com.codename1.properties.Property Maven / Gradle / Ivy
/*
* Copyright (c) 2012, Codename One and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Codename One designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Codename One through http://www.codenameone.com/ if you
* need additional information or have any questions.
*/
package com.codename1.properties;
import java.util.ArrayList;
/**
* Base class for a property, it can store a generic value of any type and broadcast change events to
* external listeners
*
* @author Shai Almog
*/
public class Property extends PropertyBase {
private T value;
/**
* Constructs a property with the given name and value
* @param name the name of the property
* @param value the default value for the property
*/
public Property(String name, T value) {
super(name);
this.value = value;
}
/**
* Constructs a property with the given name and value
* @param name the name of the property
* @param genericType the type of the property
* @param value the default value for the property
*/
public Property(String name, Class genericType, T value) {
super(name, genericType);
this.value = value;
}
/**
* Constructs a property with null value
* @param name the name of the property
*/
public Property(String name) {
super(name);
}
/**
* Constructs a property with null value
* @param genericType the type of the property
* @param name the name of the property
*/
public Property(String name, Class genericType) {
super(name, genericType);
}
/**
* Gets the property value
* @return the property value
*/
public T get() {
internalGet();
return value;
}
/**
* Sets the property value and potentially fires a change event
* @param value the new value
*/
public K set(T value) {
if(!(this.value == value ||
(this.value != null && this.value.equals(value)))) {
this.value = value;
firePropertyChanged();
internalSet();
}
if(parent == null) {
// allows properties to work even if they aren't registered in the index
return null;
}
return (K)parent.parent;
}
/**
* Compares this property to another property
* @param obj the other property
* @return true if they are equal in name and value
*/
@Override
public boolean equals(Object obj) {
if(!super.equals(obj)) {
return false;
}
Property other = (Property)obj;
Object otherval = other.get();
if(otherval == value) {
return true;
}
return otherval != null && otherval.equals(value);
}
/**
* Returns the internal hashcode or 0 for null property
* @return the hashcode value
*/
@Override
public int hashCode() {
if(value == null) return 0;
return value.hashCode();
}
@Override
public String toString() {
return "" + value;
}
@Override
void setImpl(Object val) {
set((T)val);
}
}