Mode to display information in the topmost line of a window

Mode to display information in the topmost line of a window

[Geralt]

Hi,

iirc there's a mode in Emacs to display some information in the
topmost line of a window, but I don't recall its name anymore.
Do you know what I'm talking about? And if yes do you know if it's
possible to display ElDoc's output in this line instead of the echo
area?



Thanks,

Geralt.

Re: Mode to display information in the topmost line of a window

[Tassilo Horn]

Geralt <usr.gentoo@googlemail.com> writes:

Hi Geralt,

> iirc there's a mode in Emacs to display some information in the
> topmost line of a window, but I don't recall its name anymore.  Do you
> know what I'm talking about?

Yes, but it's no mode, it's a simple variable you can set.

,----[ C-h v header-line-format RET ]
| header-line-format is a variable defined in `C source code'.
| Its value is nil
| 
|   Automatically becomes buffer-local when set in any fashion.
|   This variable is potentially risky when used as a file local variable.
| 
| Documentation:
| Analogous to `mode-line-format', but controls the header line.
| The header line appears, optionally, at the top of a window;
| the mode line appears at the bottom.
`----

> And if yes do you know if it's possible to display ElDoc's output in
> this line instead of the echo area?

I guess you could redefine the function `eldoc-message' and set
`header-line-format' there.

Bye,
Tassilo

Re: Mode to display information in the topmost line of a window

[Geralt]

On Thu, Jul 30, 2009 at 5:19 PM, Tassilo Horn<tassilo@member.fsf.org> wrote:
> Geralt <usr.gentoo@googlemail.com> writes:
>
> Hi Geralt,
>
>> iirc there's a mode in Emacs to display some information in the
>> topmost line of a window, but I don't recall its name anymore.  Do you
>> know what I'm talking about?
>
> Yes, but it's no mode, it's a simple variable you can set.
>
> ,----[ C-h v header-line-format RET ]
> | header-line-format is a variable defined in `C source code'.
> | Its value is nil
> |
> |   Automatically becomes buffer-local when set in any fashion.
> |   This variable is potentially risky when used as a file local variable.
> |
> | Documentation:
> | Analogous to `mode-line-format', but controls the header line.
> | The header line appears, optionally, at the top of a window;
> | the mode line appears at the bottom.
> `----
>
>> And if yes do you know if it's possible to display ElDoc's output in
>> this line instead of the echo area?
>
> I guess you could redefine the function `eldoc-message' and set
> `header-line-format' there.
>
> Bye,
> Tassilo
>
>
>
>
Hi Tassilo,

thanks, that helped me a lot! From what I've found it's as simple as
changing eldoc-message to:

(defun eldoc-message (&rest args)
  (let ((omessage eldoc-last-message))
    (setq eldoc-last-message
	  (cond ((eq (car args) eldoc-last-message) eldoc-last-message)
		((null (car args)) nil)
		;; If only one arg, no formatting to do, so put it in
		;; eldoc-last-message so eq test above might succeed on
		;; subsequent calls.
		((null (cdr args)) (car args))
		(t (apply 'format args))))
    ;; In emacs 19.29 and later, and XEmacs 19.13 and later, all messages
    ;; are recorded in a log.  Do not put eldoc messages in that log since
    ;; they are Legion.
    ;; Emacs way of preventing log messages.
    (let ((message-log-max nil))
      (cond (eldoc-last-message (setq header-line-format eldoc-last-message))
	    (omessage (message nil)))))
  eldoc-last-message)



What's the prefered way to overwrite a function? Just putting this one
into .emacs?




Geralt.

