getComputedStyle() not working in angular directive when using ionic framework

I have a directive that uses the computed style of its parent element to calculate its own width.

The first time a view is loaded that contains the directive, I get the correct computed style for the parent element. But after that, whenever I load the same view again, I get the wrong style.

I figure this must be something to do with caching within ionic, but I get the same issue when I turn caching off for the view AND when I turn caching off globally. Any ideas what I am missing?

This is the gist of what i am doing:

angular.module('app.directive')

    .directive('myDirective', function ($window) {

        var link = function (scope, element, attrs) {
            var elementStyleMap = $window.getComputedStyle(element.parent()[0], null);
            var paddingTop = elementStyleMap.getPropertyValue("padding-top").replace("px", "");
            // first time this is called, padding top is 10px, which is correct
            // all subsequent times the view is loaded and this is called, padding top is 1px
        };

        return {
            restrict: 'E',
            replace: true,
            templateUrl: 'path/to/template.html',
            link: link
        };
    });