More PEP8 changes

IPython/html/widgets/widget.py

@@ -1,449 +1,429 b''
 """Base Widget class.  Allows user to create widgets in the back-end that render
 in the IPython notebook front-end.
 """
 #-----------------------------------------------------------------------------
 # Copyright (c) 2013, the IPython Development Team.
 #
 # Distributed under the terms of the Modified BSD License.
 #
 # The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from contextlib import contextmanager
 import inspect
 import types
 
 from IPython.kernel.comm import Comm
 from IPython.config import LoggingConfigurable
 from IPython.utils.traitlets import Unicode, Dict, Instance, Bool
 from IPython.utils.py3compat import string_types
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 class Widget(LoggingConfigurable):
 
     # Shared declarations (Class level)
     widget_construction_callback = None
     widgets = {}
 
     def on_widget_constructed(callback):
-        """Class method, registers a callback to be called when a widget is
-        constructed.  The callback must have the following signature:
+        """Registers a callback to be called when a widget is constructed.  
+
+        The callback must have the following signature:
         callback(widget)"""
         Widget.widget_construction_callback = callback
 
     def _call_widget_constructed(widget):
         """Class method, called when a widget is constructed."""
         if Widget.widget_construction_callback is not None and callable(Widget.widget_construction_callback):
             Widget.widget_construction_callback(widget)
 
-    
-
     # Public declarations (Instance level)
     model_name = Unicode('WidgetModel', help="""Name of the backbone model 
         registered in the front-end to create and sync this widget with.""")
     view_name = Unicode(help="""Default view registered in the front-end
         to use to represent the widget.""", sync=True)
 
     @contextmanager
     def property_lock(self, key, value):
         """Lock a property-value pair.
 
         NOTE: This, in addition to the single lock for all state changes, is 
         flawed.  In the future we may want to look into buffering state changes 
         back to the front-end."""
         self._property_lock = (key, value)
         try:
             yield
         finally:
             self._property_lock = (None, None)
 
     def should_send_property(self, key, value):
         """Check the property lock (property_lock)"""
         return key != self._property_lock[0] or \
         value != self._property_lock[1]
 
     @property
     def keys(self):
         if self._keys is None:
             self._keys = []
             for trait_name in self.trait_names():
                 if self.trait_metadata(trait_name, 'sync'):
                     self._keys.append(trait_name)
         return self._keys
 
     # Private/protected declarations
     _comm = Instance('IPython.kernel.comm.Comm')
     
     def __init__(self, **kwargs):
-        """Public constructor
-        """
+        """Public constructor"""
         self.closed = False
         self._property_lock = (None, None)
         self._display_callbacks = []
         self._msg_callbacks = []
         self._keys = None
         super(Widget, self).__init__(**kwargs)
 
         self.on_trait_change(self._handle_property_changed, self.keys)
         Widget._call_widget_constructed(self)
 
     def __del__(self):
         """Object disposal"""
         self.close()
 
     def close(self):
-        """Close method.  Closes the widget which closes the underlying comm.
+        """Close method.  
+
+        Closes the widget which closes the underlying comm.
         When the comm is closed, all of the widget views are automatically
         removed from the front-end."""
         if not self.closed:
             self._comm.close() 
             self._close()
 
-
     def _close(self):
         """Unsafe close"""
         del Widget.widgets[self.model_id]
         self._comm = None
         self.closed = True
 
-
     @property
     def comm(self):
         if self._comm is None:
             # Create a comm.
             self._comm = Comm(target_name=self.model_name)
             self._comm.on_msg(self._handle_msg)
             self._comm.on_close(self._close)
             Widget.widgets[self.model_id] = self
 
             # first update
             self.send_state()
         return self._comm
     
     @property
     def model_id(self):
         return self.comm.comm_id
 
     # Event handlers
     def _handle_msg(self, msg):
         """Called when a msg is received from the front-end"""
         data = msg['content']['data']
         method = data['method']
         if not method in ['backbone', 'custom']:
             self.log.error('Unknown front-end to back-end widget msg with method "%s"' % method)
 