Re: Mode to display information in the topmost line of a window

[Lennart Borgman]

On Thu, Jul 30, 2009 at 5:47 PM, Geralt<usr.gentoo@googlemail.com> wrote:
> On Thu, Jul 30, 2009 at 5:19 PM, Tassilo Horn<tassilo@member.fsf.org> wrote:
>> Geralt <usr.gentoo@googlemail.com> writes:
>>
>> Hi Geralt,
>>
>>> iirc there's a mode in Emacs to display some information in the
>>> topmost line of a window, but I don't recall its name anymore.  Do you
>>> know what I'm talking about?
>>
>> Yes, but it's no mode, it's a simple variable you can set.
>>
>> ,----[ C-h v header-line-format RET ]
>> | header-line-format is a variable defined in `C source code'.
>> | Its value is nil
>> |
>> |   Automatically becomes buffer-local when set in any fashion.
>> |   This variable is potentially risky when used as a file local variable.
>> |
>> | Documentation:
>> | Analogous to `mode-line-format', but controls the header line.
>> | The header line appears, optionally, at the top of a window;
>> | the mode line appears at the bottom.
>> `----
>>
>>> And if yes do you know if it's possible to display ElDoc's output in
>>> this line instead of the echo area?
>>
>> I guess you could redefine the function `eldoc-message' and set
>> `header-line-format' there.
>>
>> Bye,
>> Tassilo
>>
>>
>>
>>
> Hi Tassilo,
>
> thanks, that helped me a lot! From what I've found it's as simple as
> changing eldoc-message to:
>
> (defun eldoc-message (&rest args)
>  (let ((omessage eldoc-last-message))
>    (setq eldoc-last-message
>          (cond ((eq (car args) eldoc-last-message) eldoc-last-message)
>                ((null (car args)) nil)
>                ;; If only one arg, no formatting to do, so put it in
>                ;; eldoc-last-message so eq test above might succeed on
>                ;; subsequent calls.
>                ((null (cdr args)) (car args))
>                (t (apply 'format args))))
>    ;; In emacs 19.29 and later, and XEmacs 19.13 and later, all messages
>    ;; are recorded in a log.  Do not put eldoc messages in that log since
>    ;; they are Legion.
>    ;; Emacs way of preventing log messages.
>    (let ((message-log-max nil))
>      (cond (eldoc-last-message (setq header-line-format eldoc-last-message))
>            (omessage (message nil)))))
>  eldoc-last-message)
>
>
>
> What's the prefered way to overwrite a function? Just putting this one
> into .emacs?


Looking through it more carefully and submitting a patch to Emacs.

Re: Mode to display information in the topmost line of a window

[Tassilo Horn]

Geralt <usr.gentoo@googlemail.com> writes:

Hi Geralt,

> thanks, that helped me a lot! From what I've found it's as simple as
> changing eldoc-message to:
> [...]

Great!

> What's the prefered way to overwrite a function? Just putting this one
> into .emacs?

Yes.

Bye,
Tassilo

Re: Mode to display information in the topmost line of a window

[Kevin Rodgers]

Geralt wrote:
> What's the prefered way to overwrite a function? Just putting this one
> into .emacs?

Don't overwrite it, so that you don't have to track changes to its
implementation:

(defadvice eldoc-message (after header-line-format activate)
   "If `eldoc-last-message' is non-nil, set `header-line-format'."
   (when eldoc-last-message
     (setq header-line-format 'eldoc-last-message)
     (force-mode-line-update)))

-- 
Kevin Rodgers
Denver, Colorado, USA

Re: Mode to display information in the topmost line of a window

[Tassilo Horn]

Kevin Rodgers <kevin.d.rodgers@gmail.com> writes:

Hi Kevin,

>> What's the prefered way to overwrite a function? Just putting this
>> one into .emacs?
>
> Don't overwrite it, so that you don't have to track changes to its
> implementation:
>
> (defadvice eldoc-message (after header-line-format activate)
>   "If `eldoc-last-message' is non-nil, set `header-line-format'."
>   (when eldoc-last-message
>     (setq header-line-format 'eldoc-last-message)
>     (force-mode-line-update)))

I'd generally agree, but I guess Gerald doesn't want to duplicate the
eldoc output in the header line, but instead he wants it to be there
only.

BTW: In contrast to the echo area, the header-line allows only one
single line of content.  So you might want to let-bind
`eldoc-echo-area-use-multiline-p' to nil.

