Added shorcuts to split cell, merge cell above and merge cell below.

[damianavila]

OK, I think that we desperately need a shortcut key to split cell function... and also it would be great to have the same for merge cell above and merge cell below.

The task of splitting cell is a common task when you write documents containing a lot of text... or when you are doing a presentation using slideshow preset in the CellToolBar. The same, although with a less frequency, happens with merge cell functions... but yet I think they deserve a shortcut.

This PR implements this key events, and I have assigned the following keys (available in a row):

• Ctrl-m 7 --- split cell
• Ctrl-m 8 --- merge cell above
• Ctrl-m 9 --- merge cell below

That's all...

Damián

pinging @ivanov who agreed with me in the SciPy sprint about the split shortcut... hehe... 👍

UPDATE: For now, we are only considering the split shortcut as Ctrl-m -

[minrk]

numbers are already assigned to heading cell levels, so probably not the best choice.

[damianavila]

cell levels 1-6... 7, 8, 9 are free... but i don't have problem to change them... but...if not IPython shortcuts, the others keys are used by the browsers... so if not the numbers keys, what keys do you recommend?

[minrk]

pinging @ellisonbg for review on this one.

[ellisonbg]

I agree we need keyboard shortcuts, but I think the numbers are bad choices. What letter are free?

[damianavila]

I think we have almost all the letters covered... at least using Ctrl-m...
q is free (i don't know if some browsers use it, at least Chromium don't),
w-e-r-u-f-g are used by almost all the browsers,
and the rest of the letters are used by IPython.
Maybe using some symbols... if we want to keep Ctrl-m... or change to Alt or Shift, but It will be better I think to keep Ctrl-m...

[Carreau]

I would tend to think that split and merge are not that important, and that we better have fix the hard coded keyboard shortcut than piling up shortcut. especially if we want dual-mode editor, we could free up shortcut later.

[damianavila]

Hi, @Carreau... I fundamentally disagree with you in that ;-)
Maybe is a bias in my way to use the notebook, but I think a lot of people will find very very useful to have the split/merge functions linking to keyboard events because is a very recurrent event in the workflow of writing, editing and formatting a ipynb.
I don't know what is the current status of the dual-mode editor... we talked about getting it ready for 1.0, but I don't know how advanced is @ellisonbg in this modification... if the dual-mode is ready for 1.0, we can for sure wait for this and make what you suggested, but if it is not ready for 1.0, I think would be appropriate to have the shortcut for split/merge done in the current status of hard coded keyboard shortcuts.
I mean, hard-coded or after dual-mode, I think the the split/merge functions need shortcuts for the 1.0 release.

[takluyver]

I'm pretty sure that the intention is to have the new editing system in
place before 1.0 - that's why we were focussing so much on it in the sprint.

[ellisonbg]

I am making good progress on the dual mode work. I should have a PR ready this week. That the request, however, wont change that the number of available keyboard shortcuts.

Sent from my iPhone

On Jul 7, 2013, at 5:59 AM, Thomas Kluyver notifications@github.com wrote:

I'm pretty sure that the intention is to have the new editing system in
place before 1.0 - that's why we were focussing so much on it in the sprint.
—
Reply to this email directly or view it on GitHub.

[damianavila]

Ok @ellisonbg, if your PR is not going to free some keyboard shortcuts, we have to deal with the decision to add or not add the shortcuts for this split/merge functions... I believe we have to add them...

[takluyver]

That change won't make any more shortcuts available while editing, but it
will while navigating, because keystrokes won't be captured by the editor
then. Merge above/below could easily be done while navigating, but split
needs to be done while editing, because it hinges on the cursor position.

On 7 July 2013 17:23, Damián Avila notifications@github.com wrote:

Ok @ellisonbg https://github.com/ellisonbg, if your PR is not going to
free some keyboard shortcuts, we have to deal with the decision to add or
not add the shortcuts for this split/merge funcions... I believe we have to
add them...

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Reply to this email directly or view it on GitHubhttps://github.com//pull/3571#issuecomment-20573108
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[damianavila]

I agree with you but... we will use the same keyboard shortcuts to do different things depending of the context?
Maybe, it sounds strange to me because I use IPython and a plain text editor to code...
This multiple behavior is common in vim or emacs?
From a pedagogical perspective, this can be very confusing for users not used to deal with advanced coding tools, like me... hehe

[takluyver]

I wouldn't think of it as doing different things depending on context.
Rather, I think there will be certain things that you can only do while not
editing a cell. This isn't unusual: e.g. in GMail, I can normally type 'c'
to start composing a new e-mail. But if I'm already writing an e-mail,
typing 'c' just adds a c in the message. I guess we'll add some similar
single-key shortcuts which only apply when you're not entering text.

