Text selection can't be erased by pressing delete

Text selection can't be erased by pressing delete

[Gabriel TEIXEIRA]

Hello all,

I've been working with three simultaneous emacs windows, each one 
containing a diferent project, and I noticed that two of those three are 
presenting a weird behaviour. When I select a text in those windows 
(like by pushing Shift and then the arrow keys), and then I push the key 
Delete, I expect that the selected/highlighted text be erased, but 
instead, it erases a single character to the left of the cursor (like 
would happen without the selection) and the selection disappears 
(although the same operation works with Backspace or Shift+Delete 
normally). It seems that the Delete key is not anymore aware of the text 
selection. It is even more weird the fact that this doesn't happen with 
the window that I opened the last and the other windows that I opened 
after to check the behaviour. I seems that emacs "wears" after some time 
opened. Anyone have any idea of what's this? Is this a bug or I typed 
accidentaly any command that triggers this behaviour?

Thanks in advance
Gabriel Teixeira

Re: Text selection can't be erased by pressing delete

[Eli Zaretskii]

> Date: Fri, 20 Aug 2010 14:08:57 +0200
> From: Gabriel TEIXEIRA <gabriel_teixeira@sdesigns.eu>
> 
> I've been working with three simultaneous emacs windows, each one 
> containing a diferent project, and I noticed that two of those three are 
> presenting a weird behaviour. When I select a text in those windows 
> (like by pushing Shift and then the arrow keys), and then I push the key 
> Delete, I expect that the selected/highlighted text be erased, but 
> instead, it erases a single character to the left of the cursor (like 
> would happen without the selection) and the selection disappears 
> (although the same operation works with Backspace or Shift+Delete 
> normally). It seems that the Delete key is not anymore aware of the text 
> selection. It is even more weird the fact that this doesn't happen with 
> the window that I opened the last and the other windows that I opened 
> after to check the behaviour. I seems that emacs "wears" after some time 
> opened. Anyone have any idea of what's this? Is this a bug or I typed 
> accidentaly any command that triggers this behaviour?

What does the following command display, when you invoke it from each
of the 3 windows?

  C-h c <Delete>

That is, type "C-h c", the press the <Delete> key.

Also, what version of Emacs is that?  What does "M-x emacs-version"
display?

Re: Text selection can't be erased by pressing delete

[Pascal J. Bourguignon]

Gabriel TEIXEIRA <gabriel_teixeira@sdesigns.eu> writes:

> Hello all,
>
> I've been working with three simultaneous emacs windows, each one
> containing a diferent project, and I noticed that two of those three
> are presenting a weird behaviour. When I select a text in those
> windows (like by pushing Shift and then the arrow keys), and then I
> push the key Delete, I expect that the selected/highlighted text be
> erased, but instead, it erases a single character to the left of the
> cursor (like would happen without the selection) and the selection
> disappears (although the same operation works with Backspace or
> Shift+Delete normally). 

This is the normal emacs behavior.  You've been distorted by the later
"graphical user interfaces".

You see, emacs stays consistent.  There's a command to delete the
previous character, and there's another command to delete a region.
Each one is bound to a different key.  There's no reason why that should
change just because you change the selected region.

So, to delete the previous character, you use delete-backward-char,
which is usually bound to DEL, and to delete the region you use
kill-region, which is usually bound to C-w (like: Control "wipe").


> It seems that the Delete key is not anymore
> aware of the text selection. It is even more weird the fact that this
> doesn't happen with the window that I opened the last and the other
> windows that I opened after to check the behaviour. I seems that emacs
> "wears" after some time opened. Anyone have any idea of what's this?
> Is this a bug or I typed accidentaly any command that triggers this
> behaviour?

There are major modes, and minor modes, and also random code that can
change the key maps.

You could bind your own command globally to DEL, but it will still be
overriden by specific modes.

For example, you could do:

    (defun distorted-gui-delete (start end)
       (interactive "*r")
       (message "%S %S" start end)
       (if (= start end)
          (delete-backward-char 1)
          (delete-region start end)))

    (global-set-key (kbd "DEL") 'distorted-gui-delete)


But some modes will still override this binding with their specific mapping.


