Enable StringUtils to split CharSequence like String#split

This is a groundwork for enabling LocaleSpan.

To enable LocaleSpan everywhere, we need to switch to
CharSequence from String so that Span infromation can be
preserved end-to-end.  To achieve this, we need to have
CharSequence version of String#split.

BUG: 16029304
Change-Id: I0dd103185dcf62fb1e25054a374340790e6a4678
Yohei Yukawa 2014-07-19 04:10:24 +09:00
parent e645715b25
commit eac8670830
2 changed files with 222 additions and 0 deletions

View File

@ -18,6 +18,7 @@ package com.android.inputmethod.latin.utils;
import static com.android.inputmethod.latin.Constants.CODE_UNSPECIFIED; import static com.android.inputmethod.latin.Constants.CODE_UNSPECIFIED;
import android.text.Spanned;
import android.text.TextUtils; import android.text.TextUtils;
import com.android.inputmethod.annotations.UsedForTesting; import com.android.inputmethod.annotations.UsedForTesting;
@ -26,6 +27,8 @@ import com.android.inputmethod.latin.Constants;
import java.util.ArrayList; import java.util.ArrayList;
import java.util.Arrays; import java.util.Arrays;
import java.util.Locale; import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public final class StringUtils { public final class StringUtils {
public static final int CAPITALIZE_NONE = 0; // No caps, or mixed case public static final int CAPITALIZE_NONE = 0; // No caps, or mixed case
@ -503,6 +506,55 @@ public final class StringUtils {
return lastIndex - i; return lastIndex - i;
} }
/**
* Splits the given {@code charSequence} with at occurrences of the given {@code regex}.
* <p>
* This is equivalent to
* {@code charSequence.toString().split(regex, preserveTrailingEmptySegments ? -1 : 0)}
* except that the spans are preserved in the result array.
* </p>
* @param input the character sequence to be split.
* @param regex the regex pattern to be used as the separator.
* @param preserveTrailingEmptySegments {@code true} to preserve the trailing empty
* segments. Otherwise, trailing empty segments will be removed before being returned.
* @return the array which contains the result. All the spans in the {@param input} is
* preserved.
*/
@UsedForTesting
public static CharSequence[] split(final CharSequence charSequence, final String regex,
final boolean preserveTrailingEmptySegments) {
// A short-cut for non-spanned strings.
if (!(charSequence instanceof Spanned)) {
// -1 means that trailing empty segments will be preserved.
return charSequence.toString().split(regex, preserveTrailingEmptySegments ? -1 : 0);
}
// Hereafter, emulate String.split for CharSequence.
final ArrayList<CharSequence> sequences = new ArrayList<>();
final Matcher matcher = Pattern.compile(regex).matcher(charSequence);
int nextStart = 0;
boolean matched = false;
while (matcher.find()) {
sequences.add(charSequence.subSequence(nextStart, matcher.start()));
nextStart = matcher.end();
matched = true;
}
if (!matched) {
// never matched. preserveTrailingEmptySegments is ignored in this case.
return new CharSequence[] { charSequence };
}
sequences.add(charSequence.subSequence(nextStart, charSequence.length()));
if (!preserveTrailingEmptySegments) {
for (int i = sequences.size() - 1; i >= 0; --i) {
if (!TextUtils.isEmpty(sequences.get(i))) {
break;
}
sequences.remove(i);
}
}
return sequences.toArray(new CharSequence[sequences.size()]);
}
@UsedForTesting @UsedForTesting
public static class Stringizer<E> { public static class Stringizer<E> {
public String stringize(final E element) { public String stringize(final E element) {

