/* ******************************************************************************* * * Copyright (C) 2011-2014 International Business Machines * Corporation and others. All Rights Reserved. * ******************************************************************************* */ #ifndef INDEXCHARS_H #define INDEXCHARS_H #include "unicode/utypes.h" #include "unicode/uobject.h" #include "unicode/locid.h" #if !UCONFIG_NO_COLLATION /** * \file * \brief C++ API: Index Characters */ U_CDECL_BEGIN /** * Constants for Alphabetic Index Label Types. * The form of these enum constants anticipates having a plain C API * for Alphabetic Indexes that will also use them. * @stable ICU 4.8 */ typedef enum UAlphabeticIndexLabelType { /** * Normal Label, typically the starting letter of the names * in the bucket with this label. * @stable ICU 4.8 */ U_ALPHAINDEX_NORMAL = 0, /** * Undeflow Label. The bucket with this label contains names * in scripts that sort before any of the bucket labels in this index. * @stable ICU 4.8 */ U_ALPHAINDEX_UNDERFLOW = 1, /** * Inflow Label. The bucket with this label contains names * in scripts that sort between two of the bucket labels in this index. * Inflow labels are created when an index contains normal labels for * multiple scripts, and skips other scripts that sort between some of the * included scripts. * @stable ICU 4.8 */ U_ALPHAINDEX_INFLOW = 2, /** * Overflow Label. Te bucket with this label contains names in scripts * that sort after all of the bucket labels in this index. * @stable ICU 4.8 */ U_ALPHAINDEX_OVERFLOW = 3 } UAlphabeticIndexLabelType; struct UHashtable; U_CDECL_END U_NAMESPACE_BEGIN // Forward Declarations class BucketList; class Collator; class RuleBasedCollator; class StringEnumeration; class UnicodeSet; class UVector; /** * AlphabeticIndex supports the creation of a UI index appropriate for a given language. * It can support either direct use, or use with a client that doesn't support localized collation. * The following is an example of what an index might look like in a UI: * * <pre> * <b>... A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ...</b> * * <b>A</b> * Addison * Albertson * Azensky * <b>B</b> * Baker * ... * </pre> * * The class can generate a list of labels for use as a UI "index", that is, a list of * clickable characters (or character sequences) that allow the user to see a segment * (bucket) of a larger "target" list. That is, each label corresponds to a bucket in * the target list, where everything in the bucket is greater than or equal to the character * (according to the locale's collation). Strings can be added to the index; * they will be in sorted order in the right bucket. * <p> * The class also supports having buckets for strings before the first (underflow), * after the last (overflow), and between scripts (inflow). For example, if the index * is constructed with labels for Russian and English, Greek characters would fall * into an inflow bucket between the other two scripts. * <p> * The AlphabeticIndex class is not intended for public subclassing. * * <p><em>Note:</em> If you expect to have a lot of ASCII or Latin characters * as well as characters from the user's language, * then it is a good idea to call addLabels(Locale::getEnglish(), status).</p> * * <h2>Direct Use</h2> * <p>The following shows an example of building an index directly. * The "show..." methods below are just to illustrate usage. * * <pre> * // Create a simple index. "Item" is assumed to be an application * // defined type that the application's UI and other processing knows about, * // and that has a name. * * UErrorCode status = U_ZERO_ERROR; * AlphabeticIndex index = new AlphabeticIndex(desiredLocale, status); * index->addLabels(additionalLocale, status); * for (Item *item in some source of Items ) { * index->addRecord(item->name(), item, status); * } * ... * // Show index at top. We could skip or gray out empty buckets * * while (index->nextBucket(status)) { * if (showAll || index->getBucketRecordCount() != 0) { * showLabelAtTop(UI, index->getBucketLabel()); * } * } * ... * // Show the buckets with their contents, skipping empty buckets * * index->resetBucketIterator(status); * while (index->nextBucket(status)) { * if (index->getBucketRecordCount() != 0) { * showLabelInList(UI, index->getBucketLabel()); * while (index->nextRecord(status)) { * showIndexedItem(UI, static_cast<Item *>(index->getRecordData())) * </pre> * * The caller can build different UIs using this class. * For example, an index character could be omitted or grayed-out * if its bucket is empty. Small buckets could also be combined based on size, such as: * * <pre> * <b>... A-F G-N O-Z ...