         # Handle backbone sync methods CREATE, PATCH, and UPDATE all in one.
         if method == 'backbone' and 'sync_data' in data:
             sync_data = data['sync_data']
             self._handle_receive_state(sync_data) # handles all methods
 
         # Handle a custom msg from the front-end
         elif method == 'custom':
             if 'custom_content' in data:
                 self._handle_custom_msg(data['custom_content'])
 
-
     def _handle_receive_state(self, sync_data):
         """Called when a state is received from the front-end."""
         for name in self.keys:
             if name in sync_data:
                 value = self._unpack_widgets(sync_data[name])
                 with self.property_lock(name, value):
                     setattr(self, name, value)
 
-
     def _handle_custom_msg(self, content):
         """Called when a custom msg is received."""
         for handler in self._msg_callbacks:
             handler(self, content)
 
-
     def _handle_property_changed(self, name, old, new):
         """Called when a property has been changed."""
         # Make sure this isn't information that the front-end just sent us.
         if self.should_send_property(name, new):
             # Send new state to front-end
             self.send_state(key=name)
 
     def _handle_displayed(self, **kwargs):
         """Called when a view has been displayed for this widget instance"""
         for handler in self._display_callbacks:
             handler(self, **kwargs)
 
     # Public methods
     def send_state(self, key=None):
         """Sends the widget state, or a piece of it, to the front-end.
 
         Parameters
         ----------
         key : unicode (optional)
             A single property's name to sync with the front-end.
         """
         self._send({"method": "update",
             "state": self.get_state()})
 
     def get_state(self, key=None):
         """Gets the widget state, or a piece of it.
 
         Parameters
         ----------
         key : unicode (optional)
             A single property's name to get.
         """
         keys = self.keys if key is None else [key]
         return {k: self._pack_widgets(getattr(self, k)) for k in keys} 
 
-
     def _pack_widgets(self, values):
-        """This function recursively converts all widget instances to model id
-        strings.
+        """Recursively converts all widget instances to model id strings.
 
         Children widgets will be stored and transmitted to the front-end by 
         their model ids."""
         if isinstance(values, dict):
             new_dict = {}
             for key, value in values.items():
                 new_dict[key] = self._pack_widgets(value)
             return new_dict
         elif isinstance(values, list):
             new_list = []
             for value in values:
                 new_list.append(self._pack_widgets(value))
             return new_list
         elif isinstance(values, Widget):
             return values.model_id
         else:
             return values
 
-
     def _unpack_widgets(self, values):
-        """This function recursively converts all model id strings to widget 
-        instances.
+        """Recursively converts all model id strings to widget instances.
 
         Children widgets will be stored and transmitted to the front-end by 
         their model ids."""
         if isinstance(values, dict):
             new_dict = {}
             for key, values in values.items():
                 new_dict[key] = self._unpack_widgets(values[key])
             return new_dict
         elif isinstance(values, list):
             new_list = []
             for value in values:
                 new_list.append(self._unpack_widgets(value))
             return new_list
         elif isinstance(values, string_types):
             if values in Widget.widgets:
                 return Widget.widgets[values]
             else:
                 return values
         else:
             return values
 
-
     def send(self, content):
         """Sends a custom msg to the widget model in the front-end.
 
         Parameters
         ----------
         content : dict
             Content of the message to send.
         """
         self._send({"method": "custom", "custom_content": content})
 
-
     def on_msg(self, callback, remove=False):
-        """Register or unregister a callback for when a custom msg is recieved 
-        from the front-end.
+        """(Un)Register a custom msg recieve callback.
 
