Autodesk 15606-011408-9300 - MAP R6.3 UPG, Developer'S Manual

Page: 71 / 208

Working with Event Handlers
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Browser Differences
The following table summarizes the basic differences between how Netscape
Navigator and Internet Explorer handle events:
Event Observer Set Methods
There are some
MGMap
methods whose sole function is to allow you to set an
observer for a specific event. For example, when the map view changes (for
example, in response to a user panning or zooming), you can set the observer
for the
onViewChanged
by creating a function called
onLoad
(a browser
event) and inserting the
MGMap.setViewChangedObserver
method to set
the observer for the
onViewChanged
event. You can do this for each of the
events you want to handle. Note that specifying an observer is not required
for all events—just for the events you want to handle.
Netscape Navigator Internet Explorer
For Netscape Navigator, Autodesk
MapGuide provides an observer applet
that you embed in your application
using the <
APPLET>
tag.
For Autodesk MapGuide Viewer Plug-In,
this applet is called:
MapGuideObserver6.class
For Autodesk MapGuide Viewer, Java
Edition, it is called:
MapGuideObserver6J.class
You can use the same instance of the
observer applet for all events.
For Internet Explorer, you write a few lines
of
VBScript
code that tell Internet
Explorer the name of the event handler.
You must create a separate event handler
for each type of event you want to handle.
To call an Autodesk MapGuide method
that triggers an event, you pass the
Autodesk MapGuide observer as a
parameter. Internet Explorer knows how to find the
event handler without being passed its
name because it assumes the event han-
dler name will match the event it is
handling.