| /* |
| * Copyright © {1999}, International Business Machines Corporation and others. All Rights Reserved. |
| ********************************************************************** |
| * Date Name Description |
| * 11/17/99 aliu Creation. |
| ********************************************************************** |
| */ |
| #ifndef TRANSLIT_H |
| #define TRANSLIT_H |
| |
| #include "unicode/unistr.h" |
| |
| class Replaceable; |
| class UnicodeFilter; |
| class TransliterationRuleData; |
| struct UHashtable; |
| class U_I18N_API UVector; |
| class CompoundTransliterator; |
| |
| /** |
| * <code>Transliterator</code> is an abstract class that |
| * transliterates text from one format to another. The most common |
| * kind of transliterator is a script, or alphabet, transliterator. |
| * For example, a Russian to Latin transliterator changes Russian text |
| * written in Cyrillic characters to phonetically equivalent Latin |
| * characters. It does not <em>translate</em> Russian to English! |
| * Transliteration, unlike translation, operates on characters, without |
| * reference to the meanings of words and sentences. |
| * |
| * <p>Although script conversion is its most common use, a |
| * transliterator can actually perform a more general class of tasks. |
| * In fact, <code>Transliterator</code> defines a very general API |
| * which specifies only that a segment of the input text is replaced |
| * by new text. The particulars of this conversion are determined |
| * entirely by subclasses of <code>Transliterator</code>. |
| * |
| * <p><b>Transliterators are stateless</b> |
| * |
| * <p><code>Transliterator</code> objects are <em>stateless</em>; they |
| * retain no information between calls to |
| * <code>transliterate()</code>. (However, this does <em>not</em> |
| * mean that threads may share transliterators without synchronizing |
| * them. Transliterators are not immutable, so they must be |
| * synchronized when shared between threads.) This1 might seem to |
| * limit the complexity of the transliteration operation. In |
| * practice, subclasses perform complex transliterations by delaying |
| * the replacement of text until it is known that no other |
| * replacements are possible. In other words, although the |
| * <code>Transliterator</code> objects are stateless, the source text |
| * itself embodies all the needed information, and delayed operation |
| * allows arbitrary complexity. |
| * |
| * <p><b>Batch transliteration</b> |
| * |
| * <p>The simplest way to perform transliteration is all at once, on a |
| * string of existing text. This is referred to as <em>batch</em> |
| * transliteration. For example, given a string <code>input</code> |
| * and a transliterator <code>t</code>, the call |
| * |
| * <blockquote><code>String result = t.transliterate(input); |
| * </code></blockquote> |
| * |
| * will transliterate it and return the result. Other methods allow |
| * the client to specify a substring to be transliterated and to use |
| * {@link Replaceable} objects instead of strings, in order to |
| * preserve out-of-band information (such as text styles). |
| * |
| * <p><b>Keyboard transliteration</b> |
| * |
| * <p>Somewhat more involved is <em>keyboard</em>, or incremental |
| * transliteration. This is the transliteration of text that is |
| * arriving from some source (typically the user's keyboard) one |
| * character at a time, or in some other piecemeal fashion. |
| * |
| * <p>In keyboard transliteration, a <code>Replaceable</code> buffer |
| * stores the text. As text is inserted, as much as possible is |
| * transliterated on the fly. This means a GUI that displays the |
| * contents of the buffer may show text being modified as each new |
| * character arrives. |
| * |
| * <p>Consider the simple <code>RuleBasedTransliterator</code>: |
| * |
| * <blockquote><code> |
| * th>{theta}<br> |
| * t>{tau} |
| * </code></blockquote> |
| * |
| * When the user types 't', nothing will happen, since the |
| * transliterator is waiting to see if the next character is 'h'. To |
| * remedy this, we introduce the notion of a cursor, marked by a '|' |
| * in the output string: |
| * |
| * <blockquote><code> |
| * t>|{tau}<br> |
| * {tau}h>{theta} |
| * </code></blockquote> |
| * |
| * Now when the user types 't', tau appears, and if the next character |
