/*
********************************************************************************
*   Copyright (C) 1997-1999, International Business Machines
*   Corporation and others.  All Rights Reserved.
********************************************************************************
*
* File FIELDPOS.H
*
* Modification History:
*
*   Date        Name        Description
*   02/25/97    aliu        Converted from java.
*   03/17/97    clhuang     Updated per Format implementation.
*    07/17/98    stephen        Added default/copy ctors, and operators =, ==, !=
********************************************************************************
*/
// *****************************************************************************
// This file was generated from the java source file FieldPosition.java
// *****************************************************************************
 
#ifndef FIELDPOS_H
#define FIELDPOS_H

#include "unicode/utypes.h"

/**
 * <code>FieldPosition</code> is a simple class used by <code>Format</code>
 * and its subclasses to identify fields in formatted output. Fields are
 * identified by constants, whose names typically end with <code>_FIELD</code>,
 * defined in the various subclasses of <code>Format</code>. See
 * <code>ERA_FIELD</code> and its friends in <code>DateFormat</code> for
 * an example.
 *
 * <p>
 * <code>FieldPosition</code> keeps track of the position of the
 * field within the formatted output with two indices: the index
 * of the first character of the field and the index of the last
 * character of the field.
 *
 * <p>
 * One version of the <code>format</code> method in the various
 * <code>Format</code> classes requires a <code>FieldPosition</code>
 * object as an argument. You use this <code>format</code> method
 * to perform partial formatting or to get information about the
 * formatted output (such as the position of a field).
 *
 * <p>
 * Below is an example of using <code>FieldPosition</code> to aid
 * alignment of an array of formatted floating-point numbers on
 * their decimal points:
 * <pre>
 * .      double doubleNum[] = {123456789.0, -12345678.9, 1234567.89, -123456.789,
 * .                 12345.6789, -1234.56789, 123.456789, -12.3456789, 1.23456789};
 * .      int dNumSize = (int)(sizeof(doubleNum)/sizeof(double));
 * .      
 * .      UErrorCode status = U_ZERO_ERROR;
 * .      DecimalFormat* fmt = (DecimalFormat*) NumberFormat::createInstance(status);
 * .      fmt->setDecimalSeparatorAlwaysShown(true);
 * .      
 * .      const int tempLen = 20;
 * .      char temp[tempLen];
 * .      
 * .      for (int i=0; i&lt;dNumSize; i++) {
 * .          FieldPosition pos(NumberFormat::INTEGER_FIELD);
 * .          UnicodeString buf;
 * .          char fmtText[tempLen];
 * .          ToCharString(fmt->format(doubleNum[i], buf, pos), fmtText);
 * .          for (int j=0; j&lt;tempLen; j++) temp[j] = ' '; // clear with spaces
 * .          temp[__min(tempLen, tempLen-pos.getEndIndex())] = '\0';
 * .          cout &lt;&lt; temp &lt;&lt; fmtText   &lt;&lt; endl;
 * .      }
 * .      delete fmt;
 * </pre>
 * <p>
 * The code will generate the following output:
 * <pre>
 * .          123,456,789.000
 * .          -12,345,678.900
 * .            1,234,567.880
 * .             -123,456.789
 * .               12,345.678
 * .               -1,234.567
 * .                  123.456
 * .                  -12.345
 * .                    1.234
 * </pre>
*/
class U_I18N_API FieldPosition {
public:
    /**
     * DONT_CARE may be specified as the field to indicate that the
     * caller doesn't need to specify a field.  Do not subclass.
     */
    enum { DONT_CARE = -1 };

    /**
     * Creates a FieldPosition object with a non-specified field.
     */
    FieldPosition() 
        : fField(DONT_CARE), fBeginIndex(0), fEndIndex(0) {}

    /**
     * Creates a FieldPosition object for the given field.  Fields are
     * identified by constants, whose names typically end with _FIELD,
     * in the various subclasses of Format.
     *
     * @see NumberFormat#INTEGER_FIELD
     * @see NumberFormat#FRACTION_FIELD
     * @see DateFormat#YEAR_FIELD
     * @see DateFormat#MONTH_FIELD
     */
    FieldPosition(int32_t field) 
        : fField(field), fBeginIndex(0), fEndIndex(0) {}

    /**
     * Copy constructor
     * @param copy the object to be copied from.
     */
    FieldPosition(const FieldPosition& copy) 
        : fField(copy.fField), fBeginIndex(copy.fBeginIndex), fEndIndex(copy.fEndIndex) {}

    /**
     * Destructor
     */
    ~FieldPosition() {}

    /**
     * Assignment operator
     */
    FieldPosition&      operator=(const FieldPosition& copy);

    /** 
     * Equality operator.
     * @return TRUE if the two field positions are equal, FALSE otherwise.
     */
    bool_t              operator==(const FieldPosition& that) const;

    /** 
     * Equality operator.
     * @return TRUE if the two field positions are not equal, FALSE otherwise.
     */
    bool_t              operator!=(const FieldPosition& that) const;

    /**
     * Retrieve the field identifier.
     */
    int32_t getField(void) const { return fField; }

    /**
     * Retrieve the index of the first character in the requested field.
     */
    int32_t getBeginIndex(void) const { return fBeginIndex; }

    /**
     * Retrieve the index of the character following the last character in the
     * requested field.
     */
    int32_t getEndIndex(void) const { return fEndIndex; }
 
    /**
     * Set the field.
     */
    void setField(int32_t f) { fField = f; }

    /**
     * Set the begin index.  For use by subclasses of Format.
     */
    void setBeginIndex(int32_t bi) { fBeginIndex = bi; }

    /**
     * Set the end index.  For use by subclasses of Format.
     */
    void setEndIndex(int32_t ei) { fEndIndex = ei; }
    
private:
    /**
     * Input: Desired field to determine start and end offsets for.
     * The meaning depends on the subclass of Format.
     */
    int32_t fField;

    /**
     * Output: End offset of field in text.
     * If the field does not occur in the text, 0 is returned.
     */
    int32_t fEndIndex;

    /**
     * Output: Start offset of field in text.
     * If the field does not occur in the text, 0 is returned.
     */
    int32_t fBeginIndex;
};

inline FieldPosition&
FieldPosition::operator=(const FieldPosition& copy)
{
    fField         = copy.fField;
    fEndIndex     = copy.fEndIndex;
    fBeginIndex = copy.fBeginIndex;
    return *this;
}

inline bool_t
FieldPosition::operator==(const FieldPosition& copy) const
{
    if(    fField         != copy.fField || 
        fEndIndex     != copy.fEndIndex ||
        fBeginIndex != copy.fBeginIndex) 
        return FALSE;
    else
        return TRUE;
}

inline bool_t
FieldPosition::operator!=(const FieldPosition& copy) const
{
    return !operator==(copy);
}

#endif // _FIELDPOS
//eof