IPythonQt end of GSoC status

Enthought approved some funding for our mentors to develop the basis of this big projects that are rising. Yay!
Fernando Perez and Brian Granger (and I think Evan Patterson too) are working on a new communication interface between the kernel and any frontend(kernelmanager or kernel proxy in the diagram), to ease and standarize the work done by every frontend developer.

There're some changes also in the kernel by Fernando and Bryan.
And a reimplementation of the kernel manager by Evan using qt signals instead of callbacks for messages handling.
The floor is a little loose so the building of this scyscraper has to be more careful, and slow written and designed, but it will be for a greater good since its core it's getting robust and trustworthy.
Since the way to communicate with the kernel, and the kernel itself has changed, almost every part of the development before mid-term had to be written again, with a few stones in the way 'cause it depends on a bunch of people (just to mention that Evan and I are sharing QtKernelManager).
A new branch was created http://github.com/muzgash/ipython/tree/ipythonqt-km to implement kernelmanager.

Yesterday I was beginning the tooltip and tab completion support, it's not trivial, and since today is the 'suggested pencils down' date I'm going to improve the documentation and write some tests to fulfill Google and IPython's requirements.

8th week log, Mid-term evaluation!

A lot of details about pdb support and the organization of the output cells were discussed this week.

The characteristics added are:

• The output cells are appended as they appear in the space between th executed cell and the next executable cell. i.e.

for i in range(3):     print i**2

0

1

4

• When you execute again a cell the previous output cells are erased(if any)
• If a new cell is created by the program (not the user) the scroll bar goes to its maximum value. This is not the right way to approach the automatic movement of the viewport I know, I'll work on it on the weekend.
• You can clean the notebook of output cells by clicking a button in evaluate menu.

The last one is part of the details  usually add when my brain is stuck, I try to add a little thing every couple of days.

Today I'm working on subprocess, i.e. communication with the shell. I think I need to create an ipython's instance or inherit InteractiveShell, I'm waiting a hand from Fernando but this shouldn't be too dificult.

I also hope to finish everything planned round next week to put some effort on the highlighting and autoindentation.

Behind raw_input

This was a pretty heavy week.

there were two ways of approaching the raw_input problem, the right one, and the wrong one(lol):

• To fill the widget definition with signals and slots which will communicate the different IOs to the mainwindow and this one then will communicate those IOs to the kernel.
• To import zmq in the ipqt_popup module and manage the communication directly with the kernel.

I innocently chose the fist one (FAIL), "entia non sunt multiplicanda praeter necessitatem".

The widget was almost done when Fernando corrected me the design stating that it will be better to print all the messages from raw_input or pdb in the mainwidow not in a popped up widget.

Fortunately I managed to understand the mechanisms required for this to work correctly and I'm finishing it right now.

Some screenshots

Bryan suggested some screen shots of what's working. Just a pair of very, very simple examples:

Here we can see the main function of the frontend (run code) and some of its code in the back. (Yes, I'm very used to graphical editors)

And here we can see my yakuake terminal with some useless stuff and a terminal frontend for ipython which connects to the same kernel (i.e.communicate through the same ports), this one changing the value of 'a' which has been already assigned in the IPythonQt window, so a message appears in the new widget on the right (plz don't heed the preview).

Added features to June 29

What can you do?
When you open IPythonQt you see a menubar and a (still undeletable) input cell in which you can write ipython/python code.

You can execute the code written by pressing Ctrl+Return (shift doesn't work, I dunno why), or just go to the menu 'evaluate'.

You can call a context menu inside the cell which besides the standard buttons it has a new one to delete the cell.

If you right-click somewhere else in the notebook, a tiny context menu should appear to append a new input cell or to delete the last focused cell. A focused cell is the last you clicked, not the last you hover.

If you connect another frontend to the same kernel, another widget will come out with the info of the variables that changed and the user.

Some shortcuts has been created for the keyboard lover:

Ctrl+UpArrow goes to the previous cell

Ctrl+DownArrow goes to the next cell

Ctrl+Shift+UpArrow goes to the previous executable cell

Ctrl+Shift+DownArrow goes tot he next executable cell

Ctrl+Shift+N appends a new cell

Ctrl+Shift+Delete removes the current cell

Ctrl+Return Executes the current cell if it's executable

Ctrl+Q Quits

What you cannot do (yet):

The code still doesn't capture pyout, so code like:

_cell__

|a=10  |

|a        |

won't produce any output.

Calls to raw_input, %, !, system commands, tab completion, function tooltips, gdb and help.

Work right in progress:

Stdin support, since I have to have it finished for the mid-term evaluation, it's the main concern. The popup widget it's finished but there's still the raw_input function in the kernel that needs to be implemented correctly.

There's a new output cell if the same input cell is modified.

There's a discussion in the mailing list about if the different outputs from the same input should be on different cells (packable) or in the same cell.

The resizing of the cell when the block(line without '/n') is larger than the size of the window. For what I've seen this is not trivial.

Testing IPythonQt

For you to test IPythonQt you first need to set up some stuff first:

1. Install the following: git g++ cython uuid-dev python-qt4-dev pyqt4-dev-tools , I think that would be enough.
2. You also need to install zeromq and pyzmq from sources here's a good guide to do that.
3. Take into account that you need python2.6.

Now you can download IPythonQt's code from http://github.com/muzgash/ipython/tree/ipythonqt
check if you are in the right_branch (ipythonqt, not master): git branch
if not right_branch:
    git checkout ipythonqt

cd ipython/IPython/gui/qt

run ./kernel.py

Open a new terminal and run ./ipythonqt.py

Obviously it's not working with all its features, I just remove some dock widgets that were in the original design of the main view, but they're just commented because they don't do anything yet.

Repositories GitHub

You can check the progress at GitHub:
http://github.com/muzgash/ipython

The commits are a little slow because some issues with GitHub and its ssh keys