Precision.java
// © 2017 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
package com.ibm.icu.number;
import com.ibm.icu.impl.number.DecimalQuantity;
import com.ibm.icu.impl.number.MultiplierProducer;
import com.ibm.icu.impl.number.RoundingUtils;
import com.ibm.icu.number.NumberFormatter.RoundingPriority;
import com.ibm.icu.number.NumberFormatter.TrailingZeroDisplay;
import com.ibm.icu.text.PluralRules.Operand;
import com.ibm.icu.util.Currency;
import com.ibm.icu.util.Currency.CurrencyUsage;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.math.MathContext;
/**
* A class that defines the rounding precision to be used when formatting numbers in
* NumberFormatter.
*
* <p>To create a Precision, use one of the factory methods.
*
* @stable ICU 62
* @see NumberFormatter
*/
public abstract class Precision {
/* package-private final */ MathContext mathContext;
/* package-private final */ TrailingZeroDisplay trailingZeroDisplay;
/* package-private */ Precision() {
mathContext = RoundingUtils.DEFAULT_MATH_CONTEXT_UNLIMITED;
}
/**
* Show all available digits to full precision.
*
* <p><strong>NOTE:</strong> When formatting a <em>double</em>, this method, along with {@link
* #minFraction} and {@link #minSignificantDigits}, will trigger complex algorithm similar to
* <em>Dragon4</em> to determine the low-order digits and the number of digits to display based
* on the value of the double. If the number of fraction places or significant digits can be
* bounded, consider using {@link #maxFraction} or {@link #maxSignificantDigits} instead to
* maximize performance. For more information, read the following blog post.
*
* <p>http://www.serpentine.com/blog/2011/06/29/here-be-dragons-advances-in-problems-you-didnt-even-know-you-had/
*
* @return A Precision for chaining or passing to the NumberFormatter precision() setter.
* @stable ICU 60
* @see NumberFormatter
*/
public static Precision unlimited() {
return constructInfinite();
}
/**
* Show numbers rounded if necessary to the nearest integer.
*
* @return A FractionPrecision for chaining or passing to the NumberFormatter precision()
* setter.
* @stable ICU 60
* @see NumberFormatter
*/
public static FractionPrecision integer() {
return constructFraction(0, 0);
}
/**
* Show numbers rounded if necessary to a certain number of fraction places (numerals after the
* decimal separator). Additionally, pad with zeros to ensure that this number of places are
* always shown.
*
* <p>Example output with minMaxFractionPlaces = 3:
*
* <p>87,650.000<br>
* 8,765.000<br>
* 876.500<br>
* 87.650<br>
* 8.765<br>
* 0.876<br>
* 0.088<br>
* 0.009<br>
* 0.000 (zero)
*
* <p>This method is equivalent to {@link #minMaxFraction} with both arguments equal.
*
* @param minMaxFractionPlaces The minimum and maximum number of numerals to display after the
* decimal separator (rounding if too long or padding with zeros if too short).
* @return A FractionPrecision for chaining or passing to the NumberFormatter precision()
* setter.
* @throws IllegalArgumentException if the input number is too big or smaller than 0.
* @stable ICU 60
* @see NumberFormatter
*/
public static FractionPrecision fixedFraction(int minMaxFractionPlaces) {
if (minMaxFractionPlaces >= 0 && minMaxFractionPlaces <= RoundingUtils.MAX_INT_FRAC_SIG) {
return constructFraction(minMaxFractionPlaces, minMaxFractionPlaces);
} else {
throw new IllegalArgumentException(
"Fraction length must be between 0 and "
+ RoundingUtils.MAX_INT_FRAC_SIG
+ " (inclusive)");
}
}
/**
* Always show at least a certain number of fraction places after the decimal separator, padding
* with zeros if necessary. Do not perform rounding (display numbers to their full precision).
*
* <p><strong>NOTE:</strong> If you are formatting <em>doubles</em>, see the performance note in
* {@link #unlimited}.
