com.codename1.properties.MapAdapter 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.HashMap;
import java.util.Map;
/**
* Instances of this class adapt an arbitrary object type so a property can
* appear differently when it's placed into a Map or initialized from a Map.
* This impacts JSON generation too as it relies heavily on the process of
* transforming elements to/from maps.
* To use this class create a new subclass of it and override the appropriate
* methods.
*
* @author Shai Almog
*/
public abstract class MapAdapter {
private final Class type;
private final static Map lookup = new HashMap();
/**
* By default subclasses should target a specific type but this can be
* further narrowed by overriding {@link #useAdapterFor(com.codename1.properties.PropertyBase)}.
* @param type the type to which the map adapter is bound
*/
protected MapAdapter(Class type) {
this.type = type;
lookup.put(type.getName(), this);
}
static MapAdapter checkInstance(PropertyBase b) {
if(b.getGenericType() != null) {
MapAdapter a = lookup.get(b.getGenericType().getName());
if(a != null && a.useAdapterFor(b)) {
return a;
}
}
return null;
}
/**
* Returns true if the adapter should be used for this property
*
* @param b the property
* @return true if this adapter should be used for this property
*/
public boolean useAdapterFor(PropertyBase b) {
return b.getGenericType() == type;
}
/**
* Places the given property into the given map
* @param b the property object
* @param m the map instance
*/
public void placeInMap(PropertyBase b, Map m) {
m.put(b.getName(), b.get());
}
/**
* Sets the value of the property from the map object
* @param b the property object
* @param m the map instance
*/
public void setFromMap(PropertyBase b, Map m){
b.setImpl(m.get(b.getName()));
}
}