</b> * </pre> * * <h2>Client Support</h2> * <p>Callers can also use the AlphabeticIndex::ImmutableIndex, or the AlphabeticIndex itself, * to support sorting on a client that doesn't support AlphabeticIndex functionality. * * <p>The ImmutableIndex is both immutable and thread-safe. * The corresponding AlphabeticIndex methods are not thread-safe because * they "lazily" build the index buckets. * <ul> * <li>ImmutableIndex.getBucket(index) provides random access to all * buckets and their labels and label types. * <li>The AlphabeticIndex bucket iterator or ImmutableIndex.getBucket(0..getBucketCount-1) * can be used to get a list of the labels, * such as "...", "A", "B",..., and send that list to the client. * <li>When the client has a new name, it sends that name to the server. * The server needs to call the following methods, * and communicate the bucketIndex and collationKey back to the client. * * <pre> * int32_t bucketIndex = index.getBucketIndex(name, status); * const UnicodeString &label = immutableIndex.getBucket(bucketIndex)->getLabel(); // optional * int32_t skLength = collator.getSortKey(name, sk, skCapacity); * </pre> * * <li>The client would put the name (and associated information) into its bucket for bucketIndex. The sort key sk is a * sequence of bytes that can be compared with a binary compare, and produce the right localized result.</li> * </ul> * * @stable ICU 4.8 */ class U_I18N_API AlphabeticIndex: public UObject { public: /** * An index "bucket" with a label string and type. * It is referenced by getBucketIndex(), * and returned by ImmutableIndex.getBucket(). * * The Bucket class is not intended for public subclassing. * @stable ICU 51 */ class U_I18N_API Bucket : public UObject { public: /** * Destructor. * @stable ICU 51 */ virtual ~Bucket(); /** * Returns the label string. * * @return the label string for the bucket * @stable ICU 51 */ const UnicodeString &getLabel() const { return label_; } /** * Returns whether this bucket is a normal, underflow, overflow, or inflow bucket. * * @return the bucket label type * @stable ICU 51 */ UAlphabeticIndexLabelType getLabelType() const { return labelType_; } private: friend class AlphabeticIndex; friend class BucketList; UnicodeString label_; UnicodeString lowerBoundary_; UAlphabeticIndexLabelType labelType_; Bucket *displayBucket_; int32_t displayIndex_; UVector *records_; // Records are owned by the inputList_ vector. Bucket(const UnicodeString &label, // Parameter strings are copied. const UnicodeString &lowerBoundary, UAlphabeticIndexLabelType type); }; /** * Immutable, thread-safe version of AlphabeticIndex. * This class provides thread-safe methods for bucketing, * and random access to buckets and their properties, * but does not offer adding records to the index. * * The ImmutableIndex class is not intended for public subclassing. * * @stable ICU 51 */ class U_I18N_API ImmutableIndex : public UObject { public: /** * Destructor. * @stable ICU 51 */ virtual ~ImmutableIndex(); /** * Returns the number of index buckets and labels, including underflow/inflow/overflow. * * @return the number of index buckets * @stable ICU 51 */ int32_t getBucketCount() const; /** * Finds the index bucket for the given name and returns the number of that bucket. * Use getBucket() to get the bucket's properties. * * @param name the string to be sorted into an index bucket * @return the bucket number for the name * @stable ICU 51 */ int32_t getBucketIndex(const UnicodeString &name, UErrorCode &errorCode) const; /** * Returns the index-th bucket. Returns NULL if the index is out of range. * * @param index bucket number * @return the index-th bucket * @stable ICU 51 */ const Bucket *getBucket(int32_t index) const; private: friend class AlphabeticIndex; ImmutableIndex(BucketList *bucketList, Collator *collatorPrimaryOnly) : buckets_(bucketList), collatorPrimaryOnly_(collatorPrimaryOnly) {} BucketList *buckets_; Collator *collatorPrimaryOnly_; }; /** * Construct an AlphabeticIndex object for the specified locale. If the locale's * data does not include index characters, a set of them will be * synthesized based on the locale's exemplar characters. The locale * determines the sorting order for both the index characters and the * user item names appearing under each Index character. * * @param locale the desired locale. * @param status Error code, will be set with the reason if the construction * of the AlphabeticIndex object fails. * @stable ICU 4.8 */ AlphabeticIndex(const Locale &locale, UErrorCode &status); /** * Construct an AlphabeticIndex that uses a specific collator. * * The