*
* @param minFractionPlaces The minimum number of numerals to display after the decimal
* separator (padding with zeros if necessary).
* @return A FractionPrecision for chaining or passing to the NumberFormatter precision()
* setter.
* @throws IllegalArgumentException if the input number is too big or smaller than 0.
* @stable ICU 60
* @see NumberFormatter
*/
public static FractionPrecision minFraction(int minFractionPlaces) {
if (minFractionPlaces >= 0 && minFractionPlaces <= RoundingUtils.MAX_INT_FRAC_SIG) {
return constructFraction(minFractionPlaces, -1);
} else {
throw new IllegalArgumentException(
"Fraction length must be between 0 and "
+ RoundingUtils.MAX_INT_FRAC_SIG
+ " (inclusive)");
}
}
/**
* Show numbers rounded if necessary to a certain number of fraction places (numerals after the
* decimal separator). Unlike the other fraction rounding strategies, this strategy does
* <em>not</em> pad zeros to the end of the number.
*
* @param maxFractionPlaces The maximum number of numerals to display after the decimal mark
* (rounding if necessary).
* @return A FractionPrecision for chaining or passing to the NumberFormatter precision()
* setter.
* @throws IllegalArgumentException if the input number is too big or smaller than 0.
* @stable ICU 60
* @see NumberFormatter
*/
public static FractionPrecision maxFraction(int maxFractionPlaces) {
if (maxFractionPlaces >= 0 && maxFractionPlaces <= RoundingUtils.MAX_INT_FRAC_SIG) {
return constructFraction(0, maxFractionPlaces);
} else {
throw new IllegalArgumentException(
"Fraction length must be between 0 and "
+ RoundingUtils.MAX_INT_FRAC_SIG
+ " (inclusive)");
}
}
/**
* Show numbers rounded if necessary to a certain number of fraction places (numerals after the
* decimal separator); in addition, always show at least a certain number of places after the
* decimal separator, padding with zeros if necessary.
*
* @param minFractionPlaces The minimum number of numerals to display after the decimal
* separator (padding with zeros if necessary).
* @param maxFractionPlaces The maximum number of numerals to display after the decimal
* separator (rounding if necessary).
* @return A FractionPrecision for chaining or passing to the NumberFormatter precision()
* setter.
* @throws IllegalArgumentException if the input number is too big or smaller than 0.
* @stable ICU 60
* @see NumberFormatter
*/
public static FractionPrecision minMaxFraction(int minFractionPlaces, int maxFractionPlaces) {
if (minFractionPlaces >= 0
&& maxFractionPlaces <= RoundingUtils.MAX_INT_FRAC_SIG
&& minFractionPlaces <= maxFractionPlaces) {
return constructFraction(minFractionPlaces, maxFractionPlaces);
} else {
throw new IllegalArgumentException(
"Fraction length must be between 0 and "
+ RoundingUtils.MAX_INT_FRAC_SIG
+ " (inclusive)");
}
}
/**
* Show numbers rounded if necessary to a certain number of significant digits or significant
* figures. Additionally, pad with zeros to ensure that this number of significant
* digits/figures are always shown.
*
* <p>This method is equivalent to {@link #minMaxSignificantDigits} with both arguments equal.
*
* @param minMaxSignificantDigits The minimum and maximum number of significant digits to
* display (rounding if too long or padding with zeros if too short).
* @return A Precision for chaining or passing to the NumberFormatter precision() setter.
* @throws IllegalArgumentException if the input number is too big or smaller than 1.
* @stable ICU 62
* @see NumberFormatter
*/
public static Precision fixedSignificantDigits(int minMaxSignificantDigits) {
if (minMaxSignificantDigits >= 1
&& minMaxSignificantDigits <= RoundingUtils.MAX_INT_FRAC_SIG) {
return constructSignificant(minMaxSignificantDigits, minMaxSignificantDigits);
} else {
throw new IllegalArgumentException(
"Significant digits must be between 1 and "
+ RoundingUtils.MAX_INT_FRAC_SIG
+ " (inclusive)");
}
}
/**
* Always show at least a certain number of significant digits/figures, padding with zeros if
* necessary. Do not perform rounding (display numbers to their full precision).