| * is 'h', the tau changes to a theta. This is accomplished by |
| * maintaining a cursor position (independent of the insertion point, |
| * and invisible in the GUI) across calls to |
| * <code>transliterate()</code>. Typically, the cursor will |
| * be coincident with the insertion point, but in a case like the one |
| * above, it will precede the insertion point. |
| * |
| * <p>Keyboard transliteration methods maintain a set of three indices |
| * that are updated with each call to |
| * <code>transliterate()</code>, including the cursor, start, |
| * and limit. Since these indices are changed by the method, they are |
| * passed in an <code>int[]</code> array. The <code>START</code> index |
| * marks the beginning of the substring that the transliterator will |
| * look at. It is advanced as text becomes committed (but it is not |
| * the committed index; that's the <code>CURSOR</code>). The |
| * <code>CURSOR</code> index, described above, marks the point at |
| * which the transliterator last stopped, either because it reached |
| * the end, or because it required more characters to disambiguate |
| * between possible inputs. The <code>CURSOR</code> can also be |
| * explicitly set by rules in a <code>RuleBasedTransliterator</code>. |
| * Any characters before the <code>CURSOR</code> index are frozen; |
| * future keyboard transliteration calls within this input sequence |
| * will not change them. New text is inserted at the |
| * <code>LIMIT</code> index, which marks the end of the substring that |
| * the transliterator looks at. |
| * |
| * <p>Because keyboard transliteration assumes that more characters |
| * are to arrive, it is conservative in its operation. It only |
| * transliterates when it can do so unambiguously. Otherwise it waits |
| * for more characters to arrive. When the client code knows that no |
| * more characters are forthcoming, perhaps because the user has |
| * performed some input termination operation, then it should call |
| * <code>finishTransliteration()</code> to complete any |
| * pending transliterations. |
| * |
| * <p><b>Inverses</b> |
| * |
| * <p>Pairs of transliterators may be inverses of one another. For |
| * example, if transliterator <b>A</b> transliterates characters by |
| * incrementing their Unicode value (so "abc" -> "def"), and |
| * transliterator <b>B</b> decrements character values, then <b>A</b> |
| * is an inverse of <b>B</b> and vice versa. If we compose <b>A</b> |
| * with <b>B</b> in a compound transliterator, the result is the |
| * indentity transliterator, that is, a transliterator that does not |
| * change its input text. |
| * |
| * The <code>Transliterator</code> method <code>getInverse()</code> |
| * returns a transliterator's inverse, if one exists, or |
| * <code>null</code> otherwise. However, the result of |
| * <code>getInverse()</code> usually will <em>not</em> be a true |
| * mathematical inverse. This is because true inverse transliterators |
| * are difficult to formulate. For example, consider two |
| * transliterators: <b>AB</b>, which transliterates the character 'A' |
| * to 'B', and <b>BA</b>, which transliterates 'B' to 'A'. It might |
| * seem that these are exact inverses, since |
| * |
| * <blockquote>"A" x <b>AB</b> -> "B"<br> |
| * "B" x <b>BA</b> -> "A"</blockquote> |
| * |
| * where 'x' represents transliteration. However, |
| * |
| * <blockquote>"ABCD" x <b>AB</b> -> "BBCD"<br> |
| * "BBCD" x <b>BA</b> -> "AACD"</blockquote> |
| * |
| * so <b>AB</b> composed with <b>BA</b> is not the |
| * identity. Nonetheless, <b>BA</b> may be usefully considered to be |
| * <b>AB</b>'s inverse, and it is on this basis that |
| * <b>AB</b><code>.getInverse()</code> could legitimately return |
| * <b>BA</b>. |
| * |
| * <p><b>IDs and display names</b> |
| * |
| * <p>A transliterator is designated by a short identifier string or |
| * <em>ID</em>. IDs follow the format <em>source-destination</em>, |
| * where <em>source</em> describes the entity being replaced, and |
| * <em>destination</em> describes the entity replacing |
| * <em>source</em>. The entities may be the names of scripts, |
| * particular sequences of characters, or whatever else it is that the |
| * transliterator converts to or from. For example, a transliterator |