index will be created with no labels; the addLabels() function must be called * after creation to add the desired labels to the index. * * The index adopts the collator, and is responsible for deleting it. * The caller should make no further use of the collator after creating the index. * * @param collator The collator to use to order the contents of this index. * @param status Error code, will be set with the reason if the * operation fails. * @stable ICU 51 */ AlphabeticIndex(RuleBasedCollator *collator, UErrorCode &status); /** * Add Labels to this Index. The labels are additions to those * that are already in the index; they do not replace the existing * ones. * @param additions The additional characters to add to the index, such as A-Z. * @param status Error code, will be set with the reason if the * operation fails. * @return this, for chaining * @stable ICU 4.8 */ virtual AlphabeticIndex &addLabels(const UnicodeSet &additions, UErrorCode &status); /** * Add the index characters from a Locale to the index. The labels * are added to those that are already in the index; they do not replace the * existing index characters. The collation order for this index is not * changed; it remains that of the locale that was originally specified * when creating this Index. * * @param locale The locale whose index characters are to be added. * @param status Error code, will be set with the reason if the * operation fails. * @return this, for chaining * @stable ICU 4.8 */ virtual AlphabeticIndex &addLabels(const Locale &locale, UErrorCode &status); /** * Destructor * @stable ICU 4.8 */ virtual ~AlphabeticIndex(); /** * Builds an immutable, thread-safe version of this instance, without data records. * * @return an immutable index instance * @stable ICU 51 */ ImmutableIndex *buildImmutableIndex(UErrorCode &errorCode); /** * Get the Collator that establishes the ordering of the items in this index. * Ownership of the collator remains with the AlphabeticIndex instance. * * The returned collator is a reference to the internal collator used by this * index. It may be safely used to compare the names of items or to get * sort keys for names. However if any settings need to be changed, * or other non-const methods called, a cloned copy must be made first. * * @return The collator * @stable ICU 4.8 */ virtual const RuleBasedCollator &getCollator() const; /** * Get the default label used for abbreviated buckets <i>between</i> other index characters. * For example, consider the labels when Latin and Greek are used: * X Y Z ... Α Β Γ. * * @return inflow label * @stable ICU 4.8 */ virtual const UnicodeString &getInflowLabel() const; /** * Set the default label used for abbreviated buckets <i>between</i> other index characters. * An inflow label will be automatically inserted if two otherwise-adjacent label characters * are from different scripts, e.g. Latin and Cyrillic, and a third script, e.g. Greek, * sorts between the two. The default inflow character is an ellipsis (...) * * @param inflowLabel the new Inflow label. * @param status Error code, will be set with the reason if the operation fails. * @return this * @stable ICU 4.8 */ virtual AlphabeticIndex &setInflowLabel(const UnicodeString &inflowLabel, UErrorCode &status); /** * Get the special label used for items that sort after the last normal label, * and that would not otherwise have an appropriate label. * * @return the overflow label * @stable ICU 4.8 */ virtual const UnicodeString &getOverflowLabel() const; /** * Set the label used for items that sort after the last normal label, * and that would not otherwise have an appropriate label. * * @param overflowLabel the new overflow label. * @param status Error code, will be set with the reason if the operation fails. * @return this * @stable ICU 4.8 */ virtual AlphabeticIndex &setOverflowLabel(const UnicodeString &overflowLabel, UErrorCode &status); /** * Get the special label used for items that sort before the first normal label, * and that would not otherwise have an appropriate label. * * @return underflow label * @stable ICU 4.8 */ virtual const UnicodeString &getUnderflowLabel() const; /** * Set the label used for items that sort before the first normal label, * and that would not otherwise have an appropriate label. * * @param underflowLabel the new underflow label. * @param status Error code, will be set with the reason if the operation fails. * @return this * @stable ICU 4.8 */ virtual AlphabeticIndex &setUnderflowLabel(const UnicodeString &underflowLabel, UErrorCode &status); /** * Get the limit on the number of labels permitted in the index. * The