*
* <p><strong>NOTE:</strong> If you are formatting <em>doubles</em>, see the performance note in
* {@link #unlimited}.
*
* @param minSignificantDigits The minimum number of significant digits to display (padding with
* zeros if too short).
* @return A Precision for chaining or passing to the NumberFormatter precision() setter.
* @throws IllegalArgumentException if the input number is too big or smaller than 1.
* @stable ICU 62
* @see NumberFormatter
*/
public static Precision minSignificantDigits(int minSignificantDigits) {
if (minSignificantDigits >= 1 && minSignificantDigits <= RoundingUtils.MAX_INT_FRAC_SIG) {
return constructSignificant(minSignificantDigits, -1);
} else {
throw new IllegalArgumentException(
"Significant digits must be between 1 and "
+ RoundingUtils.MAX_INT_FRAC_SIG
+ " (inclusive)");
}
}
/**
* Show numbers rounded if necessary to a certain number of significant digits/figures.
*
* @param maxSignificantDigits The maximum number of significant digits to display (rounding if
* too long).
* @return A Precision for chaining or passing to the NumberFormatter precision() setter.
* @throws IllegalArgumentException if the input number is too big or smaller than 1.
* @stable ICU 62
* @see NumberFormatter
*/
public static Precision maxSignificantDigits(int maxSignificantDigits) {
if (maxSignificantDigits >= 1 && maxSignificantDigits <= RoundingUtils.MAX_INT_FRAC_SIG) {
return constructSignificant(1, maxSignificantDigits);
} else {
throw new IllegalArgumentException(
"Significant digits must be between 1 and "
+ RoundingUtils.MAX_INT_FRAC_SIG
+ " (inclusive)");
}
}
/**
* Show numbers rounded if necessary to a certain number of significant digits/figures; in
* addition, always show at least a certain number of significant digits, padding with zeros if
* necessary.
*
* @param minSignificantDigits The minimum number of significant digits to display (padding with
* zeros if necessary).
* @param maxSignificantDigits The maximum number of significant digits to display (rounding if
* necessary).
* @return A Precision for chaining or passing to the NumberFormatter precision() setter.
* @throws IllegalArgumentException if the input number is too big or smaller than 1.
* @stable ICU 62
* @see NumberFormatter
*/
public static Precision minMaxSignificantDigits(
int minSignificantDigits, int maxSignificantDigits) {
if (minSignificantDigits >= 1
&& maxSignificantDigits <= RoundingUtils.MAX_INT_FRAC_SIG
&& minSignificantDigits <= maxSignificantDigits) {
return constructSignificant(minSignificantDigits, maxSignificantDigits);
} else {
throw new IllegalArgumentException(
"Significant digits must be between 1 and "
+ RoundingUtils.MAX_INT_FRAC_SIG
+ " (inclusive)");
}
}
/**
* Show numbers rounded if necessary to the closest multiple of a certain rounding increment.
* For example, if the rounding increment is 0.5, then round 1.2 to 1 and round 1.3 to 1.5.
*
* <p>In order to ensure that numbers are padded to the appropriate number of fraction places,
* set the scale on the rounding increment BigDecimal. For example, to round to the nearest 0.5
* and always display 2 numerals after the decimal separator (to display 1.2 as "1.00" and 1.3
* as "1.50"), you can run:
*
* <pre>
* Precision.increment(new BigDecimal("0.50"))
* </pre>
*
* <p>For more information on the scale of Java BigDecimal, see {@link
* java.math.BigDecimal#scale()}.
*
* @param roundingIncrement The increment to which to round numbers.
* @return A Precision for chaining or passing to the NumberFormatter precision() setter.
