It is important that you know that lesson files created by the VISITview Lesson Builder contain several additional HTML tags. These tags are used to help the Builder maintain the links between the image files and pages, overlays and portals. Do NOT alter the information in these tags!
If a tag is not listed on this page as
The HTML used for VISITview defines the lesson. In remotely-accessed lessons, the students' Web browser reads this HTML and then downloads and starts a Java applet. In locally-accessed lessons, the students start a Java application right on their desktop which reads the same HTML file to define the information needed to connect everyone together.
Recall that VISITview clients have one of three possible configurations: master, student, or listener. The master configuration is the most complex, the student and listener can easily be created directly from the master HTML, so I recommend starting there.
Here's what the master HTML looks like:
<HTML> <HEAD> <TITLE>Test of VISITView </TITLE> </HEAD> <BODY BGCOLOR=#F0F0F0> <center> Put any text you want to show up before the applet region here. <p> <APPLET code="ViewClient.class" width=660 height=560 > <PARAM name="Master" value="true"> <PARAM name="labels" value="(100) National IR/radar Composite,1KM Wisconsin,National Vis,National IR, National Water Vapor, 31 May case"> <PARAM name="filenames" value="radar,local,vis,ir,wat,kan_4_"> <PARAM name="number_frames" value="3,4,3,3,3,5"> <PARAM name="group" value="test"> </APPLET> <p> You are connected as a "Master". This is the 5/13 update. <p> </center> </BODY> </HTML>Here's what it means:
The APPLET tag identifies the Java code to run. The width and height values must provide sufficient space for the images plus the controls. The width should be at least 640; the height should be at least 80 more than the height of the images.
Each of the PARAM statements that follow define values for the various parameters that can be controlled within the applet.
You must name your files accordingly. Even if the page contains only one single file, the naming convention is used.
There is a variant of this that is permitted when using the VisitRemote or pre-loaded (that is, non-browser) client -- you may specify the image filename as URL, complete with a list of string substiutions. Please refer to this document for details.
||radar0 radar1 radar2 radar3|
||vis.gif0 vis.gif1 vis.gif2|
||local0.gif local1,gif local2.gif|
||wat0 wat1 wat2 wat3 wat4|
<PARAM name="Master" value="true">should be changed to:
<PARAM name="Student" value="true">
<PARAM name="group" value="test">
specifies that anyone using this .html file will be connected to a VISITview group named "test". If this PARAMeter is omitted from the .html file, then a dialog box will pop up when the master or student starts up the applet. This dialog will ask the user to select an existing group (if any) to join, or to enter the name of a completely new group to start.
The applet tag:
<PARAM name="group_suffix" value="(name)">
specifies that whenever a group name is typed in (see above),
the suffix '(name)' will be appended to the group name. This
parameter can be used to keep collaboration groups more clearly
<PARAM name="register" value="true">
specifies that when the VISITview client starts up, it will
open a small window to require the student to enter a name or
some other identification. (This same window would appear if
this student requested a "chat" and had not previously
registered.) The advantage to this is that it makes identifying
students easier when the "stat" button or "page quiz" are used.
<PARAM name="phrases" value="thunderstorm ,hail ,front,max top">
specifies a pre-defined list of phrases that can be used
to seed the ALT+T (write text on screen) mode during a lesson.
This is a comma-separated list (no other punctuation allowed).
Using the ALT+O (letter oh) during the lesson will pop-up a
window with the list of phrases in it; clicking on one of them
will select it and then start the ALT+T mode.
<PARAM name="font_size" value="18">
specifies that an 18 point font will be used for the annotation text (ALT+T) for all pages during the lesson.
Alternatively, you may specify individual sizes either in the
phrases (above) or as you are typing, by preceding the
text with the font size in brackets. For example:
Hail would cause this text to be rendered in 30pt
font when it is displayed on everyone's screens (it will show up
in the default font size as you are typing, however).