So better remember that DEL deletes the previous character(s), and C-w
kills the region.  (Notice that M-w saves it to the kill-ring, so that
you can later yank it with C-y).

Notice also that you can type M-DEL to kill the previous word, so that
you often don't need to select anything to kill what you want.



-- 
__Pascal Bourguignon__                     http://www.informatimago.com/

Re: Text selection can't be erased by pressing delete

[Gabriel TEIXEIRA]

In the ill windows:

DEL (translated from <backspace>) runs the command c-electric-backspace
DEL (translated from <backspace>) runs the command c-electric-backspace

And in the good windows:
DEL (translated from <backspace>) runs the command c-electric-backspace

And, yes, I forgot to tell the emacs version before asking. Here it is:
GNU Emacs 24.0.50.1 (x86_64-unknown-linux-gnu, GTK+ Version 2.20.1) of 
2010-07-22 on kobe

On 20/08/2010 14:27, Eli Zaretskii wrote:
>> Date: Fri, 20 Aug 2010 14:08:57 +0200
>> From: Gabriel TEIXEIRA<gabriel_teixeira@sdesigns.eu>
>>
>> I've been working with three simultaneous emacs windows, each one
>> containing a diferent project, and I noticed that two of those three are
>> presenting a weird behaviour. When I select a text in those windows
>> (like by pushing Shift and then the arrow keys), and then I push the key
>> Delete, I expect that the selected/highlighted text be erased, but
>> instead, it erases a single character to the left of the cursor (like
>> would happen without the selection) and the selection disappears
>> (although the same operation works with Backspace or Shift+Delete
>> normally). It seems that the Delete key is not anymore aware of the text
>> selection. It is even more weird the fact that this doesn't happen with
>> the window that I opened the last and the other windows that I opened
>> after to check the behaviour. I seems that emacs "wears" after some time
>> opened. Anyone have any idea of what's this? Is this a bug or I typed
>> accidentaly any command that triggers this behaviour?
>>      
> What does the following command display, when you invoke it from each
> of the 3 windows?
>
>    C-h c<Delete>
>
> That is, type "C-h c", the press the<Delete>  key.
>
> Also, what version of Emacs is that?  What does "M-x emacs-version"
> display?
>
>
>    

Re: Text selection can't be erased by pressing delete

[Gabriel TEIXEIRA]

> On 20/08/2010 14:27, Eli Zaretskii wrote:
>>> Date: Fri, 20 Aug 2010 14:08:57 +0200
>>> From: Gabriel TEIXEIRA<gabriel_teixeira@sdesigns.eu>
>>>
>>> I've been working with three simultaneous emacs windows, each one
>>> containing a diferent project, and I noticed that two of those three 
>>> are
>>> presenting a weird behaviour. When I select a text in those windows
>>> (like by pushing Shift and then the arrow keys), and then I push the 
>>> key
>>> Delete, I expect that the selected/highlighted text be erased, but
>>> instead, it erases a single character to the left of the cursor (like
>>> would happen without the selection) and the selection disappears
>>> (although the same operation works with Backspace or Shift+Delete
>>> normally). It seems that the Delete key is not anymore aware of the 
>>> text
>>> selection. It is even more weird the fact that this doesn't happen with
>>> the window that I opened the last and the other windows that I opened
>>> after to check the behaviour. I seems that emacs "wears" after some 
>>> time
>>> opened. Anyone have any idea of what's this? Is this a bug or I typed
>>> accidentaly any command that triggers this behaviour?
>> What does the following command display, when you invoke it from each
>> of the 3 windows?
>>
>>    C-h c<Delete>
>>
>> That is, type "C-h c", the press the<Delete>  key.
>>
>> Also, what version of Emacs is that?  What does "M-x emacs-version"
>> display?
>>
>
Please, disconsider my last e-mail, here it is the correct stuff:

In the ill windows:

C-d (translated from <delete>) runs the command c-electric-delete-forward
C-d (translated from <delete>) runs the command c-electric-delete-forward

And in the good windows:
C-d (translated from <delete>) runs the command c-electric-delete-forward