* @throws IllegalArgumentException if the rounding increment is null or non-positive.
* @stable ICU 60
* @see NumberFormatter
*/
public static Precision increment(BigDecimal roundingIncrement) {
if (roundingIncrement != null && roundingIncrement.compareTo(BigDecimal.ZERO) > 0) {
return constructIncrement(roundingIncrement);
} else {
throw new IllegalArgumentException("Rounding increment must be positive and non-null");
}
}
/**
* Show numbers rounded and padded according to the rules for the currency unit. The most common
* rounding precision settings for currencies include <code>Precision.fixedFraction(2)</code>,
* <code>Precision.integer()</code>, and <code>Precision.increment(0.05)</code> for cash
* transactions ("nickel rounding").
*
* <p>The exact rounding details will be resolved at runtime based on the currency unit
* specified in the NumberFormatter chain. To round according to the rules for one currency
* while displaying the symbol for another currency, the withCurrency() method can be called on
* the return value of this method.
*
* @param currencyUsage Either STANDARD (for digital transactions) or CASH (for transactions
* where the rounding increment may be limited by the available denominations of cash or
* coins).
* @return A CurrencyPrecision for chaining or passing to the NumberFormatter precision()
* setter.
* @throws IllegalArgumentException if currencyUsage is null.
* @stable ICU 60
* @see NumberFormatter
*/
public static CurrencyPrecision currency(CurrencyUsage currencyUsage) {
if (currencyUsage != null) {
return constructCurrency(currencyUsage);
} else {
throw new IllegalArgumentException("CurrencyUsage must be non-null");
}
}
/**
* Configure how trailing zeros are displayed on numbers. For example, to hide trailing zeros
* when the number is an integer, use HIDE_IF_WHOLE.
*
* @param trailingZeroDisplay Option to configure the display of trailing zeros.
* @stable ICU 69
*/
public Precision trailingZeroDisplay(TrailingZeroDisplay trailingZeroDisplay) {
Precision result = this.createCopy();
result.trailingZeroDisplay = trailingZeroDisplay;
return result;
}
/**
* Sets a MathContext to use on this Precision.
*
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public Precision withMode(MathContext mathContext) {
if (this.mathContext.equals(mathContext)) {
return this;
}
Precision other = createCopy();
other.mathContext = mathContext;
return other;
}
/** Package-private clone method */
abstract Precision createCopy();
/**
* Call this function to copy the fields from the Precision base class.
*
* <p>Note: It would be nice if this returned the copy, but most impls return the child class,
* not Precision.
*/
/* package-private */ void createCopyHelper(Precision copy) {
copy.mathContext = mathContext;
copy.trailingZeroDisplay = trailingZeroDisplay;
}
/**
* @internal
* @deprecated ICU 60 This API is ICU internal only.
*/
@Deprecated
public abstract void apply(DecimalQuantity value);
//////////////////////////
// PACKAGE-PRIVATE APIS //
//////////////////////////
/**
* @internal
* @deprecated ICU internal only.
