// ASM: a very small and fast Java bytecode manipulation framework
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package org.objectweb.asm;

A visitor to visit a Java field. The methods of this class must be called in the following order: ( visitAnnotation | visitTypeAnnotation | visitAttribute )* 
visitEnd. 
Author:
Eric Bruneton/**
 * A visitor to visit a Java field. The methods of this class must be called in the following order:
 * ( {@code visitAnnotation} | {@code visitTypeAnnotation} | {@code visitAttribute} )* {@code
 * visitEnd}.
 *
 * @author Eric Bruneton
 */
public abstract class FieldVisitor {

  
The ASM API version implemented by this visitor. The value of this field must be one of Opcodes.ASM4, Opcodes.ASM5, Opcodes.ASM6 or Opcodes.ASM7. /**
   * The ASM API version implemented by this visitor. The value of this field must be one of {@link
   * Opcodes#ASM4}, {@link Opcodes#ASM5}, {@link Opcodes#ASM6} or {@link Opcodes#ASM7}.
   */
  protected final int api;

  
The field visitor to which this visitor must delegate method calls. May be null. /** The field visitor to which this visitor must delegate method calls. May be {@literal null}. */
  protected FieldVisitor fv;

  
Constructs a new FieldVisitor. 
Params:
api – the ASM API version implemented by this visitor. Must be one of Opcodes.ASM4, Opcodes.ASM5, Opcodes.ASM6 or Opcodes.ASM7./**
   * Constructs a new {@link FieldVisitor}.
   *
   * @param api the ASM API version implemented by this visitor. Must be one of {@link
   *     Opcodes#ASM4}, {@link Opcodes#ASM5}, {@link Opcodes#ASM6} or {@link Opcodes#ASM7}.
   */
  public FieldVisitor(final int api) {
    this(api, null);
  }

  
Constructs a new FieldVisitor. 
Params:
api – the ASM API version implemented by this visitor. Must be one of Opcodes.ASM4, Opcodes.ASM5, Opcodes.ASM6 or Opcodes.ASM7.
fieldVisitor – the field visitor to which this visitor must delegate method calls. May be
    null./**
   * Constructs a new {@link FieldVisitor}.
   *
   * @param api the ASM API version implemented by this visitor. Must be one of {@link
   *     Opcodes#ASM4}, {@link Opcodes#ASM5}, {@link Opcodes#ASM6} or {@link Opcodes#ASM7}.
   * @param fieldVisitor the field visitor to which this visitor must delegate method calls. May be
   *     null.
   */
  public FieldVisitor(final int api, final FieldVisitor fieldVisitor) {
    if (api != Opcodes.ASM7
        && api != Opcodes.ASM6
        && api != Opcodes.ASM5
        && api != Opcodes.ASM4
        && api != Opcodes.ASM8_EXPERIMENTAL) {
      throw new IllegalArgumentException("Unsupported api " + api);
    }
    if (api == Opcodes.ASM8_EXPERIMENTAL) {
      Constants.checkAsm8Experimental(this);
    }
    this.api = api;
    this.fv = fieldVisitor;
  }

  
Visits an annotation of the field.
Params:
descriptor – the class descriptor of the annotation class.
visible – true if the annotation is visible at runtime.
Returns:
a visitor to visit the annotation values, or null if this visitor is not interested in visiting this annotation./**
   * Visits an annotation of the field.
   *
   * @param descriptor the class descriptor of the annotation class.
   * @param visible {@literal true} if the annotation is visible at runtime.
   * @return a visitor to visit the annotation values, or {@literal null} if this visitor is not
   *     interested in visiting this annotation.
   */
  public AnnotationVisitor visitAnnotation(final String descriptor, final boolean visible) {
    if (fv != null) {
      return fv.visitAnnotation(descriptor, visible);
    }
    return null;
  }

  
Visits an annotation on the type of the field.
Params:
typeRef – a reference to the annotated type. The sort of this type reference must be TypeReference.FIELD. See TypeReference.
typePath – the path to the annotated type argument, wildcard bound, array element type, or static inner type within 'typeRef'. May be null if the annotation targets 'typeRef' as a whole.
descriptor – the class descriptor of the annotation class.
visible – true if the annotation is visible at runtime.
Returns:
a visitor to visit the annotation values, or null if this visitor is not interested in visiting this annotation./**
   * Visits an annotation on the type of the field.
   *
   * @param typeRef a reference to the annotated type. The sort of this type reference must be
   *     {@link TypeReference#FIELD}. See {@link TypeReference}.
   * @param typePath the path to the annotated type argument, wildcard bound, array element type, or
   *     static inner type within 'typeRef'. May be {@literal null} if the annotation targets
   *     'typeRef' as a whole.
   * @param descriptor the class descriptor of the annotation class.
   * @param visible {@literal true} if the annotation is visible at runtime.
   * @return a visitor to visit the annotation values, or {@literal null} if this visitor is not
   *     interested in visiting this annotation.
   */
  public AnnotationVisitor visitTypeAnnotation(
      final int typeRef, final TypePath typePath, final String descriptor, final boolean visible) {
    if (api < Opcodes.ASM5) {
      throw new UnsupportedOperationException("This feature requires ASM5");
    }
    if (fv != null) {
      return fv.visitTypeAnnotation(typeRef, typePath, descriptor, visible);
    }
    return null;
  }

  
Visits a non standard attribute of the field.
Params:
attribute – an attribute./**
   * Visits a non standard attribute of the field.
   *
   * @param attribute an attribute.
   */
  public void visitAttribute(final Attribute attribute) {
    if (fv != null) {
      fv.visitAttribute(attribute);
    }
  }

  
Visits the end of the field. This method, which is the last one to be called, is used to inform
the visitor that all the annotations and attributes of the field have been visited.
/**
   * Visits the end of the field. This method, which is the last one to be called, is used to inform
   * the visitor that all the annotations and attributes of the field have been visited.
   */
  public void visitEnd() {
    if (fv != null) {
      fv.visitEnd();
    }
  }
}