Android:TextUtils类介绍以及常见使用

　对于字符串处理Android为我们提供了一个简单实用的TextUtils类，如果处理比较简单的内容不用去思考正则表达式不妨试试这个在android.text.TextUtils的类，主要的功能如下:

//是否为空字符
Log.e("textUtils+isEmpty", "******" + TextUtils.isEmpty("12344556"));
Log.e("textUtils+isEmpty", "******" + TextUtils.isEmpty("")); （此处注意：空格返回false）
//判断是否只含有数字
Log.e("textUtils+isDigitsOnly", TextUtils.isDigitsOnly("123432")
+ "***" + TextUtils.isDigitsOnly("sssssss")
+ "***" + TextUtils.isDigitsOnly("123ssss"));
//判断是否含有可打印字符
Log.e("textUtils+isGraphic", TextUtils.isGraphic('2')
+ "***" + TextUtils.isGraphic("s32414314"));
//翻转指定的字符串
Log.e("textUtils+getReverse", TextUtils.getReverse("hello", 1, 5) + "");
//拼接字符串
Log.e("textUtils+concat", TextUtils.concat("one", " ", "two!").toString());
//判断字符串是否相等
Log.e("textUtils+equals", TextUtils.equals("equal", "equal")
+ "***" + TextUtils.equals("hello", "Hello")
+ "***" + TextUtils.equals("one1", "equal"));
//判断字符串长度，首位去空字符
Log.e("textUtils+getTrimmedLength", TextUtils.getTrimmedLength("length")
+ "***" + TextUtils.getTrimmedLength(" leng th"));
//判断子字符串第一次出现的位置返回位置数
Log.e("textUtils+indexOf", TextUtils.indexOf("hello android ,you are so wonderful!", "android") + "");
//截取字符串
Log.e("textUtils+substring", TextUtils.substring("Hello android!", 0, 5));
//分割字符串并获取分割后指定位置的子字符串
Log.e("textUtils+split", TextUtils.split(" Hello android!", "e")[0]
+ "***" + TextUtils.split(" Hello android!", "e")[1]);
// 在数组中每个元素之间使用“-”来连接
Log.e("textUtils+split", TextUtils.join("-", list));
// 使用html编码字符串
Log.e("textUtils+split", TextUtils.htmlEncode(f) + "");

附上TextUtils源码供大家自行探索：

[java] view plain copy

/*
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.text;
import android.content.res.Resources;
import android.os.Parcel;
import android.os.Parcelable;
import android.text.style.AbsoluteSizeSpan;
import android.text.style.AlignmentSpan;
import android.text.style.BackgroundColorSpan;
import android.text.style.BulletSpan;
import android.text.style.CharacterStyle;
import android.text.style.EasyEditSpan;
import android.text.style.ForegroundColorSpan;
import android.text.style.LeadingMarginSpan;
import android.text.style.LocaleSpan;
import android.text.style.MetricAffectingSpan;
import android.text.style.QuoteSpan;
import android.text.style.RelativeSizeSpan;
import android.text.style.ReplacementSpan;
import android.text.style.ScaleXSpan;
import android.text.style.SpellCheckSpan;
import android.text.style.StrikethroughSpan;
import android.text.style.StyleSpan;
import android.text.style.SubscriptSpan;
import android.text.style.SuggestionRangeSpan;
import android.text.style.SuggestionSpan;
import android.text.style.SuperscriptSpan;
import android.text.style.TextAppearanceSpan;
import android.text.style.TypefaceSpan;
import android.text.style.URLSpan;
import android.text.style.UnderlineSpan;
import android.util.Log;
import android.util.Printer;
import android.view.View;
import com.android.internal.R;
import com.android.internal.util.ArrayUtils;
import libcore.icu.ICU;
import java.lang.reflect.Array;
import java.util.Iterator;
import java.util.Locale;
import java.util.regex.Pattern;
public class TextUtils {
private static final String TAG = "TextUtils";
private TextUtils() { /* cannot be instantiated */ }
public static void getChars(CharSequence s, int start, int end,
char[] dest, int destoff) {
Class<? extends CharSequence> c = s.getClass();
if (c == String.class)
((String) s).getChars(start, end, dest, destoff);
else if (c == StringBuffer.class)
((StringBuffer) s).getChars(start, end, dest, destoff);
else if (c == StringBuilder.class)
((StringBuilder) s).getChars(start, end, dest, destoff);
else if (s instanceof GetChars)
((GetChars) s).getChars(start, end, dest, destoff);
else {
for (int i = start; i < end; i++)
dest[destoff++] = s.charAt(i);
}
}
public static int indexOf(CharSequence s, char ch) {
return indexOf(s, ch, 0);
}
public static int indexOf(CharSequence s, char ch, int start) {
