程序包 ohos.global.icu.text

类 ConstrainedFieldPosition

java.lang.Object

ohos.global.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.

构造器概要

构造器

构造器	说明
ConstrainedFieldPosition()	Initializes a CategoryFieldPosition.

方法概要

限定符和类型	方法	说明
void	constrainClass(Class<?> classConstraint)	Sets a constraint on the field class.
void	constrainField(Format.Field field)	Sets a constraint on the field.
Format.Field	getField()	Gets the field for the current position.
Object	getFieldValue()	Gets the value associated with the current field position.
long	getInt64IterationContext()	Gets an int64 that FormattedValue implementations may use for storage.
int	getLimit()	Gets the EXCLUSIVE end index stored for the current position.
int	getStart()	Gets the INCLUSIVE start index for the current position.
boolean	matchesField(Format.Field field, Object fieldValue)	Determines whether a given field and value should be included given the constraints.
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.
void	setInt64IterationContext(long context)	Sets an int64 that FormattedValue implementations may use for storage.
void	setState(Format.Field field, Object value, int start, int limit)	Sets new values for the primary public getters.
String	toString()	Returns a string representation of the object.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

构造器详细资料

ConstrainedFieldPosition

public ConstrainedFieldPosition()

Initializes a CategoryFieldPosition. By default, the CategoryFieldPosition has no iteration constraints.

方法详细资料

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, 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.

参数:

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, 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
 }
 

参数:

classConstraint - The field class 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.

返回:

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.

返回:

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.

返回:

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.

返回:

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.

返回:

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.

参数:

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!

参数:

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.

参数:

field - The field to test.

fieldValue - The field value to test. Should be null if there is no value.

返回:

Whether the field should be included given the constraints.

toString

public String toString()

Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

 getClass().getName() + '@' + Integer.toHexString(hashCode())
 

覆盖:

toString 在类中 Object

返回:

a string representation of the object.