Fix for #305

- The drag events were not ported to jschannel.
- Incorporated fix (updated to the current HEAD) for issue #262 too

h/js/inject/host.coffee

@@ -14,6 +14,8 @@ class Annotator.Host extends Annotator
     delta: 0
     last: null
     tick: false
+    #Do we enable dragging
+    canDrag: false
 
   constructor: (element, options) ->
     super
@@ -141,6 +143,10 @@ class Annotator.Host extends Annotator
           $('html, body').stop().animate {scrollTop: y}, 600
         )
 
+        .bind('setDrag', (ctx, drag) =>
+          @canDrag = drag
+        )
+
   scanDocument: (reason = "something happened") =>
     try
       console.log "Analyzing host frame, because " + reason + "..."
@@ -190,6 +196,7 @@ class Annotator.Host extends Annotator
           @panel?.notify method: 'publish', params: 'hostUpdated'
     document.addEventListener 'touchmove', update
     document.addEventListener 'touchstart', =>
+      unless @canDrag then return
       touch = true
       @frame?.css
         display: 'none'
@@ -202,6 +209,7 @@ class Annotator.Host extends Annotator
         @drag.tick = true
         window.requestAnimationFrame this._dragRefresh
     document.addEventListener 'dragleave', (event) =>
+      unless @canDrag then return
       if @drag.last?
         @drag.delta += event.screenX - @drag.last
       @drag.last = event.screenX

h/js/services.coffee

@@ -15,6 +15,7 @@ class Hypothesis extends Annotator
 
   # Internal state
   visible: false      # *  Whether the sidebar is visible
+  dragging: false     # * To enable dragging only when we really want to
 
   # Here as a noop just to make the Permissions plugin happy
   # XXX: Change me when Annotator stops assuming things about viewers
@@ -191,13 +192,17 @@ class Hypothesis extends Annotator
     handle.addEventListener 'dragstart', (event) =>
       event.dataTransfer.setData 'text/plain', ''
       event.dataTransfer.setDragImage el, 0, 0
-      @provider.dragFrame event.screenX
+      @dragging = true
+      @provider.notify method: 'setDrag', params: true      
+      @provider.notify method: 'dragFrame', params: event.screenX
     handle.addEventListener 'dragend', (event) =>
-      @provider.dragFrame event.screenX
+      @dragging = false
+      @provider.notify method: 'setDrag', params: false      
+      @provider.notify method: 'dragFrame', params: event.screenX
     @element[0].addEventListener 'dragover', (event) =>
-      @provider.dragFrame event.screenX
+      if @dragging then @provider.notify method: 'dragFrame', params: event.screenX
     @element[0].addEventListener 'dragleave', (event) =>
-      @provider.dragFrame event.screenX
+      if @dragging then @provider.notify method: 'dragFrame', params: event.screenX
 
     this