Class<? extends CharSequence> c = s.getClass();
if (c == String.class)
return ((String) s).indexOf(ch, start);
return indexOf(s, ch, start, s.length());
}
public static int indexOf(CharSequence s, char ch, int start, int end) {
Class<? extends CharSequence> c = s.getClass();
if (s instanceof GetChars || c == StringBuffer.class ||
c == StringBuilder.class || c == String.class) {
final int INDEX_INCREMENT = 500;
char[] temp = obtain(INDEX_INCREMENT);
while (start < end) {
int segend = start + INDEX_INCREMENT;
if (segend > end)
segend = end;
getChars(s, start, segend, temp, 0);
int count = segend - start;
for (int i = 0; i < count; i++) {
if (temp[i] == ch) {
recycle(temp);
return i + start;
}
}
start = segend;
}
recycle(temp);
return -1;
}
for (int i = start; i < end; i++)
if (s.charAt(i) == ch)
return i;
return -1;
}
public static int lastIndexOf(CharSequence s, char ch) {
return lastIndexOf(s, ch, s.length() - 1);
}
public static int lastIndexOf(CharSequence s, char ch, int last) {
Class<? extends CharSequence> c = s.getClass();
if (c == String.class)
return ((String) s).lastIndexOf(ch, last);
return lastIndexOf(s, ch, 0, last);
}
public static int lastIndexOf(CharSequence s, char ch,
int start, int last) {
if (last < 0)
return -1;
if (last >= s.length())
last = s.length() - 1;
int end = last + 1;
Class<? extends CharSequence> c = s.getClass();
if (s instanceof GetChars || c == StringBuffer.class ||
c == StringBuilder.class || c == String.class) {
final int INDEX_INCREMENT = 500;
char[] temp = obtain(INDEX_INCREMENT);
while (start < end) {
int segstart = end - INDEX_INCREMENT;
if (segstart < start)
segstart = start;
getChars(s, segstart, end, temp, 0);
int count = end - segstart;
for (int i = count - 1; i >= 0; i--) {
if (temp[i] == ch) {
recycle(temp);
return i + segstart;
}
}
end = segstart;
}
recycle(temp);
return -1;
}
for (int i = end - 1; i >= start; i--)
if (s.charAt(i) == ch)
return i;
return -1;
}
public static int indexOf(CharSequence s, CharSequence needle) {
return indexOf(s, needle, 0, s.length());
}
public static int indexOf(CharSequence s, CharSequence needle, int start) {
return indexOf(s, needle, start, s.length());
}
public static int indexOf(CharSequence s, CharSequence needle,
int start, int end) {
int nlen = needle.length();
if (nlen == 0)
return start;
char c = needle.charAt(0);
for (;;) {
start = indexOf(s, c, start);
if (start > end - nlen) {
break;
}
if (start < 0) {
return -1;
}
if (regionMatches(s, start, needle, 0, nlen)) {
return start;
}
start++;
}
return -1;
}
public static boolean regionMatches(CharSequence one, int toffset,
CharSequence two, int ooffset,
int len) {
char[] temp = obtain(2 * len);
getChars(one, toffset, toffset + len, temp, 0);
getChars(two, ooffset, ooffset + len, temp, len);
boolean match = true;
for (int i = 0; i < len; i++) {
if (temp[i] != temp[i + len]) {
match = false;
break;
}
}
recycle(temp);
return match;
}
/**
* Create a new String object containing the given range of characters
* from the source string. This is different than simply calling
* {@link CharSequence#subSequence(int, int) CharSequence.subSequence}
* in that it does not preserve any style runs in the source sequence,
* allowing a more efficient implementation.
*/
public static String substring(CharSequence source, int start, int end) {
if (source instanceof String)
return ((String) source).substring(start, end);
if (source instanceof StringBuilder)
return ((StringBuilder) source).substring(start, end);
if (source instanceof StringBuffer)
return ((StringBuffer) source).substring(start, end);
char[] temp = obtain(end - start);
getChars(source, start, end, temp, 0);
String ret = new String(temp, 0, end - start);
recycle(temp);
return ret;
}
/**
* Returns list of multiple {@link CharSequence} joined into a single
* {@link CharSequence} separated by localized delimiter such as ", ".
