TweetFollow Us on Twitter

Apr 97 Top 10

Volume Number: 13 (1997)
Issue Number: 4
Column Tag: Symantec Top Ten

Symantec Top 10

By Matthew Hopkins

In this month's column, we are focusing on customer issues pertaining to our C++ and Java development environments, including the newly released Visual Café. Let's warm up with a question regarding Visual Page, a dynamic web-authoring utility

Q: In Visual Page, how do you tell what size a document is before you save it?

A: By selecting Download Statistics... from the Edit menu, you can see a dialog box which not only tells you the total document size, but also tells you how long (on the average) it will take to download your page, depending upon the speed of your modem.

Q: I am using Visual Café, and I am having a problem getting the GridLayout to work properly. For instance, when I set the number of columns to 3 in the Property Manager, the applet doesn't respond at all visually. What's going on here?

A: Visual Café behaves in this manner because of how GridLayout is implemented in Java. When the rows and columns are both defined to anything other than 0, the Layout Manager will ignore the number of columns you have specified and calculate them based upon the number of rows and the number of elements. If you are interested in having the Layout Manager organize your elements according to a certain number of columns, set the number of rows to 0 (meaning "any"), and the Layout Manager will make the number of rows dependent upon the number of columns.

Q: I am getting an error of type -43 when running my Java application in Symantec Café. How do I correct this?

A: In an application, the main function needs to be static, and the main class needs to be set in the Project Options window.

Q: I am running the following program in Symantec Café and it does nothing but hang. Could you tell me why?

class PrintThread implements Runnable {
         String str;
         public PrintThread (String str) {
                 this.str = str;

         public void run() {
                 for (;;)

class ConcurrencyTest {
         public static void main(String argv[]) {
                 new Thread(new PrintThread("A")).start();
                 new Thread(new PrintThread("B")).start();

A: This does not actually cause a freeze. It just appears that way because the System.out.print never receives a "" character, so it never shows you what's going on; it adds characters to the print stream indefinitely. To achieve the results you intended (mainly, seeing A and B printed forever), either call PrintThread with "A" and "B", or change the line reading System.out.print(str) to System.out.println(str).

Q: Which folder do you put packages into in Symantec Café for the Mac?

A: You have two options:

1) Place any additional class packages into the {java libraries} folder.

2) Place them in whatever folder you like as long as you open the Preferences:Paths window and add the search path to the upper window so that Café will know to search that folder.

Q: I am developing an application in Café that includes HTML text and embedded Applets. Some of the applets need to read local files whose names are supplied by the user, but the applet security rules prevent applets from reading local files. Is there a standard way of reading user-OK'ed local files that I am missing?

A: The names of the files have to be "fully qualified" (i.e. volume/folder/file), and there can be no non-standard characters anywhere in the path (like ƒ after folder names.) You can use something like this

FileDialog file_dialog_open;
file_dialog_open = new FileDialog(this, "Open A File", FileDialog.LOAD);

public void loadFile() {
   if (file_dialog_open.getFile() != null) {
      currentFolder = file_dialog_open.getDirectory();
      selectedFile = new String(file_dialog_open.getFile());
      fullPath = currentFolder + "/" + selectedFile;

This lets the user select a file and then pass the fully qualified path name for the file to the method that actually accesses the data.

Q: Is there a simple way to use ImageMaps for applets in Java? I need to write an applet that loads a graphic file at the proper coordinates when the mouse is moved over a certain location.

A: The key to this problem is the Component action method mouseEnter(). This works for all components, including buttons, windows, etc. In order to implement ImageMaps, I find the canvas component to work the best, being invisible. Here is a small snippet of code written in Visual Café that illustrates this

import java.awt.*;
import java.applet.*;

public class Applet1 extends Applet {    
        public void init() {
                theMap = new ImageMap("myMap", 50, 50, getGraphics());

        public boolean handleEvent(Event event) {
                return super.handleEvent(event);
        ImageMap theMap;

class ImageMap extends Canvas {
        boolean on;
        String label;
        Graphics g;

        ImageMap(String label, int sizex, int sizey, Graphics g) {
                resize(sizex, sizey);
        public void paint(Graphics g) {
        public void update(Graphics g) {
                if(on) {
                        this.g.drawString("Hello, World!", 25, 25);
        public boolean mouseEnter(Event evt, int x, int y) {
                return true;

Here, the text Hello, World! has been substituted for the image that should be displayed. In case you wish to remove the image when the mouse is removed from the area, use the method mouseExit() in the same way.

