// This Source Code is Copyright & Licenced as indicated below
package org.litesoft.GWT.client.widgets.nonpublic.external;
/*
 * 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.
 */

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

public abstract class EventDelegateAdaptor implements EventDelegate {
    private final int m_eventBits;

    /**
     * Default constructor for convienence. Subclasses must override
     * {@link #getEventBits()} if they want to process events.
     */
    public EventDelegateAdaptor() {
        m_eventBits = 0;
    }

    /**
     * Creates an event delegate which is interested in the specified bits.
     *
     * @param eventBits a bitmask of the events to process
     *
     * @see Event
     */
    public EventDelegateAdaptor( int eventBits ) {
        m_eventBits = eventBits;
    }

    /*
      *  (non-Javadoc)
      * @see asquare.gwt.tk.client.ui.behavior.EventDelegate#onBrowserEvent(com.google.gwt.user.client.ui.Widget, com.google.gwt.user.client.Event)
      */
    @Override
    public void onBrowserEvent( Widget widget, Event event ) {
        if ( !doBrowserEvent( widget, event ) ) {
            DOM.eventPreventDefault( event );
            DOM.eventCancelBubble( event, true );
        }
    }

    /**
     * A convenience method for processing events. The event is cancelled if the
     * return value is false.
     *
     * @return false to cancel the event
     */
    protected boolean doBrowserEvent( Widget widget, Event event ) {
        return true;
    }

    /**
     * {@inheritDoc}
     * Override in subclass if using the default constructor.
     */
    @Override
    public int getEventBits() {
        return m_eventBits;
    }
}