| * from Russian to Latin might be named "Russian-Latin". A |
| * transliterator from keyboard escape sequences to Latin-1 characters |
| * might be named "KeyboardEscape-Latin1". By convention, system |
| * entity names are in English, with the initial letters of words |
| * capitalized; user entity names may follow any format so long as |
| * they do not contain dashes. |
| * |
| * <p>In addition to programmatic IDs, transliterator objects have |
| * display names for presentation in user interfaces, returned by |
| * {@link #getDisplayName}. |
| * |
| * <p><b>Factory methods and registration</b> |
| * |
| * <p>In general, client code should use the factory method |
| * <code>getInstance()</code> to obtain an instance of a |
| * transliterator given its ID. Valid IDs may be enumerated using |
| * <code>getAvailableIDs()</code>. Since transliterators are mutable, |
| * multiple calls to <code>getInstance()</code> with the same ID will |
| * return distinct objects. |
| * |
| * <p>In addition to the system transliterators registered at startup, |
| * user transliterators may be registered by calling |
| * <code>registerInstance()</code> at run time. A registered instance |
| * acts a template; future calls to <tt>getInstance()</tt> with the ID |
| * of the registered object return clones of that object. Thus any |
| * object passed to <tt>registerInstance()</tt> must implement |
| * <tt>clone()</tt> propertly. To register a transliterator subclass |
| * without instantiating it (until it is needed), users may call |
| * <code>registerClass()</code>. In this case, the objects are |
| * instantiated by invoking the zero-argument public constructor of |
| * the class. |
| * |
| * <p><b>Subclassing</b> |
| * |
| * Subclasses must implement the abstract method |
| * <code>handleTransliterate()</code>. <p>Subclasses should override |
| * the <code>transliterate()</code> method taking a |
| * <code>Replaceable</code> and the <code>transliterate()</code> |
| * method taking a <code>String</code> and <code>StringBuffer</code> |
| * if the performance of these methods can be improved over the |
| * performance obtained by the default implementations in this class. |
| * |
| * @author Alan Liu |
| */ |
| class U_I18N_API Transliterator { |
| |
| public: |
| |
| /** |
| * Direction constant indicating the direction in a transliterator, e.g., |
| * the forward or reverse rules of a RuleBasedTransliterator. An "A-B" |
| * transliterator transliterates A to B when operating in the forward |
| * direction, and B to A when operating in the reverse direction. |
| */ |
| enum Direction { |
| FORWARD, |
| REVERSE |
| }; |
| |
| class Position { |
| public: |
| /** |
| * In <code>transliterate()</code>, the beginning index, inclusive |
| */ |
| int32_t start; |
| |
| /** |
| * In <code>transliterate()</code>, the ending index, exclusive |
| */ |
| int32_t limit; |
| |
| /** |
| * In <code>transliterate()</code>, the next character to be |
| * considered for transliteration |
| */ |
| int32_t cursor; |
| }; |
| |
| private: |
| |
| /** |
| * Programmatic name, e.g., "Latin-Arabic". |
| */ |
| UnicodeString ID; |
| |
| /** |
| * This transliterator's filter. Any character for which |
| * <tt>filter.contains()</tt> returns <tt>false</tt> will not be |
| * altered by this transliterator. If <tt>filter</tt> is |
| * <tt>null</tt> then no filtering is applied. |
| */ |
| UnicodeFilter* filter; |
| |
| int32_t maximumContextLength; |
| |
| /** |
| * Dictionary of known transliterators. Keys are <code>String</code> |
| * names, values are one of the following: |
| * |
| * <ul><li><code>Transliterator</code> objects |
| * |
| * <li><code>Class</code> objects. Such objects must represent |
| * subclasses of <code>Transliterator</code>, and must satisfy the |
| * constraints described in <code>registerClass()</code> |
| * |
| * <li><code>RULE_BASED_PLACEHOLDER</code>, in which case the ID |
| * will have its first '-' removed and be appended to |
| * RB_RULE_BASED_PREFIX to form a resource bundle name from which |
| * the RB_RULE key is looked up to obtain the rule. |
| * |
| * <li><code>REVERSE_RULE_BASED_PLACEHOLDER</code>. Like |
| * <code>RULE_BASED_PLACEHOLDER</code>, except the entity names in |
| * the ID are reversed, and the argument |
| * RuleBasedTransliterator.REVERSE is pased to the |
