/******************************************************************************* * Copyright (c) 2000, 2008 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.core.variables; /** * A variable with a value that can be set and retrieved. The context in which * a value variable is referenced does not effect the value of the variable. * A value variable can be contributed by an extension or created programmatically. * A contributor may optionally specify an initial value for a variable, or * provide a delegate that will initialize the variable with a value. *
* Since 3.3, a variable can be specified as a "read only" preventing users from changing * the value after it has been initialized. Furthermore, a read only variable that is * contributed by an extension will always load the value from the extension. *
** Example of a value variable contribution with an initial value, the specified * variable is created with the initial value "/usr/local/foo". *
* <extension point="org.eclipse.core.variables.valueVariables"> * <variable * name="FOO_HOME" * initialValue="/usr/local/foo"> * </variable> * </extension> ** *
* Example of a value variable contribution with an initializer class, the class * "com.example.FooLocator" will be used to initialize the value the first time * it's requested. *
* <extension point="org.eclipse.core.variables.valueVariables"> * <variable * name="FOO_HOME" * initializerClass="com.example.FooLocator"> * </variable> * </extension> ** * @since 3.0 * @noimplement This interface is not intended to be implemented by clients. */ public interface IValueVariable extends IStringVariable { /** * Sets the value of this variable to the given value. * Since 3.3, this has no effect if this variable is read only. * * @param value variable value */ public void setValue(String value); /** * Returns the value of this variable, or
null
if none.
*
* @return the value of this variable, or null
if none
*/
public String getValue();
/**
* Returns whether this variable was contributed by an extension.
*
* @return whether this variable was contributed by an extension
*/
public boolean isContributed();
/**
* Returns whether this variable is read only.
*
* @return whether this variable is read only
* @since 3.3
*/
public boolean isReadOnly();
/**
* Sets the description of this variable to the given value.
*
* @param description variable description, possibly null
*/
public void setDescription(String description);
}