                 console.log 'HTML pasting mode turned off.'
           cmDrop = editor.display.dragFunctions.drop
           editor.setOption 'dragDrop', false
+          ## Embed files as images if dragged to beginning of line or after
+          ## a space or table separator (| for Markdown, & for LaTeX).
+          useImage = (pos) ->
+            pos.ch == 0 or
+            /^[\s|&]$/.test editor.getRange
+              line: pos.line
+              ch: pos.ch - 1
+            , pos
+          embedFile = (type, id, pos) ->
+            if useImage pos
+              switch type
+                when 'image', 'video', 'pdf'
+                  switch ti.data.format
+                    when 'markdown'
+                      return "![](coauthor:#{id})"
+                    when 'latex'
+                      return "\\includegraphics{coauthor:#{id}}"
+                    when 'html'
+                      return """<img src="coauthor:#{id}">"""
+                #when 'video'
+                #  """<video controls><source src="coauthor:#{id}"></video>"""
+            "coauthor:#{id}"
           editor.display.dragFunctions.drop = (e) ->
             text = e.dataTransfer?.getData 'text'
             id = e.dataTransfer?.getData 'application/coauthor-id'

              text = e.clipboardData.getData 'text/plain'
              if match = parseCoauthorMessageUrl text, true
                paste = ["coauthor:#{match.message}#{match.hash}"]
              else if match = parseCoauthorAuthorUrl text
                paste = ["@#{match.author}"]
          editor.on 'beforeChange', (cm, change) ->

            if username
              replacement = "@#{username}"
            else if id
              pos = require 'codemirror/src/measurement/position_measurement.js'
              .posFromMouse editor, e, true
              replacement = embedFile type, id, pos
            else if match = parseCoauthorMessageUrl text, true
              replacement = "coauthor:#{match.message}#{match.hash}"
            else if match = parseCoauthorAuthorUrl text