And, yes, I forgot to tell the emacs version before asking. Here it is:
GNU Emacs 24.0.50.1 (x86_64-unknown-linux-gnu, GTK+ Version 2.20.1) of 
2010-07-22 on kobe

Re: Text selection can't be erased by pressing delete

[Gabriel TEIXEIRA]

On 20/08/2010 15:15, Gabriel TEIXEIRA wrote:
>
>> On 20/08/2010 14:27, Eli Zaretskii wrote:
>>>> Date: Fri, 20 Aug 2010 14:08:57 +0200
>>>> From: Gabriel TEIXEIRA<gabriel_teixeira@sdesigns.eu>
>>>>
>>>> I've been working with three simultaneous emacs windows, each one
>>>> containing a diferent project, and I noticed that two of those 
>>>> three are
>>>> presenting a weird behaviour. When I select a text in those windows
>>>> (like by pushing Shift and then the arrow keys), and then I push 
>>>> the key
>>>> Delete, I expect that the selected/highlighted text be erased, but
>>>> instead, it erases a single character to the left of the cursor (like
>>>> would happen without the selection) and the selection disappears
>>>> (although the same operation works with Backspace or Shift+Delete
>>>> normally). It seems that the Delete key is not anymore aware of the 
>>>> text
>>>> selection. It is even more weird the fact that this doesn't happen 
>>>> with
>>>> the window that I opened the last and the other windows that I opened
>>>> after to check the behaviour. I seems that emacs "wears" after some 
>>>> time
>>>> opened. Anyone have any idea of what's this? Is this a bug or I typed
>>>> accidentaly any command that triggers this behaviour?
>>> What does the following command display, when you invoke it from each
>>> of the 3 windows?
>>>
>>>    C-h c<Delete>
>>>
>>> That is, type "C-h c", the press the<Delete>  key.
>>>
>>> Also, what version of Emacs is that?  What does "M-x emacs-version"
>>> display?
>>>
>>
> Please, disconsider my last e-mail, here it is the correct stuff:
>
> In the ill windows:
>
> C-d (translated from <delete>) runs the command c-electric-delete-forward
> C-d (translated from <delete>) runs the command c-electric-delete-forward
>
> And in the good windows:
> C-d (translated from <delete>) runs the command c-electric-delete-forward
>
> And, yes, I forgot to tell the emacs version before asking. Here it is:
> GNU Emacs 24.0.50.1 (x86_64-unknown-linux-gnu, GTK+ Version 2.20.1) of 
> 2010-07-22 on kobe
>
>
I also found that when doing a selection and hitting Enter or any other 
character inserting key, the entire selection will be replaced by the 
character in the good window but in the ill windows the character will 
be just inserted and the selection will be unselected. Hopefully this 
can help.

Re: Text selection can't be erased by pressing delete

[Bob Proulx]

Gabriel TEIXEIRA wrote:
> I've been working with three simultaneous emacs windows, each one  
> containing a diferent project, and I noticed that two of those three are  
> presenting a weird behaviour.

On what system are you running emacs?  Is this GNU/Unix, Cygwin, MSYS,
other?  Running in a terminal window, or under a X11, or other native
graphics?

> When I select a text in those windows (like by pushing Shift and
> then the arrow keys), and then I push the key Delete, I expect that
> the selected/highlighted text be erased, but instead, it erases a
> single character to the left of the cursor (like would happen
> without the selection) and the selection disappears (although the
> same operation works with Backspace or Shift+Delete normally).  It
> seems that the Delete key is not anymore aware of the text
> selection.

That would be the "normal" traditional behavior of Emacs on Unix
machines for all of time prior to the recent introduction of Microsoft
key bindings.

> It is even more weird the fact that this doesn't happen with the
> window that I opened the last and the other windows that I opened
> after to check the behaviour. I seems that emacs "wears" after some
> time opened.

That does seem strange that it would change behavior depending upon
whether you have launched subsequent emacs processes.

> Anyone have any idea of what's this? Is this a bug or I typed
> accidentaly any command that triggers this behaviour?

