engagement_generation: engagement_generation/src/edu/wpi/hri/gen/comm/GazeListener.java Source File

00001 /*
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00004  * Copyright (c) 2010, Worcester Polytechnic Institute All rights reserved.
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00014  * nor the names of its contributors may be used to endorse or promote products
00015  * derived from this software without specific prior written permission.
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00029 package edu.wpi.hri.gen.comm;
00030 
00040 public abstract class GazeListener {
00041 
00042         protected final GazeListener next;
00043         protected String target;
00044 
00045         protected GazeListener(GazeListener next) {
00046                 this.next = next;
00047         }
00048 
00049         protected boolean setTarget(String target) {
00050                 this.target = target;
00051                 return this.trySetGaze(target);
00052         }
00053 
00062         public boolean trySetGaze(String target) {
00063                 if (this.target == null || this.target.isEmpty())
00064                         return next.trySetGaze(target);
00065                 else
00066                         return next.trySetGaze(this.target);
00067         }
00068 
00081         public abstract void gazeChanged(String target, boolean face, boolean lock);
00082 }