net.e6tech.elements.common.resources.Binding Maven / Gradle / Ivy
/*
Copyright 2015-2019 Futeh Kao
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package net.e6tech.elements.common.resources;
import net.e6tech.elements.common.logging.Logger;
/**
* Created by futeh.
*/
public class Binding {
private Resources resources;
private String name; // if it's a named binding
private boolean oldValueExists;
private Class boundClass;
private T oldValue;
private T currentValue;
public Binding(Class boundClass, T value) {
this.boundClass = boundClass;
this.currentValue = value;
this.oldValue = value;
}
public Binding(String name, Class boundClass, T value) {
this.name = name;
this.boundClass = boundClass;
this.currentValue = value;
this.oldValue = value;
}
public Binding(Resources resources, Class boundClass) {
this.resources = resources;
this.boundClass = boundClass;
try {
oldValue = resources.getInstance(boundClass);
oldValueExists = true;
} catch (InstanceNotFoundException ex) {
Logger.suppress(ex);
oldValueExists = false;
}
currentValue = oldValue;
}
public boolean isNotNull() {
return currentValue != null;
}
public T get() {
return currentValue;
}
public Binding rebind(T newValue) {
currentValue = resources.rebind(boundClass, newValue);
return this;
}
public T restore() {
if (oldValueExists) {
return resources.rebind(boundClass, oldValue);
} else {
return resources.unbind(boundClass);
}
}
public String getName() {
return name;
}
public Class getBoundClass() {
return boundClass;
}
}