*
* @hide
*/
public static CharSequence join(Iterable list) {
final CharSequence delimiter = Resources.getSystem().getText(R.string.list_delimeter);
return join(delimiter, list);
}
/**
* Returns a string containing the tokens joined by delimiters.
* @param tokens an array objects to be joined. Strings will be formed from
* the objects by calling object.toString().
*/
public static String join(CharSequence delimiter, Object[] tokens) {
StringBuilder sb = new StringBuilder();
boolean firstTime = true;
for (Object token: tokens) {
if (firstTime) {
firstTime = false;
} else {
sb.append(delimiter);
}
sb.append(token);
}
return sb.toString();
}
/**
* Returns a string containing the tokens joined by delimiters.
* @param tokens an array objects to be joined. Strings will be formed from
* the objects by calling object.toString().
*/
public static String join(CharSequence delimiter, Iterable tokens) {
StringBuilder sb = new StringBuilder();
boolean firstTime = true;
for (Object token: tokens) {
if (firstTime) {
firstTime = false;
} else {
sb.append(delimiter);
}
sb.append(token);
}
return sb.toString();
}
/**
* String.split() returns [''] when the string to be split is empty. This returns []. This does
* not remove any empty strings from the result. For example split("a,", "," ) returns {"a", ""}.
*
* @param text the string to split
* @param expression the regular expression to match
* @return an array of strings. The array will be empty if text is empty
*
* @throws NullPointerException if expression or text is null
*/
public static String[] split(String text, String expression) {
if (text.length() == 0) {
return EMPTY_STRING_ARRAY;
} else {
return text.split(expression, -1);
}
}
/**
* Splits a string on a pattern. String.split() returns [''] when the string to be
* split is empty. This returns []. This does not remove any empty strings from the result.
* @param text the string to split
* @param pattern the regular expression to match
* @return an array of strings. The array will be empty if text is empty
*
* @throws NullPointerException if expression or text is null
*/
public static String[] split(String text, Pattern pattern) {
if (text.length() == 0) {
return EMPTY_STRING_ARRAY;
} else {
return pattern.split(text, -1);
}
}
/**
* An interface for splitting strings according to rules that are opaque to the user of this
* interface. This also has less overhead than split, which uses regular expressions and
* allocates an array to hold the results.
*
*
The most efficient way to use this class is:
*
*
```
 
```
* // Once
* TextUtils.StringSplitter splitter = new TextUtils.SimpleStringSplitter(delimiter);
*
* // Once per string to split
* splitter.setString(string);
* for (String s : splitter) {
* ...
* }
*
*/
public interface StringSplitter extends Iterable {
public void setString(String string);
}
/**
* A simple string splitter.
*
*
If the final character in the string to split is the delimiter then no empty string will
* be returned for the empty string after that delimeter. That is, splitting "a,b," on
* comma will return "a", "b", not "a", "b", "".
*/
public static class SimpleStringSplitter implements StringSplitter, Iterator {
private String mString;
private char mDelimiter;
private int mPosition;
private int mLength;
/**
* Initializes the splitter. setString may be called later.
* @param delimiter the delimeter on which to split
*/
public SimpleStringSplitter(char delimiter) {
mDelimiter = delimiter;
}
/**
* Sets the string to split
* @param string the string to split
*/
public void setString(String string) {
mString = string;
mPosition = 0;
mLength = mString.length();
}
public Iterator iterator() {
return this;
}
public boolean hasNext() {
return mPosition < mLength;
}
public String next() {
int end = mString.indexOf(mDelimiter, mPosition);
if (end == -1) {
end = mLength;
}
String nextString = mString.substring(mPosition, end);
mPosition = end + 1; // Skip the delimiter.
return nextString;
}
public void remove() {
throw new UnsupportedOperationException();
}
}
public static CharSequence stringOrSpannedString(CharSequence source) {
if (source == null)
return null;
if (source instanceof SpannedString)
return source;
if (source instanceof Spanned)
return new SpannedString(source);
return source.toString();
}
/**
* Returns true if the string is null or 0-length.
* @param str the string to be examined
* @return true if str is null or zero length
*/
public static boolean isEmpty(CharSequence str) {
if (str == null || str.length() == 0)
return true;
else
return false;
}
/**
* Returns the length that the specified CharSequence would have if
* spaces and control characters were trimmed from the start and end,
* as by {@link String#trim}.
*/
public static int getTrimmedLength(CharSequence s) {
int len = s.length();
int start = 0;
while (start < len && s.charAt(start) <= ' ') {
start++;
}
int end = len;
while (end > start && s.charAt(end - 1) <= ' ') {
end--;
}
return end - start;
}
/**
* Returns true if a and b are equal, including if they are both null.