         Parameters
         ----------
         callback: method handler
             Can have a signature of:
             - callback(content)
             - callback(sender, content)
         remove: bool
             True if the callback should be unregistered."""
         if remove and callback in self._msg_callbacks:
             self._msg_callbacks.remove(callback)
         elif not remove and not callback in self._msg_callbacks:
             if callable(callback):
                 argspec = inspect.getargspec(callback)
                 nargs = len(argspec[0])
 
                 # Bound methods have an additional 'self' argument
                 if isinstance(callback, types.MethodType):
                     nargs -= 1
 
                 # Call the callback
                 if nargs == 1:
                     self._msg_callbacks.append(lambda sender, content: callback(content))
                 elif nargs == 2:
                     self._msg_callbacks.append(callback)
                 else:
                     raise TypeError('Widget msg callback must ' \
                         'accept 1 or 2 arguments, not %d.' % nargs)
             else:
                 raise Exception('Callback must be callable.')
 
-
     def on_displayed(self, callback, remove=False):
-        """Register or unregister a callback to be called when the widget has 
-        been displayed.
+        """(Un)Register a widget displayed callback.
 
         Parameters
         ----------
         callback: method handler
             Can have a signature of:
             - callback(sender, **kwargs)
               kwargs from display call passed through without modification.
         remove: bool
             True if the callback should be unregistered."""
         if remove and callback in self._display_callbacks:
             self._display_callbacks.remove(callback)
         elif not remove and not callback in self._display_callbacks:
             if callable(handler):
                 self._display_callbacks.append(callback)
             else:
                 raise Exception('Callback must be callable.')
 
-
     # Support methods
     def _ipython_display_(self, **kwargs):
-        """Function that is called when `IPython.display.display` is called on
-        the widget."""
-            
+        """Called when `IPython.display.display` is called on the widget."""
         # Show view.  By sending a display message, the comm is opened and the
         # initial state is sent.
         self._send({"method": "display"})
         self._handle_displayed(**kwargs)
 
-
     def _send(self, msg):
-        """Sends a message to the model in the front-end"""
+        """Sends a message to the model in the front-end."""
         self.comm.send(msg)
 
 
 class DOMWidget(Widget):
     visible = Bool(True, help="Whether or not the widget is visible.", sync=True)
 
     # Private/protected declarations
     _css = Dict(sync=True) # Internal CSS property dict
 
     def get_css(self, key, selector=""):
         """Get a CSS property of the widget.
 
         Note: This function does not actually request the CSS from the 
         front-end;  Only properties that have been set with set_css can be read.
 
         Parameters
         ----------
         key: unicode
             CSS key
         selector: unicode (optional)
             JQuery selector used when the CSS key/value was set.
         """
         if selector in self._css and key in self._css[selector]:
             return self._css[selector][key]
         else:
             return None
 
     def set_css(self, *args, **kwargs):
         """Set one or more CSS properties of the widget.
 
         This function has two signatures:
         - set_css(css_dict, selector='')
         - set_css(key, value, selector='')
 
         Parameters
         ----------
         css_dict : dict
             CSS key/value pairs to apply
         key: unicode
             CSS key
         value
             CSS value
         selector: unicode (optional)
             JQuery selector to use to apply the CSS key/value.  If no selector 
             is provided, an empty selector is used.  An empty selector makes the 
             front-end try to apply the css to a default element.  The default
             element is an attribute unique to each view, which is a DOM element
             of the view that should be styled with common CSS (see 
             `$el_to_style` in the Javascript code).
         """
         selector = kwargs.get('selector', '')
         if not selector in self._css:
             self._css[selector] = {}
             
         # Signature 1: set_css(css_dict, selector='')
         if len(args) == 1:
             if isinstance(args[0], dict):
                 for (key, value) in args[0].items():
                     if not (key in self._css[selector] and value == self._css[selector][key]):
                         self._css[selector][key] = value
                 self.send_state('_css')
             else:
                 raise Exception('css_dict must be a dict.')
 