| * RuleBasedTransliterator constructor. |
| * </ul> |
| */ |
| static UHashtable* cache; |
| |
| /** |
| * The mutex controlling access to the cache. |
| */ |
| static UMTX cacheMutex; |
| |
| /** |
| * When set to TRUE, the cache has been initialized. Any code must |
| * check this boolean before accessing the cache, and if the boolean |
| * is FALSE, it must call initializeCache(). We do this form of lazy |
| * evaluation for two reasons: (1) so we don't initialize if we don't |
| * have to (i.e., if no one is using Transliterator, but has included |
| * the code as part of a shared library, and (2) to avoid static |
| * intialization problems. |
| */ |
| static bool_t cacheInitialized; |
| |
| /** |
| * In Java, the cache stores objects of different types and |
| * singleton objects as placeholders for rule-based |
| * transliterators to be built as needed. In C++ we use the |
| * following struct to achieve the same purpose. Instances of |
| * this struct can be placeholders, can represent prototype |
| * transliterators to be cloned, or can represent |
| * RuleBasedTransliterator::Data objects. We don't support |
| * storing classes in the cache because we don't have the rtti |
| * infrastructure for it. We could easily add this if there is a |
| * need for it in the future. The rbFile is the resource bundle |
| * file name for rule-based transliterators. |
| */ |
| struct CacheEntry { |
| enum Type { |
| RULE_BASED_PLACEHOLDER, |
| REVERSE_RULE_BASED_PLACEHOLDER, |
| PROTOTYPE, |
| RBT_DATA, |
| NONE // Only used for uninitialized entries |
| } entryType; |
| UnicodeString rbFile; // For *PLACEHOLDER |
| union { |
| Transliterator* prototype; // For PROTOTYPE |
| TransliterationRuleData* data; // For RBT_DATA |
| } u; |
| CacheEntry(); |
| ~CacheEntry(); |
| void adoptPrototype(Transliterator* adopted); |
| }; |
| |
| /** |
| * Prefix for resource bundle key for the display name for a |
| * transliterator. The ID is appended to this to form the key. |
| * The resource bundle value should be a String. |
| */ |
| static const char* RB_DISPLAY_NAME_PREFIX; |
| |
| /** |
| * Prefix for resource bundle key for the display name for a |
| * transliterator SCRIPT. The ID is appended to this to form the key. |
| * The resource bundle value should be a String. |
| */ |
| static const char* RB_SCRIPT_DISPLAY_NAME_PREFIX; |
| |
| /** |
| * Resource bundle key for display name pattern. |
| * The resource bundle value should be a String forming a |
| * MessageFormat pattern, e.g.: |
| * "{0,choice,0#|1#{1} Transliterator|2#{1} to {2} Transliterator}". |
| */ |
| static const char* RB_DISPLAY_NAME_PATTERN; |
| |
| /** |
| * Resource bundle key for the list of RuleBasedTransliterator IDs. |
| * The resource bundle value should be a String[] with each element |
| * being a valid ID. The ID will be appended to RB_RULE_BASED_PREFIX |
| * to obtain the class name in which the RB_RULE key will be sought. |
| */ |
| static const char* RB_RULE_BASED_IDS; |
| |
| /** |
| * Resource bundle key for the RuleBasedTransliterator rule. |
| */ |
| static const char* RB_RULE; |
| |
| protected: |
| |
| /** |
| * Default constructor. |
| * @param ID the string identifier for this transliterator |
| * @param adoptedFilter the filter. Any character for which |
| * <tt>filter.contains()</tt> returns <tt>false</tt> will not be |
| * altered by this transliterator. If <tt>filter</tt> is |
| * <tt>null</tt> then no filtering is applied. |
| */ |
| Transliterator(const UnicodeString& ID, UnicodeFilter* adoptedFilter); |
| |
| /** |
| * Copy constructor. |
| */ |
| Transliterator(const Transliterator&); |
| |
| /** |
| * Assignment operator. |
| */ |
| Transliterator& operator=(const Transliterator&); |
| |
| public: |
| |
| /** |
| * Destructor. |
| */ |
| virtual ~Transliterator(); |
| |
| /** |
| * Implements Cloneable. |
| * All subclasses are encouraged to implement this method if it is |
| * possible and reasonable to do so. Subclasses that are to be |
| * registered with the system using <tt>registerInstance()<tt> |
| * are required to implement this method. If a subclass does not |
| * implement clone() properly and is registered with the system |
| * using registerInstance(), then the default clone() implementation |
