Introduce tui_win_info::clear_detail method

This introduces the clear_detail method and updates the various
subclasses of tui_win_info to implement it.  A subsequent patch will
remove tui_clear_win_detail, but that isn't done for now because at
this point it isn't readily obvious that the NULL check is not needed.

gdb/ChangeLog
2019-06-25  Tom Tromey  <tom@tromey.com>

	* tui/tui-data.h (struct tui_win_info, struct tui_source_window)
	(struct tui_data_window, struct tui_cmd_window): Declare
	clear_detail method.
	* tui/tui-data.c (tui_source_window::clear_detail)
	(tui_cmd_window::clear_detail, tui_data_window::clear_detail): New
	methods.
	(tui_clear_win_detail): Simplify.

gdb/ChangeLog

@@ -1,3 +1,13 @@
+2019-06-25  Tom Tromey  <tom@tromey.com>
+
+	* tui/tui-data.h (struct tui_win_info, struct tui_source_window)
+	(struct tui_data_window, struct tui_cmd_window): Declare
+	clear_detail method.
+	* tui/tui-data.c (tui_source_window::clear_detail)
+	(tui_cmd_window::clear_detail, tui_data_window::clear_detail): New
+	methods.
+	(tui_clear_win_detail): Simplify.
+
 2019-06-25  Tom Tromey  <tom@tromey.com>
 
 	* tui/tui-layout.c (make_source_window, make_disasm_window)

gdb/tui/tui-data.c

@@ -178,37 +178,44 @@ tui_add_to_source_windows (struct tui_win_info *win_info)
     source_windows.list[source_windows.count++] = win_info;
 }
 
+/* See tui-data.h.  */
+
+void
+tui_source_window::clear_detail ()
+{
+  detail.source_info.gdbarch = NULL;
+  detail.source_info.start_line_or_addr.loa = LOA_ADDRESS;
+  detail.source_info.start_line_or_addr.u.addr = 0;
+  detail.source_info.horizontal_offset = 0;
+}
+
+/* See tui-data.h.  */
+
+void
+tui_cmd_window::clear_detail ()
+{
+  wmove (generic.handle, 0, 0);
+}
+
+/* See tui-data.h.  */
+
+void
+tui_data_window::clear_detail ()
+{
+  detail.data_display_info.data_content = NULL;
+  detail.data_display_info.data_content_count = 0;
+  detail.data_display_info.regs_content = NULL;
+  detail.data_display_info.regs_content_count = 0;
+  detail.data_display_info.regs_column_count = 1;
+  detail.data_display_info.display_regs = FALSE;
+}
 
 /* Clear the pertinant detail in the windows.  */
 void
 tui_clear_win_detail (struct tui_win_info *win_info)
 {
   if (win_info != NULL)
-    {
+    win_info->clear_detail ();
-      switch (win_info->generic.type)
-	{
-	case SRC_WIN:
-	case DISASSEM_WIN:
-	  win_info->detail.source_info.gdbarch = NULL;
-	  win_info->detail.source_info.start_line_or_addr.loa = LOA_ADDRESS;
-	  win_info->detail.source_info.start_line_or_addr.u.addr = 0;
-	  win_info->detail.source_info.horizontal_offset = 0;
-	  break;
-	case CMD_WIN:
-	  wmove (win_info->generic.handle, 0, 0);
-	  break;
-	case DATA_WIN:
-	  win_info->detail.data_display_info.data_content = NULL;
-	  win_info->detail.data_display_info.data_content_count = 0;
-	  win_info->detail.data_display_info.regs_content = NULL;
-	  win_info->detail.data_display_info.regs_content_count = 0;
-	  win_info->detail.data_display_info.regs_column_count = 1;
-	  win_info->detail.data_display_info.display_regs = FALSE;
-	  break;
-	default:
-	  break;
-	}
-    }
 }
 
 

gdb/tui/tui-data.h

@@ -280,6 +280,9 @@ public:
 
   virtual ~tui_win_info ();
 
+  /* Clear the pertinent detail in the window.  */
+  virtual void clear_detail () = 0;
+
   struct tui_gen_win_info generic;	/* General window information.  */
   union
   {
@@ -300,18 +303,24 @@ struct tui_source_window : public tui_win_info
 {
   explicit tui_source_window (enum tui_win_type type);
   DISABLE_COPY_AND_ASSIGN (tui_source_window);
+
+  void clear_detail () override;
 };
 
 struct tui_data_window : public tui_win_info
 {
   tui_data_window ();
   DISABLE_COPY_AND_ASSIGN (tui_data_window);
+
+  void clear_detail () override;
 };
 
 struct tui_cmd_window : public tui_win_info
 {
   tui_cmd_window ();
   DISABLE_COPY_AND_ASSIGN (tui_cmd_window);
+
+  void clear_detail () override;
 };
 
 extern int tui_win_is_source_type (enum tui_win_type win_type);