*/
@Deprecated public static final BogusRounder BOGUS_PRECISION = new BogusRounder();
static final InfiniteRounderImpl NONE = new InfiniteRounderImpl();
static final FractionRounderImpl FIXED_FRAC_0 = new FractionRounderImpl(0, 0);
static final FractionRounderImpl FIXED_FRAC_2 = new FractionRounderImpl(2, 2);
static final FractionRounderImpl DEFAULT_MAX_FRAC_6 = new FractionRounderImpl(0, 6);
static final SignificantRounderImpl FIXED_SIG_2 = new SignificantRounderImpl(2, 2);
static final SignificantRounderImpl FIXED_SIG_3 = new SignificantRounderImpl(3, 3);
static final SignificantRounderImpl RANGE_SIG_2_3 = new SignificantRounderImpl(2, 3);
static final FracSigRounderImpl COMPACT_STRATEGY =
new FracSigRounderImpl(0, 0, 1, 2, RoundingPriority.RELAXED, false);
static final IncrementFiveRounderImpl NICKEL =
new IncrementFiveRounderImpl(new BigDecimal("0.05"), 2, 2);
static final CurrencyRounderImpl MONETARY_STANDARD =
new CurrencyRounderImpl(CurrencyUsage.STANDARD);
static final CurrencyRounderImpl MONETARY_CASH = new CurrencyRounderImpl(CurrencyUsage.CASH);
static Precision constructInfinite() {
return NONE;
}
static FractionPrecision constructFraction(int minFrac, int maxFrac) {
if (minFrac == 0 && maxFrac == 0) {
return FIXED_FRAC_0;
} else if (minFrac == 2 && maxFrac == 2) {
return FIXED_FRAC_2;
} else if (minFrac == 0 && maxFrac == 6) {
return DEFAULT_MAX_FRAC_6;
} else {
return new FractionRounderImpl(minFrac, maxFrac);
}
}
/** Assumes that minSig <= maxSig. */
static Precision constructSignificant(int minSig, int maxSig) {
if (minSig == 2 && maxSig == 2) {
return FIXED_SIG_2;
} else if (minSig == 3 && maxSig == 3) {
return FIXED_SIG_3;
} else if (minSig == 2 && maxSig == 3) {
return RANGE_SIG_2_3;
} else {
return new SignificantRounderImpl(minSig, maxSig);
}
}
static Precision constructFractionSignificant(
FractionPrecision base_,
int minSig,
int maxSig,
RoundingPriority priority,
boolean retain) {
assert base_ instanceof FractionRounderImpl;
FractionRounderImpl base = (FractionRounderImpl) base_;
Precision returnValue;
if (base.minFrac == 0
&& base.maxFrac == 0
&& minSig == 1
&& maxSig == 2
&& priority == RoundingPriority.RELAXED
&& !retain) {
returnValue = COMPACT_STRATEGY;
} else {
returnValue =
new FracSigRounderImpl(
base.minFrac, base.maxFrac, minSig, maxSig, priority, retain);
}
return returnValue.withMode(base.mathContext);
}
static Precision constructIncrement(BigDecimal increment) {
// NOTE: .equals() is what we want, not .compareTo()
if (increment.equals(NICKEL.increment)) {
return NICKEL;
}
// Note: For number formatting, the BigDecimal increment is used for IncrementRounderImpl
// but not mIncrementOneRounderImpl or IncrementFiveRounderImpl. However, fIncrement is
// used in all three when constructing a skeleton.
BigDecimal reduced = increment.stripTrailingZeros();
if (reduced.precision() == 1) {
int minFrac = increment.scale();
int maxFrac = reduced.scale();
BigInteger digit = reduced.unscaledValue();
if (digit.intValue() == 1) {
return new IncrementOneRounderImpl(increment, minFrac, maxFrac);
} else if (digit.intValue() == 5) {
return new IncrementFiveRounderImpl(increment, minFrac, maxFrac);
}
}
return new IncrementRounderImpl(increment);
}
static CurrencyPrecision constructCurrency(CurrencyUsage usage) {
if (usage == CurrencyUsage.STANDARD) {
return MONETARY_STANDARD;
} else if (usage == CurrencyUsage.CASH) {
return MONETARY_CASH;
} else {
throw new AssertionError();
}
}
static Precision constructFromCurrency(CurrencyPrecision base_, Currency currency) {
assert base_ instanceof CurrencyRounderImpl;
CurrencyRounderImpl base = (CurrencyRounderImpl) base_;
double incrementDouble = currency.getRoundingIncrement(base.usage);
Precision returnValue;
if (incrementDouble != 0.0) {
BigDecimal increment = BigDecimal.valueOf(incrementDouble);
returnValue = constructIncrement(increment);
} else {
int minMaxFrac = currency.getDefaultFractionDigits(base.usage);
returnValue = constructFraction(minMaxFrac, minMaxFrac);
}
return returnValue.withMode(base.mathContext);
}
/**
* Returns a valid working Rounder. If the Rounder is a CurrencyRounder, applies the given
* currency. Otherwise, simply passes through the argument.