| * will return null, and calls to createInstance() will fail. |
| * |
| * @see #registerInstance |
| */ |
| virtual Transliterator* clone() const { return 0; } |
| |
| /** |
| * Transliterates a segment of a string, with optional filtering. |
| * |
| * @param text the string to be transliterated |
| * @param start the beginning index, inclusive; <code>0 <= start |
| * <= limit</code>. |
| * @param limit the ending index, exclusive; <code>start <= limit |
| * <= text.length()</code>. |
| * @param filter the filter. Any character for which |
| * <tt>filter.contains()</tt> returns <tt>false</tt> will not be |
| * altered by this transliterator. If <tt>filter</tt> is |
| * <tt>null</tt> then no filtering is applied. |
| * @return The new limit index. The text previously occupying <code>[start, |
| * limit)</code> has been transliterated, possibly to a string of a different |
| * length, at <code>[start, </code><em>new-limit</em><code>)</code>, where |
| * <em>new-limit</em> is the return value. |
| */ |
| virtual int32_t transliterate(Replaceable& text, |
| int32_t start, int32_t limit) const; |
| |
| /** |
| * Transliterates an entire string in place. Convenience method. |
| * @param text the string to be transliterated |
| */ |
| virtual void transliterate(Replaceable& text) const; |
| |
| /** |
| * Transliterates the portion of the text buffer that can be |
| * transliterated unambiguosly after new text has been inserted, |
| * typically as a result of a keyboard event. The new text in |
| * <code>insertion</code> will be inserted into <code>text</code> |
| * at <code>index.limit</code>, advancing |
| * <code>index.limit</code> by <code>insertion.length()</code>. |
| * Then the transliterator will try to transliterate characters of |
| * <code>text</code> between <code>index.cursor</code> and |
| * <code>index.limit</code>. Characters before |
| * <code>index.cursor</code> will not be changed. |
| * |
| * <p>Upon return, values in <code>index</code> will be updated. |
| * <code>index.start</code> will be advanced to the first |
| * character that future calls to this method will read. |
| * <code>index.cursor</code> and <code>index.limit</code> will |
| * be adjusted to delimit the range of text that future calls to |
| * this method may change. |
| * |
| * <p>Typical usage of this method begins with an initial call |
| * with <code>index.start</code> and <code>index.limit</code> |
| * set to indicate the portion of <code>text</code> to be |
| * transliterated, and <code>index.cursor == index.start</code>. |
| * Thereafter, <code>index</code> can be used without |
| * modification in future calls, provided that all changes to |
| * <code>text</code> are made via this method. |
| * |
| * <p>This method assumes that future calls may be made that will |
| * insert new text into the buffer. As a result, it only performs |
| * unambiguous transliterations. After the last call to this |
| * method, there may be untransliterated text that is waiting for |
| * more input to resolve an ambiguity. In order to perform these |
| * pending transliterations, clients should call {@link |
| * #finishTransliteration} after the last call to this |
| * method has been made. |
| * |
| * @param text the buffer holding transliterated and untransliterated text |
| * @param index an array of three integers. |
| * |
| * <ul><li><code>index.start</code>: the beginning index, |
| * inclusive; <code>0 <= index.start <= index.limit</code>. |
| * |
| * <li><code>index.limit</code>: the ending index, exclusive; |
| * <code>index.start <= index.limit <= text.length()</code>. |
| * <code>insertion</code> is inserted at |
| * <code>index.limit</code>. |
| * |
| * <li><code>index.cursor</code>: the next character to be |
| * considered for transliteration; <code>index.start <= |
| * index.cursor <= index.limit</code>. Characters before |
| * <code>index.cursor</code> will not be changed by future calls |
| * to this method.</ul> |
| * |
| * @param insertion text to be inserted and possibly |
| * transliterated into the translation buffer at |
| * <code>index.limit</code>. If <code>null</code> then no text |
| * is inserted. |
| * @see #handleTransliterate |
| * @exception IllegalArgumentException if <code>index</code> |
| * is invalid |
| */ |
| virtual void transliterate(Replaceable& text, Position& index, |