*
Note: In platform versions 1.1 and earlier, this method only worked well if

* both the arguments were instances of String.
* @param a first CharSequence to check
* @param b second CharSequence to check
* @return true if a and b are equal
*/
public static boolean equals(CharSequence a, CharSequence b) {
if (a == b) return true;
int length;
if (a != null && b != null && (length = a.length()) == b.length()) {
if (a instanceof String && b instanceof String) {
return a.equals(b);
} else {
for (int i = 0; i < length; i++) {
if (a.charAt(i) != b.charAt(i)) return false;
}
return true;
}
}
return false;
}
// XXX currently this only reverses chars, not spans
public static CharSequence getReverse(CharSequence source,
int start, int end) {
return new Reverser(source, start, end);
}
private static class Reverser
implements CharSequence, GetChars
{
public Reverser(CharSequence source, int start, int end) {
mSource = source;
mStart = start;
mEnd = end;
}
public int length() {
return mEnd - mStart;
}
public CharSequence subSequence(int start, int end) {
char[] buf = new char[end - start];
getChars(start, end, buf, 0);
return new String(buf);
}
@Override
public String toString() {
return subSequence(0, length()).toString();
}
public char charAt(int off) {
return AndroidCharacter.getMirror(mSource.charAt(mEnd - 1 - off));
}
public void getChars(int start, int end, char[] dest, int destoff) {
TextUtils.getChars(mSource, start + mStart, end + mStart,
dest, destoff);
AndroidCharacter.mirror(dest, 0, end - start);
int len = end - start;
int n = (end - start) / 2;
for (int i = 0; i < n; i++) {
char tmp = dest[destoff + i];
dest[destoff + i] = dest[destoff + len - i - 1];
dest[destoff + len - i - 1] = tmp;
}
}
private CharSequence mSource;
private int mStart;
private int mEnd;
}
/** @hide */
public static final int ALIGNMENT_SPAN = 1;
/** @hide */
public static final int FIRST_SPAN = ALIGNMENT_SPAN;
/** @hide */
public static final int FOREGROUND_COLOR_SPAN = 2;
/** @hide */
public static final int RELATIVE_SIZE_SPAN = 3;
/** @hide */
public static final int SCALE_X_SPAN = 4;
/** @hide */
public static final int STRIKETHROUGH_SPAN = 5;
/** @hide */
public static final int UNDERLINE_SPAN = 6;
/** @hide */
public static final int STYLE_SPAN = 7;
/** @hide */
public static final int BULLET_SPAN = 8;
/** @hide */
public static final int QUOTE_SPAN = 9;
/** @hide */
public static final int LEADING_MARGIN_SPAN = 10;
/** @hide */
public static final int URL_SPAN = 11;
/** @hide */
public static final int BACKGROUND_COLOR_SPAN = 12;
/** @hide */
public static final int TYPEFACE_SPAN = 13;
/** @hide */
public static final int SUPERSCRIPT_SPAN = 14;
/** @hide */
public static final int SUBSCRIPT_SPAN = 15;
/** @hide */
public static final int ABSOLUTE_SIZE_SPAN = 16;
/** @hide */
public static final int TEXT_APPEARANCE_SPAN = 17;
/** @hide */
public static final int ANNOTATION = 18;
/** @hide */
public static final int SUGGESTION_SPAN = 19;
/** @hide */
public static final int SPELL_CHECK_SPAN = 20;
/** @hide */
public static final int SUGGESTION_RANGE_SPAN = 21;
/** @hide */
public static final int EASY_EDIT_SPAN = 22;
/** @hide */
public static final int LOCALE_SPAN = 23;
/** @hide */
public static final int LAST_SPAN = LOCALE_SPAN;
/**
* Flatten a CharSequence and whatever styles can be copied across processes
* into the parcel.
