javascript - Keydown / Keyup gets called 7 times -

i'm building angularjs website game. here want use keyboard resume/pause , control game. code have add eventlistener following:

$window.addeventlistener('keydown', function(e) {      if ($scope.gamestate.playing) {         (var control in controls) {             if (controls.left.indexof(e.keycode) > -1) {                 gameengine.startleft();             } else if (controls.right.indexof(e.keycode) > -1) {                 gameengine.startright();             } else if (controls.powerjump.indexof(e.keycode) > -1) {                 gameengine.powerjump();             } else if (controls.pause.indexof(e.keycode) > -1) {                 $scope.pausegame();             }         }     } }); 

the content of function isn't important, problem gets called 7 times every time press key. same keyup. fast or slow press it.

var gameapp = angular.module('gameapp', []); gameapp.controller('gamecontroller', function($scope, $timeout, $window) 

the above code how create angular app , controller $window argument.

i couldn't find solution this. hope knows why that's happening.

wild guess: event handler registered 7 times?

to check like:

$window.addeventlistener('keydown', function(e) {   if(e.iamnotalone) {     throw new error('oh dear!');   }    e.iamnotalone = true;    /* control in control thingy goes here */ }); 

are setting in singleton part of service or in sort of controller (which recreated every time , explain behaviour) ?