/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

package com.sun.org.apache.bcel.internal.generic;

/* ====================================================================

 * The Apache Software License, Version 1.1

 *

 * Copyright (c) 2001 The Apache Software Foundation.  All rights

 * reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

 * 3. The end-user documentation included with the redistribution,

 *    if any, must include the following acknowledgment:

 *       "This product includes software developed by the

 *        Apache Software Foundation (http://www.apache.org/)."

 *    Alternately, this acknowledgment may appear in the software itself,

 *    if and wherever such third-party acknowledgments normally appear.

 *

 * 4. The names "Apache" and "Apache Software Foundation" and

 *    "Apache BCEL" must not be used to endorse or promote products

 *    derived from this software without prior written permission. For

 *    written permission, please contact apache@apache.org.

 *

 * 5. Products derived from this software may not be called "Apache",

 *    "Apache BCEL", nor may "Apache" appear in their name, without

 *    prior written permission of the Apache Software Foundation.

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 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

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 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR

 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,

 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT

 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 * ====================================================================

 *

 * This software consists of voluntary contributions made by many

 * individuals on behalf of the Apache Software Foundation.  For more

 * information on the Apache Software Foundation, please see

 * <http://www.apache.org/>.

 */

import com.sun.org.apache.bcel.internal.Constants;

import com.sun.org.apache.bcel.internal.classfile.*;

import java.util.ArrayList;

import java.util.Iterator;

/**

 * Template class for building up a field.  The only extraordinary thing

 * one can do is to add a constant value attribute to a field (which must of

 * course be compatible with to the declared type).

 *

 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>

 * @see Field

 */

public class FieldGen extends FieldGenOrMethodGen {

  private Object value = null;

  /**

   * Declare a field. If it is static (isStatic() == true) and has a

   * basic type like int or String it may have an initial value

   * associated with it as defined by setInitValue().

   *

   * @param access_flags access qualifiers

   * @param type  field type

   * @param name field name

   * @param cp constant pool

   */

  public FieldGen(int access_flags, Type type, String name, ConstantPoolGen cp) {

    setAccessFlags(access_flags);

    setType(type);

    setName(name);

    setConstantPool(cp);

  }

  /**

   * Instantiate from existing field.

   *

   * @param field Field object

   * @param cp constant pool (must contain the same entries as the field's constant pool)

   */

  public FieldGen(Field field, ConstantPoolGen cp) {

    this(field.getAccessFlags(), Type.getType(field.getSignature()), field.getName(), cp);

    Attribute[] attrs = field.getAttributes();

    for(int i=0; i < attrs.length; i++) {

      if(attrs[i] instanceof ConstantValue)

        setValue(((ConstantValue)attrs[i]).getConstantValueIndex());

      else

        addAttribute(attrs[i]);

    }

  }

  private void setValue(int index) {

    ConstantPool cp  = this.cp.getConstantPool();

    Constant     c   = cp.getConstant(index);

    value = ((ConstantObject)c).getConstantValue(cp);

  }

  /**

   * Set (optional) initial value of field, otherwise it will be set to null/0/false

   * by the JVM automatically.

   */

  public void setInitValue(String str) {

    checkType(new ObjectType("java.lang.String"));

    if(str != null)

      value = str;

  }

  public void setInitValue(long l) {

    checkType(Type.LONG);

    if(l != 0L)

      value = new Long(l);

  }

  public void setInitValue(int i) {

    checkType(Type.INT);

    if(i != 0)

      value = new Integer(i);

  }

  public void setInitValue(short s) {

    checkType(Type.SHORT);

    if(s != 0)

      value = new Integer(s);

  }

  public void setInitValue(char c) {

    checkType(Type.CHAR);

    if(c != 0)

      value = new Integer(c);

  }

  public void setInitValue(byte b) {

    checkType(Type.BYTE);

    if(b != 0)

      value = new Integer(b);

  }

  public void setInitValue(boolean b) {

    checkType(Type.BOOLEAN);

    if(b)

      value = new Integer(1);

  }

  public void setInitValue(float f) {

    checkType(Type.FLOAT);

    if(f != 0.0)

      value = new Float(f);

  }

  public void setInitValue(double d) {

    checkType(Type.DOUBLE);

    if(d != 0.0)

      value = new Double(d);

  }

  /** Remove any initial value.

   */

  public void cancelInitValue() {

    value = null;

  }

  private void checkType(Type atype) {

    if(type == null)

      throw new ClassGenException("You haven't defined the type of the field yet");

    if(!isFinal())

      throw new ClassGenException("Only final fields may have an initial value!");

    if(!type.equals(atype))

      throw new ClassGenException("Types are not compatible: " + type + " vs. " + atype);

  }

  /**

   * Get field object after having set up all necessary values.

   */

  public Field getField() {

    String      signature       = getSignature();

    int         name_index      = cp.addUtf8(name);

    int         signature_index = cp.addUtf8(signature);

    if(value != null) {

      checkType(type);

      int index = addConstant();

      addAttribute(new ConstantValue(cp.addUtf8("ConstantValue"),

                                     2, index, cp.getConstantPool()));

    }

    return new Field(access_flags, name_index, signature_index, getAttributes(),

                     cp.getConstantPool());

  }

  private int addConstant() {

    switch(type.getType()) {

    case Constants.T_INT: case Constants.T_CHAR: case Constants.T_BYTE:

    case Constants.T_BOOLEAN: case Constants.T_SHORT:

      return cp.addInteger(((Integer)value).intValue());

    case Constants.T_FLOAT:

      return cp.addFloat(((Float)value).floatValue());

    case Constants.T_DOUBLE:

      return cp.addDouble(((Double)value).doubleValue());

    case Constants.T_LONG:

      return cp.addLong(((Long)value).longValue());

    case Constants.T_REFERENCE:

      return cp.addString(((String)value));

    default:

      throw new RuntimeException("Oops: Unhandled : " + type.getType());

    }

  }

  public String  getSignature()  { return type.getSignature(); }

  private ArrayList observers;

  /** Add observer for this object.

   */

  public void addObserver(FieldObserver o) {

    if(observers == null)

      observers = new ArrayList();

    observers.add(o);

  }

  /** Remove observer for this object.

   */

  public void removeObserver(FieldObserver o) {

    if(observers != null)

      observers.remove(o);

  }

  /** Call notify() method on all observers. This method is not called

   * automatically whenever the state has changed, but has to be

   * called by the user after he has finished editing the object.

   */

  public void update() {

    if(observers != null)

      for(Iterator e = observers.iterator(); e.hasNext(); )

        ((FieldObserver)e.next()).notify(this);

  }

  public String getInitValue() {

    if(value != null) {

      return value.toString();

    } else

      return null;

  }

  /**

   * Return string representation close to declaration format,

   * `public static final short MAX = 100', e.g..

   *

   * @return String representation of field

   */

  public final String toString() {

    String name, signature, access; // Short cuts to constant pool

    access    = Utility.accessToString(access_flags);

    access    = access.equals("")? "" : (access + " ");

    signature = type.toString();

    name      = getName();

    StringBuffer buf = new StringBuffer(access + signature + " " + name);

    String value = getInitValue();

    if(value != null)

      buf.append(" = " + value);

    return buf.toString();

  }

  /** @return deep copy of this field

   */

  public FieldGen copy(ConstantPoolGen cp) {

    FieldGen fg = (FieldGen)clone();

    fg.setConstantPool(cp);

    return fg;

  }

}