*/
public static void writeToParcel(CharSequence cs, Parcel p,
int parcelableFlags) {
if (cs instanceof Spanned) {
p.writeInt(0);
p.writeString(cs.toString());
Spanned sp = (Spanned) cs;
Object[] os = sp.getSpans(0, cs.length(), Object.class);
// note to people adding to this: check more specific types
// before more generic types. also notice that it uses
// "if" instead of "else if" where there are interfaces
// so one object can be several.
for (int i = 0; i < os.length; i++) {
Object o = os[i];
Object prop = os[i];
if (prop instanceof CharacterStyle) {
prop = ((CharacterStyle) prop).getUnderlying();
}
if (prop instanceof ParcelableSpan) {
ParcelableSpan ps = (ParcelableSpan)prop;
int spanTypeId = ps.getSpanTypeId();
if (spanTypeId < FIRST_SPAN || spanTypeId > LAST_SPAN) {
Log.e(TAG, "external class \"" + ps.getClass().getSimpleName()
+ "\" is attempting to use the frameworks-only ParcelableSpan"
+ " interface");
} else {
p.writeInt(spanTypeId);
ps.writeToParcel(p, parcelableFlags);
writeWhere(p, sp, o);
}
}
}
p.writeInt(0);
} else {
p.writeInt(1);
if (cs != null) {
p.writeString(cs.toString());
} else {
p.writeString(null);
}
}
}
private static void writeWhere(Parcel p, Spanned sp, Object o) {
p.writeInt(sp.getSpanStart(o));
p.writeInt(sp.getSpanEnd(o));
p.writeInt(sp.getSpanFlags(o));
}
public static final Parcelable.Creator CHAR_SEQUENCE_CREATOR
= new Parcelable.Creator() {
/**
* Read and return a new CharSequence, possibly with styles,
* from the parcel.
*/
public CharSequence createFromParcel(Parcel p) {
int kind = p.readInt();
String string = p.readString();
if (string == null) {
return null;
}
if (kind == 1) {
return string;
}
SpannableString sp = new SpannableString(string);
while (true) {
kind = p.readInt();
if (kind == 0)
break;
switch (kind) {
case ALIGNMENT_SPAN:
readSpan(p, sp, new AlignmentSpan.Standard(p));
break;
case FOREGROUND_COLOR_SPAN:
readSpan(p, sp, new ForegroundColorSpan(p));
break;
case RELATIVE_SIZE_SPAN:
readSpan(p, sp, new RelativeSizeSpan(p));
break;
case SCALE_X_SPAN:
readSpan(p, sp, new ScaleXSpan(p));
break;
case STRIKETHROUGH_SPAN:
readSpan(p, sp, new StrikethroughSpan(p));
break;
case UNDERLINE_SPAN:
readSpan(p, sp, new UnderlineSpan(p));
break;
case STYLE_SPAN:
readSpan(p, sp, new StyleSpan(p));
break;
case BULLET_SPAN:
readSpan(p, sp, new BulletSpan(p));
break;
case QUOTE_SPAN:
readSpan(p, sp, new QuoteSpan(p));
break;
case LEADING_MARGIN_SPAN:
readSpan(p, sp, new LeadingMarginSpan.Standard(p));
break;
case URL_SPAN:
readSpan(p, sp, new URLSpan(p));
break;
case BACKGROUND_COLOR_SPAN:
readSpan(p, sp, new BackgroundColorSpan(p));
break;
case TYPEFACE_SPAN:
readSpan(p, sp, new TypefaceSpan(p));
break;
case SUPERSCRIPT_SPAN:
readSpan(p, sp, new SuperscriptSpan(p));
break;
case SUBSCRIPT_SPAN:
readSpan(p, sp, new SubscriptSpan(p));
break;
case ABSOLUTE_SIZE_SPAN:
readSpan(p, sp, new AbsoluteSizeSpan(p));
break;
case TEXT_APPEARANCE_SPAN:
readSpan(p, sp, new TextAppearanceSpan(p));
break;
case ANNOTATION:
readSpan(p, sp, new Annotation(p));
break;
case SUGGESTION_SPAN:
readSpan(p, sp, new SuggestionSpan(p));
break;
case SPELL_CHECK_SPAN:
readSpan(p, sp, new SpellCheckSpan(p));
break;
case SUGGESTION_RANGE_SPAN:
readSpan(p, sp, new SuggestionRangeSpan(p));
break;
case EASY_EDIT_SPAN:
readSpan(p, sp, new EasyEditSpan(p));
break;
case LOCALE_SPAN:
readSpan(p, sp, new LocaleSpan(p));
break;
default:
throw new RuntimeException("bogus span encoding " + kind);
}
}
return sp;
}
public CharSequence[] newArray(int size)
{
return new CharSequence[size];
}
};
/**
* Debugging tool to print the spans in a CharSequence. The output will
* be printed one span per line. If the CharSequence is not a Spanned,
* then the entire string will be printed on a single line.
