diff --git a/gdb/tui/tui-layout.c b/gdb/tui/tui-layout.c
index 6fd176d9235..c890b86b026 100644
--- a/gdb/tui/tui-layout.c
+++ b/gdb/tui/tui-layout.c
@@ -451,7 +451,7 @@ tui_layout_window::get_sizes (bool height, int *min_value, int *max_value)
 /* See tui-layout.h.  */
 
 bool
-tui_layout_window::top_boxed_p () const
+tui_layout_window::first_edge_has_border_p () const
 {
   gdb_assert (m_window != nullptr);
   return m_window->can_box ();
@@ -460,7 +460,7 @@ tui_layout_window::top_boxed_p () const
 /* See tui-layout.h.  */
 
 bool
-tui_layout_window::bottom_boxed_p () const
+tui_layout_window::last_edge_has_border_p () const
 {
   gdb_assert (m_window != nullptr);
   return m_window->can_box ();
@@ -561,21 +561,21 @@ tui_layout_split::get_sizes (bool height, int *min_value, int *max_value)
 /* See tui-layout.h.  */
 
 bool
-tui_layout_split::top_boxed_p () const
+tui_layout_split::first_edge_has_border_p () const
 {
   if (m_splits.empty ())
     return false;
-  return m_splits[0].layout->top_boxed_p ();
+  return m_splits[0].layout->first_edge_has_border_p ();
 }
 
 /* See tui-layout.h.  */
 
 bool
-tui_layout_split::bottom_boxed_p () const
+tui_layout_split::last_edge_has_border_p () const
 {
   if (m_splits.empty ())
     return false;
-  return m_splits.back ().layout->top_boxed_p ();
+  return m_splits.back ().layout->last_edge_has_border_p ();
 }
 
 /* See tui-layout.h.  */
@@ -785,8 +785,8 @@ tui_layout_split::apply (int x_, int y_, int width_, int height_)
       /* Two adjacent boxed windows will share a border, making a bit
 	 more size available.  */
       if (i > 0
-	  && m_splits[i - 1].layout->bottom_boxed_p ()
-	  && m_splits[i].layout->top_boxed_p ())
+	  && m_splits[i - 1].layout->last_edge_has_border_p ()
+	  && m_splits[i].layout->first_edge_has_border_p ())
 	info[i].share_box = true;
     }
 
diff --git a/gdb/tui/tui-layout.h b/gdb/tui/tui-layout.h
index 26de3c3a979..9cfcfb8e81f 100644
--- a/gdb/tui/tui-layout.h
+++ b/gdb/tui/tui-layout.h
@@ -62,11 +62,13 @@ public:
      HEIGHT is true to fetch height, false to fetch width.  */
   virtual void get_sizes (bool height, int *min_value, int *max_value) = 0;
 
-  /* True if the topmost item in this layout is boxed.  */
-  virtual bool top_boxed_p () const = 0;
+  /* True if the topmost (for vertical layouts), or the leftmost (for
+     horizontal layouts) item in this layout is boxed.  */
+  virtual bool first_edge_has_border_p () const = 0;
 
-  /* True if the bottommost item in this layout is boxed.  */
-  virtual bool bottom_boxed_p () const = 0;
+  /* True if the bottommost (for vertical layouts), or the rightmost (for
+     horizontal layouts) item in this layout is boxed.  */
+  virtual bool last_edge_has_border_p () const = 0;
 
   /* Return the name of this layout's window, or nullptr if this
      layout does not represent a single window.  */
@@ -141,9 +143,9 @@ public:
     return m_contents == name ? FOUND : NOT_FOUND;
   }
 
-  bool top_boxed_p () const override;
+  bool first_edge_has_border_p () const override;
 
-  bool bottom_boxed_p () const override;
+  bool last_edge_has_border_p () const override;
 
   void remove_windows (const char *name) override
   {
@@ -213,9 +215,9 @@ public:
     return set_size (name, new_width, true);
   }
 
-  bool top_boxed_p () const override;
+  bool first_edge_has_border_p () const override;
 
-  bool bottom_boxed_p () const override;
+  bool last_edge_has_border_p () const override;
 
   void remove_windows (const char *name) override;