Merge pull request #142 from sharelatex/pdfng-scrollhandler

Pdfng scrollhandler performance improvements

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

@@ -29,59 +29,36 @@ define [
 					canvasElement.width(w)
 					scope.page.sized = true
 
-				isVisible = (containerSize) ->
+				# keep track of our page element, so we can access it in the
-					elemTop = element.offset().top - containerSize[2]
+				# parent with scope.pages[i].element, and the contained
-					elemBottom = elemTop + element.innerHeight()
+				# elements for each part
-					visible = (elemTop < containerSize[1] and elemBottom > 0)
+				scope.page.element = element
-					scope.page.visible = visible
+				scope.page.elementChildren = {
-					scope.page.elemTop = elemTop
-					scope.page.elemBottom = elemBottom
-					return visible
-
-				renderPage = () ->
-					scope.document.renderPage {
 					canvas: canvasElement,
 					text: textElement
 					annotations: annotationsElement
 					highlights: highlightsElement
-					}, scope.page.pageNum
+					container: element
+				}
 
-				pausePage = () ->
+				if !scope.page.sized
-					scope.document.pause {
+					if scope.defaultPageSize?
-						canvas: canvasElement,
-						text: textElement
-					}, scope.page.pageNum
-
-				# keep track of our page element, so we can access it in the
-				# parent with scope.pages[i].element
-				scope.page.element = element
-
-				if (!scope.page.sized && scope.defaultPageSize)
 						updatePageSize scope.defaultPageSize
+					else
+						# shouldn't get here - the default page size should now
+						# always be set before redraw is called
+						handler = scope.$watch 'defaultPageSize', (defaultPageSize) ->
+							return unless defaultPageSize?
+							updatePageSize defaultPageSize
+							handler()
 
 				if scope.page.current
 						# console.log 'we must scroll to this page', scope.page.pageNum, 'at position', scope.page.position
-						renderPage()
 						# this is the current page, we want to scroll it into view
+						# and render it immediately
+						scope.document.renderPage scope.page
 						ctrl.setPdfPosition(scope.page, scope.page.position)
 
-				scope.$watch 'defaultPageSize', (defaultPageSize) ->
-					return unless defaultPageSize?
-					updatePageSize defaultPageSize
-
-				watchHandle = scope.$watch 'containerSize', (containerSize, oldVal) ->
-					return unless containerSize?
-					return unless scope.page.sized
-					oldVisible = scope.page.visible
-					newVisible = isVisible containerSize
-					scope.page.visible = newVisible
-					if newVisible && !oldVisible
-						renderPage()
-						# TODO deregister this listener after the page is rendered
-						#watchHandle()
-					else if !newVisible && oldVisible
-						pausePage()
-
 				element.on 'dblclick', (e) ->
 					offset = $(element).find('.pdf-canvas').offset()
 					dx = e.pageX - offset.left
@@ -99,7 +76,7 @@ define [
 					highlights: highlightsElement
 				})
 
-				scope.$watch 'highlights', (highlights, oldVal) ->
+				scope.$on 'pdf:highlights', (event, highlights) ->
 					return unless highlights?
 					return unless highlights.length > 0
 					if scope.timeoutHandler

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

@@ -25,6 +25,7 @@ define [
 					pdfDocument.getDownloadInfo().then () =>
 						@options.loadedCallback()
 				@errorCallback = @options.errorCallback
+				@pageSizeChangeCallback = @options.pageSizeChangeCallback
 				@pdfjs.catch (exception) =>
 					# console.log 'ERROR in get document', exception
 					@errorCallback(exception)
@@ -89,13 +90,6 @@ define [
 			setScale: (@scale) ->
 				@resetState()
 
-			pause: (element, pagenum) ->
-				return if @complete[pagenum]
-				return if @shuttingDown
-				@renderQueue = @renderQueue.filter (q) ->
-					q.pagenum != pagenum
-				@spinner.stop(element.canvas)
-
 			triggerRenderQueue: (interval = @JOB_QUEUE_INTERVAL) ->
 				$timeout () =>
 					@processRenderQueue()
@@ -107,14 +101,23 @@ define [
 				@jobs = @jobs - 1
 				@triggerRenderQueue(0)
 
