public
abstract
class
UCharacterIterator
extends Object
implements
Cloneable
| java.lang.Object | |
| ↳ | android.icu.text.UCharacterIterator |
Abstract class that defines an API for iteration on text objects.This is an
interface for forward and backward iteration and random access into a text
object. Forward iteration is done with post-increment and backward iteration
is done with pre-decrement semantics, while the
java.text.CharacterIterator interface methods provided forward
iteration with "pre-increment" and backward iteration with pre-decrement
semantics. This API is more efficient for forward iteration over code points.
The other major difference is that this API can do both code unit and code point
iteration, java.text.CharacterIterator can only iterate over
code units and is limited to BMP (0 - 0xFFFF)
Constants | |
|---|---|
int |
DONE
Indicator that we have reached the ends of the UTF16 text. |
Protected constructors | |
|---|---|
UCharacterIterator()
Protected default constructor for the subclasses |
|
Public methods | |
|---|---|
Object
|
clone()
Creates a copy of this iterator, independent from other iterators. |
abstract
int
|
current()
Returns the code unit at the current index. |
int
|
currentCodePoint()
Returns the codepoint at the current index. |
CharacterIterator
|
getCharacterIterator()
Returns a |
abstract
int
|
getIndex()
Gets the current index in text. |
static
final
UCharacterIterator
|
getInstance(String source)
Returns a |
static
final
UCharacterIterator
|
getInstance(StringBuffer source)
Returns a |
static
final
UCharacterIterator
|
getInstance(Replaceable source)
Returns a |
static
final
UCharacterIterator
|
getInstance(CharacterIterator source)
Returns a |
static
final
UCharacterIterator
|
getInstance(char[] source, int start, int limit)
Returns a |
static
final
UCharacterIterator
|
getInstance(char[] source)
Returns a |
abstract
int
|
getLength()
Returns the length of the text |
abstract
int
|
getText(char[] fillIn, int offset)
Fills the buffer with the underlying text storage of the iterator If the buffer capacity is not enough a exception is thrown. |
String
|
getText()
Convenience method for returning the underlying text storage as as string |
final
int
|
getText(char[] fillIn)
Convenience override for |
int
|
moveCodePointIndex(int delta)
Moves the current position by the number of code points specified, either forward or backward depending on the sign of delta (positive or negative respectively). |
int
|
moveIndex(int delta)
Moves the current position by the number of code units specified, either forward or backward depending on the sign of delta (positive or negative respectively). |
abstract
int
|
next()
Returns the UTF16 code unit at index, and increments to the next code unit (post-increment semantics). |
int
|
nextCodePoint()
Returns the code point at index, and increments to the next code point (post-increment semantics). |
abstract
int
|
previous()
Decrement to the position of the previous code unit in the text, and return it (pre-decrement semantics). |
int
|
previousCodePoint()
Retreat to the start of the previous code point in the text, and return it (pre-decrement semantics). |
abstract
void
|
setIndex(int index)
Sets the index to the specified index in the text. |
void
|
setToLimit()
Sets the current index to the limit. |
void
|
setToStart()
Sets the current index to the start. |
Inherited methods | |
|---|---|
 From
class
java.lang.Object
| |
int DONE
Indicator that we have reached the ends of the UTF16 text.
Constant Value: -1 (0xffffffff)
UCharacterIterator ()
Protected default constructor for the subclasses
Object clone ()
Creates a copy of this iterator, independent from other iterators. If it is not possible to clone the iterator, returns null.
| Returns | |
|---|---|
Object |
copy of this iterator |
| Throws | |
|---|---|
CloneNotSupportedException |
|
int current ()
Returns the code unit at the current index. If index is out of range, returns DONE. Index is not changed.
| Returns | |
|---|---|
int |
current code unit |
int currentCodePoint ()
Returns the codepoint at the current index. If the current index is invalid, DONE is returned. If the current index points to a lead surrogate, and there is a following trail surrogate, then the code point is returned. Otherwise, the code unit at index is returned. Index is not changed.
| Returns | |
|---|---|
int |
current codepoint |
CharacterIterator getCharacterIterator ()
Returns a java.text.CharacterIterator object for
the underlying text of this iterator. The returned iterator is
independent of this iterator.
| Returns | |
|---|---|
CharacterIterator |
java.text.CharacterIterator object |
int getIndex ()
Gets the current index in text.
| Returns | |
|---|---|
int |
current index in text. |
UCharacterIterator getInstance (String source)
Returns a UCharacterIterator object given a
source string.
| Parameters | |
|---|---|
source |
String:
a string |
| Returns | |
|---|---|
UCharacterIterator |
UCharacterIterator object |
| Throws | |
|---|---|
IllegalArgumentException |
if the argument is null |
UCharacterIterator getInstance (StringBuffer source)
Returns a UCharacterIterator object given a
source StringBuffer.
| Parameters | |
|---|---|
source |
StringBuffer:
an string buffer of UTF-16 code units |
| Returns | |
|---|---|
UCharacterIterator |
UCharacterIterator object |
| Throws | |
|---|---|
IllegalArgumentException |
if the argument is null |
UCharacterIterator getInstance (Replaceable source)
Returns a UCharacterIterator object given a
Replaceable object.
| Parameters | |
|---|---|
source |
Replaceable:
a valid source as a Replaceable object |
| Returns | |
|---|---|
UCharacterIterator |
UCharacterIterator object |
| Throws | |
|---|---|
IllegalArgumentException |
if the argument is null |
UCharacterIterator getInstance (CharacterIterator source)
Returns a UCharacterIterator object given a
CharacterIterator.
