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added in API level 24

ValueIterator

public interface ValueIterator

android.icu.util.ValueIterator


Interface for enabling iteration over sets of <int, Object>, where int is the sorted integer index in ascending order, and Object its associated value.

The ValueIterator allows iterations over integer indexes in the range of Integer.MIN_VALUE to Integer.MAX_VALUE inclusive. Implementations of ValueIterator should specify their own maximum subrange within the above range that is meaningful to its applications.

Most implementations will be created by factory methods, such as the character name iterator in UCharacter.getNameIterator. See example below. Example of use:

 ValueIterator iterator = UCharacter.getNameIterator();
 ValueIterator.Element result = new ValueIterator.Element();
 iterator.setRange(UCharacter.MIN_VALUE, UCharacter.MAX_VALUE);
 while (iterator.next(result)) {
     System.out.println("Codepoint \\u" +
                        Integer.toHexString(result.integer) +
                        " has the character name " + (String)result.value);
 }
 

Summary

Nested classes

class ValueIterator.Element

The return result container of each iteration. 

Public methods

abstract boolean next(ValueIterator.Element element)

Returns the next result for this iteration and returns true if we are not at the end of the iteration, false otherwise.

abstract void reset()

Resets the iterator to start iterating from the integer index Integer.MIN_VALUE or X if a setRange(X, Y) has been called previously.

abstract void setRange(int start, int limit)

Restricts the range of integers to iterate and resets the iteration to begin at the index argument start.

Public methods

next

added in API level 24
public abstract boolean next (ValueIterator.Element element)

Returns the next result for this iteration and returns true if we are not at the end of the iteration, false otherwise.

If this returns a false, the contents of elements will not be updated.

Parameters
element ValueIterator.Element: for storing the result index and value

Returns
boolean true if we are not at the end of the iteration, false otherwise.

reset

added in API level 24
public abstract void reset ()

Resets the iterator to start iterating from the integer index Integer.MIN_VALUE or X if a setRange(X, Y) has been called previously.

setRange

added in API level 24
public abstract void setRange (int start, 
                int limit)

Restricts the range of integers to iterate and resets the iteration to begin at the index argument start.

If setRange(start, end) is not performed before next(element) is called, the iteration will start from the integer index Integer.MIN_VALUE and end at Integer.MAX_VALUE.

If this range is set outside the meaningful range specified by the implementation, next(element) will always return false.

Parameters
start int: first integer in the range to iterate

limit int: one more than the last integer in the range

Throws
IllegalArgumentException thrown when attempting to set an illegal range. E.g limit <= start