I do not use CUA mode but the behavior makes me wonder if something is
causing it to be enabled and then disabled somehow.

  http://www.emacswiki.org/CuaMode

What is the behavior when using emacs without customizations?

  emacs -q

And without any initialization?

  emacs -Q

Thinking that there must be something in the initialization that is
behaving undesirably.

Bob

Re: Text selection can't be erased by pressing delete

[Gabriel TEIXEIRA]

On 20/08/2010 18:42, Bob Proulx wrote:
> Gabriel TEIXEIRA wrote:
>    
>> I've been working with three simultaneous emacs windows, each one
>> containing a diferent project, and I noticed that two of those three are
>> presenting a weird behaviour.
>>      
> On what system are you running emacs?  Is this GNU/Unix, Cygwin, MSYS,
> other?  Running in a terminal window, or under a X11, or other native
> graphics?
>
>    
It is under Ubuntu Linux 10.04 x64 in the graphics mode.
>> When I select a text in those windows (like by pushing Shift and
>> then the arrow keys), and then I push the key Delete, I expect that
>> the selected/highlighted text be erased, but instead, it erases a
>> single character to the left of the cursor (like would happen
>> without the selection) and the selection disappears (although the
>> same operation works with Backspace or Shift+Delete normally).  It
>> seems that the Delete key is not anymore aware of the text
>> selection.
>>      
> That would be the "normal" traditional behavior of Emacs on Unix
> machines for all of time prior to the recent introduction of Microsoft
> key bindings.
>
>    
Which I think is a good behaviour since the delete key is just above the 
arrow keys in my keyboard while the backspace is a little further. Since 
I do selections using Shift + arrows, the delete lies just within the 
range of my middle finger, while the backspace would need to elevate the 
entire hand up to there, so I prefer use the delete. Besides the fact 
that I can just select the text and overwrite it directly.
>> It is even more weird the fact that this doesn't happen with the
>> window that I opened the last and the other windows that I opened
>> after to check the behaviour. I seems that emacs "wears" after some
>> time opened.
>>      
> That does seem strange that it would change behavior depending upon
> whether you have launched subsequent emacs processes.
>
>    
As I told already, maybe I mistyped something that led to this 
behaviour. Those instances are opened for weeks and the behaviour 
appeared after some days. I would like to know how to resolve this 
without doing the Microsoft solution (restarting emacs), which works, 
but lose all the layout of windows and the undo history.
>> Anyone have any idea of what's this? Is this a bug or I typed
>> accidentaly any command that triggers this behaviour?
>>      
> I do not use CUA mode but the behavior makes me wonder if something is
> causing it to be enabled and then disabled somehow.
>
>    http://www.emacswiki.org/CuaMode
>
> What is the behavior when using emacs without customizations?
>
>    emacs -q
>
>    
It behaves in the "normal" mode, no deletion with delete
> And without any initialization?
>
>    emacs -Q
>
>    
The same, 'course.
> Thinking that there must be something in the initialization that is
> behaving undesirably.
>    
More likely to be any crazy (or lazy) finger of mine, but I leave the 
hypotesys of "time wear", like a bug caused by any memory leak, 
overflowed counter or command that is disabling the mode unexpectedly 
(which I think is very unlikely).
> Bob
>
>    
Thanks for the advice about the cua-mode. I gave a read to the page and 
when I did M-x cua-mode, it got back to my favourite mode! Now I must 
figure out which command sequence is disabling the cua-mode in order 
that I don't do this anymore. I think that ad infinitum I will stop 
doing those mistakes. I noticed that emacs commands are easy to mistake 
one for another while typing, like, in an AZERTY kb, the C-x (one of the 
most used) for the C-w (after I deleted 100 lines of c code and saved 
the file unaware of that. By luck, I had a copy in the CVS).

Gabriel Teixeira

Re: Text selection can't be erased by pressing delete

[Pascal J. Bourguignon]

Gabriel TEIXEIRA <gabriel_teixeira@sdesigns.eu> writes:

> Thanks for the advice about the cua-mode. I gave a read to the page
> and when I did M-x cua-mode, it got back to my favourite mode! Now I
> must figure out which command sequence is disabling the cua-mode in
> order that I don't do this anymore. I think that ad infinitum I will
> stop doing those mistakes. I noticed that emacs commands are easy to
> mistake one for another while typing, like, in an AZERTY kb, the C-x
> (one of the most used) for the C-w (after I deleted 100 lines of c
> code and saved the file unaware of that. By luck, I had a copy in the
> CVS).