<PARAM name="pause" value="200">
<PARAM name="pause_on_first" value="50">
specify that all animations will have a 200ms delay added to
the dwell rate of the last frame, and a 50ms delay added to the
dwell of the first frame. The default for both of these is
<PARAM name="loop_speed" value="50">
will cause the initial animation rate of any page with a loop to be set to 50. The actual dwell rate is (430 - value) in ms. (So, 380ms dwell on each frame, in this case.) The default value is 200 (that is, a 230ms dwell on each frame).
As an alternative, you may also specify the initial looping speeds to be different for each page. The applet tag:
<PARAM name="initial_loop_speeds" value="50, 220, 400, 30...">
will cause the initial looping speed on page 1 to be 50, on the second page to be 220, etc. The units of these values is the same as for the loop_speed parameter, above.
Only one of the above loop-speed-setting tags should be used!
<PARAM name="can_fade" value="f,f,f,f,t,f,t,f,f">
specifies whether each page can be 'faded' or not.
Caution: when a 'fade' is done, 10 images are generated
between each frame of the page. Thus, if you have 4 frames on a
page, 30 images are generated to accomplish the fading. If this
tag is omitted, the default is that only pages with fewer than 4
frames may be faded. A value of 'f' means cannot be
faded, whereas a value of 't' means can be faded.
<PARAM name="start_looping" value="f,f,t,f,t,t,t,f">
specifies for each page in the lesson whether a multi-framed
page should start animating automatically or not. A value of 'f'
means not initially looping, while a value of 't' means
<PARAM name="cursor_position" value="x,x,200&155,x,x">
specifies that when the 3rd page of this lesson is loaded for the first time, the Big Red Pointer should be positioned at x=200 and y=155 (or 200 pixels from the left and 155 lines from the top of the image). You must have one comma-separated item per page to use this function. The default value of "x" means do not change th position of the BRP when loading this page. If you do not need this feature, simply omit the "cursor_position" parameter altogether.
Instead of an (x,y) coordinate, you may also use the keyword
"OFF" to indicate that when this page is loaded, the BRP should be
turned off. The BRP is turned back on again automatically
whenever someone repositions it by clicking the mouse button
within the image.
<PARAM name="tearoff" value="true">
specifies that the control panel may be torn off by the user by clicking on the green bar. A separate window will pop-up with the controls. If this window is closed, the controls will be re-attached to the main display.
The applet tag:
<PARAM name="tearoff" value="always">
specifies that the control panel will always be in a separate window.
The applet tag:
<PARAM name="tearoff" value="false">
specifies that the control panel will always be in attached to the main window.
Note that whenever the controls are in a separate window, a
right mouse button click or pressing ALT+M will
bring the control panel to the top.
<PARAM name="portals" value="x,x,wat,x,vis,x"> <PARAM name="portal_x" value="x,x,0,x,100,x"> <PARAM name="portal_y" value="x,x,100,x,200,x"> <PARAM name="portal_height" value="x,x,200,x,200,x"> <PARAM name="portal_width" value="x,x,200,x,100,x">Here's what the extra PARAMs mean:
<PARAM name="portals" value="x,x,wat &
<PARAM name="portal_x" value="x,x,0 & 300,x,100,x">
<PARAM name="portal_y" value="x,x,100&100,x,200,x">
<PARAM name="portal_height" value="x,x,200&200,x,200,x">
<PARAM name="portal_width" value="x,x,200&200,x,100,x">
This would then add a second portal to the right of the first one, showing images from files beginning with the name "radar". Note that spaces may be used around the individual elements to help with readability. You may define as many portals as desired, but keep in mind that each portal defines a complete set of images, so there may be considerations of download time, as well as real estate.
Finally, please note that all images used in one of these types of displays must be the same size and have the same navigation in order for this portal/scrolling to work properly.
<PARAM name="zoom_portal" value="true">
The 'true' value of this tag will enable portal zooming along with the normal zooming of the main image.
