[OpenLayers-Dev] map div has 0 height, width when loading in non-active tab

[crb]

Greetings OL-devvers.

We have an issue that's proving hard to fix/workaround and I'm hoping this
forum can help.  We have a .NET app that has a main page with two tabs, a
'Search' tab and a 'Data' tab.  The OL map is in the 'Search' tab.  Whenever
the page loads in the Data tab, then the map.div height and width are 0 and
the map fails to initialize and throws an exception, which if uncaught
causes all subsequent page javascript to fail.  As a test we tried
explicitly setting the div height and width to fixed pixel values in the
div's style but we get the same results.  

The error occurs when the layer does a loadMapObject() (in this case
VirtualEarth, but we've also seen it occur in a vector layer) which does the
following:

var veDiv = OpenLayers.Util.createDiv(this.name);
var sz = this.map.getSize();         // returns null
vsDiv.style.width = sz.w + "px";    // throws an exception


and is traceable back to this code in the Map.js:

getSize: function () {
    var size = null;
    if (this.size != null) {
        size = this.size.clone();
    } 

    return size;
}


The full call stack beginning with our custom code is:
this.map.addLayer(layer) -> Map.addLayer() -> layer.setMap(this) ->
EventPane.setMap() -> this.loadMapObject() -> VirtualEarth.loadMapObject()
-> map.getSize()

When the map successfully loads (i.e. when the active tab is the Search tab)
the map.div has the following valid property values (all are based on my
screen size, obviously, but importantly non-zero):
clientHeight: 473
clientWidth: 787
offsetHeight: 475
offsetWidth: 789
get scrollHeight: 473
scrollWidth: 787

When it fails, it has the following:
clientHeight: 0
clientWidth: 0
offsetHeight: 0
offsetWidth: 0
get scrollHeight: 0
scrollWidth: 0

Unfortunately forcing the page to load on the Search tab every time is not a
viable option for us.

Has anyone else ever run across anything similar and/or have any thoughts on
how we might overcome this?
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