#!/usr/bin/env python
# coding: utf-8

# # Keyboard Shortcut Customization

# Starting with Jupyter Notebook 5.0, you can customize the `command` mode shortcuts from within the Notebook Application itself. 
# 
# Head to the **`Help`** menu and select the **`Edit keyboard Shortcuts`** item.
# A dialog will guide you through the process of adding custom keyboard shortcuts.
# 
# Keyboard shortcut set from within the Notebook Application will be persisted to your configuration file. 
# A single action may have several shortcuts attached to it.

# # Keyboard Shortcut Customization (Pre Notebook 5.0)

# Starting with IPython 2.0 keyboard shortcuts in command and edit mode are fully customizable. These customizations are made using the Jupyter JavaScript API. Here is an example that makes the `r` key available for running a cell:

# In[ ]:


get_ipython().run_cell_magic('javascript', '', "\nJupyter.keyboard_manager.command_shortcuts.add_shortcut('r', {\n    help : 'run cell',\n    help_index : 'zz',\n    handler : function (event) {\n        IPython.notebook.execute_cell();\n        return false;\n    }}\n);\n")


# "By default the keypress `r`, while in command mode, changes the type of the selected cell to `raw`.  This shortcut is overridden by the code in the previous cell, and thus the action no longer be available via the keypress `r`."

# There are a couple of points to mention about this API:
# 
# * The `help_index` field is used to sort the shortcuts in the Keyboard Shortcuts help dialog. It defaults to `zz`.
# * When a handler returns `false` it indicates that the event should stop propagating and the default action should not be performed. For further details about the `event` object or event handling, see the jQuery docs.
# * If you don't need a `help` or `help_index` field, you can simply pass a function as the second argument to `add_shortcut`.

# In[ ]:


get_ipython().run_cell_magic('javascript', '', "\nJupyter.keyboard_manager.command_shortcuts.add_shortcut('r', function (event) {\n    IPython.notebook.execute_cell();\n    return false;\n});\n")


# Likewise, to remove a shortcut, use `remove_shortcut`:

# In[ ]:


get_ipython().run_cell_magic('javascript', '', "\nJupyter.keyboard_manager.command_shortcuts.remove_shortcut('r');\n")


# If you want your keyboard shortcuts to be active for all of your notebooks, put the above API calls into your `custom.js` file.

# Of course we provide name for majority of existing action so that you do not have to re-write everything, here is for example how to bind `r` back to it's initial behavior:

# In[ ]:


get_ipython().run_cell_magic('javascript', '', "\nJupyter.keyboard_manager.command_shortcuts.add_shortcut('r', 'jupyter-notebook:change-cell-to-raw');\n")