glypheventtable.java

一个基于PlaceLab的室内和室外的智能导航系统

/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.placelab.util.swt;


import org.eclipse.swt.SWT;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.TypedEvent;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;



/**
 * Instances of this class implement a simple
 * look up mechanism that maps an event type
 * to a listener.  Muliple listeners for the
 * same event type are supported.
 */

public class GlyphEventTable {
	int [] types;
	Listener [] listeners;
	int level;
	
	public void hook (int eventType, Listener listener) {
		if (types == null) types = new int [4];
		if (listeners == null) listeners = new Listener [4];
		int length = types.length, index = length - 1;
		while (index >= 0) {
			if (types [index] != 0) break;
			--index;
		}
		index++;
		if (index == length) {
			if (level == 0) {
				index = 0;
				for (int i=0; i<types.length; i++) {
					if (types [i] != 0) {
						types [index] = types [i];
						listeners[index]= listeners[i];
						index++;
					}
				}
				for (int i=index; i<types.length; i++) {
					types [i] = 0;
					listeners [i] = null;
				}
			}
			if (index == length) {
				int [] newTypes = new int [length + 4];
				System.arraycopy(types,0, newTypes, 0, length);
				types = newTypes;
				Listener[] newListeners=new Listener[length+4];
				System.arraycopy(listeners, 0, newListeners, 
						 0, length);
				listeners = newListeners;
			}
		}
		types [index] = eventType;
		listeners [index] = listener;
	}
	
	public boolean hooks (int eventType) {
		if (types == null) return false;
		for (int i=0; i<types.length; i++) {
			if (types [i] == eventType) return true;
		}
		return false;
	}
	
	public void sendEvent (Event event) {
		if (types == null) return;
		level++;
		try {
			for (int i=0; i<types.length; i++) {
				if (types [i] == event.type) {
					Listener listener = listeners [i];
					if (listener != null) 
						listener.handleEvent (event);
				}
			}
		} finally {
			--level;
		}
	}
	
	public int size () {
		if (types == null) return 0;
		int count = 0;
		for (int i=0; i<types.length; i++) {
			if (types [i] != 0) count++;
		}
		return count;
	}
	
	void remove (int index) {
		if (level == 0) {
			int end = types.length - 1;
			System.arraycopy (types, index + 1, types, index, 
					  end - index);
			System.arraycopy (listeners, index + 1, listeners, 
					  index, end - index);
			index = end;
		}
		types [index] = 0;
		listeners [index] = null;
	}
	
	public void unhook (int eventType, Listener listener) {
		if (types == null) return;
		for (int i=0; i<types.length; i++) {
			if (types [i] == eventType && listeners [i]==listener){
				remove (i);
				return;
			}
		}
	}

	public static Event getEvent(TypedEvent te) {
		Event e   = new Event();
		e.display = te.display;
		e.widget  = te.widget;
		e.time    = te.time;
		e.data    = te.data;
		return e;
	}
	public static Event getEvent(PaintEvent pe) {
		Event e  = getEvent((TypedEvent)pe);
		e.type   = SWT.Paint;
		e.gc     = pe.gc;
		e.x      = pe.x;
		e.y      = pe.y;
		e.width  = pe.width;
		e.height = pe.height;
		e.count  = pe.count;
		return e;
	}
	public static Event getEvent(MouseEvent me) {
		Event e     = getEvent((TypedEvent)me);
		e.x         = me.x;
		e.y         = me.y;
		e.button    = me.button;
		e.stateMask = me.stateMask;
		return e;
	}
	
	/*public void unhook (int eventType, SWTEventListener listener) {
		if (types == null) return;
		for (int i=0; i<types.length; i++) {
			if (types [i] == eventType) {
				if (listeners [i] instanceof TypedListener) {
					TypedListener typedListener = 
						(TypedListener) listeners [i];
					if (typedListener.getEventListener() ==
					    listener) {
						remove (i);
						return;
					}
				}
			}
		}
		}*/
}