BTW2: I think this eldoc-in-header-line is really nice.  Gerald, you
might want to built that into eldoc.el directly as an option, and submit
a patch to emacs-devel, so that others can share the experience.

Bye,
Tassilo

Re: Mode to display information in the topmost line of a window

[Geralt]

On Fri, Jul 31, 2009 at 9:12 AM, Tassilo Horn<tassilo@member.fsf.org> wrote:
> Kevin Rodgers <kevin.d.rodgers@gmail.com> writes:
>
> Hi Kevin,
>
>>> What's the prefered way to overwrite a function? Just putting this
>>> one into .emacs?
>>
>> Don't overwrite it, so that you don't have to track changes to its
>> implementation:
>>
>> (defadvice eldoc-message (after header-line-format activate)
>>   "If `eldoc-last-message' is non-nil, set `header-line-format'."
>>   (when eldoc-last-message
>>     (setq header-line-format 'eldoc-last-message)
>>     (force-mode-line-update)))
>
> I'd generally agree, but I guess Gerald doesn't want to duplicate the
> eldoc output in the header line, but instead he wants it to be there
> only.
>
Hi,

yes, that's right, I want the information in the header line only.

> BTW: In contrast to the echo area, the header-line allows only one
> single line of content.  So you might want to let-bind
> `eldoc-echo-area-use-multiline-p' to nil.
>
That's right, but I'm using ElDoc not for Emacs Lisp, but with
c-eldoc[1] to display C function signatures, or anything C-related
that's at point.
I don't like it if ElDoc is overwriting all the time the messages in
the echo area, the header line is a better place for that (I think),
but only since it's rarely used (and thus it's never overwriting
anything).

> BTW2: I think this eldoc-in-header-line is really nice.  Gerald, you
> might want to built that into eldoc.el directly as an option, and submit
> a patch to emacs-devel, so that others can share the experience.
>
I can try, but my Emacs Lisp knowledge is quite limited, I'll try to
come up with something customizable and I'll post it here for review
:)





Geralt.



P.S. It's Geralt with a t at the end (and don't worry, no offensive taken!).

RE: Mode to display information in the topmost line of a window

[Drew Adams]

As an alternative, you might want to put the info in the mode line.
This is what I use:

(defun show-in-mode-line (text &optional buffer)
  "Display TEXT in BUFFER's mode line for 10 sec (or until user event).
Note: This sits for 10 sec or until a user event, so call this last in
a sequence of user-visible actions."
  (with-current-buffer (or buffer (current-buffer))
    (make-local-variable 'mode-line-format)
    (let ((mode-line-format  text))
     (force-mode-line-update) (sit-for 10))
    (force-mode-line-update)))

Re: Mode to display information in the topmost line of a window

[Geralt]

[-- Attachment #1: Type: text/plain, Size: 1998 bytes --]

On Fri, Jul 31, 2009 at 6:19 PM, Drew Adams<drew.adams@oracle.com> wrote:
> As an alternative, you might want to put the info in the mode line.
> This is what I use:
>
> (defun show-in-mode-line (text &optional buffer)
>  "Display TEXT in BUFFER's mode line for 10 sec (or until user event).
> Note: This sits for 10 sec or until a user event, so call this last in
> a sequence of user-visible actions."
>  (with-current-buffer (or buffer (current-buffer))
>    (make-local-variable 'mode-line-format)
>    (let ((mode-line-format  text))
>     (force-mode-line-update) (sit-for 10))
>    (force-mode-line-update)))
>
>
Hi,

I've already got a lot of information there, especially when I'm
clocking a task with org-mode.


