What's the smartest way to manage balloons with the Google Earth plugin?

My company develops a web application (in Java using GWT) that employs the Google Earth plugin to display specific sites and other data on the globe. We're currently managing balloons on a per-use basis, meaning each function that needs to display a balloon is managing the destruction(if needed) and creation of the balloon itself. This leads to issues where the GE plugin will sometimes crash if we try to open a balloon while another is still open. Though we've worked this out in almost every case, I'm thinking it would be smart开发者_开发技巧(er) to manage the balloons centrally, instead of in each place that uses them.

Hurdles:

• many sites to show, the locations of which must be very precise;

• multiple layers are in use, each of which may show balloons;

Has anyone created a "BalloonManager"-type thing that handles this sort of thing? How might you do this?

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It sounds like you should be using encapsulation, look at moving the balloon creation into a single separate method.

Also, with regard to "issues where the GE plugin will sometimes crash if we try to open a balloon while another is still open" - make sure you simply call ge.setBalloon(null) before opening any balloons, or better still, simply reuse any current balloon rather than creating a new one if it is available.

The following code should help to explain - it is using the api methods you would need so it should be of some use.

public void function OpenFeatureBalloon(GEPlugin plugin, IKMLFeature feature) 
{
  // Get any open balloon
  IGEFeatureBalloon balloon = plugin.getBalloon();

  if (balloon == null) 
  {
     // not there, so create one
     balloon = plugin.createHtmlStringBalloon("");
  }

  // set the balloon to the features geographic location
  balloon.setFeature(feature);

  // open the balloon in the plugin
  ge.setBalloon(balloon);
}

If you did not want to pass a feature to the method, it would be fairly trivial to ammed the method to accept something like a latitude and longitude as doubles for example.