*
* @param currency A currency object to use in case the input object needs it.
* @return A Rounder object ready for use.
*/
Precision withLocaleData(Currency currency) {
if (this instanceof CurrencyPrecision) {
return ((CurrencyPrecision) this).withCurrency(currency);
} else {
return this;
}
}
/**
* Rounding endpoint used by Engineering and Compact notation. Chooses the most appropriate
* multiplier (magnitude adjustment), applies the adjustment, rounds, and returns the chosen
* multiplier.
*
* <p>In most cases, this is simple. However, when rounding the number causes it to cross a
* multiplier boundary, we need to re-do the rounding. For example, to display 999,999 in
* Engineering notation with 2 sigfigs, first you guess the multiplier to be -3. However, then
* you end up getting 1000E3, which is not the correct output. You then change your multiplier
* to be -6, and you get 1.0E6, which is correct.
*
* @param input The quantity to process.
* @param producer Function to call to return a multiplier based on a magnitude.
* @return The number of orders of magnitude the input was adjusted by this method.
*/
int chooseMultiplierAndApply(DecimalQuantity input, MultiplierProducer producer) {
// Do not call this method with zero, NaN, or infinity.
assert !input.isZeroish();
// Perform the first attempt at rounding.
int magnitude = input.getMagnitude();
int multiplier = producer.getMultiplier(magnitude);
input.adjustMagnitude(multiplier);
apply(input);
// If the number rounded to zero, exit.
if (input.isZeroish()) {
return multiplier;
}
// If the new magnitude after rounding is the same as it was before rounding, then we are
// done.
// This case applies to most numbers.
if (input.getMagnitude() == magnitude + multiplier) {
return multiplier;
}
// If the above case DIDN'T apply, then we have a case like 99.9 -> 100 or 999.9 -> 1000:
// The number rounded up to the next magnitude. Check if the multiplier changes; if it
// doesn't,
// we do not need to make any more adjustments.
int _multiplier = producer.getMultiplier(magnitude + 1);
if (multiplier == _multiplier) {
return multiplier;
}
// We have a case like 999.9 -> 1000, where the correct output is "1K", not "1000".
// Fix the magnitude and re-apply the rounding strategy.
input.adjustMagnitude(_multiplier - multiplier);
apply(input);
return _multiplier;
}
///////////////
// INTERNALS //
///////////////
/**
* An BogusRounder's MathContext into precision.
*
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public static class BogusRounder extends Precision {
/**
* Default constructor.
*
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public BogusRounder() {}
/**
* {@inheritDoc}
*
* @internal
* @deprecated This API is ICU internal only.
*/
@Override
@Deprecated
public void apply(DecimalQuantity value) {
throw new AssertionError("BogusRounder must not be applied");
}
@Override
BogusRounder createCopy() {
BogusRounder copy = new BogusRounder();
createCopyHelper(copy);
return copy;
}
/**
* Copies the BogusRounder's MathContext into precision.
