Copyright (c) 2000, 2008 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.debug.core;


import org.eclipse.debug.core.model.IExpression;
import org.eclipse.debug.core.model.IWatchExpression;
import org.eclipse.debug.core.model.IWatchExpressionDelegate;

The expression manager manages the collection of registered
expressions in the workspace. An expression is a snippet of code
that can be evaluated to produce a value. Expression creation
and evaluation are client responsibilities.

Clients interested in expression change notification may
register with the expression manager - see
IExpressionListener and IExpressionsListener.

See Also:
IExpression
IExpressionListener
IExpressionsListener
Since:
2.0
@noimplement
This interface is not intended to be implemented by clients.
@noextend
This interface is not intended to be extended by clients./**
 * The expression manager manages the collection of registered
 * expressions in the workspace. An expression is a snippet of code
 * that can be evaluated to produce a value. Expression creation
 * and evaluation are client responsibilities.
 * <p>
 * Clients interested in expression change notification may
 * register with the expression manager - see
 * <code>IExpressionListener</code> and <code>IExpressionsListener</code>.
 * </p>
 * @see org.eclipse.debug.core.model.IExpression
 * @see org.eclipse.debug.core.IExpressionListener
 * @see org.eclipse.debug.core.IExpressionsListener
 * @since 2.0
 * @noimplement This interface is not intended to be implemented by clients.
 * @noextend This interface is not intended to be extended by clients.
 */
public interface IExpressionManager {
	
Adds the given expression to the collection of registered expressions
in the workspace and notifies all registered listeners. This has no effect
if the given expression is already registered.
Params:
expression – the expression to add/**
	 * Adds the given expression to the collection of registered expressions
	 * in the workspace and notifies all registered listeners. This has no effect
	 * if the given expression is already registered.
	 *
	 * @param expression the expression to add
	 */
	void addExpression(IExpression expression);

	
Adds the given expressions to the collection of registered expressions
in the workspace and notifies all registered listeners. Has no effect
on expressions already registered.
Params:
expressions – the expressions to add
Since:
2.1/**
	 * Adds the given expressions to the collection of registered expressions
	 * in the workspace and notifies all registered listeners. Has no effect
	 * on expressions already registered.
	 *
	 * @param expressions the expressions to add
	 * @since 2.1
	 */
	void addExpressions(IExpression[] expressions);

	
Creates and returns a new watch expression with the
given text. The returned expression is not added to
this manager.
Params:
expressionText – the text for the new expression
Returns:
new watch expression
Since:
3.0/**
	 * Creates and returns a new watch expression with the
	 * given text. The returned expression is <b>not</b> added to
	 * this manager.
	 *
	 * @return new watch expression
	 * @param expressionText the text for the new expression
	 * @since 3.0
	 */
	IWatchExpression newWatchExpression(String expressionText);

	
Returns a collection of all registered expressions,
possibly empty.
Returns:
an array of expressions/**
	 * Returns a collection of all registered expressions,
	 * possibly empty.
	 *
	 * @return an array of expressions
	 */
	IExpression[] getExpressions();

	
Returns whether there are any registered expressions
Returns:
whether there are any registered expressions/**
	 * Returns whether there are any registered expressions
	 *
	 * @return whether there are any registered expressions
	 */
	boolean hasExpressions();

	
Returns a collection of all expressions registered for the
given debug model,possibly empty.
Params:
modelIdentifier – identifier of a debug model plug-in
Returns:
an array of expressions/**
	 * Returns a collection of all expressions registered for the
	 * given debug model,possibly empty.
	 *
	 * @param modelIdentifier identifier of a debug model plug-in
	 * @return an array of expressions
	 */
	IExpression[] getExpressions(String modelIdentifier);

	
Removes the given expression from the expression manager,
and notifies all registered listeners. Has no effect if the
given expression is not currently registered.
Params:
expression – the expression to remove/**
	 * Removes the given expression from the expression manager,
	 * and notifies all registered listeners. Has no effect if the
	 * given expression is not currently registered.
	 *
	 * @param expression the expression to remove
	 */
	void removeExpression(IExpression expression);

	
Removes the given expressions from the collection of registered expressions
in the workspace and notifies all registered listeners. Has no effect
on expressions not already registered.
Params:
expressions – the expressions to remove
Since:
2.1/**
	 * Removes the given expressions from the collection of registered expressions
	 * in the workspace and notifies all registered listeners. Has no effect
	 * on expressions not already registered.
	 *
	 * @param expressions the expressions to remove
	 * @since 2.1
	 */
	void removeExpressions(IExpression[] expressions);

	
Adds the given listener to the collection of registered expression listeners.
Has no effect if an identical listener is already registered.
Params:
listener – the listener to add/**
	 * Adds the given listener to the collection of registered expression listeners.
	 * Has no effect if an identical listener is already registered.
	 *
	 * @param listener the listener to add
	 */
	void addExpressionListener(IExpressionListener listener);

	
Removes the given listener from the collection of registered expression listeners.
Has no effect if an identical listener is not already registered.
Params:
listener – the listener to remove/**
	 * Removes the given listener from the collection of registered expression listeners.
	 * Has no effect if an identical listener is not already registered.
	 *
	 * @param listener the listener to remove
	 */
	void removeExpressionListener(IExpressionListener listener);

	
Adds the given listener to the collection of registered expression listeners.
Has no effect if an identical listener is already registered.
Params:
listener – the listener to add
Since:
2.1/**
	 * Adds the given listener to the collection of registered expression listeners.
	 * Has no effect if an identical listener is already registered.
	 *
	 * @param listener the listener to add
	 * @since 2.1
	 */
	void addExpressionListener(IExpressionsListener listener);

	
Removes the given listener from the collection of registered expression listeners.
Has no effect if an identical listener is not already registered.
Params:
listener – the listener to remove
Since:
2.1/**
	 * Removes the given listener from the collection of registered expression listeners.
	 * Has no effect if an identical listener is not already registered.
	 *
	 * @param listener the listener to remove
	 * @since 2.1
	 */
	void removeExpressionListener(IExpressionsListener listener);

	
Returns a new watch expression delegate for the given debug
model or null if no delegate is available.
Params:
id – the unique identifier of a debug model for which a
 watch expression delegate has been contributed
See Also:
IWatchExpressionDelegate
Returns:
a watch expression delegate associated with the given model
		or null if none
Since:
3.0/**
	 * Returns a new watch expression delegate for the given debug
	 * model or <code>null</code> if no delegate is available.
	 *
	 * @param id the unique identifier of a debug model for which a
	 *  watch expression delegate has been contributed
	 * @return a watch expression delegate associated with the given model
	 * 		or <code>null</code> if none
	 * @since 3.0
	 * @see IWatchExpressionDelegate
	 */
	IWatchExpressionDelegate newWatchExpressionDelegate(String id);

	
Returns whether a watch expression delegate has been contributed for
the given debug model.
Params:
id – the unique identifier of a debug model
See Also:
IWatchExpressionDelegate
Returns:
whether a watch expression delegate has been contributed for
   the given debug model
Since:
3.1/**
	 * Returns whether a watch expression delegate has been contributed for
	 * the given debug model.
	 *
	 * @param id the unique identifier of a debug model
	 * @return whether a watch expression delegate has been contributed for
	 *    the given debug model
	 * @since 3.1
	 * @see IWatchExpressionDelegate
	 */
	boolean hasWatchExpressionDelegate(String id);
}