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UnicodeFilter
  public
  
  
  abstract
  class
  UnicodeFilter
  
    extends Object
  
  
  
  
  
      implements
      
        UnicodeMatcher
      
  
  
  
    
      
        
          Known direct subclasses
          
  
  
    
  
  
    
      
        | UnicodeSet | 
        
          A mutable set of Unicode characters and multicharacter strings. 
          
    
         | 
       
      
    
   
   
         
       | 
    
  
  
  
    
  UnicodeFilter defines a protocol for selecting a
 subset of the full range (U+0000 to U+FFFF) of Unicode characters.
 Currently, filters are used in conjunction with classes like
 Transliterator
 to only process selected characters through a
 transformation.
Summary
Inherited constants | 
  
  
    
      From interface
        android.icu.text.UnicodeMatcher
      
      
        
    
    
        char | 
        
          ETHER
          The character at index i, where i < contextStart || i >= contextLimit,
 is ETHER.
          
    
 
         | 
     
    
    
    
        int | 
        
          U_MATCH
          Constant returned by matches() indicating a
 complete match between the text and this matcher.
          
    
 
         | 
     
    
    
    
        int | 
        
          U_MISMATCH
          Constant returned by matches() indicating a
 mismatch between the text and this matcher.
          
    
 
         | 
     
    
    
    
        int | 
        
          U_PARTIAL_MATCH
          Constant returned by matches() indicating a
 partial match between the text and this matcher.
          
    
 
         | 
     
    
    
       
     
   | 
Public methods | 
  
  
  
    
        abstract
        
        
        
        
        boolean
     | 
  
    
      
      contains(int c)
      
      
        Returns true for characters that are in the selected
 subset.
        
    
 
      
     | 
  
  
  
  
  
    
        
        
        
        
        
        int
     | 
  
    
      
      matches(Replaceable text, int[] offset, int limit, boolean incremental)
      
      
        Default implementation of UnicodeMatcher::matches() for Unicode
 filters.
        
    
 
      
     | 
  
  
Inherited methods | 
  
    From class
      
        
          java.lang.Object
        
      
    
    
      
  
  
  
    
        
        
        
        
        
        Object
     | 
  
    
      
      clone()
      
      
        Creates and returns a copy of this object.
        
    
 
      
     | 
   
  
  
  
  
    
        
        
        
        
        
        boolean
     | 
  
    
      
      equals(Object obj)
      
      
        Indicates whether some other object is "equal to" this one.
        
    
 
      
     | 
   
  
  
  
  
    
        
        
        
        
        
        void
     | 
  
    
      
      finalize()
      
      
        Called by the garbage collector on an object when garbage collection
 determines that there are no more references to the object.
        
    
 
      
     | 
   
  
  
  
  
    
        
        
        
        final
        
        Class<?>
     | 
  
    
      
      getClass()
      
      
        Returns the runtime class of this Object.
        
    
 
      
     | 
   
  
  
  
  
    
        
        
        
        
        
        int
     | 
  
    
      
      hashCode()
      
      
        Returns a hash code value for the object.
        
    
 
      
     | 
   
  
  
  
  
    
        
        
        
        final
        
        void
     | 
  
    
      
      notify()
      
      
        Wakes up a single thread that is waiting on this object's
 monitor.
        
    
 
      
     | 
   
  
  
  
  
    
        
        
        
        final
        
        void
     | 
  
    
      
      notifyAll()
      
      
        Wakes up all threads that are waiting on this object's monitor.
        
    
 
      
     | 
   
  
  
  
  
    
        
        
        
        
        
        String
     | 
  
    
      
      toString()
      
      
        Returns a string representation of the object.
        
    
 
      
     | 
   
  
  
  
  
    
        
        
        
        final
        
        void
     | 
  
    
      
      wait(long timeoutMillis, int nanos)
      
      
        Causes the current thread to wait until it is awakened, typically
 by being notified or interrupted, or until a
 certain amount of real time has elapsed.
        
    
 
      
     | 
   
  
  
  
  
    
        
        
        
        final
        
        void
     | 
  
    
      
      wait(long timeoutMillis)
      
      
        Causes the current thread to wait until it is awakened, typically
 by being notified or interrupted, or until a
 certain amount of real time has elapsed.
        
    
 
      
     | 
   
  
  
  
  
    
        
        
        
        final
        
        void
     | 
  
    
      
      wait()
      
      
        Causes the current thread to wait until it is awakened, typically
 by being notified or interrupted.
        
    
 
      
     | 
   
  
     
   
 | 
  
    From interface
      
        
          android.icu.text.UnicodeMatcher
        
      
    
    
      
  
  
  
    
        abstract
        
        
        
        
        void
     | 
  
    
      
      addMatchSetTo(UnicodeSet toUnionTo)
      
      
        Union the set of all characters that may be matched by this object
 into the given set.
        
    
 
      
     | 
   
  
  
  
  
    
        abstract
        
        
        
        
        int
     | 
  
    
      
      matches(Replaceable text, int[] offset, int limit, boolean incremental)
      
      
        Return a UMatchDegree value indicating the degree of match for
 the given text at the given offset.
        
    
 
      
     | 
   
  
  
  
  
    
        abstract
        
        
        
        
        boolean
     | 
  
    
      
      matchesIndexValue(int v)
      
      
        Returns true if this matcher will match a character c, where c
 & 0xFF == v, at offset, in the forward direction (with limit >
 offset).
        
    
 
      
     | 
   
  
  
  
  
    
        abstract
        
        
        
        
        String
     | 
  
    
      
      toPattern(boolean escapeUnprintable)
      
      
        Returns a string representation of this matcher.
        
    
 
      
     | 
   
  
     
   
 | 
Public methods
    contains
    
public abstract boolean contains (int c)
    
    
    
  Returns true for characters that are in the selected
 subset.  In other words, if a character is to be
 filtered, then contains() returns
 false.
    
    
 
    matches
    
public int matches (Replaceable text, 
                int[] offset, 
                int limit, 
                boolean incremental)
    
    
    
  Default implementation of UnicodeMatcher::matches() for Unicode
 filters.  Matches a single 16-bit code unit at offset.
    
    | Parameters | 
      
        text | 
        
          Replaceable: the text to be matched | 
      
      
        offset | 
        
          int: on input, the index into text at which to begin
 matching.  On output, the limit of the matched text.  The
 number of matched characters is the output value of offset
 minus the input value.  Offset should always point to the
 HIGH SURROGATE (leading code unit) of a pair of surrogates,
 both on entry and upon return. | 
      
      
        limit | 
        
          int: the limit index of text to be matched.  Greater
 than offset for a forward direction match, less than offset for
 a backward direction match.  The last character to be
 considered for matching will be text.charAt(limit-1) in the
 forward direction or text.charAt(limit+1) in the backward
 direction. | 
      
      
        incremental | 
        
          boolean: if true, then assume further characters may
 be inserted at limit and check for partial matching.  Otherwise
 assume the text as given is complete. | 
      
    
    
      | Returns | 
      
        int | 
        a match degree value indicating a full match, a partial
 match, or a mismatch.  If incremental is false then
 U_PARTIAL_MATCH should never be returned. | 
      
    
 
 
 
  
  
    
  
 
  
    
      
      
    
    
      
    
    
  
       
    
    
      
    
  
  
  Content and code samples on this page are subject to the licenses described in the Content License. Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
  Last updated 2025-02-10 UTC.
  
  
  
    
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