Add up/down split options when opening uri in a workspace

src/pane.coffee

@@ -678,6 +678,30 @@ class Pane extends Model
     else
       @splitRight()
 
+  # If the parent is a vertical axis, returns its first child if it is a pane;
+  # otherwise returns this pane.
+  findTopmostSibling: ->
+    if @parent.orientation is 'vertical'
+      [topmostSibling] = @parent.children
+      if topmostSibling instanceof PaneAxis
+        this
+      else
+        topmostSibling
+    else
+      this
+
+  # If the parent is a vertical axis, returns its last child if it is a pane;
+  # otherwise returns a new pane created by splitting this pane bottomward.
+  findOrCreateBottommostSibling: ->
+    if @parent.orientation is 'vertical'
+      bottommostSibling = last(@parent.children)
+      if bottommostSibling instanceof PaneAxis
+        @splitRight()
+      else
+        bottommostSibling
+    else
+      @splitDown()
+
   close: ->
     @destroy() if @confirmClose()
 

src/workspace.coffee

@@ -361,9 +361,11 @@ class Workspace extends Model
   #     initially. Defaults to `0`.
   #   * `initialColumn` A {Number} indicating which column to move the cursor to
   #     initially. Defaults to `0`.
-  #   * `split` Either 'left' or 'right'. If 'left', the item will be opened in
-  #     leftmost pane of the current active pane's row. If 'right', the
-  #     item will be opened in the rightmost pane of the current active pane's row.
+  #   * `split` Either 'left', 'right', 'top' or 'bottom'.
+  #     If 'left', the item will be opened in leftmost pane of the current active pane's row.
+  #     If 'right', the item will be opened in the rightmost pane of the current active pane's row.
+  #     If 'up', the item will be opened in topmost pane of the current active pane's row.
+  #     If 'down', the item will be opened in the bottommost pane of the current active pane's row.
   #   * `activatePane` A {Boolean} indicating whether to call {Pane::activate} on
   #     containing pane. Defaults to `true`.
   #   * `searchAllPanes` A {Boolean}. If `true`, the workspace will attempt to
@@ -383,6 +385,10 @@ class Workspace extends Model
         @getActivePane().findLeftmostSibling()
       when 'right'
         @getActivePane().findOrCreateRightmostSibling()
+      when 'up'
+        @getActivePane().findTopmostSibling()
+      when 'down'
+        @getActivePane().findOrCreateBottommostSibling()
       else
         @getActivePane()