support old and new pdf viewers depending on feature switch

services/web/app/views/project/editor.jade

@@ -112,13 +112,20 @@ block content
 
 	- locals.suppressDefaultJs = true
 
-	- var pdfPath = 'libs/pdf.worker.js'
-	- if (user.featureSwitches && user.featureSwitches.pdfng) { pdfPath = 'libs/pdfjs-1.0.712/pdf.worker.js'; }
+	- // user.featureSwitches = {} // override
+	- var usePdfNG = user.featureSwitches && user.featureSwitches.pdfng;
+	- var pdfPath = 'libs/pdf.worker.js';
+	- if (usePdfNG) { pdfPath = 'libs/pdfjs-1.0.712/pdf.worker.js'; }
 	- var fingerprintedPath = fingerprint(jsPath+pdfPath)
 	- var pdfJsWorkerPath = jsPath+pdfPath+'?fingerprint='+fingerprintedPath
 	script(type='text/javascript').
 		window.pdfJsWorkerPath = "#{pdfJsWorkerPath}";
 
+	// when using pdfng we need a different pdfjs version
+	if usePdfNG
+		script(type='text/javascript').
+			window.requirejs.paths['libs/pdf'] = 'libs/pdfjs-1.0.712/pdf'
+
 	script(
 		data-main=jsPath+"ide.js",
 		baseurl=jsPath,

services/web/app/views/project/editor/pdf.jade

@@ -58,26 +58,32 @@ div.full-size.pdf(ng-controller="PdfController")
 				i.split-screen
 
 	.pdf-viewer(ng-show="pdf.url && pdf.view == 'pdf' && !pdf.failure && !pdf.timeout && !pdf.error")
-		div(	
-			pdfjs
-			ng-if="settings.pdfViewer == 'pdfjs' && !(user.featureSwitches && user.featureSwitches.pdfng)"
-			pdf-src="pdf.url"
-			key="{{ project_id }}"
-			resize-on="layout:main:resize,layout:pdf:resize"
-			highlights="pdf.highlights"
-			position="pdf.position"
-			dbl-click-callback="syncToCode"
-		)
-		div(
-			pdfng
-			ng-if="settings.pdfViewer == 'pdfjs' && user.featureSwitches && user.featureSwitches.pdfng"
-			pdf-src="pdf.url"
-			key="{{ project_id }}"
-			resize-on="layout:main:resize,layout:pdf:resize"
-			highlights="pdf.highlights"
-			position="pdf.position"
-			dbl-click-callback="syncToCode"
-		)
+		- // user.featureSwitches = {} // override
+		- var usePdfNG = user.featureSwitches && user.featureSwitches.pdfng;
+		- console.log('USER FEATURE SWITCHES', user.featureSwitches, usePdfNG);
+		if !usePdfNG
+			div(
+				pdfjs
+				ng-if="settings.pdfViewer == 'pdfjs'"
+				pdf-src="pdf.url"
+				key="{{ project_id }}"
+				resize-on="layout:main:resize,layout:pdf:resize"
+				highlights="pdf.highlights"
+				position="pdf.position"
+				dbl-click-callback="syncToCode"
+			)
+		else
+			div(
+				pdfng
+				ng-if="settings.pdfViewer == 'pdfjs'"
+				pdf-src="pdf.url"
+				key="{{ project_id }}"
+				resize-on="layout:main:resize,layout:pdf:resize"
+				highlights="pdf.highlights"
+				position="pdf.position"
+				dbl-click-callback="syncToCode"
+			)
+
 		iframe(
 			ng-src="{{ pdf.url }}"
 			ng-if="settings.pdfViewer == 'native'"

services/web/public/coffee/ide.coffee

@@ -6,7 +6,7 @@ define [
 	"ide/online-users/OnlineUsersManager"
 	"ide/track-changes/TrackChangesManager"
 	"ide/permissions/PermissionsManager"
-	"ide/pdfng/PdfManager"
+	"ide/pdf/PdfManager"
 	"ide/binary-files/BinaryFilesManager"
 	"ide/settings/index"
 	"ide/share/index"
@@ -106,4 +106,4 @@ define [
 			else
 				$scope.darkTheme = false
 
-	angular.bootstrap(document.body, ["SharelatexApp"])
+	angular.bootstrap(document.body, ["SharelatexApp"])

services/web/public/coffee/ide/pdf/PdfManager.coffee

@@ -2,6 +2,7 @@ define [
 	"ide/pdf/controllers/PdfController"
 	"ide/pdf/controllers/PdfViewToggleController"
 	"ide/pdf/directives/pdfJs"
+	"ide/pdfng/directives/pdfJs"  # alternative incremental viewer
 ], () ->
 	class PdfManager
 		constructor: (@ide, @$scope) ->

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

@@ -5,7 +5,7 @@ define [
 	"ide/pdfng/directives/pdfHighlights"
 	"ide/pdfng/directives/pdfRenderer"
 	"ide/pdfng/directives/pdfPage"
-	"libs/pdfjs-1.0.712/pdf"
+	"libs/pdf"  # needs pdfjs-1.0.712, override the path in require.js to get it
 ], (
 	App
 	pdfTextLayer