ICU 56 update step 1

source/i18n/valueformatter.h

+/*
+*******************************************************************************
+* Copyright (C) 2015, International Business Machines Corporation and         *
+* others. All Rights Reserved.                                                *
+*******************************************************************************
+*/
+
+#ifndef VALUEFORMATTER_H
+#define VALUEFORMATTER_H
+
+#if !UCONFIG_NO_FORMATTING
+
+#include "unicode/uobject.h"
+#include "unicode/utypes.h"
+
+
+
+U_NAMESPACE_BEGIN
+
+class UnicodeString;
+class DigitList;
+class FieldPositionHandler;
+class DigitGrouping;
+class PluralRules;
+class FixedPrecision;
+class DigitFormatter;
+class DigitFormatterOptions;
+class ScientificPrecision;
+class SciFormatterOptions;
+class FixedDecimal;
+class VisibleDigitsWithExponent;
+
+
+/**
+ * A closure around rounding and formatting a value. As these instances are
+ * designed to be short lived (they only exist while formatting a value), they
+ * do not own their own attributes. Rather the caller maintains ownership of
+ * all attributes. A caller first calls a prepareXXX method on an instance
+ * to share its data before using that instance. Using an
+ * instance without first calling a prepareXXX method results in an
+ * assertion error and a program crash.
+ */
+class U_I18N_API ValueFormatter : public UObject {
+public:
+    ValueFormatter() : fType(kFormatTypeCount) {
+    }
+
+    virtual ~ValueFormatter();
+
+    /**
+     * This function is here only to support the protected round() method
+     * in DecimalFormat. It serves no ther purpose than that.
+     *
+     * @param value this value is rounded in place.
+     * @param status any error returned here.
+     */
+    DigitList &round(DigitList &value, UErrorCode &status) const;
+
+    /**
+     * Returns TRUE if the absolute value of value can be fast formatted
+     * using ValueFormatter::formatInt32.
+     */
+    UBool isFastFormattable(int32_t value) const;
+
+    /**
+     * Converts value to a VisibleDigitsWithExponent.
+     * Result may be fixed point or scientific.
+     */
+    VisibleDigitsWithExponent &toVisibleDigitsWithExponent(
+            int64_t value,
+            VisibleDigitsWithExponent &digits,
+            UErrorCode &status) const;
+
+    /**
+     * Converts value to a VisibleDigitsWithExponent.
+     * Result may be fixed point or scientific.
+     */
+    VisibleDigitsWithExponent &toVisibleDigitsWithExponent(
+            DigitList &value,
+            VisibleDigitsWithExponent &digits,
+            UErrorCode &status) const;
+
+    /**
+     * formats positiveValue and appends to appendTo. Returns appendTo.
+     * @param positiveValue If negative, no negative sign is formatted.
+     * @param handler stores the field positions
+     * @param appendTo formatted value appended here.
+     */
+    UnicodeString &format(
+        const VisibleDigitsWithExponent &positiveValue,
+        FieldPositionHandler &handler,
+        UnicodeString &appendTo) const;
+
+
+    /**
+     * formats positiveValue and appends to appendTo. Returns appendTo.
+     * value must be positive. Calling formatInt32 to format a value when
+     * isFastFormattable indicates that the value cannot be fast formatted
+     * results in undefined behavior.
+     */
+    UnicodeString &formatInt32(
+        int32_t positiveValue,
+        FieldPositionHandler &handler,
+        UnicodeString &appendTo) const;
+
+    /**
+     * Returns the number of code points needed to format.
+     * @param positiveValue if negative, the negative sign is not included
+     *   in count.
+     */
+    int32_t countChar32(
+            const VisibleDigitsWithExponent &positiveValue) const;
+  
+    /**
+     * Prepares this instance for fixed decimal formatting.
+     */
+    void prepareFixedDecimalFormatting(
+        const DigitFormatter &formatter,
+        const DigitGrouping &grouping,
+        const FixedPrecision &precision,
+        const DigitFormatterOptions &options);
+
+    /**
+     * Prepares this instance for scientific formatting.
+     */
+    void prepareScientificFormatting(
+        const DigitFormatter &formatter,
+        const ScientificPrecision &precision,
+        const SciFormatterOptions &options);
+
+private:
+    ValueFormatter(const ValueFormatter &);
+    ValueFormatter &operator=(const ValueFormatter &);
+    enum FormatType {
+        kFixedDecimal,
+        kScientificNotation,
+        kFormatTypeCount
+    };
+
+    FormatType fType;
+
+    // for fixed decimal and scientific formatting
+    const DigitFormatter *fDigitFormatter;
+
+    // for fixed decimal formatting
+    const FixedPrecision *fFixedPrecision;
+    const DigitFormatterOptions *fFixedOptions;
+    const DigitGrouping *fGrouping;
+
+    // for scientific formatting
+    const ScientificPrecision *fScientificPrecision;
+    const SciFormatterOptions *fScientificOptions;
+};
+
+U_NAMESPACE_END
+
+#endif /* !UCONFIG_NO_FORMATTING */
+
+#endif /* VALUEFORMATTER_H */