/*
 * Copyright 2006 Mat Gessel <mat.gessel@gmail.com>
 * 
 * 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 org.litesoft.GWT.client.widgets.nonpublic.external;

import com.google.gwt.user.client.*;
import com.google.gwt.user.client.ui.*;

/**
 * An EventDelegate processes events from a widget.
 * <p/>
 * Example: <br/> To override default focus behavior you need to preview and
 * cancel tab events. The KeyboardListener interface does not receive the actual
 * events. EventPreview is really intended for popups and dialogs and will not
 * function if another popup/dialog is shown (think a non-modal dialog or popup
 * without autoclose). A solution is to have widget can delegate events to a
 * focus manager implementing EventDelegate.
 * </p>
 */
public interface EventDelegate
{
    /**
     * Get a bitmask representing events this delegate is interested in
     * processing.
     *
     * @return a bitmask of the events to process
     *
     * @see Event
     */
    int getEventBits();

    /**
     * Call this from your widget's onBrowserEvent() method
     * to to delegate events.
     * <p/>
     * <p>Example: <p>
     * <pre>
     * public void onBrowserEvent(Event event)
     * {
     *   super.onBrowserEvent(event);
     *   delegate.onBrowserEvent(this, event);
     * }
     * </pre>
     *
     * @param widget the wiget that originated the event
     * @param event  the event
     */
    void onBrowserEvent( Widget widget, Event event );
}