LAT/Long read out

[Geospectrum]

Im looking for a way to get a dynamicly changing read out of the lat
long of the center point of the plug in screen and display this data
on screen. A bit like the readout on the status bar but I need to
position the information in a diffrent location to simulate a HUD.
(www.geospectrum.co.uk/ge/globe.html) is what I have so far. If you
switch on the HUD display you will see what I am getting at. I need
the lat long display to be positioned where it says 'Platform'.

I am not a developer but an happy to fiddle with code and make it work
the way I want if I can get some indication of the right approach.
Any ideas?

Also, how should I go about turning the 'Display HUD' button into a
toggle switch? here is the code:

----snip---

function showHUD() {
var screenOverlay = ge.createScreenOverlay('');
screenOverlay.setIcon(ge.createIcon(''));
screenOverlay.getIcon().
setHref("http://www.geospectrum.co.uk/ge/hudoverlay.png");

// Set the point inside the overlay that is used as the
positioning
// anchor point.
screenOverlay.getOverlayXY().setXUnits(ge.UNITS_FRACTION);
screenOverlay.getOverlayXY().setYUnits(ge.UNITS_FRACTION);
screenOverlay.getOverlayXY().setX(.5);
screenOverlay.getOverlayXY().setY(.5);

// Set screen position to center of screen
screenOverlay.getOverlayXY().setXUnits(ge.UNITS_FRACTION);
screenOverlay.getOverlayXY().setYUnits(ge.UNITS_FRACTION);
screenOverlay.getOverlayXY().setX(.5);
screenOverlay.getOverlayXY().setY(.5);

// Set object's size in pixels.
screenOverlay.getSize().setXUnits(ge.UNITS_PIXELS);
screenOverlay.getSize().setYUnits(ge.UNITS_PIXELS);
screenOverlay.getSize().setX(750);
screenOverlay.getSize().setY(450);

ge.getFeatures().appendChild(screenOverlay);

}

---snip---

Thanks for any suggestions

[fraser]

Hi Geospectrum,

You can use a technique call "View-Based Refresh Queries" to track the
center point of the view.
This technique requires some CGI scripting to work (i.e. PHP, Python,
etc)

Go to this page: http://code.google.com/apis/kml/documentation/kml_tut.html#network_links
And look for "Tracking a Point Directly Under Your View"

You could easily adapt the code given to return a KML file that would
draw you HUD for you.
Also, If you adopted this technique then toggling the HUD would be as
simple as setting <visibility> in the KML overlay.

Hope that helps.

F.

[Geospectrum]

Will this approach work with the GE Plugin or Google earth client?

> > Thanks for any suggestions- Hide quoted text -
>
> - Show quoted text -

[fraser]

Hi Geospectrum,

The technique can be used with both the full aplication and the plug-
in.


F.

> > - Show quoted text -- Hide quoted text -

[fraser]

Hi,

Just to note you could also achieve this in javascript by using the
copyAsLookAt method.
The following snippet would need to be called periodically or
triggered by an event...
-----------------------------------------------------------
var la = ge.getView().copyAsLookAt(ge.ALTITUDE_RELATIVE_TO_GROUND);
var lat = la.getLatitude();
var lng = la.getLongitude();
-----------------------------------------------------------
Which ever way you go with this you will need to work out a way to
update your HUD to show the coordinate data.
This is going to entail building the overlay locally using the
javascript API or remotely using a CGI language.

Regards,

Fraser.

On Sep 25, 12:09 pm, Geospectrum wrote:

> > - Show quoted text -- Hide quoted text -

[Geospectrum]

So, Just for my clarification. I call the python script from the kml
which I parse using the GE API Right? (you can tell I am not a
developer!

[fraser]

Sure, that is it exactly...

F.