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International Component for Unicode for Java (ICU4J) is a mature, widely used Java library
providing Unicode and Globalization support
/*
*******************************************************************************
* Copyright (C) 2012-2014, Google, International Business Machines Corporation and
* others. All Rights Reserved.
*******************************************************************************
*/
package com.ibm.icu.text;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;
import com.ibm.icu.impl.ICUCache;
import com.ibm.icu.impl.ICUResourceBundle;
import com.ibm.icu.impl.SimpleCache;
import com.ibm.icu.impl.SimplePatternFormatter;
import com.ibm.icu.util.ULocale;
import com.ibm.icu.util.UResourceBundle;
/**
* Immutable class for formatting a list, using data from CLDR (or supplied
* separately). The class is not subclassable.
*
* @author Mark Davis
* @stable ICU 50
*/
final public class ListFormatter {
private final SimplePatternFormatter two;
private final SimplePatternFormatter start;
private final SimplePatternFormatter middle;
private final SimplePatternFormatter end;
private final ULocale locale;
/**
* Indicates the style of Listformatter
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public enum Style {
/**
* Standard style.
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
STANDARD("standard"),
/**
* Style for full durations
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
DURATION("unit"),
/**
* Style for durations in abbrevated form
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
DURATION_SHORT("unit-short"),
/**
* Style for durations in narrow form
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
DURATION_NARROW("unit-narrow");
private final String name;
Style(String name) {
this.name = name;
}
/**
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public String getName() {
return name;
}
}
/**
* Internal: Create a ListFormatter from component strings,
* with definitions as in LDML.
*
* @param two
* string for two items, containing {0} for the first, and {1}
* for the second.
* @param start
* string for the start of a list items, containing {0} for the
* first, and {1} for the rest.
* @param middle
* string for the start of a list items, containing {0} for the
* first part of the list, and {1} for the rest of the list.
* @param end
* string for the end of a list items, containing {0} for the
* first part of the list, and {1} for the last item.
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public ListFormatter(String two, String start, String middle, String end) {
this(
SimplePatternFormatter.compile(two),
SimplePatternFormatter.compile(start),
SimplePatternFormatter.compile(middle),
SimplePatternFormatter.compile(end),
null);
}
private ListFormatter(SimplePatternFormatter two, SimplePatternFormatter start, SimplePatternFormatter middle, SimplePatternFormatter end, ULocale locale) {
this.two = two;
this.start = start;
this.middle = middle;
this.end = end;
this.locale = locale;
}
/**
* Create a list formatter that is appropriate for a locale.
*
* @param locale
* the locale in question.
* @return ListFormatter
* @stable ICU 50
*/
public static ListFormatter getInstance(ULocale locale) {
return getInstance(locale, Style.STANDARD);
}
/**
* Create a list formatter that is appropriate for a locale.
*
* @param locale
* the locale in question.
* @return ListFormatter
* @stable ICU 50
*/
public static ListFormatter getInstance(Locale locale) {
return getInstance(ULocale.forLocale(locale), Style.STANDARD);
}
/**
* Create a list formatter that is appropriate for a locale and style.
*
* @param locale the locale in question.
* @param style the style
* @return ListFormatter
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public static ListFormatter getInstance(ULocale locale, Style style) {
return cache.get(locale, style.getName());
}
/**
* Create a list formatter that is appropriate for the default FORMAT locale.
*
* @return ListFormatter
* @stable ICU 50
*/
public static ListFormatter getInstance() {
return getInstance(ULocale.getDefault(ULocale.Category.FORMAT));
}
/**
* Format a list of objects.
*
* @param items
* items to format. The toString() method is called on each.
* @return items formatted into a string
* @stable ICU 50
*/
public String format(Object... items) {
return format(Arrays.asList(items));
}
/**
* Format a collection of objects. The toString() method is called on each.
*
* @param items
* items to format. The toString() method is called on each.
* @return items formatted into a string
* @stable ICU 50
*/
public String format(Collection items) {
// TODO optimize this for the common case that the patterns are all of the
// form {0}{1}.
// We avoid MessageFormat, because there is no "sub" formatting.
return format(items, -1).toString();
}
// Formats a collection of objects and returns the formatted string plus the offset
// in the string where the index th element appears. index is zero based. If index is
// negative or greater than or equal to the size of items then this function returns -1 for
// the offset.
