Re: mode-line with Tramp

[Nick Roberts <nickrob@snap.net.nz>]

 > > And %R (not implemented yet) works a bit like %*: print R or hyphen
 > > depending on whether (file-remote-p default-directory) is true or not.
 > 
 > I don't know whether it is OK to call pure Lisp functions in
 > decode_mode_spec. Besides of this, it looks natural to me.
                     (Apart from this?)

Using call1 seems to work. The function file-remote-p is in file.el which gets
built into Emacs through loadup.el, so I guess it's OK.

 > And one could also think about a host indication %h, which is a
 > candidate for frame-title-format or header-line-format.
 > 
 > However, I'm rather chary with changes in xdisp.c, bindings.el etc,
 > because I don't know whether they are accepted by the majority.

It's just one character on the mode-line.  Here's a patch that they can try.

-- 
Nick                                           http://www.inet.net.nz/~nickrob


Index: src/xdisp.c
===================================================================
RCS file: /sources/emacs/emacs/src/xdisp.c,v
retrieving revision 1.1156
diff -p -r1.1156 xdisp.c
*** src/xdisp.c	17 Jun 2007 01:45:46 -0000	1.1156
--- src/xdisp.c	18 Jul 2007 08:38:44 -0000
*************** decode_mode_spec (w, c, field_width, pre
*** 17994,17999 ****
--- 17994,18009 ----
  #endif
        break;
  
+     case 'R':
+       {
+ 	Lisp_Object val;
+ 	val = call1 (intern ("file-remote-p"), current_buffer->directory);
+ 	if (NILP (val))
+ 	  return "-";
+ 	else
+ 	  return "R";
+       }
+ 
      case 't':			/* indicate TEXT or BINARY */
  #ifdef MODE_LINE_BINARY_TEXT
        return MODE_LINE_BINARY_TEXT (b);
Index: src/buffer.c
===================================================================
RCS file: /sources/emacs/emacs/src/buffer.c,v
retrieving revision 1.528
diff -p -r1.528 buffer.c
*** src/buffer.c	27 Jun 2007 11:33:29 -0000	1.528
--- src/buffer.c	18 Jul 2007 08:38:51 -0000
*************** A string is printed verbatim in the mode
*** 5501,5506 ****
--- 5501,5508 ----
    %P -- print percent of buffer above bottom of window, perhaps plus Top,
          or print Bottom or All.
    %n -- print Narrow if appropriate.
+   %R -- print R or hyphen.  R means that default-directory is on a
+         remote machine.
    %t -- visited file is text or binary (if OS supports this distinction).
    %z -- print mnemonics of keyboard, terminal, and buffer coding systems.
    %Z -- like %z, but including the end-of-line format.
Index: lisp/bindings.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/bindings.el,v
retrieving revision 1.178
diff -p -r1.178 bindings.el
*** lisp/bindings.el	11 Feb 2007 22:11:48 -0000	1.178
--- lisp/bindings.el	18 Jul 2007 08:38:53 -0000
*************** Normally nil in most modes, since there 
*** 248,253 ****
--- 248,270 ----
  
  (make-variable-buffer-local 'mode-line-modified)
  
+ (defvar mode-line-remote
+   (list (propertize
+ 	 "%1R"
+ 	 'help-echo (purecopy (lambda (window object point)
+  				(format "%s"
+ 					(save-selected-window
+ 					  (select-window window)
+ 					  (concat 
+ 					  (if (file-remote-p default-directory)
+ 					      "Remote: "
+ 					    "Local: ")
+ 					  default-directory)))))))
+   "Mode-line flag to show if default-directory for the current buffer
+ is on a remote machine.")
+ 
+ (make-variable-buffer-local 'mode-line-remote)
+ 
  ;; Actual initialization is below.
  (defvar mode-line-position nil
    "Mode-line control for displaying the position in the buffer.
*************** Keymap to display on minor modes.")
*** 287,292 ****
--- 304,310 ----
  	 (propertize "-" 'help-echo help-echo)
  	 'mode-line-mule-info
  	 'mode-line-modified
+ 	 'mode-line-remote
  	 'mode-line-frame-identification
  	 'mode-line-buffer-identification
  	 (propertize "   " 'help-echo help-echo)
Index: lisp/files.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/files.el,v
retrieving revision 1.912
diff -p -r1.912 files.el
*** lisp/files.el	17 Jul 2007 21:07:49 -0000	1.912
--- lisp/files.el	18 Jul 2007 08:39:02 -0000
*************** asking you for confirmation."
*** 2464,2469 ****
--- 2464,2470 ----
  	mode-line-mule-info
  	mode-line-position
  	mode-line-process
+ 	mode-line-remote
  	mode-name
  	outline-level
  	overriding-local-map