| Parameters | |
|---|---|
source |
CharacterIterator:
a valid CharacterIterator object. |
| Returns | |
|---|---|
UCharacterIterator |
UCharacterIterator object |
| Throws | |
|---|---|
IllegalArgumentException |
if the argument is null |
UCharacterIterator getInstance (char[] source, int start, int limit)
Returns a UCharacterIterator object given a
source character array.
| Parameters | |
|---|---|
source |
char:
an array of UTF-16 code units |
start |
int
|
limit |
int
|
| Returns | |
|---|---|
UCharacterIterator |
UCharacterIterator object |
| Throws | |
|---|---|
IllegalArgumentException |
if the argument is null |
UCharacterIterator getInstance (char[] source)
Returns a UCharacterIterator object given a
source character array.
| Parameters | |
|---|---|
source |
char:
an array of UTF-16 code units |
| Returns | |
|---|---|
UCharacterIterator |
UCharacterIterator object |
| Throws | |
|---|---|
IllegalArgumentException |
if the argument is null |
int getLength ()
Returns the length of the text
| Returns | |
|---|---|
int |
length of the text |
Developers
int getText (char[] fillIn,
int offset)
Fills the buffer with the underlying text storage of the iterator
If the buffer capacity is not enough a exception is thrown. The capacity
of the fill in buffer should at least be equal to length of text in the
iterator obtained by calling getLength()).
Usage:
UChacterIterator iter = new UCharacterIterator.getInstance(text);
char[] buf = new char[iter.getLength()];
iter.getText(buf);
OR
char[] buf= new char[1];
int len = 0;
for(;;){
try{
len = iter.getText(buf);
break;
}catch(IndexOutOfBoundsException e){
buf = new char[iter.getLength()];
}
}
| Parameters | |
|---|---|
fillIn |
char:
an array of chars to fill with the underlying UTF-16 code
units. |
offset |
int:
the position within the array to start putting the data. |
| Returns | |
|---|---|
int |
the number of code units added to fillIn, as a convenience |
| Throws | |
|---|---|
IndexOutOfBoundsException |
exception if there is not enough room after offset in the array, or if offset < 0. |
String getText ()
Convenience method for returning the underlying text storage as as string
| Returns | |
|---|---|
String |
the underlying text storage in the iterator as a string |
int getText (char[] fillIn)
Convenience override for getText(char[], int) that provides
an offset of 0.
| Parameters | |
|---|---|
fillIn |
char:
an array of chars to fill with the underlying UTF-16 code
units. |
| Returns | |
|---|---|
int |
the number of code units added to fillIn, as a convenience |
| Throws | |
|---|---|
IndexOutOfBoundsException |
exception if there is not enough room in the array. |
int moveCodePointIndex (int delta)
Moves the current position by the number of code points specified, either forward or backward depending on the sign of delta (positive or negative respectively). If the current index is at a trail surrogate then the first adjustment is by code unit, and the remaining adjustments are by code points. If the resulting index would be less than zero, the index is set to zero, and if the resulting index would be greater than limit, the index is set to limit.
| Parameters | |
|---|---|
delta |
int:
the number of code units to move the current index. |
| Returns | |
|---|---|
int |
the new index |
| Throws | |
|---|---|
IndexOutOfBoundsException |
is thrown if an invalid delta is supplied |
int moveIndex (int delta)
Moves the current position by the number of code units specified, either forward or backward depending on the sign of delta (positive or negative respectively). If the resulting index would be less than zero, the index is set to zero, and if the resulting index would be greater than limit, the index is set to limit.
| Parameters | |
|---|---|
delta |
int:
the number of code units to move the current
index. |
| Returns | |
|---|---|
int |
the new index. |
| Throws | |
|---|---|
IndexOutOfBoundsException |
is thrown if an invalid index is supplied |
int next ()
Returns the UTF16 code unit at index, and increments to the next code unit (post-increment semantics). If index is out of range, DONE is returned, and the iterator is reset to the limit of the text.
| Returns | |
|---|---|
int |
the next UTF16 code unit, or DONE if the index is at the limit of the text. |
int nextCodePoint ()
Returns the code point at index, and increments to the next code
point (post-increment semantics). If index does not point to a
valid surrogate pair, the behavior is the same as
next(). Otherwise the iterator is incremented past
the surrogate pair, and the code point represented by the pair
is returned.
| Returns | |
|---|---|
int |
the next codepoint in text, or DONE if the index is at the limit of the text. |
int previous ()
Decrement to the position of the previous code unit in the text, and return it (pre-decrement semantics). If the resulting index is less than 0, the index is reset to 0 and DONE is returned.
| Returns | |
|---|---|
int |
the previous code unit in the text, or DONE if the new index is before the start of the text. |
int previousCodePoint ()
Retreat to the start of the previous code point in the text,
and return it (pre-decrement semantics). If the index is not
preceeded by a valid surrogate pair, the behavior is the same
as previous(). Otherwise the iterator is
decremented to the start of the surrogate pair, and the code
point represented by the pair is returned.
| Returns | |
|---|---|
int |
the previous code point in the text, or DONE if the new index is before the start of the text. |
void setIndex (int index)
Sets the index to the specified index in the text.
| Parameters | |
|---|---|
index |
int:
the index within the text. |
| Throws | |
|---|---|
IndexOutOfBoundsException |
is thrown if an invalid index is supplied |