For reference, the 'dual-mode' behaviour (I'm trying to avoid calling it
that) is characteristic of vim, though apparently Emacs also has something
similar.

[damianavila]

OK, thanks for explaining... but if this is the case, then we have the problem of lack of enough keys again... ;-)

[ivanov]

for the record, though I do think we need a keyboard shortcut for splitting cells, Ctrl-m 7 was not what I had in mind ;)

[minrk]

Is Ctrl-M - available for split (like drawing a horizontal line)?

[damianavila]

for the record, though I do think we need a keyboard shortcut for splitting cells, Ctrl-m 7 was not what I had in mind ;)

he he he ;-)

Is Ctrl-M - available for split (like drawing a horizontal line)?

I like it... I assume that you think the merge function can wait for shortcuts... ;-)

[minrk]

I assume that you think the merge function can wait for shortcuts... ;-)

I just don't have an idea for what they should be. If I remember correctly, we can switch on shift, so maybe shift-A and shift-B for merge above/below? shortcuts are precious, and I think merge is not a high priority action (select/cut/up/paste covers it - a bit slow, but not difficult).

[damianavila]

I just don't have an idea for what they should be. If I remember correctly, we can switch on shift, so maybe shift-A and shift-B for merge above/below? shortcuts are precious, and I think merge is not a high priority action (select/cut/up/paste covers it - a bit slow, but not difficult).

Yeah, I know they are precious, I can live without merge shortcuts for now... ;-)

OK, I like Ctrl-M - for splitting purpose... anyone else has something to say... if not I will update the PR only with the shortcut split, we can discuss later (probably in another PR after the land of the dual mode) if we need the merge ones.

[Carreau]

I just don't have an idea for what they should be. If I remember correctly, we can switch on shift, so maybe shift-A and shift-B for merge above/below? shortcuts are precious, and I think merge is not a high priority action (select/cut/up/paste covers it - a bit slow, but not difficult).

I must admit that with shift-cmd-down, cmd-x,C-m,b,cmd-v I'm pretty fast too to split too.

[damianavila]

I must admit that with shift-cmd-down, cmd-x,C-m,b,cmd-v I'm pretty fast too to split too.

But not enough fast when you have to split multiple times when you are formatting a large document or change types of slides in your slideshows... I can live without merge shortcuts, but not having a split shortcut is actually annoying, because you (I mean, I... maybe the workflow of others is different) split cells with a high frequency ;-)

[ellisonbg]

I like the Ctrl-M - shortcut

On Tue, Jul 9, 2013 at 1:00 PM, Damián Avila notifications@github.comwrote:

I must admit that with shift-cmd-down, cmd-x,C-m,b,cmd-v I'm pretty fast
too to split too.

But not enough fast when you have to split multiple times when you are
formatting a large document or change types of slides in your slideshows...
I can live without merge shortcuts, but not having a split shortcut is
actually annoying, because you (I mean, I... maybe the workflow of others
is different) split cells with a high frequency ;-)

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Reply to this email directly or view it on GitHubhttps://github.com//pull/3571#issuecomment-20701154
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Brian E. Granger
Cal Poly State University, San Luis Obispo
bgranger@calpoly.edu and ellisonbg@gmail.com

[ellisonbg]

I am OK with this as is, how do others feel about the Crtl-M - shortcut?

[ivanov]

+1 on Ctrl-M -

[Carreau]

Neutral for me.

[damianavila]

OK, we have at least three :+1 and one neutral... anyone else out there to make a vote? ;-)

[Carreau]

@ellisonbg this will conflict with your #3605 what should we do ?

[jakobgager]

Neutral for me too, as I've never used the split option but don't see a reason not to implement this shortcut.

[jasongrout]

For merging in the Sage notebook---if you are at the first position in a cell and press backspace, it will merge with the previous cell. That's a way to do it without shortcut keys, and is rather natural.

[ellisonbg]

It is probably easiest if I just add this to my PR.

On Thu, Jul 11, 2013 at 5:17 AM, Matthias Bussonnier <
notifications@github.com> wrote:

@ellisonbg https://github.com/ellisonbg this will conflict with your
#3605 #3605 what should we do ?

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Brian E. Granger
Cal Poly State University, San Luis Obispo
bgranger@calpoly.edu and ellisonbg@gmail.com

[damianavila]

OK, after listen to Brian, I think we can merge it ;-)

[damianavila]

Thanks! I love the split shortcut 👍

[dpsanders]

Just found this discussion -- +1 for the split shortcut!