*
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public Precision into(Precision precision) {
Precision copy = precision.createCopy();
createCopyHelper(copy);
return copy;
}
}
static class InfiniteRounderImpl extends Precision {
public InfiniteRounderImpl() {}
@Override
public void apply(DecimalQuantity value) {
value.roundToInfinity();
setResolvedMinFraction(value, 0);
}
@Override
InfiniteRounderImpl createCopy() {
InfiniteRounderImpl copy = new InfiniteRounderImpl();
createCopyHelper(copy);
return copy;
}
}
static class FractionRounderImpl extends FractionPrecision {
final int minFrac;
final int maxFrac;
public FractionRounderImpl(int minFrac, int maxFrac) {
this.minFrac = minFrac;
this.maxFrac = maxFrac;
}
@Override
public void apply(DecimalQuantity value) {
value.roundToMagnitude(getRoundingMagnitudeFraction(maxFrac), mathContext);
setResolvedMinFraction(value, Math.max(0, -getDisplayMagnitudeFraction(minFrac)));
}
@Override
FractionRounderImpl createCopy() {
FractionRounderImpl copy = new FractionRounderImpl(minFrac, maxFrac);
createCopyHelper(copy);
return copy;
}
}
static class SignificantRounderImpl extends Precision {
final int minSig;
final int maxSig;
public SignificantRounderImpl(int minSig, int maxSig) {
this.minSig = minSig;
this.maxSig = maxSig;
}
@Override
public void apply(DecimalQuantity value) {
value.roundToMagnitude(getRoundingMagnitudeSignificant(value, maxSig), mathContext);
setResolvedMinFraction(
value, Math.max(0, -getDisplayMagnitudeSignificant(value, minSig)));
// Make sure that digits are displayed on zero.
if (value.isZeroish() && minSig > 0) {
value.setMinInteger(1);
}
}
/**
* Version of {@link #apply} that obeys minInt constraints. Used for scientific notation
* compatibility mode.
*/
public void apply(DecimalQuantity quantity, int minInt) {
assert quantity.isZeroish();
setResolvedMinFraction(quantity, minSig - minInt);
}
@Override
SignificantRounderImpl createCopy() {
SignificantRounderImpl copy = new SignificantRounderImpl(minSig, maxSig);
createCopyHelper(copy);
return copy;
}
}
static class FracSigRounderImpl extends Precision {
final int minFrac;
final int maxFrac;
final int minSig;
final int maxSig;
final RoundingPriority priority;
final boolean retain;
public FracSigRounderImpl(
int minFrac,
int maxFrac,
int minSig,
int maxSig,
RoundingPriority priority,
boolean retain) {
this.minFrac = minFrac;
this.maxFrac = maxFrac;
this.minSig = minSig;
this.maxSig = maxSig;
this.priority = priority;
this.retain = retain;
}
@Override
public void apply(DecimalQuantity value) {
int roundingMag1 = getRoundingMagnitudeFraction(maxFrac);
int roundingMag2 = getRoundingMagnitudeSignificant(value, maxSig);
int roundingMag;
if (priority == RoundingPriority.RELAXED) {
roundingMag = Math.min(roundingMag1, roundingMag2);
} else {
roundingMag = Math.max(roundingMag1, roundingMag2);
}
if (!value.isZeroish()) {
int upperMag = value.getMagnitude();
value.roundToMagnitude(roundingMag, mathContext);
if (!value.isZeroish()
&& value.getMagnitude() != upperMag
&& roundingMag1 == roundingMag2) {
// roundingMag2 needs to be the magnitude after rounding
roundingMag2 += 1;
}
}
int displayMag1 = getDisplayMagnitudeFraction(minFrac);
int displayMag2 = getDisplayMagnitudeSignificant(value, minSig);
int displayMag;
if (retain) {
// withMinDigits + withMaxDigits
displayMag = Math.min(displayMag1, displayMag2);
} else if (priority == RoundingPriority.RELAXED) {
if (roundingMag2 <= roundingMag1) {
displayMag = displayMag2;
} else {
displayMag = displayMag1;
}
} else {
assert (priority == RoundingPriority.STRICT);
if (roundingMag2 <= roundingMag1) {
displayMag = displayMag1;
} else {
displayMag = displayMag2;
}
}
setResolvedMinFraction(value, Math.max(0, -displayMag));
}
@Override
FracSigRounderImpl createCopy() {
FracSigRounderImpl copy =
new FracSigRounderImpl(minFrac, maxFrac, minSig, maxSig, priority, retain);
createCopyHelper(copy);
return copy;
}
}
/** Used for strange increments like 3.14. */
static class IncrementRounderImpl extends Precision {
final BigDecimal increment;
public IncrementRounderImpl(BigDecimal increment) {
this.increment = increment;
}
@Override
public void apply(DecimalQuantity value) {
value.roundToIncrement(increment, mathContext);
setResolvedMinFraction(value, Math.max(0, increment.scale()));
}
@Override
IncrementRounderImpl createCopy() {
IncrementRounderImpl copy = new IncrementRounderImpl(increment);
createCopyHelper(copy);
return copy;
}
}
/**
* Used for increments with 1 as the only digit. This is different than fraction rounding
* because it supports having additional trailing zeros. For example, this class is used to
* round with the increment 0.010.
