Wait for Google Earth to finish loading before invoking the next command

I am working on feeding Matlab's simulation data to Google Earth Plug-in via COM.

My problem is that the command,which should be invoked after Google Earth finished loading, is invoked before that. That brings of course error.

I could use the pause command to pause the code waiting the Google Earth to load. But, this solution is not that efficient, as I don't know exactly how fast or how slow Google Earth will load on different machines.

I've also tried using the properties of the COM object. It was close, but no cigar. The code looks like this

    waitfor(h.Document.parentWindow.document,'readyState','complete')

or also this one:

    while strcmp(h.Document.parentWindow.document.readyState,'complete')== 0
        pause(1);

    end

Is there any object properties that could be used? Thanks!

Answer 1

[Jason Ross]

I don't have a particular answer to this exact question, but when faced with similar situations in the past, most specifically waiting for a network resource to be up, I added a check that polls for an expected result (for example, a network share exists) and then continues.

So you might want to actually try to do something trivial that requires the application be available and functioning (get the version, get some data, etc), and only continue when you get a decent response. You would likely also want to add an overall timeout, as well -- in the event you can never connect due to some other problem.

[Wan Nawi]

Thanks for your answer. Somehow, I did manage to resolve it!

Google Earth Plug-in will call the "initCallback" method when it finished loading.

By adding a line on "initCallback" method, I change the title of my html document to other name, which indicates that the plugin is loaded.

function initCallback(pluginInstance) {

ge = pluginInstance;

ge.getWindow().setVisibility(true);

// tell the application the plugin is ready

//(window.external.JSInitSuccessCallback_(pluginInstance);

document.title = "Google Earth Plugin - Ready";

// prevent mouse navigation in the plugin

ge.getOptions().setMouseNavigationEnabled(false);

}

At MATLAB's end, I just added the a while loop, comparing the html document title, pausing the executing until the plugin is finished loading.

while strcmp(h.Document.title,'Google Earth Plugin - Ready')~=1

pause(0.01)

end

Maybe there is other more elegant solution, love to hear your feedbacks