<PARAM name="supress_portal_cursor" value="true">
The 'true' value of this tag will supress the display of the "little" Red Pointer in the portal(s). The keyboard Alt + K can always be used to toggle this value, however.
in-low in-hi lo-red hi-red lo-green hi-green lo-blue hi-bluewhere in- give the source brightness value range (from 0-255) and the lo-/hi- for each color specify the range (from 0-255) for each color to use in the display. After you've created the file you must add one more line to the HTML (this must appear in both the Master and Student HTML files:
<PARAM name="enhance" value="enh.tab">(substitute for "enh.tab" the name of the file you created).
<PARAM name="URL_list" value="x,x,http://www.ssec.wisc.edu/localweather/.weather.html,x,x,desc.au,x,x,x">
The presence of this will cause a new button, labelled Show Text to appear just below the buttons for erasing the graphics. When the student clicks on this button, the default browser (in Windows) or Netscape (in Unix) will either be launched or aimed at the URL named herein.
On page 3, in the above example, the URL at www.ssec.wisc.edu
will pop up in a browser window if the user clicks the Show
Text button. On page 6, however, if they click on the button
the audio clip in the file "desc.au" will be played. Audio clips
must be in .AU format and the file(s) should reside in the
same directory as images (or include a subdirectory name).
To specify a transparent level, you would use:
<PARAM name="transparent" value="#rrggbb">
where the "rrggbb" value refers to intensity of Red, Green, and Blue.
The intensity is given as a hexidecimal value from 00 to FF (the same way
it is given for colors in the HTML). Once you specify this value,
it is used for the entire lesson whenever a page is faded. By default,
transparency is turned off.
<PARAM name="port" value="1631">Note that port 1631 has been registered for use by VISITview.
<PARAM name="do_local_server" value="yes">specifies that the VISITview client (ViewClient) shall start up, and link to, a local VISITview server. This mode should only be used for stand-alone audio playback through a web browser! You must also use the parameter "Player" (see above) in place of "Master" in the viewmaster.html file (or, preferably, a copy of that file).
You should also remove the <param name="register"...> tag in the HTML if it is specified. Finally, if this is to be used only for web browser-based playback you can also remove the jre sub-directory to save space.
(Note: This capability was
introduced in the April, 2002 release of VISITview and can only be used
with lessons packaged with the VISITview code after that release. Otherwise,
you will need to update the VISITview code using the visitlessoncode.zip file.)
For example, if some of the files in the above example were in the subdirectory lesson3 off the home directory, and others were in the lesson3a directory, the HTML for this PARAM might look like:
<PARAM name="filenames" value="lesson3/radar,lesson3/local,lesson3a/vis,lesson3/ir,lesson3/wat,lesson3/kan_4_">However. . . . . if your lesson is to be packaged and distributed to students to use in a local mode, then you should put everything in the same directory.
When VISITview clients are run in the application mode, that is when all the lesson files have been downloaded to the client machine and the server is used only for control communication, the Lesson Builder provides for DOS batch files that may be used to start up the client session.
The visitpack.zip file comes with one such as a template for you to use for manual editting, if needed. The form of the command to start up the client session is:
.\jre\bin\java -Xmx256m -cp .\ VisitFrame viewmaster.html www.ssec.wisc.eduwhere 'viewmaster.html' is the name of the file containing the appropriate HTML, and 'www.ssec.wisc.edu' is the hostname of the server to attach to. If you use the Lesson Builder, you will find a few of these batch files generated -- pairs for instructor/master and students for each of the servers you disignate, plus the visitlocal.bat which is used for stand-alone lessons. In this latter file, there is also a DOS start command that invokes the VISITview server running in local mode. You may also note that in this case, an extra paramter is appended to the client start-up ("44444") -- this is the local TCP/IP port number to use for communication between the client and server on the local machine.
Return to VISITview home page.