*/
public static void dumpSpans(CharSequence cs, Printer printer, String prefix) {
if (cs instanceof Spanned) {
Spanned sp = (Spanned) cs;
Object[] os = sp.getSpans(0, cs.length(), Object.class);
for (int i = 0; i < os.length; i++) {
Object o = os[i];
printer.println(prefix + cs.subSequence(sp.getSpanStart(o),
sp.getSpanEnd(o)) + ": "
+ Integer.toHexString(System.identityHashCode(o))
+ " " + o.getClass().getCanonicalName()
+ " (" + sp.getSpanStart(o) + "-" + sp.getSpanEnd(o)
+ ") fl=#" + sp.getSpanFlags(o));
}
} else {
printer.println(prefix + cs + ": (no spans)");
}
}
/**
* Return a new CharSequence in which each of the source strings is
* replaced by the corresponding element of the destinations.
*/
public static CharSequence replace(CharSequence template,
String[] sources,
CharSequence[] destinations) {
SpannableStringBuilder tb = new SpannableStringBuilder(template);
for (int i = 0; i < sources.length; i++) {
int where = indexOf(tb, sources[i]);
if (where >= 0)
tb.setSpan(sources[i], where, where + sources[i].length(),
Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
}
for (int i = 0; i < sources.length; i++) {
int start = tb.getSpanStart(sources[i]);
int end = tb.getSpanEnd(sources[i]);
if (start >= 0) {
tb.replace(start, end, destinations[i]);
}
}
return tb;
}
/**
* Replace instances of "^1", "^2", etc. in the
* template CharSequence with the corresponding
* values. "^^" is used to produce a single caret in
* the output. Only up to 9 replacement values are supported,
* "^10" will be produce the first replacement value followed by a
* '0'.
*
* @param template the input text containing "^1"-style
* placeholder values. This object is not modified; a copy is
* returned.
*
* @param values CharSequences substituted into the template. The
* first is substituted for "^1", the second for "^2", and so on.
*
* @return the new CharSequence produced by doing the replacement
*
* @throws IllegalArgumentException if the template requests a
* value that was not provided, or if more than 9 values are
* provided.
*/
public static CharSequence expandTemplate(CharSequence template,
CharSequence... values) {
if (values.length > 9) {
throw new IllegalArgumentException("max of 9 values are supported");
}
SpannableStringBuilder ssb = new SpannableStringBuilder(template);
try {
int i = 0;
while (i < ssb.length()) {
if (ssb.charAt(i) == '^') {
char next = ssb.charAt(i+1);
if (next == '^') {
ssb.delete(i+1, i+2);
++i;
continue;
} else if (Character.isDigit(next)) {
int which = Character.getNumericValue(next) - 1;
if (which < 0) {
throw new IllegalArgumentException(
"template requests value ^" + (which+1));
}
if (which >= values.length) {
throw new IllegalArgumentException(
"template requests value ^" + (which+1) +
"; only " + values.length + " provided");
}
ssb.replace(i, i+2, values[which]);
i += values[which].length();
continue;
}
}
++i;
}
} catch (IndexOutOfBoundsException ignore) {
// happens when ^ is the last character in the string.
}
return ssb;
}
public static int getOffsetBefore(CharSequence text, int offset) {
if (offset == 0)
return 0;
if (offset == 1)
return 0;
char c = text.charAt(offset - 1);
if (c >= '\uDC00' && c <= '\uDFFF') {
char c1 = text.charAt(offset - 2);
if (c1 >= '\uD800' && c1 <= '\uDBFF')
offset -= 2;
else
offset -= 1;
} else {
offset -= 1;
}
if (text instanceof Spanned) {
ReplacementSpan[] spans = ((Spanned) text).getSpans(offset, offset,
ReplacementSpan.class);
for (int i = 0; i < spans.length; i++) {
int start = ((Spanned) text).getSpanStart(spans[i]);
int end = ((Spanned) text).getSpanEnd(spans[i]);
if (start < offset && end > offset)
offset = start;
}
}
return offset;
}
public static int getOffsetAfter(CharSequence text, int offset) {
int len = text.length();
if (offset == len)
return len;
if (offset == len - 1)
return len;
char c = text.charAt(offset);
if (c >= '\uD800' && c <= '\uDBFF') {
char c1 = text.charAt(offset + 1);
if (c1 >= '\uDC00' && c1 <= '\uDFFF')
offset += 2;
else
offset += 1;
} else {
offset += 1;
}
if (text instanceof Spanned) {
ReplacementSpan[] spans = ((Spanned) text).getSpans(offset, offset,
ReplacementSpan.class);
for (int i = 0; i < spans.length; i++) {
int start = ((Spanned) text).getSpanStart(spans[i]);
int end = ((Spanned) text).getSpanEnd(spans[i]);
if (start < offset && end > offset)
offset = end;
}
}
return offset;
}
private static void readSpan(Parcel p, Spannable sp, Object o) {
sp.setSpan(o, p.readInt(), p.readInt(), p.readInt());
}
/**
* Copies the spans from the region start...end in
* source to the region
* destoff...destoff+end-start in dest.