*/
static class IncrementOneRounderImpl extends IncrementRounderImpl {
final int minFrac;
final int maxFrac;
public IncrementOneRounderImpl(BigDecimal increment, int minFrac, int maxFrac) {
super(increment);
this.minFrac = minFrac;
this.maxFrac = maxFrac;
}
@Override
public void apply(DecimalQuantity value) {
value.roundToMagnitude(-maxFrac, mathContext);
setResolvedMinFraction(value, minFrac);
}
@Override
IncrementOneRounderImpl createCopy() {
IncrementOneRounderImpl copy = new IncrementOneRounderImpl(increment, minFrac, maxFrac);
createCopyHelper(copy);
return copy;
}
}
/** Used for increments with 5 as the only digit (nickel rounding). */
static class IncrementFiveRounderImpl extends IncrementRounderImpl {
final int minFrac;
final int maxFrac;
public IncrementFiveRounderImpl(BigDecimal increment, int minFrac, int maxFrac) {
super(increment);
this.minFrac = minFrac;
this.maxFrac = maxFrac;
}
@Override
public void apply(DecimalQuantity value) {
value.roundToNickel(-maxFrac, mathContext);
setResolvedMinFraction(value, minFrac);
}
@Override
IncrementFiveRounderImpl createCopy() {
IncrementFiveRounderImpl copy =
new IncrementFiveRounderImpl(increment, minFrac, maxFrac);
createCopyHelper(copy);
return copy;
}
}
static class CurrencyRounderImpl extends CurrencyPrecision {
final CurrencyUsage usage;
public CurrencyRounderImpl(CurrencyUsage usage) {
this.usage = usage;
}
@Override
public void apply(DecimalQuantity value) {
// Call .withCurrency() before .apply()!
throw new AssertionError();
}
@Override
CurrencyRounderImpl createCopy() {
CurrencyRounderImpl copy = new CurrencyRounderImpl(usage);
createCopyHelper(copy);
return copy;
}
}
private static int getRoundingMagnitudeFraction(int maxFrac) {
if (maxFrac == -1) {
return Integer.MIN_VALUE;
}
return -maxFrac;
}
private static int getRoundingMagnitudeSignificant(DecimalQuantity value, int maxSig) {
if (maxSig == -1) {
return Integer.MIN_VALUE;
}
int magnitude = value.isZeroish() ? 0 : value.getMagnitude();
return magnitude - maxSig + 1;
}
private static int getDisplayMagnitudeFraction(int minFrac) {
if (minFrac == 0) {
return Integer.MAX_VALUE;
}
return -minFrac;
}
void setResolvedMinFraction(DecimalQuantity value, int resolvedMinFraction) {
if (trailingZeroDisplay == null
|| trailingZeroDisplay == TrailingZeroDisplay.AUTO
||
// PLURAL_OPERAND_T returns fraction digits as an integer
value.getPluralOperand(Operand.t) != 0) {
value.setMinFraction(resolvedMinFraction);
}
}
private static int getDisplayMagnitudeSignificant(DecimalQuantity value, int minSig) {
// Question: Is it useful to look at trailingZeroDisplay here?
int magnitude = value.isZeroish() ? 0 : value.getMagnitude();
return magnitude - minSig + 1;
}
}