How to get viewable height in Lightning Desktop as well as in Salesforce1 app when Locker Service active?

Question

I would like to get the height of the viewable screen in Lightning Dektop version as well as in Salesforce1 app.

I'm able to retrieve the window height by using $(window).height();.

But I am not able to retrieve the default header height using $("#oneHeader").height(); when Locker Service is active probably because of the "component/namespace encapsulation". (Currently I subtract the header height from window height to get the viewable screen height)

Is there anyway to get the viewable screen size so that I can ensure my component does not go outside the viewable screen size (irrespective of the screen size)?

Answer 1

I've been experimenting with something similar. You can create a component v39.0 and use it to tee up certain things outside the locker service.

cmp

<aura:component >
    <aura:attribute name="headerHeight" type="Object" />
    <aura:handler name="init" value="{!this}" action="{!c.doInit}" />

</aura:component>

controller:

doInit : function(component, event, helper) {
    component.set('v.headerHeight', window.document.getElementById('oneHeader').getBoundingClientRect().height);
}

then include that in your main cmp

<c:portal aura:id="portal" />

then

cmp.find('portal').get('v.headerHeight')

I've tinkered around with just storing the window or the element, but the lockerservice is smart enough to serve up the SecureWindow still.

You could expose a function from the 39 component that did evals, then use it something like:

cmp.find('portal').dangerousEval("window.getElementById...", function(theResultOfAnEval){...});

but that seems pretty dangerous