LED Sign Applet Parameters

This page describes the parameters that you can use with the <APPLET> tag within HTML documents that use the LED sign.

Required Applet Parameters

<param name="script" value="[URL | file]">
Specifies the script for the sign to use
<param name="font" value="[URL | file]">
Specifies the font for the sign to use
<param name="wth" value="[pos int]">
Width of the sign in LEDs. Forced to be an even number. Default: 60 (see notes)
<param name="ht" value="[pos int]">
Height of the sign in LEDs. Default: 9 (see notes)

Optional Applet Parameters

<param name="border" value="[pos int]">
The Border width in pixels. Default: 0
<param name="bordercolor" value="[0-255],[0-255],[0-255]">
Normal color of the border. Default: gray
<param name="hot_bordercolor" value="[0-255],[0-255],[0-255]">
Color of the border when there is an active URL-link. Default: blue
<param name="spacewidth" value="[pos int]">
Width of the space character in LEDs. Default: 3
<param name="ledsize" value="[1-4]">
Size of the LED's in pixels. Sizes can be 1,2,3, or 4. Default: 3
<param name="smooth_leds">
If present, causes LEDs of size 3 and 4 to be drawn as circles instead of "plus" shaped. Drawing is slightly slower but the result is more pleasing.

Example LED tag in HTML

<applet codebase="/java/classes" 
   code="com.dc3.applet.LEDSign.LED.class" 
   width=540 height=70>
   <param name="script" value="../scripts/Demo.led">
   <param name="font" value="../fonts/default.font">
   <param name="border" value="3">
   <param name="bordercolor" value="100,130,130">
   <param name="spacewidth" value="3">
   <param name="wth" value="100">
   <param name="ht" value="9">
   <param name="ledsize" value="3">
   <param name="smooth_leds">
</applet>

Notes

The applet's static width and height need to be matched to the dynamic wth and ht parameters in order for the sign to just fill the space in the document. This was a pain in earlier versions of LED Sign. With V3.1, the applet will print a message to the Java Console if there is a mispatch between these two sets of dimensions. The way to use this feature is to set the wth and ht to the dimensions you want for the sign. Then guess at width and height (really anything will do). Now run the applet and look at the Java console output. You will see a message indicating the correct values to use for width and height. Once you have correctly matched the static dimensions of the appelt area to the dynamic sigh dimensions, the applet will no longer issue the warning.

The "codebase" value is the URL of the root directory where the class hierarchy begins. The "code" parameter is the name of the "main" class, fully qualified according to the Sun recommendations. Note that it must be stored in a directory path that matches the dotted-name of the package/class, i.e., in <root>/com/dc3/applet/LEDSign/LED.class. You aren't going to like this. Get used to it... we're going to have to pay attention to name clashes, and the Sun system for package naming and class storage is a good one.

The "script" parameter is the URL of the file containing the script that the LED Sign will run. The "font" parameter is the URL of the file containing the specification of the font for the sign to use. All four of these must be correct, otherwise the applet will not start and will give a "Applet can't start: applet not initialized" error. If you get this error, make sure that "codebase", "code", "script", and "font" are correct.