* Spans in source that begin before start
* or end after end but overlap this range are trimmed
* as if they began at start or ended at end.
*
* @throws IndexOutOfBoundsException if any of the copied spans
* are out of range in dest.
*/
public static void copySpansFrom(Spanned source, int start, int end,
Class kind,
Spannable dest, int destoff) {
if (kind == null) {
kind = Object.class;
}
Object[] spans = source.getSpans(start, end, kind);
for (int i = 0; i < spans.length; i++) {
int st = source.getSpanStart(spans[i]);
int en = source.getSpanEnd(spans[i]);
int fl = source.getSpanFlags(spans[i]);
if (st < start)
st = start;
if (en > end)
en = end;
dest.setSpan(spans[i], st - start + destoff, en - start + destoff,
fl);
}
}
public enum TruncateAt {
START,
MIDDLE,
END,
MARQUEE,
/**
* @hide
*/
END_SMALL
}
public interface EllipsizeCallback {
/**
* This method is called to report that the specified region of
* text was ellipsized away by a call to {@link #ellipsize}.
*/
public void ellipsized(int start, int end);
}
/**
* Returns the original text if it fits in the specified width
* given the properties of the specified Paint,
* or, if it does not fit, a truncated
* copy with ellipsis character added at the specified edge or center.
*/
public static CharSequence ellipsize(CharSequence text,
TextPaint p,
float avail, TruncateAt where) {
return ellipsize(text, p, avail, where, false, null);
}
/**
* Returns the original text if it fits in the specified width
* given the properties of the specified Paint,
* or, if it does not fit, a copy with ellipsis character added
* at the specified edge or center.
* If preserveLength is specified, the returned copy
* will be padded with zero-width spaces to preserve the original
* length and offsets instead of truncating.
* If callback is non-null, it will be called to
* report the start and end of the ellipsized range. TextDirection
* is determined by the first strong directional character.
*/
public static CharSequence ellipsize(CharSequence text,
TextPaint paint,
float avail, TruncateAt where,
boolean preserveLength,
EllipsizeCallback callback) {
final String ellipsis = (where == TruncateAt.END_SMALL) ?
Resources.getSystem().getString(R.string.ellipsis_two_dots) :
Resources.getSystem().getString(R.string.ellipsis);
return ellipsize(text, paint, avail, where, preserveLength, callback,
TextDirectionHeuristics.FIRSTSTRONG_LTR,
ellipsis);
}
/**
* Returns the original text if it fits in the specified width
* given the properties of the specified Paint,
* or, if it does not fit, a copy with ellipsis character added
* at the specified edge or center.
* If preserveLength is specified, the returned copy
* will be padded with zero-width spaces to preserve the original
* length and offsets instead of truncating.
* If callback is non-null, it will be called to
* report the start and end of the ellipsized range.
*
* @hide
*/
public static CharSequence ellipsize(CharSequence text,
TextPaint paint,
float avail, TruncateAt where,
boolean preserveLength,
EllipsizeCallback callback,
TextDirectionHeuristic textDir, String ellipsis) {
int len = text.length();
MeasuredText mt = MeasuredText.obtain();
try {
float width = setPara(mt, paint, text, 0, text.length(), textDir);
if (width <= avail) {
if (callback != null) {
callback.ellipsized(0, 0);
}
return text;
}
// XXX assumes ellipsis string does not require shaping and
// is unaffected by style
float ellipsiswid = paint.measureText(ellipsis);
avail -= ellipsiswid;
int left = 0;
int right = len;
if (avail < 0) {
// it all goes
} else if (where == TruncateAt.START) {
right = len - mt.breakText(len, false, avail);
} else if (where == TruncateAt.END || where == TruncateAt.END_SMALL) {
left = mt.breakText(len, true, avail);
} else {
right = len - mt.breakText(len, false, avail / 2);
avail -= mt.measure(right, len);
left = mt.breakText(right, true, avail);
}
if (callback != null) {
callback.ellipsized(left, right);
}
char[] buf = mt.mChars;
Spanned sp = text instanceof Spanned ? (Spanned) text : null;
int remaining = len - (right - left);
if (preserveLength) {
if (remaining > 0) { // else eliminate the ellipsis too
buf[left++] = ellipsis.charAt(0);
}
for (int i = left; i < right; i++) {
buf[i] = ZWNBS_CHAR;
}
String s = new String(buf, 0, len);
if (sp == null) {
return s;
}
SpannableString ss = new SpannableString(s);
copySpansFrom(sp, 0, len, Object.class, ss, 0);
return ss;
}
if (remaining == 0) {
return "";
}
if (sp == null) {
StringBuilder sb = new StringBuilder(remaining + ellipsis.length());
sb.append(buf, 0, left);
sb.append(ellipsis);
sb.append(buf, right, len - right);
return sb.toString();
}
SpannableStringBuilder ssb = new SpannableStringBuilder();
ssb.append(text, 0, left);
ssb.append(ellipsis);
ssb.append(text, right, len);
return ssb;
} finally {
MeasuredText.recycle(mt);
}
}
/**
* Converts a CharSequence of the comma-separated form "Andy, Bob,
* Charles, David" that is too wide to fit into the specified width
* into one like "Andy, Bob, 2 more".