| const UnicodeString& insertion, |
| UErrorCode& status) const; |
| |
| /** |
| * Transliterates the portion of the text buffer that can be |
| * transliterated unambiguosly after a new character has been |
| * inserted, typically as a result of a keyboard event. This is a |
| * convenience method; see {@link |
| * #transliterate(Replaceable, int[], String)} for details. |
| * @param text the buffer holding transliterated and |
| * untransliterated text |
| * @param index an array of three integers. See {@link |
| * #transliterate(Replaceable, int[], String)}. |
| * @param insertion text to be inserted and possibly |
| * transliterated into the translation buffer at |
| * <code>index.limit</code>. |
| * @see #transliterate(Replaceable, int[], String) |
| */ |
| virtual void transliterate(Replaceable& text, Position& index, |
| UChar insertion, |
| UErrorCode& status) const; |
| |
| /** |
| * Transliterates the portion of the text buffer that can be |
| * transliterated unambiguosly. This is a convenience method; see |
| * {@link #transliterate(Replaceable, int[], String)} for |
| * details. |
| * @param text the buffer holding transliterated and |
| * untransliterated text |
| * @param index an array of three integers. See {@link |
| * #transliterate(Replaceable, int[], String)}. |
| * @see #transliterate(Replaceable, int[], String) |
| */ |
| virtual void transliterate(Replaceable& text, Position& index, |
| UErrorCode& status) const; |
| |
| /** |
| * Finishes any pending transliterations that were waiting for |
| * more characters. Clients should call this method as the last |
| * call after a sequence of one or more calls to |
| * <code>transliterate()</code>. |
| * @param text the buffer holding transliterated and |
| * untransliterated text. |
| * @param index the array of indices previously passed to {@link |
| * #transliterate} |
| */ |
| virtual void finishTransliteration(Replaceable& text, |
| Position& index) const; |
| |
| private: |
| |
| /** |
| * This internal method does incremental transliteration. If the |
| * 'insertion' is non-null then we append it to 'text' before |
| * proceeding. This method calls through to the pure virtual |
| * framework method handleTransliterate() to do the actual |
| * work. |
| */ |
| void _transliterate(Replaceable& text, |
| Position& index, |
| const UnicodeString* insertion, |
| UErrorCode &status) const; |
| |
| protected: |
| |
| /** |
| * Abstract method that concrete subclasses define to implement |
| * keyboard transliteration. This method should transliterate all |
| * characters between <code>index.cursor</code> and |
| * <code>index.limit</code> that can be unambiguously |
| * transliterated, regardless of future insertions of text at |
| * <code>index.limit</code>. <code>index.cursor</code> should |
| * be advanced past committed characters (those that will not |
| * change in future calls to this method). |
| * <code>index.limit</code> should be updated to reflect text |
| * replacements that shorten or lengthen the text between |
| * <code>index.cursor</code> and <code>index.limit</code>. Upon |
| * return, neither <code>index.cursor</code> nor |
| * <code>index.limit</code> should be less than the initial value |
| * of <code>index.cursor</code>. <code>index.start</code> |
| * should <em>not</em> be changed. |
| * |
| * @param text the buffer holding transliterated and |
| * untransliterated text |
| * @param index an array of three integers. See {@link |
| * #transliterate(Replaceable, int[], String)}. |
| * @see #transliterate |
| */ |
| virtual void handleTransliterate(Replaceable& text, |
| Position& index, |
| bool_t incremental) const = 0; |
| |
| // C++ requires this friend declaration so CompoundTransliterator |
| // can access handleTransliterate. Alternatively, we could |
| // make handleTransliterate public. |
| friend class CompoundTransliterator; |
| |
| public: |
| |
| /** |
| * Returns the length of the longest context required by this transliterator. |
| * This is <em>preceding</em> context. The default implementation supplied |
| * by <code>Transliterator</code> returns zero; subclasses |
| * that use preceding context should override this method to return the |
| * correct value. For example, if a transliterator translates "ddd" (where |
