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/**
* Copyright 2009 Google Inc.
*
* 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.appjet.oui;
class NoninheritedDynamicVariable[T](init: T) {
private val tl = new ThreadLocal[T] {
override def initialValue = init.asInstanceOf[T with AnyRef]
}
/** Retrieve the current value */
def value: T = tl.get.asInstanceOf[T]
/** Set the value of the variable while executing the specified
* thunk.
*
* @param newval The value to which to set the fluid
* @param thunk The code to evaluate under the new setting
*/
def withValue[S](newval: T)(thunk: =>S): S = {
val oldval = value
tl.set(newval)
try { thunk } finally {
tl.set(oldval)
}
}
/** Change the currently bound value, discarding the old value.
* Usually <code>withValue()</code> gives better semantics.
*/
def value_=(newval: T) = { tl.set(newval) }
override def toString: String = "NoninheritedDynamicVariable(" + value +")"
}
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