*
* @param text the text to truncate
* @param p the Paint with which to measure the text
* @param avail the horizontal width available for the text
* @param oneMore the string for "1 more" in the current locale
* @param more the string for "%d more" in the current locale
*/
public static CharSequence commaEllipsize(CharSequence text,
TextPaint p, float avail,
String oneMore,
String more) {
return commaEllipsize(text, p, avail, oneMore, more,
TextDirectionHeuristics.FIRSTSTRONG_LTR);
}
/**
* @hide
*/
public static CharSequence commaEllipsize(CharSequence text, TextPaint p,
float avail, String oneMore, String more, TextDirectionHeuristic textDir) {
MeasuredText mt = MeasuredText.obtain();
try {
int len = text.length();
float width = setPara(mt, p, text, 0, len, textDir);
if (width <= avail) {
return text;
}
char[] buf = mt.mChars;
int commaCount = 0;
for (int i = 0; i < len; i++) {
if (buf[i] == ',') {
commaCount++;
}
}
int remaining = commaCount + 1;
int ok = 0;
String okFormat = "";
int w = 0;
int count = 0;
float[] widths = mt.mWidths;
MeasuredText tempMt = MeasuredText.obtain();
for (int i = 0; i < len; i++) {
w += widths[i];
if (buf[i] == ',') {
count++;
String format;
// XXX should not insert spaces, should be part of string
// XXX should use plural rules and not assume English plurals
if (--remaining == 1) {
format = " " + oneMore;
} else {
format = " " + String.format(more, remaining);
}
// XXX this is probably ok, but need to look at it more
tempMt.setPara(format, 0, format.length(), textDir);
float moreWid = tempMt.addStyleRun(p, tempMt.mLen, null);
if (w + moreWid <= avail) {
ok = i + 1;
okFormat = format;
}
}
}
MeasuredText.recycle(tempMt);
SpannableStringBuilder out = new SpannableStringBuilder(okFormat);
out.insert(0, text, 0, ok);
return out;
} finally {
MeasuredText.recycle(mt);
}
}
private static float setPara(MeasuredText mt, TextPaint paint,
CharSequence text, int start, int end, TextDirectionHeuristic textDir) {
mt.setPara(text, start, end, textDir);
float width;
Spanned sp = text instanceof Spanned ? (Spanned) text : null;
int len = end - start;
if (sp == null) {
width = mt.addStyleRun(paint, len, null);
} else {
width = 0;
int spanEnd;
for (int spanStart = 0; spanStart < len; spanStart = spanEnd) {
spanEnd = sp.nextSpanTransition(spanStart, len,
MetricAffectingSpan.class);
MetricAffectingSpan[] spans = sp.getSpans(
spanStart, spanEnd, MetricAffectingSpan.class);
spans = TextUtils.removeEmptySpans(spans, sp, MetricAffectingSpan.class);
width += mt.addStyleRun(paint, spans, spanEnd - spanStart, null);
}
}
return width;
}
private static final char FIRST_RIGHT_TO_LEFT = '\u0590';
/* package */
static boolean doesNotNeedBidi(CharSequence s, int start, int end) {
for (int i = start; i < end; i++) {
if (s.charAt(i) >= FIRST_RIGHT_TO_LEFT) {
return false;
}
}
return true;
}
/* package */
static

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