character</li> |
| * <li>If there is no previous character (i.e. start == 0), use the |
| * following character</li> |
| * <li>If there is no following character (i.e. the replaceable was |
| * empty), use default metadata.<br> |
| * <li>If the code point U+FFFF is seen, it should be interpreted as |
| * a special marker having no metadata<li> |
| * </li> |
| * </ul> |
| * If this is not the behavior, the subclass should document any differences. |
| * @author Alan Liu |
| * @stable ICU 2.0 |
| */ |
| class U_COMMON_API Replaceable : public UObject { |
| |
| public: |
| /** |
| * Destructor. |
| * @stable ICU 2.0 |
| */ |
| virtual ~Replaceable(); |
| |
| /** |
| * Returns the number of 16-bit code units in the text. |
| * @return number of 16-bit code units in text |
| * @stable ICU 1.8 |
| */ |
| inline int32_t length() const; |
| |
| /** |
| * Returns the 16-bit code unit at the given offset into the text. |
| * @param offset an integer between 0 and <code>length()</code>-1 |
| * inclusive |
| * @return 16-bit code unit of text at given offset |
| * @stable ICU 1.8 |
| */ |
| inline UChar charAt(int32_t offset) const; |
| |
| /** |
| * Returns the 32-bit code point at the given 16-bit offset into |
| * the text. This assumes the text is stored as 16-bit code units |
| * with surrogate pairs intermixed. If the offset of a leading or |
| * trailing code unit of a surrogate pair is given, return the |
| * code point of the surrogate pair. |
| * |
| * @param offset an integer between 0 and <code>length()</code>-1 |
| * inclusive |
| * @return 32-bit code point of text at given offset |
| * @stable ICU 1.8 |
| */ |
| inline UChar32 char32At(int32_t offset) const; |
| |
| /** |
| * Copies characters in the range [<tt>start</tt>, <tt>limit</tt>) |
| * into the UnicodeString <tt>target</tt>. |
| * @param start offset of first character which will be copied |
| * @param limit offset immediately following the last character to |
| * be copied |
| * @param target UnicodeString into which to copy characters. |
| * @return A reference to <TT>target</TT> |
| * @stable ICU 2.1 |
| */ |
| virtual void extractBetween(int32_t start, |
| int32_t limit, |
| UnicodeString& target) const = 0; |
| |
| /** |
| * Replaces a substring of this object with the given text. If the |
| * characters being replaced have metadata, the new characters |
| * that replace them should be given the same metadata. |
| * |
| * <p>Subclasses must ensure that if the text between start and |
| * limit is equal to the replacement text, that replace has no |
| * effect. That is, any metadata |
| * should be unaffected. In addition, subclasses are encouraged to |
| * check for initial and trailing identical characters, and make a |
| * smaller replacement if possible. This will preserve as much |
| * metadata as possible. |
| * @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> |
| * @stable ICU 2.0 |
| */ |
| virtual void handleReplaceBetween(int32_t start, |
| int32_t 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. |
| |
| /** |
| * Copies a substring of this object, retaining metadata. |
| * This method is used to duplicate or reorder substrings. |
| * The destination index must not overlap the source range. |
| * |
| * @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>. |
| * @stable ICU 2.0 |
| */ |
| virtual void copy(int32_t start, int32_t limit, int32_t dest) = 0; |
| |
| /** |
| * Returns true if this object contains metadata. If a |
| * Replaceable object has metadata, calls to the Replaceable API |
| * must be made so as to preserve metadata. If it does not, calls |
| * to the Replaceable API may be optimized to improve performance. |
| * The default implementation returns true. |
| * @return true if this object contains metadata |
| * @stable ICU 2.2 |
| */ |
| virtual UBool hasMetaData() const; |
| |
| /** |
| * Clone this object, an instance of a subclass of Replaceable. |
| * Clones can be used concurrently in multiple threads. |
| * If a subclass does not implement clone(), or if an error occurs, |
| * then NULL is returned. |
| * The clone functions in all subclasses return a pointer to a Replaceable |
| * because some compilers do not support covariant (same-as-this) |
| * return types; cast to the appropriate subclass if necessary. |
| * The caller must delete the clone. |
| * |
| * @return a clone of this object |
| * |
| * @see getDynamicClassID |
| * @stable ICU 2.6 |
| */ |
| virtual Replaceable *clone() const; |
| |
| protected: |
| |
| /** |
| * Default constructor. |
| * @stable ICU 2.4 |
| */ |
| inline Replaceable(); |
| |
| /* |
| * Assignment operator not declared. The compiler will provide one |
| * which does nothing since this class does not contain any data members. |
| * API/code coverage may show the assignment operator as present and |
| * untested - ignore. |
| * Subclasses need this assignment operator if they use compiler-provided |
| * assignment operators of their own. An alternative to not declaring one |
| * here would be to declare and empty-implement a protected or public one. |
| Replaceable &Replaceable::operator=(const Replaceable &); |
| */ |
| |
| /** |
| * Virtual version of length(). |
| * @stable ICU 2.4 |
| */ |
| virtual int32_t getLength() const = 0; |
| |
| /** |
| * Virtual version of charAt(). |
| * @stable ICU 2.4 |
| */ |
| virtual UChar getCharAt(int32_t offset) const = 0; |
| |
| /** |
| * Virtual version of char32At(). |
| * @stable ICU 2.4 |
| */ |
| virtual UChar32 getChar32At(int32_t offset) const = 0; |
| }; |
| |
| inline Replaceable::Replaceable() {} |
| |
| inline int32_t |
| Replaceable::length() const { |
| return getLength(); |
| } |
| |
| inline UChar |
| Replaceable::charAt(int32_t offset) const { |
| return getCharAt(offset); |
| } |
| |
| inline UChar32 |
| Replaceable::char32At(int32_t offset) const { |
| return getChar32At(offset); |
| } |
| |
| // There is no rep.cpp, see unistr.cpp for Replaceable function implementations. |
| |
| U_NAMESPACE_END |
| |
| #endif |
