Event bounds_changed triggers too often, problem

[Jurgis Stepanovs]

Hi!

I use code bellow to read markers from DB, when user visible map area
changes.
...
google.maps.event.addListener(map, 'bounds_changed', function() { //
bounds_changed or zoom_changed or center_changed
readDataFromDB;
});

...
But serious problem is that listener executes to often 3 or 4 times
when expecting only 1, and my
DB server gets huge loads of unnecessary queries. I think most on fast
mouse wheeling (zooming in and out).

How to set this trigger to work more slowly?

I tried setTimeout(readDataFromDB(),2000), but it seems not to do
right thing, because
I suppose that during that timeout happens more bounds_change events
that waits
for JavasScript code execution loop. At the end code is executed also
3,4 times, but with 2sec
delay.

Todays Internet user is a lot using mouse wheel, and a lots moving
around with mouse, and it will kill my application if things will not
change ;)

I suggest Google API 3 engineers to implement this timeout option
directly
in the core of 'bounds_changed' listener.

May be someone has developed solution already?

PS I’m testing app on Chrome and IE …

[Luke Mahé]

Hi Jurgis,

Instead of bounds_changed you can listen to 'idle' or if you want to go down the timeout approach, you will need to cancel the timeout before creating another one.

var myTimeout;

google.maps.event.addListener(map, 'bounds_changed', function() {

  if (myTimeout) {

    window.clearTimeout(myTimeout);

  }

  myTimeout = window.setTimeout(readDataFromDB, 2000);

});

Hope this helps

-- Luke

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[Jurgis Stepanovs]

Thanks, Luke! I'll try to implement your solution, after some cups of
coffee :)

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> > .

[Drew Noakes]

Note that a new event has been added to take care of this. You don't
need to write this kind of hack any more.

Read about it here: http://code.google.com/p/gmaps-api-issues/issues/detail?id=1371

google.maps.event.addListener(map, 'idle', function(event) {
// fires when movement has stopped
});

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> > .