number does not include over, under and inflow labels. * * @return maxLabelCount maximum number of labels. * @stable ICU 4.8 */ virtual int32_t getMaxLabelCount() const; /** * Set a limit on the number of labels permitted in the index. * The number does not include over, under and inflow labels. * Currently, if the number is exceeded, then every * nth item is removed to bring the count down. * A more sophisticated mechanism may be available in the future. * * @param maxLabelCount the maximum number of labels. * @param status error code * @return This, for chaining * @stable ICU 4.8 */ virtual AlphabeticIndex &setMaxLabelCount(int32_t maxLabelCount, UErrorCode &status); /** * Add a record to the index. Each record will be associated with an index Bucket * based on the record's name. The list of records for each bucket will be sorted * based on the collation ordering of the names in the index's locale. * Records with duplicate names are permitted; they will be kept in the order * that they were added. * * @param name The display name for the Record. The Record will be placed in * a bucket based on this name. * @param data An optional pointer to user data associated with this * item. When iterating the contents of a bucket, both the * data pointer the name will be available for each Record. * @param status Error code, will be set with the reason if the operation fails. * @return This, for chaining. * @stable ICU 4.8 */ virtual AlphabeticIndex &addRecord(const UnicodeString &name, const void *data, UErrorCode &status); /** * Remove all Records from the Index. The set of Buckets, which define the headings under * which records are classified, is not altered. * * @param status Error code, will be set with the reason if the operation fails. * @return This, for chaining. * @stable ICU 4.8 */ virtual AlphabeticIndex &clearRecords(UErrorCode &status); /** Get the number of labels in this index. * Note: may trigger lazy index construction. * * @param status Error code, will be set with the reason if the operation fails. * @return The number of labels in this index, including any under, over or * in-flow labels. * @stable ICU 4.8 */ virtual int32_t getBucketCount(UErrorCode &status); /** Get the total number of Records in this index, that is, the number * of <name, data> pairs added. * * @param status Error code, will be set with the reason if the operation fails. * @return The number of records in this index, that is, the total number * of (name, data) items added with addRecord(). * @stable ICU 4.8 */ virtual int32_t getRecordCount(UErrorCode &status); /** * Given the name of a record, return the zero-based index of the Bucket * in which the item should appear. The name need not be in the index. * A Record will not be added to the index by this function. * Bucket numbers are zero-based, in Bucket iteration order. * * @param itemName The name whose bucket position in the index is to be determined. * @param status Error code, will be set with the reason if the operation fails. * @return The bucket number for this name. * @stable ICU 4.8 * */ virtual int32_t getBucketIndex(const UnicodeString &itemName, UErrorCode &status); /** * Get the zero based index of the current Bucket from an iteration * over the Buckets of this index. Return -1 if no iteration is in process. * @return the index of the current Bucket * @stable ICU 4.8 */ virtual int32_t getBucketIndex() const; /** * Advance the iteration over the Buckets of this index. Return FALSE if * there are no more Buckets. * * @param status Error code, will be set with the reason if the operation fails. * U_ENUM_OUT_OF_SYNC_ERROR will be reported if the index is modified while * an enumeration of its contents are in process. * * @return TRUE if success, FALSE if at end of iteration * @stable ICU 4.8 */ virtual UBool nextBucket(UErrorCode &status); /** * Return the name of the Label of the current bucket from an iteration over the buckets. * If the iteration is before the first Bucket (nextBucket() has not been called), * or after the last, return an empty string. * * @return the bucket label. * @stable ICU 4.8 */ virtual const UnicodeString &getBucketLabel() const; /** * Return the type of the label for the current Bucket (selected by the * iteration over Buckets.) * * @return the label type. * @stable ICU 4.8 */ virtual UAlphabeticIndexLabelType getBucketLabelType() const; /** * Get the number of <name, data> Records in the current Bucket. * If the current bucket iteration position is before the first label or after the * last, return 0. * * @return the number of Records. * @stable ICU 4.8 */ virtual int32_t