| * d is any digit) to "555" when preceded by "(ddd)", then the preceding |
| * context length is 5, the length of "(ddd)". |
| * |
| * @return The maximum number of preceding context characters this |
| * transliterator needs to examine |
| */ |
| int32_t getMaximumContextLength(void) const; |
| |
| protected: |
| |
| /** |
| * Method for subclasses to use to set the maximum context length. |
| * @see #getMaximumContextLength |
| */ |
| void setMaximumContextLength(int32_t maxContextLength); |
| |
| public: |
| |
| /** |
| * Returns a programmatic identifier for this transliterator. |
| * If this identifier is passed to <code>getInstance()</code>, it |
| * will return this object, if it has been registered. |
| * @see #registerInstance |
| * @see #registerClass |
| * @see #getAvailableIDs |
| */ |
| virtual const UnicodeString& getID(void) const; |
| |
| /** |
| * Returns a name for this transliterator that is appropriate for |
| * display to the user in the default locale. See {@link |
| * #getDisplayName(Locale)} for details. |
| */ |
| static UnicodeString& getDisplayName(const UnicodeString& ID, |
| UnicodeString& result); |
| |
| /** |
| * Returns a name for this transliterator that is appropriate for |
| * display to the user in the given locale. This name is taken |
| * from the locale resource data in the standard manner of the |
| * <code>java.text</code> package. |
| * |
| * <p>If no localized names exist in the system resource bundles, |
| * a name is synthesized using a localized |
| * <code>MessageFormat</code> pattern from the resource data. The |
| * arguments to this pattern are an integer followed by one or two |
| * strings. The integer is the number of strings, either 1 or 2. |
| * The strings are formed by splitting the ID for this |
| * transliterator at the first '-'. If there is no '-', then the |
| * entire ID forms the only string. |
| * @param inLocale the Locale in which the display name should be |
| * localized. |
| * @see java.text.MessageFormat |
| */ |
| static UnicodeString& getDisplayName(const UnicodeString& ID, |
| const Locale& inLocale, |
| UnicodeString& result); |
| |
| /** |
| * Returns the filter used by this transliterator, or <tt>null</tt> |
| * if this transliterator uses no filter. |
| */ |
| virtual const UnicodeFilter* getFilter(void) const; |
| |
| /** |
| * Changes the filter used by this transliterator. If the filter |
| * is set to <tt>null</tt> then no filtering will occur. |
| * |
| * <p>Callers must take care if a transliterator is in use by |
| * multiple threads. The filter should not be changed by one |
| * thread while another thread may be transliterating. |
| */ |
| virtual void adoptFilter(UnicodeFilter* adoptedFilter); |
| |
| /** |
| * Returns this transliterator's inverse. See the class |
| * documentation for details. This implementation simply inverts |
| * the two entities in the ID and attempts to retrieve the |
| * resulting transliterator. That is, if <code>getID()</code> |
| * returns "A-B", then this method will return the result of |
| * <code>getInstance("B-A")</code>, or <code>null</code> if that |
| * call fails. |
| * |
| * <p>This method does not take filtering into account. The |
| * returned transliterator will have no filter. |
| * |
| * <p>Subclasses with knowledge of their inverse may wish to |
| * override this method. |
| * |
| * @return a transliterator that is an inverse, not necessarily |
| * exact, of this transliterator, or <code>null</code> if no such |
| * transliterator is registered. |
| * @see #registerInstance |
| */ |
| Transliterator* createInverse(void) const; |
| |
| /** |
| * Returns a <code>Transliterator</code> object given its ID. |
| * The ID must be either a system transliterator ID or a ID registered |
| * using <code>registerInstance()</code>. |
| * |
| * @param ID a valid ID, as enumerated by <code>getAvailableIDs()</code> |
| * @return A <code>Transliterator</code> object with the given ID |
| * @exception IllegalArgumentException if the given ID is invalid. |
| * @see #registerInstance |
| * @see #getAvailableIDs |
| * @see #getID |
| */ |
| static Transliterator* createInstance(const UnicodeString& ID, |
| Direction dir = FORWARD); |
| |
| private: |
| |
| /** |
| * This is the path to the subdirectory within the locale data |
