<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 11 (filtered medium)">
<style>
<!--
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman";}
a:link, span.MsoHyperlink
{color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:Arial;
color:windowtext;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.25in 1.0in 1.25in;}
div.Section1
{page:Section1;}
-->
</style>
</head>
<body lang=EN-US link=blue vlink=purple>
<div class=Section1>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>OpenLayers Users,<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>I am currently replacing an
ArcIMS HTML Viewer application with a new OpenLayers interface which will be a
great leap from what they have in general navigation usability. I think that I
won’t have much trouble replacing almost all of the other functionality
(Identify, Measure, Select, etc.) provided by the ArcIMS application but there
is one that I am not sure of the best way to handle in order to port over the
same effect and response... and that is a feature we call MapTips.<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>If you are not familiar with
the term “MapTips” then here is a brief description – in the
ArcIMS application only one layer can be selected/active at a time. We have a
button that toggles MapTips on or off for the selected layer. When it is turned
on the user can just mouse over any feature from that layer on the map and a
pop up (DIV) shows attribute data for the specific item they are hovering over.
It’s basically a quick identify on a feature but the information has been
preloaded so it is very quick and easy to use.<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>If you are not familiar with
ArcIMS web sites then here is some information on how they accomplish this
– by default, at least for older (pre 9.2) versions of ArcIMS, only a
single image is returned at any given time to draw the entire map. So, to
create MapTips, a spatial query is done for the current extent and selected
layer ... from the results of this query an image map is created for the
current map image thus making the “hot spots” that will capture the
mouse over event a trigger the showing of the attribute info in the DIV.<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>So, using OpenLayers instead
of the generic ArcIMS HTML Viewer poses a challenge with the tiles/grid of the
map images. At least it means that we can’t use exactly the same methodology
as before, but maybe I could take the same idea and make an image map for each
tile that comes in from my WMS service. Or, maybe I could have markers appear
on all the features of the selected layer when MapTips are toggled on so they
can handle the mouse over events. But, how will that be handled dynamically?
When the user navigates outside of the current view and new features come into
view they need to have a marker appear on them. Are the more alternatives that
might be a better way to handle this scenario?<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>I was just curious to see if
anyone has attempted something like this with OpenLayers already or if anyone
has thoughts on the best areas of OpenLayers to utilize or hook into to make
this functionality work in a graceful manner.<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>Thanks in advance for any
and all comments,<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>Wally Atkins<o:p></o:p></span></font></p>
</div>
</body>
</html>