-			renderPage: (element, pagenum) ->
+			renderPages: (pages) ->
+				return if @shuttingDown
+				@renderQueue = for page in pages
+					{
+						'element': page.elementChildren
+						'pagenum': page.pageNum
+					}
+				@triggerRenderQueue()
+
+			renderPage: (page) ->
 				return if @shuttingDown
 				current =		{
-					'element': element
+					'element': page.elementChildren
-					'pagenum': pagenum
+					'pagenum': page.pageNum
 				}
-				@renderQueue.push(current)
+				@renderQueue.push current
-				@triggerRenderQueue()
+				@processRenderQueue()
 
 			processRenderQueue: () ->
 				return if @shuttingDown
@@ -131,7 +134,9 @@ define [
 				@jobs = @jobs + 1
 
 				element.canvas.addClass('pdfng-loading')
+				spinTimer = $timeout () =>
 					@spinner.add(element.canvas)
+				, 100
 
 				completeRef = @complete
 				renderTaskRef = @renderTask
@@ -142,6 +147,7 @@ define [
 					Raven.captureMessage?('pdfng page load timed out after ' + @PAGE_LOAD_TIMEOUT + 'ms')
 					# console.log 'page load timed out', pagenum
 					timedOut = true
+					$timeout.cancel(spinTimer)
 					@spinner.stop(element.canvas)
 					# @jobs = @jobs - 1
 					# @triggerRenderQueue(0)
@@ -153,6 +159,7 @@ define [
 				@pageLoad[pagenum].then (pageObject) =>
 					# console.log 'in page load success', pagenum
 					$timeout.cancel(timer)
+					$timeout.cancel(spinTimer)
 					@renderTask[pagenum] = @doRender element, pagenum, pageObject
 					@renderTask[pagenum].then () =>
 						# complete
@@ -166,6 +173,7 @@ define [
 				.catch (error) ->
 					# console.log 'in page load error', pagenum, 'timedOut=', timedOut
 					$timeout.cancel(timer)
+					$timeout.cancel(spinTimer)
 					# console.log 'ERROR', error
 
 			doRender: (element, pagenum, page) ->
@@ -202,8 +210,14 @@ define [
 				canvas.height(newHeight + 'px')
 				canvas.width(newWidth + 'px')
 
-				element.canvas.height(newHeight)
+				oldHeight = element.canvas.height()
-				element.canvas.width(newWidth)
+				oldWidth = element.canvas.width()
+				if newHeight != oldHeight  or  newWidth != oldWidth
+					element.canvas.height(newHeight + 'px')
+					element.canvas.width(newWidth + 'px')
+					element.container.height(newHeight + 'px')
+					element.container.width(newWidth + 'px')
+					@pageSizeChangeCallback?(pagenum, newHeight - oldHeight)
 
 				if pixelRatio != 1
 					ctx.scale(pixelRatio, pixelRatio)

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

@@ -40,6 +40,8 @@ define [
 				errorCallback: (error) ->
 					Raven.captureMessage?('pdfng error ' + error)
 					$scope.$emit 'pdf:error', error
+				pageSizeChangeCallback: (pageNum, deltaH) ->
+					$scope.$broadcast 'pdf:page:size-change', pageNum, deltaH
 			})
 
 			# we will have all the main information needed to start display
@@ -144,18 +146,18 @@ define [
 			# find first visible page
 			visible = $scope.pages.some (page, i) ->
 				[topPageIdx, topPage] = [i, page] if page.visible
-			if visible
+			if visible && topPage.element?
 				# console.log 'found it', topPageIdx
 			else
 				# console.log 'CANNOT FIND TOP PAGE'
 				return
 
 			# console.log 'top page is', topPage.pageNum, topPage.elemTop, topPage.elemBottom, topPage
-			top = topPage.elemTop
+			top = topPage.element.offset().top
-			bottom = topPage.elemBottom
+			bottom = top + topPage.element.innerHeight()
-			viewportTop = 0
+			viewportTop = $element.offset().top
-			viewportHeight = $element.height()
+			viewportBottom = viewportTop + $element.height()
-			topVisible = (top >= viewportTop && top < viewportTop + viewportHeight)
+			topVisible = (top >= viewportTop && top < viewportBottom)
 			someContentVisible = (top < viewportTop && bottom > viewportTop)
 			# console.log 'in PdfListView', top, topVisible, someContentVisible, viewportTop
 			if topVisible
@@ -237,13 +239,39 @@ define [
 				layoutReady.promise.then () ->
 					# console.log 'layoutReady was resolved'
 