View File

@ -18,6 +18,9 @@ package com.android.inputmethod.latin.utils;
import android.test.AndroidTestCase; import android.test.AndroidTestCase;
import android.test.suitebuilder.annotation.SmallTest; import android.test.suitebuilder.annotation.SmallTest;
import android.text.SpannableString;
import android.text.Spanned;
import android.text.SpannedString;
import com.android.inputmethod.latin.Constants; import com.android.inputmethod.latin.Constants;
@ -326,4 +329,171 @@ public class StringAndJsonUtilsTests extends AndroidTestCase {
assertEquals(1, StringUtils.getTrailingSingleQuotesCount("'word'")); assertEquals(1, StringUtils.getTrailingSingleQuotesCount("'word'"));
assertEquals(0, StringUtils.getTrailingSingleQuotesCount("I'm")); assertEquals(0, StringUtils.getTrailingSingleQuotesCount("I'm"));
} }
private static void assertSpanCount(final int expectedCount, final CharSequence cs) {
final int actualCount;
if (cs instanceof Spanned) {
final Spanned spanned = (Spanned) cs;
actualCount = spanned.getSpans(0, spanned.length(), Object.class).length;
} else {
actualCount = 0;
}
assertEquals(expectedCount, actualCount);
}
private static void assertSpan(final CharSequence cs, final Object expectedSpan,
final int expectedStart, final int expectedEnd, final int expectedFlags) {
assertTrue(cs instanceof Spanned);
final Spanned spanned = (Spanned) cs;
final Object[] actualSpans = spanned.getSpans(0, spanned.length(), Object.class);
for (Object actualSpan : actualSpans) {
if (actualSpan == expectedSpan) {
final int actualStart = spanned.getSpanStart(actualSpan);
final int actualEnd = spanned.getSpanEnd(actualSpan);
final int actualFlags = spanned.getSpanFlags(actualSpan);
assertEquals(expectedStart, actualStart);
assertEquals(expectedEnd, actualEnd);
assertEquals(expectedFlags, actualFlags);
return;
}
}
assertTrue(false);
}
public void testSplitCharSequenceWithSpan() {
// text: " a bcd efg hij "
// span1: ^^^^^^^
// span2: ^^^^^
// span3: ^
final SpannableString spannableString = new SpannableString(" a bcd efg hij ");
final Object span1 = new Object();
final Object span2 = new Object();
final Object span3 = new Object();
final int SPAN1_FLAGS = Spanned.SPAN_EXCLUSIVE_EXCLUSIVE;
final int SPAN2_FLAGS = Spanned.SPAN_EXCLUSIVE_INCLUSIVE;
final int SPAN3_FLAGS = Spanned.SPAN_INCLUSIVE_INCLUSIVE;
spannableString.setSpan(span1, 0, 7, SPAN1_FLAGS);
spannableString.setSpan(span2, 0, 5, SPAN2_FLAGS);
spannableString.setSpan(span3, 12, 13, SPAN3_FLAGS);
final CharSequence[] charSequencesFromSpanned = StringUtils.split(
spannableString, " ", true /* preserveTrailingEmptySegmengs */);
final CharSequence[] charSequencesFromString = StringUtils.split(
spannableString.toString(), " ", true /* preserveTrailingEmptySegmengs */);
assertEquals(7, charSequencesFromString.length);
assertEquals(7, charSequencesFromSpanned.length);
// text: ""
// span1: ^
// span2: ^
// span3:
assertEquals("", charSequencesFromString[0].toString());
assertSpanCount(0, charSequencesFromString[0]);
assertEquals("", charSequencesFromSpanned[0].toString());
assertSpanCount(2, charSequencesFromSpanned[0]);
assertSpan(charSequencesFromSpanned[0], span1, 0, 0, SPAN1_FLAGS);
assertSpan(charSequencesFromSpanned[0], span2, 0, 0, SPAN2_FLAGS);
// text: "a"
// span1: ^
// span2: ^
// span3:
assertEquals("a", charSequencesFromString[1].toString());
assertSpanCount(0, charSequencesFromString[1]);
assertEquals("a", charSequencesFromSpanned[1].toString());
