Digital LED Ticker Tape

Java ShareWare - written by John Criswick


[You will need a Java capable browser to view this applet]

[You will need a Java capable browser to view this applet]

TickerTape may not currently work well on the Macintosh with Sun's JDK or Netscape's MacJava


Update - March 1996

Installing TickerTape

Using TickerTape

Even More Java Applets


Update - March 1996

For those who have been here before you will notice some changes. In particular: I have cleaned up this page, improved the installation instructions, and made TickerTape shareware.

I had been maintaining a list of links of sites that are using the TickerTape but this was too time consuming so it has been removed.

Concerning the transition from freeware to shareware: it is experimental but is an attempt to help offset the time I have been spending on providing support to people to help them install the ticker tape.

How much is it? Well, I figure $5 U.S. (or more) will do it. More details can be found at the start of the next section. This should help cover my coffee budget...

I am currently working on a major update to TickerTape so stay tuned for more!


Installing TickerTape

TickerTape is now shareware. There are 2 things that this implies if you use TickerTape:
  1. it would be greatly appreciated if you could send $5 U.S. or more (converted to your currency) either as a cheque or cash (this is a small enough amount of cash to send by mail, I figure), or some kind of reasonable product donation....:) Send it with your name and e-mail address to:
                John Criswick
                153 St-Andrew St.
                Ottawa, Ontario
                Canada   K1N 5G3
    
    (and let me know by
    e-mail that you have sent it)

  2. I would also appreciate if you put the following HTML somewhere on the same page as the TickerTape applet:
    <font size=-1>TickerTape courtesy of 
    <a href="http://www.conveyor.com/conveyor-java.html">John Criswick</a></font>
    
To install TickerTape you need to do 3 things:

To download the 3 class files either download the raw class files or a compressed archive file. Once you have the 3 class files on your site, make sure they are the same size as specified here:

The raw files:

TickerTape.class (8244 bytes)

TickerFont.class (9490 bytes)

ISO8859.class (13054 bytes)

Place the 3 class files wherever you want. Make sure that they are accessile from your HTML document through the applet tag however. In the above examples I have placed the 3 class files in a directory called classes that is at the root level of my WWW server.

The corresponding applet tag looks like:

  <applet codebase="classes" code="TickerTape" width=440 height=59>
However, I often recommend to users who are running a Java applet from their personal home page (for example a page like http://www.xyz.com/~some-name/ ) that they drop the codebase parameter and place the class files either in the same directory as their HTML file or in a directory relative to it. Then specify the location of the TickerTape using the code parameter. For example, in the following the 3 class files reside in a directory called Java that is at the same level as the HTML file in which the applet appears:
  <applet code="Java/TickerTape" width=440 height=59>

Using TickerTape

This section describes the parameters that allow you to control the behaviour of the TickerTape. There is also a section on
problems that you may encounter in installing and running the applet.

First some examples. The first TickerTape working above makes use of most of the defulat settings and specifies its text through the text parameter. It has an HTML applet tag that looks like:

  <applet codebase="classes" code="TickerTape" width=320 height=41 align=absmiddle>
  <param name=text value="The Quick Bröwn Fox Jumps Over the
        lazy dog - 0123456789 ! ? ¿ @ # % ¼ £ ......">
  <font size=-1>[You will need a Java capable browser to view this applet]</font>
  </applet>
Note that any regular HTML between the applet tags only appears in browsers that do not support Java, so this is your place to put alternative graphics or text.

The second TickerTape above makes use of more of the parameters and reads its text from a file on the server. It has an HTML applet tag that looks like:

  <applet codebase="classes" code="TickerTape" width=440 height=59 align=absmiddle>
  <param name=speed value=75>
  <param name=ledcolour value=yellow>
  <param name=backcolour value=black>
  <param name=framecolour value=darkgray>
  <param name=ledoffcolour value=darkgray>
  <param name=framethick value=2>
  <param name=ledsize value=4>
  <param name=ledtype value=1>
  <param name=href value="space.html">
  <param name=file value="java/ticker/blurb.txt">
  <font size=-1>[You will need a Java capable browser to view this applet]</font>
  </applet>
The following subsections detail each of the parameters used to define the TickerTape behaviour:

The text to display:

Text can either be entered at the parameter line or via a file reference. If both are specified the TEXT parameter takes precidence (as in the following example). The file specifies a file that is relative to the document in which the applet is displayed.

<param name=text value="The Quick Br&ouml;wn Fox Jumps Over the lazy
 dog - 0123456789 ! ? &iquest; @ # % &frac14; &pound; ......">
<param name=file value="/java/ticker/blurb.txt">
Note that the text can include HTML entity names like &ouml;. In fact it implements nearly all entity names as listed in this reference on ISO-8859.

The Colours:

Values accepted are currently the prime colours that the Java language uses: black, blue, cyan, darkgray, gray, green, lightgray, magenta, orange, pink, red, white, and yellow. You can currently set the colours of the background, the frame and the text on and off colours as follows (in the same order and with default values shown):

<param name=backcolour value="black">
<param name=framecolour value="green">
<param name=ledcolour value="green">
<param name=ledoffcolour value="darkgray">

Display Size Parameters

You have control over the height and width of the display as well as the thickness of the frame and size and spacing of the "LEDs" (the units that make up each dot in a character).

The applet width is flexible, however it is up to you to set an appropriate height value. The value for height should be more than: 11 x (the LED size + the LED spacing) + 2 x the frame thickness + 2. So for the default frame thickness of 1 and LED size of 2 and spacing of 1 a minimum height value would be 11 x 3 + 2 + 2 = 37.

height and width are the parameter you specify in the <applet> tag. You can set the frame thickness and LED appearance as follows (default values shown):

<param name=framethick value=1>
<param name=ledsize value=1>
<param name=ledtype value=0>
<param name=ledspacing value=1>

The ledtype corresponds to the shape, either square or circular. Square LEDs have ledtype of 0 and circular are ledtype 1. ledspacing is the pixel distance between LEDs - typically a value of 1 or 2 presents a good appearance.

Display Speed Parameters

There are two ways you can control the speed. One defines the scrolling time interval in millseconds, the other defines how far each scroll interval moves the text (default values shown):

<param name=speed value=100>
<param name=scrollfactor value=2>
URL Parameter

You can specify a URL that the reader is taken to when they click on the TickerTape. Either specify it as a relative URL (name="somefile.html") or as an absolute URL (name="http://www.conveyor.com/space.html") as follows:

<param name=href value="the-url.html">

In Case it Didn't Work

ClassFormatError or Applet NotFoundError - some of the most frequent problems after downloading Java code. If you have one of these problems, verify that you indeed copied the class files properly (compare the sizes). Next verify with your server administrator that their server transmits Java .class files as application/octet-stream MIME type. Many server administrators still haven't added a type specification for .class files.

If you still have a problem downloading the 3 class files to their correct size try downloading them by anonymous FTP to conveyor.com from the directory /pub/java/classes and make sure to download them as "binary".

Toll-free Support Line

If you still have trouble then contact me by e-mail at criswick@conveyor.com describing the problem and provide me the URL of your test document so that I can check it from here. Tell me also what you see in the Java Console. I generally respond within the same day - if not the same hour.


More freeware and shareware Java applets here.

Questions or comments to: John Criswick by e-mail to criswick@conveyor.com.