FormattedListBuilder format(Collection items, int index) {
Iterator it = items.iterator();
int count = items.size();
switch (count) {
case 0:
return new FormattedListBuilder("", false);
case 1:
return new FormattedListBuilder(it.next(), index == 0);
case 2:
return new FormattedListBuilder(it.next(), index == 0).append(two, it.next(), index == 1);
}
FormattedListBuilder builder = new FormattedListBuilder(it.next(), index == 0);
builder.append(start, it.next(), index == 1);
for (int idx = 2; idx < count - 1; ++idx) {
builder.append(middle, it.next(), index == idx);
}
return builder.append(end, it.next(), index == count - 1);
}
/**
* Returns the pattern to use for a particular item count.
* @param count the item count.
* @return the pattern with {0}, {1}, {2}, etc. For English,
* getPatternForNumItems(3) == "{0}, {1}, and {2}"
* @throws IllegalArgumentException when count is 0 or negative.
* @draft ICU 52
* @provisional This API might change or be removed in a future release.
*/
public String getPatternForNumItems(int count) {
if (count <= 0) {
throw new IllegalArgumentException("count must be > 0");
}
ArrayList list = new ArrayList();
for (int i = 0; i < count; i++) {
list.add(String.format("{%d}", i));
}
return format(list);
}
/**
* Returns the locale of this object.
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public ULocale getLocale() {
return locale;
}
// Builds a formatted list
static class FormattedListBuilder {
private String current;
private int offset;
// Start is the first object in the list; If recordOffset is true, records the offset of
// this first object.
public FormattedListBuilder(Object start, boolean recordOffset) {
this.current = start.toString();
this.offset = recordOffset ? 0 : -1;
}
// Appends additional object. pattern is a template indicating where the new object gets
// added in relation to the rest of the list. {0} represents the rest of the list; {1}
// represents the new object in pattern. next is the object to be added. If recordOffset
// is true, records the offset of next in the formatted string.
public FormattedListBuilder append(SimplePatternFormatter pattern, Object next, boolean recordOffset) {
if (pattern.getPlaceholderCount() != 2) {
throw new IllegalArgumentException("Need {0} and {1} only in pattern " + pattern);
}
if (recordOffset || offsetRecorded()) {
int[] offsets = new int[2];
current = pattern.format(
new StringBuilder(), offsets, current, next.toString()).toString();
if (offsets[0] == -1 || offsets[1] == -1) {
throw new IllegalArgumentException(
"{0} or {1} missing from pattern " + pattern);
}
if (recordOffset) {
offset = offsets[1];
} else {
offset += offsets[0];
}
} else {
current = pattern.format(current, next.toString());
}
return this;
}
@Override
public String toString() {
return current;
}
// Gets the last recorded offset or -1 if no offset recorded.
public int getOffset() {
return offset;
}
private boolean offsetRecorded() {
return offset >= 0;
}
}
/** JUST FOR DEVELOPMENT */
// For use with the hard-coded data
// TODO Replace by use of RB
// Verify in building that all of the patterns contain {0}, {1}.
static Map localeToData = new HashMap();
static void add(String locale, String...data) {
localeToData.put(new ULocale(locale), new ListFormatter(data[0], data[1], data[2], data[3]));
}
private static class Cache {
private final ICUCache cache =
new SimpleCache();
public ListFormatter get(ULocale locale, String style) {
String key = String.format("%s:%s", locale.toString(), style);
ListFormatter result = cache.get(key);
if (result == null) {
result = load(locale, style);
cache.put(key, result);
}
return result;
}
private static ListFormatter load(ULocale ulocale, String style) {
ICUResourceBundle r = (ICUResourceBundle)UResourceBundle.
getBundleInstance(ICUResourceBundle.ICU_BASE_NAME, ulocale);
// TODO(Travis Keep): This try-catch is a hack to cover missing aliases
// for listPattern/duration and listPattern/duration-narrow in root.txt.
try {
return new ListFormatter(
SimplePatternFormatter.compile(r.getWithFallback("listPattern/" + style + "/2").getString()),
SimplePatternFormatter.compile(r.getWithFallback("listPattern/" + style + "/start").getString()),
SimplePatternFormatter.compile(r.getWithFallback("listPattern/" + style + "/middle").getString()),
SimplePatternFormatter.compile(r.getWithFallback("listPattern/" + style + "/end").getString()),
ulocale);
} catch (MissingResourceException e) {
return new ListFormatter(
SimplePatternFormatter.compile(r.getWithFallback("listPattern/standard/2").getString()),
SimplePatternFormatter.compile(r.getWithFallback("listPattern/standard/start").getString()),
SimplePatternFormatter.compile(r.getWithFallback("listPattern/standard/middle").getString()),
SimplePatternFormatter.compile(r.getWithFallback("listPattern/standard/end").getString()),
ulocale);
}
}
}
static Cache cache = new Cache();
}