org.eclipse.swt.events.TreeListener.java Source code

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Here is the source code for org.eclipse.swt.events.TreeListener.java

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/*******************************************************************************
 * Copyright (c) 2000, 2017 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.swt.events;

import java.util.function.*;

import org.eclipse.swt.internal.*;

/**
 * Classes which implement this interface provide methods
 * that deal with the expanding and collapsing of tree
 * branches.
 * <p>
 * After creating an instance of a class that implements
 * this interface it can be added to a tree control using the
 * <code>addTreeListener</code> method and removed using
 * the <code>removeTreeListener</code> method. When a branch
 * of the tree is expanded or collapsed, the appropriate method
 * will be invoked.
 * </p>
 *
 * @see TreeAdapter
 * @see TreeEvent
 */
public interface TreeListener extends SWTEventListener {

    /**
     * Sent when a tree branch is collapsed.
     *
     * @param e an event containing information about the tree operation
     */
    void treeCollapsed(TreeEvent e);

    /**
     * Sent when a tree branch is expanded.
     *
     * @param e an event containing information about the tree operation
     */
    void treeExpanded(TreeEvent e);

    /**
     * Static helper method to create a <code>TreeListener</code> for the
     * {@link #treeCollapsed(TreeEvent e)}) method, given a lambda expression or a method reference.
     *
     * @param c the consumer of the event
     * @return TreeListener
     * @since 3.107
     */
    static TreeListener treeCollapsedAdapter(Consumer<TreeEvent> c) {
        return new TreeAdapter() {
            @Override
            public void treeCollapsed(TreeEvent e) {
                c.accept(e);
            }
        };
    }

    /**
     * Static helper method to create a <code>TreeListener</code> for the
     * {@link #treeExpanded(TreeEvent e)}) method, given a lambda expression or a method reference.
     *
     * @param c the consumer of the event
     * @return TreeListener
     * @since 3.107
     */
    static TreeListener treeExpandedAdapter(Consumer<TreeEvent> c) {
        return new TreeAdapter() {
            @Override
            public void treeExpanded(TreeEvent e) {
                c.accept(e);
            }
        };
    }
}