emacs-ipython-notebook/Enhancements.org

#+STARTUP: indent

* Overview
* Design
** Notebook Buffer

Notebook information is stored as a [[file:lisp/ein-notebook.el::ein:$notebook][struct]]. Always associated with a buffer,
[[file:lisp/ein-notebook.el::ein:notebook-buffer][ein:notebook-buffer]] is used to find buffer associated with a notebook.

Notebook does not hold cells, that is delegated to instances of the [[file:lisp/ein-worksheet.el::ein:worksheet][worksheet]]
class. Instances are stored as a list in the `ein:$notebook-worksheets` slot.

** Notebooklist Buffer
** Kernel communication
** Contents API
* Enhancements/Fixes
** Imenu/Speedbar Cooperation
Seems to be a couple ways of doing this:

 1. Configuring `[[http://emacswiki.org/emacs/ImenuMode#toc12][imenu-generic-expression]]` regex's.

 2. Redefining imenu-create-index ala python.el.

(2) seems to be the more elegant solution.

EIN currently has minimal support for imenu through
`[[file:lisp/ein-worksheet.el::ein:worksheet-imenu-create-index][ein:worksheet-imenu-create-index]]`, but all it does is look for
headings. Somehow this fails to work with speedbar and also does not handle
indexing Python code (i.e. variables, function, classes, etc.).

To get the speedbar working we will need to define a minor mode per the
following [[http://www.gnu.org/software/emacs/manual/html_node/speedbar/Minor-Display-Modes.html#Minor-Display-Modes][instructions]]. 

For /name/~-speedbar-menu-items~ can I just use ~imenu-generic-expression~?

Maybe the way to do this is for each ~[[file:lisp/ein-cell.el::ein:codecell][codecell]]~ create a temp buffer with the text
of that cell and call ~ein:imenu-create-index~.

#+BEGIN_SRC elisp
  (let ((text (ein:cell-get-text cell)))
    (with-temp-buffer
      (insert text)
      (ein:imenu-create-index)))
#+END_SRC

Still will need way to map temp buffer positions to actual positions in the
notebook buffer (~ein:cell-input-pos-min~ and ~ein:cell-input-pos-max~)

** Live links to other notebooks
    
 1. Understand how org-mode does it.
 2. Steal???
 3. Profit!!!

** Use polymode

[[https://github.com/vspinu/polymode][Polymode]] uses indirect buffers, which may or may not be a good solution for ein
notebooks.

** Access password protected notebooks
** Connect to non-python kernels
** Synergies with pymacs?
** Detect system path of opened notebook
** Jump to notebook code in traceback (issue [[https://github.com/millejoh/emacs-ipython-notebook/issues/42][#42]])

What needs to be done:

1. Carry notebook reference in the ~[[file:lisp/ein-traceback.el::ein:traceback][ein:traceback]]~ structure.
2. Look for ~<ipython-input-3-05c9758a9c21> in <module>()~. The number 3 means
   input #3 in the notebook.
3. Find cell based on input number. Can iterate through list of cells () and look for matching
   ~input-prompt-number~.
4. Call ~ein:cell-goto~ on that cell. May need to swap buffers first.

** Return of worksheets

tkf/ein and IPython 2.x allowed for multiple worksheets within an individual
notebook. This feature was removed in 3.0 since multiple worksheets do not make
much sense in the context of a tabbed web browser interface. EIN's legacy code
still supports worksheets, though at the moment that information is lost upon
saving a notebook.

Having multiple worksheet support makes some sense for ein; below is thinking on
how to reimplement this feature.

IPython nbformat 4 specifies a [[http://ipython.org/ipython-doc/3/notebook/nbformat.html#metadata][metadata]] key which can be used to store general
information. Cell metadad has a tag key which is a "A list of string tags on the
cell. Commas are not allowed in a tag."

Best place to set the tag key is when generating [[content]] for saving a notebook.