Remove all the fancy throttling of anchoring

This is premature optimization and makes things way more difficult
to reason about.

h/static/scripts/annotator/guest.coffee

@@ -149,6 +149,12 @@ module.exports = class Guest extends Annotator
   setupAnnotation: (annotation) ->
     self = this
 
+    anchors = []
+    anchoredTargets = []
+    deadHighlights = []
+
+    annotation.target ?= []
+
     locate = (target) ->
       options = {ignoreSelector: '[class^="annotator-"]'}
       return new Promise(raf)
@@ -165,10 +171,15 @@ module.exports = class Guest extends Annotator
           return anchor
       return anchor
 
-    setup = ->
-      anchors = []
-      anchoredTargets = []
-      deadHighlights = []
+    sync = (anchors) ->
+      annotation.$orphan = anchors.length > 0
+      for anchor in anchors
+        if anchor.range?
+          annotation.$orphan = false
+
+      self.anchors = self.anchors.concat(anchors)
+      self.plugins.BucketBar.update()
+      self.plugins.CrossFrame.sync([annotation])
 
     for anchor in self.anchors.splice(0, self.anchors.length)
       if anchor.annotation is annotation
@@ -189,26 +200,7 @@ module.exports = class Guest extends Annotator
       anchor = locate(target).then(highlight)
       anchors.push(anchor)
 
-      return Promise.all(anchors)
-
-    sync = (anchors) ->
-      annotation.$orphan = anchors.length > 0
-      for anchor in anchors
-        if anchor.range?
-          annotation.$orphan = false
-
-      self.anchors = self.anchors.concat(anchors)
-      self.plugins.BucketBar.update()
-      self.plugins.CrossFrame.sync([annotation])
-
-    cleanup = ->
-      delete annotation.anchors
-
-    annotation.target ?= []
-    annotation.anchors ?= Promise.resolve(annotation.anchors)
-    .then(setup)
-    .then(sync)
-    .then(cleanup, cleanup)
+    Promise.all(anchors).then(sync)
 
     return annotation
 

h/static/scripts/annotator/plugin/pdf.coffee

@@ -6,8 +6,6 @@ class PDF extends Annotator.Plugin
   documentLoaded: null
   observer: null
   pdfViewer: null
-  updatePromise: null
-  updateTimeout: null
 
   pluginInit: ->
     @pdfViewer = PDFViewerApplication.pdfViewer
@@ -59,17 +57,11 @@ class PDF extends Annotator.Plugin
       return {title, link}
 
   update: ->
-    self = this
     {annotator, pdfViewer} = this
 
-    _throttle = ->
-      if self.updateTimeout?
-        clearTimeout(self.updateTimeout)
-      self.updateTimeout = setTimeout(_update, 200)
-
-    _update = ->
-      anchors = []
-      annotations = []
+    stableAnchors = []
+    pendingAnchors = []
+    refreshAnnotations = []
 
     for page in pdfViewer.pages when page.textLayer?.renderingDone
       div = page.div ? page.el
@@ -82,27 +74,22 @@ class PDF extends Annotator.Plugin
           if placeholder?
             placeholder.parentNode.removeChild(placeholder)
 
-      for anchor in annotator.anchors when anchor.annotation not in annotations
-        unless anchor.range? and anchor.highlights?
-          delete anchor.range
-          annotations.push(anchor.annotation)
+    for anchor in annotator.anchors when anchor.highlights?
+      if anchor.annotation in refreshAnnotations
         continue
 
       for hl in anchor.highlights
         if not document.body.contains(hl)
+          delete anchor.highlights
           delete anchor.range
-            annotations.push(anchor.annotation)
+          refreshAnnotations.push(anchor.annotation)
           break
 
-      for annotation in annotations
+    for annotation in refreshAnnotations
       annotator.setupAnnotation(annotation)
-        anchors.push(annotation.anchors)
-
-      self.updateTimeout = null
-      self.updatePromise = Promise.all(anchors)
+      pendingAnchors.push(annotation.anchors)
 
-    @annotator.plugins.BucketBar?.update()
-    Promise.resolve(@updatePromise).then(_throttle)
+    annotator.plugins.BucketBar?.update()
 
 Annotator.Plugin.PDF = PDF