Yes, using an AZERTY keyboard is really desperately seeking problems.

-- 
__Pascal Bourguignon__                     http://www.informatimago.com/

Re: Text selection can't be erased by pressing delete

[Uday Reddy]

On 8/20/2010 2:15 PM, Gabriel TEIXEIRA wrote:

>
> In the ill windows:
>
> C-d (translated from <delete>) runs the command c-electric-delete-forward
> C-d (translated from <delete>) runs the command c-electric-delete-forward
>
> And in the good windows:
> C-d (translated from <delete>) runs the command c-electric-delete-forward

This means that either you don't have the CUA-mode turned on or you don't have 
a region highlighted.

Try the original question again after turning on the CUA-mode and highlighting 
regions.

Cheers,
Uday Reddy

Re: Text selection can't be erased by pressing delete

[Xah Lee]

On Aug 20, 5:08 am, Gabriel TEIXEIRA <gabriel_teixe...@sdesigns.eu>
wrote:
> Hello all,
>
> I've been working with three simultaneous emacs windows, each one
> containing a diferent project, and I noticed that two of those three are
> presenting a weird behaviour. When I select a text in those windows
> (like by pushing Shift and then the arrow keys), and then I push the key
> Delete, I expect that the selected/highlighted text be erased, but
> instead, it erases a single character to the left of the cursor (like
> would happen without the selection) and the selection disappears
> (although the same operation works with Backspace or Shift+Delete
> normally). It seems that the Delete key is not anymore aware of the text
> selection. It is even more weird the fact that this doesn't happen with
> the window that I opened the last and the other windows that I opened
> after to check the behaviour. I seems that emacs "wears" after some time
> opened. Anyone have any idea of what's this? Is this a bug or I typed
> accidentaly any command that triggers this behaviour?
>
> Thanks in advance
> Gabriel Teixeira

hi, all you need is to turn on the delete-selection-mode

• New Features in Emacs 23
  http://xahlee.org/emacs/emacs23_features.html

quote:

     Also, now you can hold down the Shift key then press arrows key
to select text. To turn this off, put:

     (setq shift-select-mode nil) ; “t” for true, “nil” for false

     However, by default, pressing delete key will not delete selected
text. If you want this, put:

     (delete-selection-mode 1) ; make typing override text selection

i don't know if that is on in emacs 24, but maybe give it a try.

note that cua-mode also turns on the typing overwrite behavior, but is
is not done by having delete-selection-mode, it implemented it's own.

also, if your selection is made by mouse, then it will automatically
have delete selection behavior, even if delete-selection-mode is not
on.

it short, the situation is a bit messy.

also, this problem happens to me too, that sometimes for some reason
the delete selection behavior is gone. Quite annoying. When this
happens, i call delete-selection-mode again to turn it back.

 Xah ∑ http://xahlee.org/ ☄

Re: Text selection can't be erased by pressing delete

[Xah Lee]

On Aug 20, 5:45 am, p...@informatimago.com (Pascal J. Bourguignon)
wrote:
> Gabriel TEIXEIRA <gabriel_teixe...@sdesigns.eu> writes:
> > Hello all,
>
> > I've been working with three simultaneous emacs windows, each one
> > containing a diferent project, and I noticed that two of those three
> > are presenting a weird behaviour. When I select a text in those
> > windows (like by pushing Shift and then the arrow keys), and then I
> > push the key Delete, I expect that the selected/highlighted text be
> > erased, but instead, it erases a single character to the left of the
> > cursor (like would happen without the selection) and the selection
> > disappears (although the same operation works with Backspace or
> > Shift+Delete normally).
>
> This is the normal emacs behavior.  You've been distorted by the later
> "graphical user interfaces".

hi Pascal, that's a point of view. From the other side, it can be
considered that YOU've been distorted by 1980's computing interfaces.

 Xah ∑ http://xahlee.org/ ☄