Now hiding the message editor when the no friends message is showing in the...

Now hiding the message editor when the no friends message is showing in the Private Conversations timeline and showing it again on other timelines. Closes #176.

Heartbeat/Base.lproj/Main.storyboard

@@ -1132,7 +1132,7 @@
                                     </subviews>
                                     <nil key="backgroundColor"/>
                                 </clipView>
-                                <scroller key="horizontalScroller" verticalHuggingPriority="750" horizontal="YES" id="b4B-VU-vU0">
+                                <scroller key="horizontalScroller" hidden="YES" verticalHuggingPriority="750" horizontal="YES" id="b4B-VU-vU0">
                                     <rect key="frame" x="1" y="119" width="223" height="15"/>
                                     <autoresizingMask key="autoresizingMask"/>
                                 </scroller>

Heartbeat/MessageSplitViewController.swift

@@ -13,7 +13,11 @@ import Cocoa
 class MessageSplitViewController: NSSplitViewController
 {
 
-    var sendMessageNotificationHandler:NotificationHandler?
+    var sendMessageNotificationHandler: NotificationHandler?
+    var timelineNoticeDisplayRequestHandler: NotificationHandler?
+    var timelineNavigationRequestHandler: NotificationHandler?
+    
+    var messageEditorSplitViewItem: NSSplitViewItem?
     
     //
     // MARK: - View lifecycle
@@ -23,6 +27,8 @@ class MessageSplitViewController: NSSplitViewController
     {
         super.viewDidAppear()
         
+        messageEditorSplitViewItem = messageEditorSplitViewItem ?? splitViewItems[1] as? NSSplitViewItem
+
         createConstraints()
         
         addNotificationHandlers()
@@ -43,6 +49,29 @@ class MessageSplitViewController: NSSplitViewController
     {
         // println("\(self): adding notification handlers.")
         
+        //
+        // Handle the showing and hiding of the message editor view based on whether a notice is showing.
+        //
+        timelineNoticeDisplayRequestHandler = timelineNoticeDisplayRequestHandler ?? handle(TimelineNoticeDisplayRequestNotification)
+        {
+            /* as */ notification in
+            
+            if let messageEditorSplitViewItem = self.messageEditorSplitViewItem
+            {
+                messageEditorSplitViewItem.animator().collapsed = true
+            }
+        }
+        
+        timelineNavigationRequestHandler = timelineNavigationRequestHandler ?? handle(TimelineNavigationRequestNotification)
+        {
+            /* as */ notification in
+            
+            if let messageEditorSplitViewItem = self.messageEditorSplitViewItem
+            {
+                messageEditorSplitViewItem.animator().collapsed = false
+            }
+        }
+        
         //
         // MARK: - .SendMessage
         //