Only show controls if presentation has been loaded.

static/partials/presentation.html

@@ -15,7 +15,7 @@
 	</div>
 	<div class="overlaybar form-horizontal" ng-class="{notvisible: hideControlsBar}">
 		<a class="overlaybar-button" ng-model="hideControlsBar" btn-checkbox btn-checkbox btn-checkbox-true="0" btn-checkbox-false="1" title="{{_('Presentation controls')}}"><i class="fa fa-cogs"></i></a>
-		<form class="overlaybar-content form-group">
+		<form class="overlaybar-content form-group" ng-show="maxPageNumber !== -1 && !downloading">
 			<a class="btn btn-prev" ng-click="prevPage()" ng-show="currentPageNumber &gt; 1" title="{{_('Prev')}}"><i class="fa fa-backward"></i></a>
 			<span class="pageinfo"><input class="form-control input-sm" type="number" ng-model="currentPageNumber" /> / {{ maxPageNumber }}</span>
 			<a class="btn btn-next" ng-click="nextPage()" ng-show="currentPageNumber &lt; maxPageNumber" title="{{_('Next')}}"><i class="fa fa-forward"></i></a>