www.pudn.com > src.rar > HeapOfFishCanvases.java

/* 
* Copyright (c) 1996, 1997 Bill Venners. All Rights Reserved. 
* 
* This Java source file is part of the Interactive Illustrations Web 
* Site, which is delivered in the applets directory of the CD-ROM 
* that accompanies the book "Inside the Java Virtual Machine" by Bill 
* Venners, published by McGraw-Hill, 1997,ISBN: 0-07-913248-0. This 
* source file is provided for evaluation purposes only, but you can 
* redistribute it under certain conditions, described in the full 
* copyright notice below. 
* 
* Full Copyright Notice: 
* 
* All the web pages and Java applets delivered in the applets 
* directory of the CD-ROM, consisting of ".html," ".gif," ".class," 
* and ".java" files, are copyrighted (c) 1996, 1997 by Bill 
* Venners, and all rights are reserved.  This material may be copied 
* and placed on any commercial or non-commercial web server on any 
* network (including the internet) provided that the following 
* guidelines are followed: 
* 
* a. All the web pages and Java Applets (".html," ".gif," ".class," 
* and ".java" files), including the source code, that are delivered 
* in the applets directory of the CD-ROM that 
* accompanies the book must be published together on the same web 
* site. 
* 
* b. All the web pages and Java Applets (".html," ".gif," ".class," 
* and ".java" files) must be published "as is" and may not be altered 
* in any way. 
* 
* c. All use and access to this web site must be free, and no fees 
* can be charged to view these materials, unless express written 
* permission is obtained from Bill Venners. 
* 
* d. The web pages and Java Applets may not be distributed on any 
* media, other than a web server on a network, and may not accompany 
* any book or publication. 
* 
* BILL VENNERS MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE 
* SUITABILITY OF THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING 
* BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, 
* FITNESS FOR PARTICULAR PURPOSE, OR NON-INFRINGEMENT.  BILL VENNERS 
* SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY A LICENSEE AS A 
* RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS 
* DERIVATIVES. 
*/ 
import java.awt.*; 
 
/** 
* This class is the panel that contains the five main components that make up the 
* bulk of the user interface of the HeapOfFish applet, the swimming fish canvas, 
* and the allocate fish, assign references, garbage collect, and compact heap 
* panels, all of which are placed via a CardLayout. 
* 
* @author  Bill Venners 
*/ 
class HeapOfFishCanvases extends Panel { 
 
    private CardLayout cl = new CardLayout(); 
    private SwimmingFishCanvas swimmers = new SwimmingFishCanvas(); 
    private String currentMode = HeapOfFishStrings.swim; 
    private AssignReferencesPanel assignRefsPanel; 
    private GarbageCollectPanel garbageCollectPanel; 
 
    HeapOfFishCanvases(GCHeap gcHeap, LocalVariables localVars, HeapOfFishTextArea ta) { 
 
        assignRefsPanel = new AssignReferencesPanel(gcHeap, localVars, ta); 
        garbageCollectPanel = new GarbageCollectPanel(gcHeap, localVars, ta); 
        setLayout(cl); 
        add(HeapOfFishStrings.allocateFish, new AllocateFishPanel(gcHeap, ta)); 
        add(HeapOfFishStrings.assignReferences, assignRefsPanel); 
        add(HeapOfFishStrings.garbageCollect, garbageCollectPanel); 
        add(HeapOfFishStrings.compactHeap, new CompactHeapPanel(gcHeap, ta)); 
        add(HeapOfFishStrings.swim, swimmers); 
        swimmers.start(); 
        cl.show(this, HeapOfFishStrings.swim); 
    } 
 
    public void setMode(String mode) { 
        if (mode.equals(HeapOfFishStrings.garbageCollect) && !currentMode.equals(HeapOfFishStrings.garbageCollect)) { 
            garbageCollectPanel.resetGCState(); 
        } 
        cl.show(this, mode); 
        if (mode.equals(HeapOfFishStrings.swim) && !currentMode.equals(HeapOfFishStrings.swim)) { 
            swimmers.start(); 
        } 
        if (!mode.equals(HeapOfFishStrings.swim) && currentMode.equals(HeapOfFishStrings.swim)) { 
            swimmers.stop(); 
        } 
        if (mode.equals(HeapOfFishStrings.assignReferences) && !currentMode.equals(HeapOfFishStrings.assignReferences)) { 
            assignRefsPanel.refreshInstructions(); 
        } 
        currentMode = mode; 
    } 
 
    public void start() { 
        swimmers.start(); 
    } 
 
    public void stop() { 
        swimmers.stop(); 
    } 
}