Q: I am using a HashTable to keep track of a number of Button objects in Symantec Café, but every time I click on the button and look up the corresponding HashTable entry, it returns null.

import java.applet.*;
import java.awt.*;
import java.util.*;

public class HashTblTest extends Applet {
        Hashtable ht = new Hashtable();
        Button[] b = new Button[3];

        public void init()       {
                for (int i = 0;i < 3;i++) {
                        b[i] = new Button("Button " + i);
                        ht.put(b[i], new Integer(i));    
        public boolean action(Event e, Object o){
                return false;

What am I doing wrong?

A: The problem here is that the Button action method counter-intuitively provides as its Object parameter a STRING which is the button's name, not the button object itself. You have entered the buttons themselves into the HashTable, but the action method is looking up a string, not a button in your table. The best way to work around this is to change your action code to read: System.out.println(ht.get(; This will achieve your desired results.

Q: I have written a program in the Think Project Manager 7.0.5 that runs in the debugger, but when I try to run it in the Finder or without the debugger, the main window does not even come up. What do I need to do to get it to work?

A: This usually indicates a failure to initialize the Macintosh toolbox. Your code seems to work in the debugger because the debugger initializes the toolbox for you.

Q: I have written a program that uses two-dimensional and three-dimensional arrays. It seems to look fine but I keep getting link errors. What can I do to fix this problem?

A: It sounds like you are putting some huge arrays on the stack! Space is allocated for these arrays prior to run-time, and if your arrays are large enough, you could be causing a stack overflow that is posing some problems for the linker. There is an excellent example on how to put these arrays on the heap (allocating them at run time) in the Think Reference under Arrays Bigger than 32k.

Special thanks to Mark Baldwin, Ted Flug, Richard Hill, Steve Howard, Scott Morrison, Kevin Kenan, and Kevin Quah.


Community Search:
MacTech Search:

Software Updates via MacUpdate

AirPort Utility 6.3.6 - Set up and manag...
Note: Most recent release available only within OS X 10.11 El Capitan update. Use AirPort Utility to set up and manage your Wi-Fi network and AirPort base stations, including AirPort Express, AirPort... Read more
Quicksilver 1.3.1 - Application launcher...
Quicksilver is a light, fast and free Mac application that gives you the power to control your Mac with keystrokes alone. Quicksilver allows you to find what you need quickly and easily, then act... Read more
Tidy Up (Five Users) 4.1.5 - Find duplic...
Tidy Up is a complete duplicate finder and disk-tidiness utility. With Tidy Up you can search for duplicate files and packages by the owner application, content, type, creator, extension, time... Read more
Mellel 3.4.3 - The word processor of cho...
Mellel is the leading word processor for OS X and has been widely considered the industry standard since its inception. Mellel focuses on writers and scholars for technical writing and multilingual... Read more
Skype - Voice-over-internet p...
Skype allows you to talk to friends, family and co-workers across the Internet without the inconvenience of long distance telephone charges. Using peer-to-peer data transmission technology, Skype... Read more
Bookends 12.6.0 - Reference management a...
Bookends is a full-featured bibliography/reference and information-management system for students and professionals. Access the power of Bookends directly from Mellel, Nisus Writer Pro, or MS Word (... Read more
Apple iBooks Author 2.4 - Create and pub...
Apple iBooks Author helps you create and publish amazing Multi-Touch books for iPad. Now anyone can create stunning iBooks textbooks, cookbooks, history books, picture books, and more for iPad. All... Read more
Web Snapper 3.3.9 - Capture entire Web p...
Web Snapper lets you capture Web pages exactly as they appear in your browser. You can send them to a file as images or vector-based, multi-page PDFs. It captures the whole Web page - eliminating the... Read more
Tunnelblick 3.6beta10 - GUI for OpenVPN...
Tunnelblick is a free, open source graphic user interface for OpenVPN on OS X. It provides easy control of OpenVPN client and/or server connections. It comes as a ready-to-use application with all... Read more
EtreCheck 2.5.1 - For troubleshooting yo...
EtreCheck is a simple little app to display the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support... Read more