I've finished the changes to eldoc and here's a patch containing them
(but you better try the patch in the attachement since GoogleMail is
doing some changes to whitespace):

--- eldoc.el	2009-07-31 18:03:58.000000000 +0200
+++ eldoc.el	2009-08-01 01:30:34.732647994 +0200
@@ -105,6 +105,11 @@
  enable argument list to fit on one line" truncate-sym-name-if-fit))
   :group 'eldoc)

+(defcustom eldoc-display-in-header-line nil
+  "If set eldoc will display its messages in the topmost line of the
window, called the header-line, instead of the echo area."
+  :type 'boolean
+  :group 'eldoc)
+
 (defface eldoc-highlight-function-argument
   '((t (:inherit bold)))
   "Face used for the argument at point in a function's argument list.
@@ -201,7 +206,9 @@
     ;; they are Legion.
     ;; Emacs way of preventing log messages.
     (let ((message-log-max nil))
-      (cond (eldoc-last-message (message "%s" eldoc-last-message))
+      (cond (eldoc-last-message (if eldoc-display-in-header-line
+				    (setq header-line-format eldoc-last-message)
+				  (message "%s" eldoc-last-message)))
 	    (omessage (message nil)))))
   eldoc-last-message)




Do you think that's good enough for a submission?




Geralt.

[-- Attachment #2: eldoc-display-in-header-line.patch --]
[-- Type: application/octet-stream, Size: 977 bytes --]

--- eldoc.el	2009-07-31 18:03:58.000000000 +0200
+++ eldoc.el	2009-08-01 01:30:34.732647994 +0200
@@ -105,6 +105,11 @@
  enable argument list to fit on one line" truncate-sym-name-if-fit))
   :group 'eldoc)
 
+(defcustom eldoc-display-in-header-line nil
+  "If set eldoc will display its messages in the topmost line of the window, called the header-line, instead of the echo area."
+  :type 'boolean
+  :group 'eldoc)
+
 (defface eldoc-highlight-function-argument
   '((t (:inherit bold)))
   "Face used for the argument at point in a function's argument list.
@@ -201,7 +206,9 @@
     ;; they are Legion.
     ;; Emacs way of preventing log messages.
     (let ((message-log-max nil))
-      (cond (eldoc-last-message (message "%s" eldoc-last-message))
+      (cond (eldoc-last-message (if eldoc-display-in-header-line
+				    (setq header-line-format eldoc-last-message)
+				  (message "%s" eldoc-last-message)))
 	    (omessage (message nil)))))
   eldoc-last-message)
 

Re: Mode to display information in the topmost line of a window

[Lennart Borgman]

On Sat, Aug 1, 2009 at 1:46 AM, Geralt<usr.gentoo@googlemail.com> wrote:
>     (let ((message-log-max nil))
> -      (cond (eldoc-last-message (message "%s" eldoc-last-message))
> +      (cond (eldoc-last-message (if eldoc-display-in-header-line
> +                                   (setq header-line-format eldoc-last-message)
> +                                 (message "%s" eldoc-last-message)))
>            (omessage (message nil)))))
>   eldoc-last-message)

Isn't the line (omessage (message nil)) clearing old messages in the
message area? If the head-line is used that should not be needed.

Re: Mode to display information in the topmost line of a window

[Geralt]

On Sat, Aug 1, 2009 at 1:51 AM, Lennart
Borgman<lennart.borgman@gmail.com> wrote:
> On Sat, Aug 1, 2009 at 1:46 AM, Geralt<usr.gentoo@googlemail.com> wrote:
>>     (let ((message-log-max nil))
>> -      (cond (eldoc-last-message (message "%s" eldoc-last-message))
>> +      (cond (eldoc-last-message (if eldoc-display-in-header-line
>> +                                   (setq header-line-format eldoc-last-message)
>> +                                 (message "%s" eldoc-last-message)))
>>            (omessage (message nil)))))
>>   eldoc-last-message)
>
> Isn't the line (omessage (message nil)) clearing old messages in the
> message area? If the head-line is used that should not be needed.
>
Yes, you're right, I'll put that one into the ELSE clause and then
I'll submit it to emacs-devel@gnu.org





Geralt.

RE: Mode to display information in the topmost line of a window

[Drew Adams]

> I've finished the changes to eldoc and here's a patch containing them
...
> Do you think that's good enough for a submission?

Send it to emacs-devel@gnu.org, and ask there. They will let you know what, if
anything, might need to be changed. help-gnu-emacs is not the best list to find
out whether a patch is good enough for a submission. emacs-devel is perfect for
that question.