| * directory that contains the rule-based transliterator resource |
| * bundle files. This is constructed dynamically the first time |
| * Transliterator::getDataDirectory() is called. |
| */ |
| static char* DATA_DIR; |
| |
| /** |
| * This is the name of a subdirectory within the locale data directory |
| * that contains the rule-based transliterator resource bundle files. |
| */ |
| static const char* RESOURCE_SUB_DIR; |
| |
| /** |
| * Returns the directory in which the transliterator resource bundle |
| * files are located. This is a subdirectory, named RESOURCE_SUB_DIR, |
| * under Locale::getDataDirectory(). It ends in a path separator. |
| */ |
| static const char* getDataDirectory(void); |
| |
| static int32_t hash(const UnicodeString& str); |
| |
| /** |
| * Returns a transliterator object given its ID. Unlike getInstance(), |
| * this method returns null if it cannot make use of the given ID. |
| */ |
| static Transliterator* _createInstance(const UnicodeString& ID); |
| |
| public: |
| |
| /** |
| * Registers a instance <tt>obj</tt> of a subclass of |
| * <code>Transliterator</code> with the system. When |
| * <tt>createInstance()</tt> is called with an ID string that is |
| * equal to <tt>obj->getID()</tt>, then <tt>obj->clone()</tt> is |
| * returned. |
| * |
| * After this call the Transliterator class owns the adoptedObj |
| * and will delete it. |
| * |
| * @param obj an instance of subclass of |
| * <code>Transliterator</code> that defines <tt>clone()</tt> |
| * @see #getInstance |
| * @see #registerClass |
| * @see #unregister |
| */ |
| static void registerInstance(Transliterator* adoptedObj, |
| UErrorCode& status); |
| |
| private: |
| |
| /** |
| * This internal method registers a prototype instance in the cache. |
| * The CALLER MUST MUTEX using cacheMutex before calling this method. |
| */ |
| static void _registerInstance(Transliterator* adoptedPrototype, |
| UErrorCode &status); |
| |
| public: |
| |
| /** |
| * Unregisters a transliterator or class. This may be either |
| * a system transliterator or a user transliterator or class. |
| * |
| * @param ID the ID of the transliterator or class |
| * @return the <code>Object</code> that was registered with |
| * <code>ID</code>, or <code>null</code> if none was |
| * @see #registerInstance |
| * @see #registerClass |
| */ |
| static void unregister(const UnicodeString& ID); |
| |
| private: |
| |
| /** |
| * Unregisters a transliterator or class. Internal method. |
| * Prerequisites: The cache must be initialized, and the |
| * caller must own the cacheMutex. |
| */ |
| static void _unregister(const UnicodeString& ID); |
| |
| /** |
| * Returns an enumeration over the programmatic names of registered |
| * <code>Transliterator</code> objects. This includes both system |
| * transliterators and user transliterators registered using |
| * <code>registerInstance()</code>. The enumerated names may be |
| * passed to <code>getInstance()</code>. |
| * |
| * @return An <code>Enumeration</code> over <code>String</code> objects |
| * @see #getInstance |
| * @see #registerInstance |
| */ |
| // virtual Enumeration getAvailableIDs(); |
| |
| /** |
| * Vector of registered IDs. |
| */ |
| static UVector cacheIDs; |
| |
| public: |
| |
| /** |
| * Return the number of IDs currently registered with the system. |
| * To retrieve the actual IDs, call getAvailableID(i) with |
| * i from 0 to countAvailableIDs() - 1. |
| */ |
| static int32_t countAvailableIDs(void); |
| |
| /** |
| * Return the index-th available ID. index must be between 0 |
| * and countAvailableIDs() - 1, inclusive. If index is out of |
| * range, the result of getAvailableID(0) is returned. |
| */ |
| static const UnicodeString& getAvailableID(int32_t index); |
| |
| protected: |
| |
| /** |
| * Method for subclasses to use to obtain a character in the given |
| * string, with filtering. |
| */ |
| UChar filteredCharAt(const Replaceable& text, int32_t i) const; |
| |
| private: |
| /** |
| * Comparison function for UVector. Compares two UnicodeString |
| * objects given void* pointers to them. |
| */ |
| static bool_t compareIDs(void* a, void* b); |
| |
| static void initializeCache(void); |
| }; |
| |
| inline int32_t Transliterator::getMaximumContextLength(void) const { |
| return maximumContextLength; |
| } |
| |
| #endif |