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1 // Copyright (C) 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 *******************************************************************************
5 * Copyright (C) 2015, International Business Machines Corporation and         *
6 * others. All Rights Reserved.                                                *
7 *******************************************************************************
8 */
9 
10 #ifndef VALUEFORMATTER_H
11 #define VALUEFORMATTER_H
12 
13 #if !UCONFIG_NO_FORMATTING
14 
15 #include "unicode/uobject.h"
16 #include "unicode/utypes.h"
17 
18 
19 
20 U_NAMESPACE_BEGIN
21 
22 class UnicodeString;
23 class DigitList;
24 class FieldPositionHandler;
25 class DigitGrouping;
26 class PluralRules;
27 class FixedPrecision;
28 class DigitFormatter;
29 class DigitFormatterOptions;
30 class ScientificPrecision;
31 class SciFormatterOptions;
32 class FixedDecimal;
33 class VisibleDigitsWithExponent;
34 
35 
36 /**
37  * A closure around rounding and formatting a value. As these instances are
38  * designed to be short lived (they only exist while formatting a value), they
39  * do not own their own attributes. Rather the caller maintains ownership of
40  * all attributes. A caller first calls a prepareXXX method on an instance
41  * to share its data before using that instance. Using an
42  * instance without first calling a prepareXXX method results in an
43  * assertion error and a program crash.
44  */
45 class U_I18N_API ValueFormatter : public UObject {
46 public:
ValueFormatter()47     ValueFormatter() : fType(kFormatTypeCount) {
48     }
49 
50     virtual ~ValueFormatter();
51 
52     /**
53      * This function is here only to support the protected round() method
54      * in DecimalFormat. It serves no ther purpose than that.
55      *
56      * @param value this value is rounded in place.
57      * @param status any error returned here.
58      */
59     DigitList &round(DigitList &value, UErrorCode &status) const;
60 
61     /**
62      * Returns TRUE if the absolute value of value can be fast formatted
63      * using ValueFormatter::formatInt32.
64      */
65     UBool isFastFormattable(int32_t value) const;
66 
67     /**
68      * Converts value to a VisibleDigitsWithExponent.
69      * Result may be fixed point or scientific.
70      */
71     VisibleDigitsWithExponent &toVisibleDigitsWithExponent(
72             int64_t value,
73             VisibleDigitsWithExponent &digits,
74             UErrorCode &status) const;
75 
76     /**
77      * Converts value to a VisibleDigitsWithExponent.
78      * Result may be fixed point or scientific.
79      */
80     VisibleDigitsWithExponent &toVisibleDigitsWithExponent(
81             DigitList &value,
82             VisibleDigitsWithExponent &digits,
83             UErrorCode &status) const;
84 
85     /**
86      * formats positiveValue and appends to appendTo. Returns appendTo.
87      * @param positiveValue If negative, no negative sign is formatted.
88      * @param handler stores the field positions
89      * @param appendTo formatted value appended here.
90      */
91     UnicodeString &format(
92         const VisibleDigitsWithExponent &positiveValue,
93         FieldPositionHandler &handler,
94         UnicodeString &appendTo) const;
95 
96 
97     /**
98      * formats positiveValue and appends to appendTo. Returns appendTo.
99      * value must be positive. Calling formatInt32 to format a value when
100      * isFastFormattable indicates that the value cannot be fast formatted
101      * results in undefined behavior.
102      */
103     UnicodeString &formatInt32(
104         int32_t positiveValue,
105         FieldPositionHandler &handler,
106         UnicodeString &appendTo) const;
107 
108     /**
109      * Returns the number of code points needed to format.
110      * @param positiveValue if negative, the negative sign is not included
111      *   in count.
112      */
113     int32_t countChar32(
114             const VisibleDigitsWithExponent &positiveValue) const;
115 
116     /**
117      * Prepares this instance for fixed decimal formatting.
118      */
119     void prepareFixedDecimalFormatting(
120         const DigitFormatter &formatter,
121         const DigitGrouping &grouping,
122         const FixedPrecision &precision,
123         const DigitFormatterOptions &options);
124 
125     /**
126      * Prepares this instance for scientific formatting.
127      */
128     void prepareScientificFormatting(
129         const DigitFormatter &formatter,
130         const ScientificPrecision &precision,
131         const SciFormatterOptions &options);
132 
133 private:
134     ValueFormatter(const ValueFormatter &);
135     ValueFormatter &operator=(const ValueFormatter &);
136     enum FormatType {
137         kFixedDecimal,
138         kScientificNotation,
139         kFormatTypeCount
140     };
141 
142     FormatType fType;
143 
144     // for fixed decimal and scientific formatting
145     const DigitFormatter *fDigitFormatter;
146 
147     // for fixed decimal formatting
148     const FixedPrecision *fFixedPrecision;
149     const DigitFormatterOptions *fFixedOptions;
150     const DigitGrouping *fGrouping;
151 
152     // for scientific formatting
153     const ScientificPrecision *fScientificPrecision;
154     const SciFormatterOptions *fScientificOptions;
155 };
156 
157 U_NAMESPACE_END
158 
159 #endif /* !UCONFIG_NO_FORMATTING */
160 
161 #endif /* VALUEFORMATTER_H */
162