[SOLVED] How to make mouse wheel scroll ONE line at a time in Emacs ?

ntubski · 07-17-2010, 12:22 AM

The -nw option would cause emacs to run inside a terminal so it can't get input from the mouse. In that case the terminal emulator is what is scrolling, not emacs. I use urxvt and it appears to scroll 5 lines at a time.

Aquarius_Girl · 07-17-2010, 12:29 AM

Quote:

Originally Posted by ntubski

The -nw option would cause emacs to run inside a terminal so it can't get input from the mouse. In that case the terminal emulator is what is scrolling, not emacs. I use urxvt and it appears to scroll 5 lines at a time.

Till now all I was telling you was w.r.t using Emacs with -nw option !!!!

Now I used

Code:

emacs file.c

and when I moved the center wheel of my mouse, the screen scrolled but not the cursor !!!

Did this happen in your case too ? I want the cursor to move not the screen !

ntubski · 07-17-2010, 12:39 AM

Quote:

Originally Posted by anishakaul

Till now all I was telling you was w.r.t using Emacs with -nw option !!!!

Hah, this has been an interesting case of online miscommunication.

Quote:

Now I used

Code:

emacs file.c

and when I moved the center wheel of my mouse, the screen scrolled but not the cursor !!!

Did this happen in your case too ? I want the cursor to move not the screen !

Yes that is the standard behaviour. Although note that in emacs, unlike in most other applications, the cursor always remains in the screen: if you move the screen far enough that the cursor goes off screen it gets "pushed" by the edge so that it stays in view.

If you want the mouse wheel to move the cursor, you can get that with

Code:

(define-key global-map (kbd "<mouse-5>") 'next-line)
(define-key global-map (kbd "<mouse-4>") 'previous-line)

Aquarius_Girl · 07-17-2010, 12:45 AM

Quote:

Originally Posted by ntubski

If you want the mouse wheel to move the cursor, you can get that with

Code:

(define-key global-map (kbd "<mouse-5>") 'next-line)
(define-key global-map (kbd "<mouse-4>") 'previous-line)

Thanks again, but that didn't help !

I added the following lines at the end of my .emacs file, closed it, restarted emacs, but again, the screen moves, cursor stays still, which is very annoying !!

Did you try that on your machine ?

ntubski · 07-17-2010, 12:47 AM

Quote:

Originally Posted by anishakaul

Did you try that on your machine ?

It works here. This is without -nw, mind.

Aquarius_Girl · 07-17-2010, 12:51 AM

I tried that once again, doesn't work,

Since you have tried it on your comp, please paste your .emacs file here, let me copy it and see what happens.

ntubski · 07-17-2010, 01:01 AM

As before I haven't put this in my own .emacs, but it works with .emacs consisting soley of the lines:

Code:

(define-key global-map (kbd "<mouse-5>") 'next-line)
(define-key global-map (kbd "<mouse-4>") 'previous-line)

Can you post the contents of *Help* buffer when you do C-h k <scroll with mouse wheel>, this is what I get:

Code:

<mouse-5> (translated from <down-mouse-5> <mouse-5>)
at that spot runs
the command next-line, which is an interactive compiled Lisp function.

It is bound to <mouse-5>, C-n.

(next-line &optional arg try-vscroll)
...

Aquarius_Girl · 07-17-2010, 01:05 AM

Thanks for bothering

Code:

<mouse-4> (translated from <down-mouse-4> <mouse-4>) at that spot runs the
command mwheel-scroll, which is an interactive compiled Lisp function.

It is bound to <mouse-5>, <S-mouse-5>, <C-mouse-5>, <mouse-4>, <S-mouse-4>,
<C-mouse-4>.

(mwheel-scroll EVENT)

Scroll up or down according to the EVENT.
This should only be bound to mouse buttons 4 and 5.

ntubski · 07-17-2010, 01:22 AM

It appears that the define-key calls didn't work.

Okay, let's see what happens with this .emacs:

Code:

(message "defining keys")
(describe-key-briefly (kbd "C-t"))
(define-key global-map (kbd "<mouse-5>") 'next-line)
(define-key global-map (kbd "<mouse-4>") 'previous-line)
(define-key global-map (kbd "C-t") 'next-line)
(message "defined keys")
(describe-key-briefly (kbd "C-t"))

Post the contents of the *Messages* buffer.

I get

Code:

For information about GNU Emacs and the GNU system, type C-h C-a.
defining keys
C-t runs the command transpose-chars
defined keys
C-t runs the command next-line

Quote:

Thanks for bothering

No problem, I'm going to be so satisfied when we figure this one out.

