add loadedCallback to pdfng, detects when pdf is fully loaded

services/web/public/coffee/ide/pdfng/directives/pdfRenderer.coffee

@@ -19,6 +19,9 @@ define [
 				@navigateFn = @options.navigateFn
 				@spinner = new pdfSpinner
 				@resetState()
+				@document.then (pdfDocument) =>
+					pdfDocument.getDownloadInfo().then () =>
+						@options.loadedCallback()
 
 			resetState: () ->
 				@page = []

services/web/public/coffee/ide/pdfng/directives/pdfViewer.coffee

@@ -35,6 +35,8 @@ define [
 					$scope.$apply()
 				progressCallback: (progress) ->
 					$scope.$emit 'progress', progress
+				loadedCallback: () ->
+					$scope.$emit 'loaded'
 			})
 
 			# we will have all the main information needed to start display
@@ -51,7 +53,6 @@ define [
 					]
 					# console.log 'resolved q.all, page size is', result
 					$scope.numPages = result.numPages
-					$scope.$emit "loaded"
 
 		@setScale = (scale, containerHeight, containerWidth) ->
 			$scope.loaded.then () ->