assertSpanCount(2, charSequencesFromSpanned[1]);
assertSpan(charSequencesFromSpanned[1], span1, 0, 1, SPAN1_FLAGS);
assertSpan(charSequencesFromSpanned[1], span2, 0, 1, SPAN2_FLAGS);
// text: "bcd"
// span1: ^^^
// span2: ^^
// span3:
assertEquals("bcd", charSequencesFromString[2].toString());
assertSpanCount(0, charSequencesFromString[2]);
assertEquals("bcd", charSequencesFromSpanned[2].toString());
assertSpanCount(2, charSequencesFromSpanned[2]);
assertSpan(charSequencesFromSpanned[2], span1, 0, 3, SPAN1_FLAGS);
assertSpan(charSequencesFromSpanned[2], span2, 0, 2, SPAN2_FLAGS);
// text: "efg"
// span1:
// span2:
// span3:
assertEquals("efg", charSequencesFromString[3].toString());
assertSpanCount(0, charSequencesFromString[3]);
assertEquals("efg", charSequencesFromSpanned[3].toString());
assertSpanCount(0, charSequencesFromSpanned[3]);
// text: "hij"
// span1:
// span2:
// span3: ^
assertEquals("hij", charSequencesFromString[4].toString());
assertSpanCount(0, charSequencesFromString[4]);
assertEquals("hij", charSequencesFromSpanned[4].toString());
assertSpanCount(1, charSequencesFromSpanned[4]);
assertSpan(charSequencesFromSpanned[4], span3, 1, 2, SPAN3_FLAGS);
// text: ""
// span1:
// span2:
// span3:
assertEquals("", charSequencesFromString[5].toString());
assertSpanCount(0, charSequencesFromString[5]);
assertEquals("", charSequencesFromSpanned[5].toString());
assertSpanCount(0, charSequencesFromSpanned[5]);
// text: ""
// span1:
// span2:
// span3:
assertEquals("", charSequencesFromString[6].toString());
assertSpanCount(0, charSequencesFromString[6]);
assertEquals("", charSequencesFromSpanned[6].toString());
assertSpanCount(0, charSequencesFromSpanned[6]);
}
public void testSplitCharSequencePreserveTrailingEmptySegmengs() {
assertEquals(1, StringUtils.split("", " ",
false /* preserveTrailingEmptySegmengs */).length);
assertEquals(1, StringUtils.split(new SpannedString(""), " ",
false /* preserveTrailingEmptySegmengs */).length);
assertEquals(1, StringUtils.split("", " ",
true /* preserveTrailingEmptySegmengs */).length);
assertEquals(1, StringUtils.split(new SpannedString(""), " ",
true /* preserveTrailingEmptySegmengs */).length);
assertEquals(0, StringUtils.split(" ", " ",
false /* preserveTrailingEmptySegmengs */).length);
assertEquals(0, StringUtils.split(new SpannedString(" "), " ",
false /* preserveTrailingEmptySegmengs */).length);
assertEquals(2, StringUtils.split(" ", " ",
true /* preserveTrailingEmptySegmengs */).length);
assertEquals(2, StringUtils.split(new SpannedString(" "), " ",
true /* preserveTrailingEmptySegmengs */).length);
assertEquals(3, StringUtils.split("a b c ", " ",
false /* preserveTrailingEmptySegmengs */).length);
assertEquals(3, StringUtils.split(new SpannedString("a b c "), " ",
false /* preserveTrailingEmptySegmengs */).length);
assertEquals(5, StringUtils.split("a b c ", " ",
true /* preserveTrailingEmptySegmengs */).length);
assertEquals(5, StringUtils.split(new SpannedString("a b c "), " ",
true /* preserveTrailingEmptySegmengs */).length);
assertEquals(6, StringUtils.split("a b ", " ",
false /* preserveTrailingEmptySegmengs */).length);
assertEquals(6, StringUtils.split(new SpannedString("a b "), " ",
false /* preserveTrailingEmptySegmengs */).length);
assertEquals(7, StringUtils.split("a b ", " ",
true /* preserveTrailingEmptySegmengs */).length);
assertEquals(7, StringUtils.split(new SpannedString("a b "), " ",
true /* preserveTrailingEmptySegmengs */).length);
}
} }