Aquarius_Girl · 07-17-2010, 01:28 AM

Thanks again,

*Messages* buffer:

Code:

Loading /usr/share/emacs/site-lisp/nxml-mode/rng-auto.el (source)...done
defining keys
C-t runs the command transpose-chars
defined keys
C-t runs the command next-line
For information about GNU Emacs and the GNU system, type C-h C-a.
Invalid image size (see `max-image-size') [10 times]

and here is the relevant code of my .emacs file

Code:

;; ========== Line by line scrolling ==========

;; scroll one line at a time (less "jumpy" than defaults)

(setq mouse-wheel-scroll-amount '(1 ((shift) . 1))) ;; one line at a time

(setq mouse-wheel-progressive-speed nil) ;; don't accelerate scrolling

(setq mouse-wheel-follow-mouse 't) ;; scroll window under mouse

(setq scroll-step 1) ;; keyboard scroll one line at a time
(setq scroll-conservatively 10000)
(setq mouse-wheel-scroll-amount '(0.01)) 

(define-key global-map (kbd "<mouse-5>") 'next-line)
(define-key global-map (kbd "<mouse-4>") 'previous-line)

(message "defining keys")
(describe-key-briefly (kbd "C-t"))
(define-key global-map (kbd "<mouse-5>") 'next-line)
(define-key global-map (kbd "<mouse-4>") 'previous-line)
(define-key global-map (kbd "C-t") 'next-line)
(message "defined keys")
(describe-key-briefly (kbd "C-t"))

Have you learnt Lisp ? Is that the reason you know so much ?

ntubski · 07-17-2010, 01:45 AM

The invalid image size looks kind of suspicious, although the define-key apparently worked on C-t.

Just to eliminate other factors, put just the following into a new file, call it scroll.el:

Code:

(message "defining keys")
(define-key global-map (kbd "<mouse-5>") 'next-line)
(define-key global-map (kbd "<mouse-4>") 'previous-line)
(message "defined keys")
(describe-key-briefly (kbd "<mouse-4>"))

Then run emacs like so

Code:

emacs -Q -l scroll.el

and post the *Messages* buffer.

Quote:

Originally Posted by anishakaul

Have you learnt Lisp ? Is that the reason you know so much ?

Learning Lisp, and also reading the manuals, and a lot of the EmacsWiki, and lots of experimenting.

Aquarius_Girl · 07-17-2010, 01:52 AM

Messages buffer:

Code:

For information about GNU Emacs and the GNU system, type C-h C-a.
defining keys
defined keys
<mouse-4> at that spot runs the command previous-line

Quote:

Originally Posted by ntubski

Learning Lisp, and also reading the manuals, and a lot of the EmacsWiki, and lots of experimenting.

Without learning Lisp, you couldn't have known all this, right ? EmacsWiki is not enough if one doesn't know Lisp !

ntubski · 07-17-2010, 02:01 AM

Quote:

Originally Posted by anishakaul

Messages buffer:

Code:

For information about GNU Emacs and the GNU system, type C-h C-a.
defining keys
defined keys
<mouse-4> at that spot runs the command previous-line

It looks like the mouse wheel was rebound correctly, did you try scrolling?

Quote:

Without learning Lisp, you couldn't have known all this, right ? EmacsWiki is not enough if one doesn't know Lisp !

Yes, knowing Lisp is what lets you adapt/create new solutions to fit the current problem, rather than just knowing a bunch of canned sequences.

Aquarius_Girl · 07-17-2010, 02:05 AM

Quote:

Originally Posted by ntubski

It looks like the mouse wheel was rebound correctly, did you try scrolling?

Yes, that did not help ! I see no point in banging my head now.

Emacs version:

Code:

GNU Emacs 23.1.1 (x86_64-suse-linux-gnu, GTK+ Version 2.18.1) of 2009-10-24 on build24

Quote:

Originally Posted by ntubski

Yes, knowing Lisp is what lets you adapt/create new solutions to fit the current problem, rather than just knowing a bunch of canned sequences.

Knowing Lisp was a part of your profession or just for knowing Emacs ?

Thanks for all your help till now.

ntubski · 07-17-2010, 02:22 AM

Quote:

Originally Posted by anishakaul

Yes, that did not help ! I see no point in banging my head now.

So just to be clear, you started with emacs -Q -l scroll.el, the *Message* buffer says that <mouse-4> is bound to previous-line, but scrolling with the mouse wheel doesn't move the cursor? If you use C-h k <mouse wheel> does it show <mouse-4> still bound to previous-line?

Quote:

Emacs version:

Code:

GNU Emacs 23.1.1 (x86_64-suse-linux-gnu, GTK+ Version 2.18.1) of 2009-10-24 on build24

Code:

GNU Emacs 23.1.1 (x86_64-pc-linux-gnu, GTK+ Version 2.18.3) of 2009-11-01 on excelsior, modified by Debian

Pretty much the same version, shouldn't be any problems there...

Quote:

Knowing Lisp was a part of your profession or just for knowing Emacs ?

Heh, still a student so I don't exactly have a profession. I learned scheme at in 1st year, and started using emacs a bit later. Then I noticed that elisp and scheme were similar so I read the An Introduction to Programming in Emacs Lisp, and I also learned Common Lisp later just for fun.