Add attachement icon to collapsed message if message has attachement

Summary: Adds attachment icon to collased message if message has attachment. I just copied the attachment icon in the thread-list to the message-list namespace in the static directory. If you want to do it another way, feel free to update

Test Plan: Tested locally. Not sure if this is worth a test, but I can write one if you want.

Reviewers: bengotow

Reviewed By: bengotow

Maniphest Tasks: T2085

Differential Revision: https://phab.nylas.com/D1687

internal_packages/message-list/lib/message-item.cjsx

@@ -54,6 +54,10 @@ class MessageItem extends React.Component
       @_renderFull()
 
   _renderCollapsed: =>
+    attachmentIcon = []
+    if @props.message.files.length > 0
+      attachmentIcon = <div className="collapsed-attachment"></div>
+
     <div className={@props.className} onClick={@_toggleCollapsed}>
       <div className="message-item-area">
         <div className="collapsed-from">
@@ -65,6 +69,7 @@ class MessageItem extends React.Component
         <div className="collapsed-timestamp">
           <MessageTimestamp date={@props.message.date} />
         </div>
+        {attachmentIcon}
       </div>
     </div>
 

internal_packages/message-list/stylesheets/message-list.less

@@ -167,6 +167,17 @@
         color: @text-color-very-subtle;
       }
 
+      .collapsed-attachment {
+        width:15px;
+        height:15px;
+        background-size: 15px;
+        background-repeat: no-repeat;
+        background-position:center;
+        padding:12px;
+        margin-left: 0.5em;
+        background-image:url(../static/images/message-list/icon-attachment-@2x.png);
+      }
+
       .collapsed-from {
         font-weight: @font-weight-semi-bold;
         color: @text-color-very-subtle;