Class ConstrainedFieldPosition

java.lang.Object
com.ibm.icu.text.ConstrainedFieldPosition

public class ConstrainedFieldPosition extends Object
Represents a span of a string containing a given field. This class differs from FieldPosition in the following ways: 1. It has information on the field category. 2. It allows you to set constraints to use when iterating over field positions. 3. It is used for the newer FormattedValue APIs.
Author:
sffc
  • Constructor Details

    • ConstrainedFieldPosition

      public ConstrainedFieldPosition()
      Initializes a CategoryFieldPosition. By default, the CategoryFieldPosition has no iteration constraints.
  • Method Details

    • reset

      public void reset()
      Resets this ConstrainedFieldPosition to its initial state, as if it were newly created: - Removes any constraints that may have been set on the instance. - Resets the iteration position.
    • constrainField

      public void constrainField(Format.Field field)
      Sets a constraint on the field. When this instance of ConstrainedFieldPosition is passed to FormattedValue.nextPosition(com.ibm.icu.text.ConstrainedFieldPosition), positions are skipped unless they have the given field. Any previously set constraints are cleared. For example, to loop over all grouping separators:
       ConstrainedFieldPosition cfpos;
       cfpos.constrainField(NumberFormat.Field.GROUPING_SEPARATOR);
       while (fmtval.nextPosition(cfpos)) {
         // handle the grouping separator position
       }
       
      Changing the constraint while in the middle of iterating over a FormattedValue does not generally have well-defined behavior.
      Parameters:
      field - The field to fix when iterating.
    • constrainClass

      public void constrainClass(Class<?> classConstraint)
      Sets a constraint on the field class. When this instance of ConstrainedFieldPosition is passed to FormattedValue.nextPosition(com.ibm.icu.text.ConstrainedFieldPosition), positions are skipped unless the field is an instance of the class constraint, including subclasses. Any previously set constraints are cleared. For example, to loop over only the number-related fields:
       ConstrainedFieldPosition cfpos;
       cfpos.constrainClass(NumberFormat.Field.class);
       while (fmtval.nextPosition(cfpos)) {
         // handle the number-related field position
       }
       
      Parameters:
      classConstraint - The field class to fix when iterating.
    • constrainFieldAndValue

      @Deprecated public void constrainFieldAndValue(Format.Field field, Object fieldValue)
      Deprecated.
      This API is for technology preview and might be changed or removed in a future release.
      Sets a constraint on field and field value. When this instance of ConstrainedFieldPosition is passed to FormattedValue.nextPosition(com.ibm.icu.text.ConstrainedFieldPosition), positions are skipped unless both the field and the field value are equal. Any previously set constraints are cleared. For example, to find the span a date interval corresponding to the first date:
       ConstrainedFieldPosition cfpos;
       cfpos.constrainFieldAndValue(DateIntervalFormat.SpanField.DATE_INTERVAL_SPAN, 0);
       while (fmtval.nextPosition(cfpos)) {
         // handle the span of the first date in the date interval
       }
       
      Parameters:
      field - The field to fix when iterating.
      fieldValue - The field value to fix when iterating.
    • getField

      public Format.Field getField()
      Gets the field for the current position. The return value is well-defined and non-null only after FormattedValue#nextPosition returns true.
      Returns:
      The field saved in the instance. See above for null conditions.
    • getStart

      public int getStart()
      Gets the INCLUSIVE start index for the current position. The return value is well-defined only after FormattedValue#nextPosition returns true.
      Returns:
      The start index saved in the instance.
    • getLimit

      public int getLimit()
      Gets the EXCLUSIVE end index stored for the current position. The return value is well-defined only after FormattedValue#nextPosition returns true.
      Returns:
      The end index saved in the instance.
    • getFieldValue

      public Object getFieldValue()
      Gets the value associated with the current field position. The field value is often not set. The return value is well-defined only after FormattedValue#nextPosition returns true.
      Returns:
      The value for the current position. Might be null.
    • getInt64IterationContext

      public long getInt64IterationContext()
      Gets an int64 that FormattedValue implementations may use for storage. The initial value is zero. Users of FormattedValue should not need to call this method.
      Returns:
      The current iteration context from setInt64IterationContext(long).
    • setInt64IterationContext

      public void setInt64IterationContext(long context)
      Sets an int64 that FormattedValue implementations may use for storage. Intended to be used by FormattedValue implementations.
      Parameters:
      context - The new iteration context.
    • setState

      public void setState(Format.Field field, Object value, int start, int limit)
      Sets new values for the primary public getters. Intended to be used by FormattedValue implementations. It is up to the implementation to ensure that the user-requested constraints are satisfied. This method does not check!
      Parameters:
      field - The new field.
      value - The new field value. Should be null if there is no value.
      start - The new inclusive start index.
      limit - The new exclusive end index.
    • matchesField

      public boolean matchesField(Format.Field field, Object fieldValue)
      Determines whether a given field and value should be included given the constraints. Intended to be used by FormattedValue implementations.
      Parameters:
      field - The field to test.
      fieldValue - The field value to test. Should be null if there is no value.
      Returns:
      Whether the field should be included given the constraints.
    • toString

      public String toString()
      Overrides:
      toString in class Object