-				# TODO can we combine this with scope.parentSize, need to finalize boxes
+				renderVisiblePages = () ->
-				updateContainer = () ->
+					pages = getVisiblePages()
-					scope.containerSize = [
+					# pages = getExtraPages visiblePages
-						element.innerWidth()
+					scope.document.renderPages(pages)
-						element.innerHeight()
+
-						element.offset().top
+				getVisiblePages = () ->
-					]
+					top = element[0].scrollTop;
+					bottom = top + element[0].clientHeight;
+					visiblePages = scope.pages.filter (page) ->
+						pageElement = page.element[0]
+						pageTop = pageElement.offsetTop
+						pageBottom = pageTop + pageElement.clientHeight
+						page.visible = pageTop < bottom and pageBottom > top
+						return page.visible
+					return visiblePages
+
+				getExtraPages = (visiblePages) ->
+					extra = []
+					firstVisiblePage = visiblePages[0].pageNum
+					firstVisiblePageIdx = firstVisiblePage - 1
+					len = visiblePages.length
+					lastVisiblePage = visiblePages[len-1].pageNum
+					lastVisiblePageIdx = lastVisiblePage - 1
+					# first page after
+					if lastVisiblePageIdx + 1 < scope.pages.length
+						extra.push scope.pages[lastVisiblePageIdx + 1]
+					# page before
+					if firstVisiblePageIdx > 0
+						extra.push scope.pages[firstVisiblePageIdx - 1]
+					# second page after
+					if lastVisiblePageIdx + 2 < scope.pages.length
+						extra.push scope.pages[lastVisiblePageIdx + 2]
+					return visiblePages.concat extra
 
 				doRescale = (scale) ->
 					# console.log 'doRescale', scale
@@ -255,6 +283,7 @@ define [
 						ctrl.setScale(scale, h, w).then () ->
 							spinner.remove(element)
 							ctrl.redraw(origposition)
+							setTimeout renderVisiblePages, 0
 
 				checkElementReady = () ->
 					# if element is zero-sized keep checking until it is ready
@@ -270,7 +299,7 @@ define [
 				scope.$on 'layout-ready', () ->
 					# console.log 'GOT LAYOUT READY EVENT'
 					# console.log 'calling refresh'
-					updateContainer()
+					# updateContainer()
 					spinner.add(element)
 					layoutReady.resolve 'layout is ready'
 					scope.parentSize = [
@@ -307,26 +336,38 @@ define [
 					# trigger a redraw
 					scope.scale = angular.copy (scope.scale)
 
+				scope.$on 'pdf:page:size-change', (event, pageNum, delta) ->
+					#console.log 'page size change event', pageNum, delta
+					origposition = angular.copy scope.position
+					#console.log 'orig position', JSON.stringify(origposition)
+					if pageNum - 1 < origposition.page && delta != 0
+						currentScrollTop =  element.scrollTop()
+						#console.log 'adjusting scroll from', currentScrollTop, 'by', delta
+						scope.adjustingScroll = true
+						element.scrollTop(currentScrollTop + delta)
+
 				element.on 'scroll', () ->
 					#console.log 'scroll event', element.scrollTop(), 'adjusting?', scope.adjustingScroll
+					#scope.scrollPosition = element.scrollTop()
 					if scope.adjustingScroll
-						updateContainer()
+						renderVisiblePages()
+						# updateContainer()
 						scope.$apply()
 						scope.adjustingScroll = false
 						return
-					scope.scrolled = true
+					#scope.scrolled = true
 					if scope.scrollHandlerTimeout
-						$timeout.cancel(scope.scrollHandlerTimeout)
+						clearTimeout(scope.scrollHandlerTimeout)
-					scope.scrollHandlerTimeout = $timeout scrollHandler, 100
+					scope.scrollHandlerTimeout = setTimeout scrollHandler, 25
 
 				scrollHandler = () ->
-					scope.scrollHandlerTimeout = null
+					renderVisiblePages()
-					updateContainer()
+					#scope.$apply()
-					scope.$apply()
 					newPosition = ctrl.getPdfPosition()
 					if newPosition?
 						scope.position = newPosition
-					scope.$apply()
+					#scope.$apply()
+					scope.scrollHandlerTimeout = null
 
 				scope.$watch 'pdfSrc', (newVal, oldVal) ->
 					# console.log 'loading pdf', newVal, oldVal
@@ -421,6 +462,8 @@ define [
 
 					return if !highlights.length
 
+					scope.$broadcast 'pdf:highlights', areas
+
 					first = highlights[0]
 
 					pageNum = scope.pages[first.page].pageNum