Use presenter for rendering overlay decorations

We’re still doing some sync DOM reads and computation in the view that
should eventually be made async and moved into the presenter, but I’m
going to leave it alone for now.

src/overlay-manager.coffee

@@ -1,47 +1,42 @@
 module.exports =
 class OverlayManager
   constructor: (@container) ->
-    @overlays = {}
+    @overlayNodesById = {}
 
   render: (props) ->
-    {presenter, editor, overlayDecorations} = props
-    lineHeight = presenter.getLineHeight()
+    {presenter} = props
 
-    existingDecorations = null
-    for markerId, {headPixelPosition, tailPixelPosition, decorations} of overlayDecorations
-      for decoration in decorations
-        pixelPosition =
-          if decoration.position is 'tail' then tailPixelPosition else headPixelPosition
+    for decorationId, {pixelPosition, item} of presenter.state.content.overlays
+      @renderOverlay(presenter, decorationId, item, pixelPosition)
 
-        @renderOverlay(editor, decoration, pixelPosition, lineHeight)
-
-        existingDecorations ?= {}
-        existingDecorations[decoration.id] = true
-
-    for id, overlay of @overlays
-      unless existingDecorations? and id of existingDecorations
-        @container.removeChild(overlay)
-        delete @overlays[id]
+    for id, overlayNode of @overlayNodesById
+      unless presenter.state.content.overlays.hasOwnProperty(id)
+        overlayNode.remove()
+        delete @overlayNodesById[id]
 
     return
 
-  renderOverlay: (editor, decoration, pixelPosition, lineHeight) ->
-    item = atom.views.getView(decoration.item)
-    unless overlay = @overlays[decoration.id]
-      overlay = @overlays[decoration.id] = document.createElement('atom-overlay')
-      overlay.appendChild(item)
-      @container.appendChild(overlay)
+  renderOverlay: (presenter, decorationId, item, pixelPosition) ->
+    item = atom.views.getView(item)
+    unless overlayNode = @overlayNodesById[decorationId]
+      overlayNode = @overlayNodesById[decorationId] = document.createElement('atom-overlay')
+      overlayNode.appendChild(item)
+      @container.appendChild(overlayNode)
 
     itemWidth = item.offsetWidth
     itemHeight = item.offsetHeight
 
+
+    {scrollTop} = presenter.state
+    {scrollLeft} = presenter.state.content
+
     left = pixelPosition.left
-    if left + itemWidth - editor.getScrollLeft() > editor.getWidth() and left - itemWidth >= editor.getScrollLeft()
+    if left + itemWidth - scrollLeft > presenter.getClientWidth() and left - itemWidth >= scrollLeft
       left -= itemWidth
 
-    top = pixelPosition.top + lineHeight
-    if top + itemHeight - editor.getScrollTop() > editor.getHeight() and top - itemHeight - lineHeight >= editor.getScrollTop()
-      top -= itemHeight + lineHeight
+    top = pixelPosition.top + presenter.getLineHeight()
+    if top + itemHeight - scrollTop > presenter.getClientHeight() and top - itemHeight - presenter.getLineHeight() >= scrollTop
+      top -= itemHeight + presenter.getLineHeight()
 
-    overlay.style.top = top + 'px'
-    overlay.style.left = left + 'px'
+    overlayNode.style.top = top + 'px'
+    overlayNode.style.left = left + 'px'