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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
*
* Copyright (C) 2011-2014 International Business Machines
* Corporation and others. All Rights Reserved.
*
*******************************************************************************
*/
#ifndef INDEXCHARS_H
#define INDEXCHARS_H
#include "unicode/utypes.h"
#if U_SHOW_CPLUSPLUS_API
#include "unicode/uobject.h"
#include "unicode/locid.h"
#include "unicode/unistr.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,
/**
* Underflow 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. The 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
* @param errorCode Error code, will be set with the reason if the
* operation fails.
* @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 nullptr 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 *between* other index characters.
* For example, consider the labels when Latin (X Y Z) and Greek (Α Β Γ) 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 nullptr 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 (private)
*/
AlphabeticIndex(const AlphabeticIndex &other) = delete;
/**
* No assignment.
*/
AlphabeticIndex &operator =(const AlphabeticIndex & /*other*/) { return *this;}
/**
* No Equality operators.
* @internal (private)
*/
virtual bool operator==(const AlphabeticIndex& other) const;
/**
* Inequality operator.
* @internal (private)
*/
virtual bool 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.
* \cond
* @internal
*/
struct Record: public UMemory {
const UnicodeString name_;
const void *data_;
Record(const UnicodeString &name, const void *data);
~Record();
};
/** \endcond */
#endif /* U_HIDE_INTERNAL_API */
private:
/**
* Holds all user records before they are distributed into buckets.
* Type of contents is (Record *)
* @internal (private)
*/
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.
// nullptr 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 /* U_SHOW_CPLUSPLUS_API */
#endif
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