getBucketRecordCount() const; /** * Reset the Bucket iteration for this index. The next call to nextBucket() * will restart the iteration at the first label. * * @param status Error code, will be set with the reason if the operation fails. * @return this, for chaining. * @stable ICU 4.8 */ virtual AlphabeticIndex &resetBucketIterator(UErrorCode &status); /** * Advance to the next record in the current Bucket. * When nextBucket() is called, Record iteration is reset to just before the * first Record in the new Bucket. * * @param status Error code, will be set with the reason if the operation fails. * U_ENUM_OUT_OF_SYNC_ERROR will be reported if the index is modified while * an enumeration of its contents are in process. * @return TRUE if successful, FALSE when the iteration advances past the last item. * @stable ICU 4.8 */ virtual UBool nextRecord(UErrorCode &status); /** * Get the name of the current Record. * Return an empty string if the Record iteration position is before first * or after the last. * * @return The name of the current index item. * @stable ICU 4.8 */ virtual const UnicodeString &getRecordName() const; /** * Return the data pointer of the Record currently being iterated over. * Return NULL if the current iteration position before the first item in this Bucket, * or after the last. * * @return The current Record's data pointer. * @stable ICU 4.8 */ virtual const void *getRecordData() const; /** * Reset the Record iterator position to before the first Record in the current Bucket. * * @return This, for chaining. * @stable ICU 4.8 */ virtual AlphabeticIndex &resetRecordIterator(); private: /** * No Copy constructor. * @internal */ AlphabeticIndex(const AlphabeticIndex &other); /** * No assignment. */ AlphabeticIndex &operator =(const AlphabeticIndex & /*other*/) { return *this;}; /** * No Equality operators. * @internal */ virtual UBool operator==(const AlphabeticIndex& other) const; /** * Inequality operator. * @internal */ virtual UBool operator!=(const AlphabeticIndex& other) const; // Common initialization, for use from all constructors. void init(const Locale *locale, UErrorCode &status); /** * This method is called to get the index exemplars. Normally these come from the locale directly, * but if they aren't available, we have to synthesize them. */ void addIndexExemplars(const Locale &locale, UErrorCode &status); /** * Add Chinese index characters from the tailoring. */ UBool addChineseIndexCharacters(UErrorCode &errorCode); UVector *firstStringsInScript(UErrorCode &status); static UnicodeString separated(const UnicodeString &item); /** * Determine the best labels to use. * This is based on the exemplars, but we also process to make sure that they are unique, * and sort differently, and that the overall list is small enough. */ void initLabels(UVector &indexCharacters, UErrorCode &errorCode) const; BucketList *createBucketList(UErrorCode &errorCode) const; void initBuckets(UErrorCode &errorCode); void clearBuckets(); void internalResetBucketIterator(); public: // The Record is declared public only to allow access from // implementation code written in plain C. // It is not intended for public use. #ifndef U_HIDE_INTERNAL_API /** * A (name, data) pair, to be sorted by name into one of the index buckets. * The user data is not used by the index implementation. * @internal */ struct Record: public UMemory { const UnicodeString name_; const void *data_; Record(const UnicodeString &name, const void *data); ~Record(); }; #endif /* U_HIDE_INTERNAL_API */ private: /** * Holds all user records before they are distributed into buckets. * Type of contents is (Record *) * @internal */ UVector *inputList_; int32_t labelsIterIndex_; // Index of next item to return. int32_t itemsIterIndex_; Bucket *currentBucket_; // While an iteration of the index in underway, // point to the bucket for the current label. // NULL when no iteration underway. int32_t maxLabelCount_; // Limit on # of labels permitted in the index. UnicodeSet *initialLabels_; // Initial (unprocessed) set of Labels. Union // of those explicitly set by the user plus // those from locales. Raw values, before // crunching into bucket labels. UVector *firstCharsInScripts_; // The first character from each script, // in collation order. RuleBasedCollator *collator_; RuleBasedCollator *collatorPrimaryOnly_; // Lazy evaluated: null means that we have not built yet. BucketList *buckets_; UnicodeString inflowLabel_; UnicodeString overflowLabel_; UnicodeString underflowLabel_; UnicodeString overflowComparisonString_; UnicodeString emptyString_; }; U_NAMESPACE_END #endif // !UCONFIG_NO_COLLATION #endif