bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/ISourceProviderListener.java

/*******************************************************************************
 * Copyright (c) 2005, 2015 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.ui;

import java.util.Map;

/**
 * <p>
 * A listener to changes in a particular source of information. This listener is
 * notified as the source changes. Typically, workbench services will implement
 * this interface, and register themselves as listeners to the
 * <code>ISourceProvider</code> instances that are registered with them.
 * </p>
 *
 * @since 3.1
 * @see org.eclipse.ui.ISources
 * @see org.eclipse.ui.ISourceProvider
 */
public interface ISourceProviderListener {

	/**
	 * Handles a change to multiple sources. The source priority should be a bit
	 * mask indicating the sources. The map will be used to construct the variables
	 * on an <code>IEvaluationContext</code>
	 *
	 * @param sourcePriority     A bit mask of all the source priorities that have
	 *                           changed.
	 * @param sourceValuesByName A mapping of the source names (<code>String</code>)
	 *                           to the source values (<code>Object</code>). The
	 *                           names should never be <code>null</code>, but the
	 *                           values may be. The map must not be
	 *                           <code>null</code>, and should contain at least two
	 *                           elements (one for each source).
	 * @see org.eclipse.core.expressions.IEvaluationContext
	 * @see ISources
	 */
	void sourceChanged(final int sourcePriority, final Map sourceValuesByName);

	/**
	 * Handles a change to one source. The source priority should indicate the
	 * source, and the name-value pair will be used to create an
	 * <code>IEvaluationContext</code> with a single variable.
	 *
	 * @param sourcePriority A bit mask of all the source priorities that have
	 *                       changed.
	 * @param sourceName     The name of the source that changed; must not be
	 *                       <code>null</code>.
	 * @param sourceValue    The new value for that source; may be
	 *                       <code>null</code>.
	 * @see org.eclipse.core.expressions.IEvaluationContext
	 * @see ISources
	 */
	void sourceChanged(final int sourcePriority, final String sourceName, final Object sourceValue);
}