Remapping notebook shortcuts

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As Jupyter notebook run in a browser for technical and practical reasons we only have a limited number of shortcuts available and choices need to be made. Often this choices may conflict with browser shortcut, and you might need to remap it.

Today I was inform by Stefan van Der Walt that Cmd-Shift-P conflict for Firefox. It is mapped both to open the Command palette for the notebook and open a new Private Browsing window.

Using Private Browsing windows is extremely useful. When developing a website you might want to look at it without being logged in, and with an empty cache. So let see how we can remap the Jupyter notebook shortcut.

TL; DR;

Use the following in your ~/.jupyter/custom/custom.js :

require(['base/js/namespace'], function(Jupyter){
  // we might want to but that in a callback on wait for 
  // en even telling us the ntebook is ready.
  console.log('== remaping command palette shortcut ==')
  // note that meta is the command key on mac.
  var source_sht = 'meta-shift-p'
  var target_sht = 'meta-/'
  var cmd_shortcuts = Jupyter.keyboard_manager.command_shortcuts;
  var action_name = cmd_shortcuts.get_shortcut(source_sht)
  cmd_shortcuts.add_shortcut(target_sht, action_name)
  cmd_shortcuts.remove_shortcut(source_sht)
  console.log('== ', action_name, 'remaped from', source_sht, 'to', target_sht )
})

details

We need to use require and register a callback once the notebook is loaded:

require(['base/js/namespace'], function(Jupyter){ ... })

Here we grab the main namespace and name it Jupyter.

Then get the object that hold the various shortcuts: var cmd_shortcuts = Jupyter.keyboard_manager.command_shortcuts.

Shortcuts are define by sequence on keys with modifiers. Modifiers are dash-separated (need to be pressed at the same time). Sequence are comma separated. Example quiting in vim would be esc,;,w,q, in emacs ctrl-x,ctrl-c.

Here we want to unbind meta-shift-p (p is lowercase despite shift being pressed) and bind meta-/ (The shortcut Stefan wants). Note that meta- is the command key on mac.

We need to get the current command bound to this shortcut (cmd_shortcuts.get_shortcut(source_sht)). You could hardcode the name of the command but it may change a bit depending on notebook version (this is not yet public API). Here it is jupyter-notebook:show-command-palette.

You now bind it to your new shortcut:

cmd_shortcuts.add_shortcut('meta-/', action_name)

And finally unbind the original one

cmd_shortcuts.remove_shortcut('meta-shift-p')

UI reflect your changes !

If you open the command palette, you should see that the Show command palette command now display Command-/ as its shortcut !

Future

We are working on an interface to edit shortcuts directly from within the UI and not to have to write a single line of code !

Questions, feedback and fixes welcomed