Camel Up (Games)
Camel Up 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: | Read more »
The Martian: Bring Him Home (Games)
The Martian: Bring Him Home 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Based on the best selling novel and critically acclaimed film, THE MARTIAN tells the story of Astronaut Mark... | Read more »
This Week at 148Apps: September 21-30, 2...
Leap Into Fall With 148Apps How do you know what apps are worth your time and money? Just look to the review team at 148Apps. We sort through the chaos and find the apps you're looking for. The ones we love become Editor’s Choice, standing out above... | Read more »
Tweetbot 4 for Twitter (Social Networki...
Tweetbot 4 for Twitter 4.0 Device: iOS Universal Category: Social Networking Price: $4.99, Version: 4.0 (iTunes) Description: *** 50% off for a limited time. *** | Read more »
Mori (Games)
Mori 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Stop, rewind and unwind with Mori. Time is always running, take a moment to take control. Mori is an action puzzle game about infinitely... | Read more »
100 Years' War (Games)
100 Years' War 1.0 Device: iOS Universal Category: Games Price: $3.99, Version: 1.0 (iTunes) Description: | Read more »
Tower in the Sky (Games)
Tower in the Sky 0.0.60 Device: iOS Universal Category: Games Price: $1.99, Version: 0.0.60 (iTunes) Description: | Read more »
hocus. (Games)
hocus. 1.0.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0.0 (iTunes) Description: New, polished, mind-bending, minimal puzzle game with dozens of levels and extra-ordinary design Features:- Beautifully crafted... | Read more »
Mos Speedrun 2 (Games)
Mos Speedrun 2 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Mos is back, in her biggest and most exciting adventure ever! Wall-jump to victory through 30 mysterious, action packed levels... | Read more »
3D Touch could be a game-changer, but it...
Were you one of the lucky/financially secure enough ones to buy a new iPhone 6s or iPhone 6s Plus over the weekend? Yup, me too (I’m not convinced I was either of those two things, but let’s go with lucky for now), so I thought I’d delve into just... | Read more »

Price Scanner via

Apple offering refurbished 2015 13-inch Retin...
Apple is offering Certified Refurbished 2015 13″ Retina MacBook Pros for up to $270 (15%) off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free: -... Read more
Apple refurbished 2015 MacBook Airs available...
Apple has Certified Refurbished 2015 11″ and 13″ MacBook Airs (the latest models), available for up to $180 off the cost of new models. An Apple one-year warranty is included with each MacBook, and... Read more
Adobe Photoshop Elements 14 Gets Haze Removal...
The latest iteration of Adobe’s powerful consumer image editing appliction Photoshop Elements 14 analyzes your photo and removes background haze, so your shot looks sharp all the way to the horizon... Read more
Apple refurbished 15-inch Retina MacBook Pros...
Apple has Certified Refurbished 2015 15″ Retina MacBook Pros available for up to $380 off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free: - 15″ 2... Read more
21-inch iMacs on sale for up to $120 off MSRP
B&H Photo has 21″ iMacs on sale for up to $100 off MSRP including free shipping plus NY sales tax only: - 21″ 1.4GHz iMac: $1029.99 $70 off - 21″ 2.7GHz iMac: $1229 $70 off - 21″ 2.9GHz iMac: $... Read more
Bare Bones Software Releases TextWrangler 5.0...
Bare Bones Software has announced the release and immediate availability of TextWrangler 5.0, a major upgrade to its free, high performance, general purpose text editor for Mac OS X. Built on a new,... Read more
Apple refurbished iPad Air 2s available for u...
Apple has Certified Refurbished iPad Air 2s available for up to $140 off the price of new models. Apple’s one-year warranty is included with each model, and shipping is free: - 128GB Wi-Fi iPad Air 2... Read more
Save up to $100 on Mac AppleCare Protection P...
Adorama has 3-Year AppleCare Warranties on sale for up to $100 off MSRP including free shipping plus NY & NJ sales tax only: - Mac Laptops 15″ and Above: $249 $100 off MSRP - Mac Laptops 13″ and... Read more
Updated Mac Price Trackers
We’ve updated our Mac Price Trackers with the latest information on prices, bundles, and availability on systems from Apple’s authorized internet/catalog resellers: - 15″ MacBook Pros - 13″ MacBook... Read more
27-inch 3.5GHz 5K iMac on sale for $81 off MS...
Adorama has the 27″ 3.5GHz 5K iMac on sale for $2218.99, $81 off MSRP, including a free copy of Apple’s 3-Year AppleCare Protection Plan, plus a free external DVD/CD drive, and a copy of Corel... Read more

Jobs Board

Senior Payments Security Manager - *Apple*...
**Job Summary** Apple , Inc. is looking for a highly motivated, innovative and hands-on senior payments security manager to join the Apple Pay security team. You will Read more
*Apple* Solutions Consultant - Retail Sales...
**Job Summary** As an Apple Solutions Consultant (ASC) you are the link between our customers and our products. Your role is to drive the Apple business in a retail Read more
*Apple* Site Security Manager - Apple (Unite...
**Job Summary** The Site Security Manager is a high-profile security position at Apple . The Site Manager is the face of Apple Global Security (GS) and primary point Read more
*Apple* Fulfillment Operations Execution Ana...
**Job Summary** The AMR Apple Fulfillment Operations Team is seeking a talented team player to drive the Apple Online Store (AOS) fulfillment performance to ensure a Read more
*Apple* Distinguished Educator (ADE) Communi...
**Job Summary** Apple is seeking candidates for a new position on the Apple Distinguished Educator (ADE) Program team as ADE Community Support Manager. Join a team Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.