         # Signature 2: set_css(key, value, selector='')
         elif len(args) == 2 or len(args) == 3:
 
             # Selector can be a positional arg if it's the 3rd value
             if len(args) == 3:
                 selector = args[2]
             if selector not in self._css:
                 self._css[selector] = {}
 
             # Only update the property if it has changed.
             key = args[0]
             value = args[1]
             if not (key in self._css[selector] and value == self._css[selector][key]):
                 self._css[selector][key] = value
                 self.send_state('_css') # Send new state to client.
         else:
             raise Exception('set_css only accepts 1-3 arguments')
 
-
     def add_class(self, class_names, selector=""):
-        """Add class[es] to a DOM element
+        """Add class[es] to a DOM element.
 
         Parameters
         ----------
         class_names: unicode or list
             Class name(s) to add to the DOM element(s).
         selector: unicode (optional)
             JQuery selector to select the DOM element(s) that the class(es) will
             be added to.
         """
         class_list = class_names
         if isinstance(class_list, list):
             class_list = ' '.join(class_list)
 
         self.send({"msg_type": "add_class",
             "class_list": class_list,
             "selector": selector})
 
-
     def remove_class(self, class_names, selector=""):
-        """Remove class[es] from a DOM element
+        """Remove class[es] from a DOM element.
 
         Parameters
         ----------
         class_names: unicode or list
             Class name(s) to remove from  the DOM element(s).
         selector: unicode (optional)
             JQuery selector to select the DOM element(s) that the class(es) will
             be removed from.
         """
         class_list = class_names
         if isinstance(class_list, list):
             class_list = ' '.join(class_list)
 
         self.send({"msg_type": "remove_class",
             "class_list": class_list,
             "selector": selector})

IPython/html/widgets/widget_bool.py

@@ -1,32 +1,33 b''
 """BoolWidget class.  
 
 Represents a boolean using a widget.
 """
 #-----------------------------------------------------------------------------
 # Copyright (c) 2013, the IPython Development Team.
 #
 # Distributed under the terms of the Modified BSD License.
 #
 # The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from .widget import DOMWidget
 from IPython.utils.traitlets import Unicode, Bool, List
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 class CheckBoxWidget(DOMWidget):
     view_name = Unicode('CheckBoxView', sync=True)
 
     # Model Keys
     value = Bool(False, help="Bool value", sync=True)
     description = Unicode('', help="Description of the boolean (label).", sync=True) 
     disabled = Bool(False, help="Enable or disable user changes.", sync=True)
 
+
 class ToggleButtonWidget(CheckBoxWidget):
     view_name = Unicode('ToggleButtonView', sync=True)
     
  No newline at end of file

IPython/html/widgets/widget_button.py

@@ -1,91 +1,88 b''
 """ButtonWidget class.  
 
 Represents a button in the frontend using a widget.  Allows user to listen for
 click events on the button and trigger backend code when the clicks are fired.
 """
 #-----------------------------------------------------------------------------
 # Copyright (c) 2013, the IPython Development Team.
 #
 # Distributed under the terms of the Modified BSD License.
 #
 # The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 import inspect
 import types
 
 from .widget import DOMWidget
 from IPython.utils.traitlets import Unicode, Bool
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 class ButtonWidget(DOMWidget):
     view_name = Unicode('ButtonView', sync=True)
 
     # Keys
     description = Unicode('', help="Description of the button (label).", sync=True)
     disabled = Bool(False, help="Enable or disable user changes.", sync=True)
     
-
     def __init__(self, **kwargs):
+        """Constructor"""
         super(ButtonWidget, self).__init__(**kwargs)
         
         self._click_handlers = []
         self.on_msg(self._handle_button_msg)
 
-
     def on_click(self, callback, remove=False):
-        """Register a callback to execute when the button is clicked.  The
-        callback can either accept no parameters or one sender parameter:
+        """Register a callback to execute when the button is clicked.  
+
+        The callback can either accept no parameters or one sender parameter:
         - callback()
         - callback(sender)
         If the callback has a sender parameter, the ButtonWidget instance that
         called the callback will be passed into the method as the sender.
 
         Parameters
         ----------
         remove : bool (optional)
             Set to true to remove the callback from the list of callbacks."""
         if remove:
             self._click_handlers.remove(callback)
         elif not callback in self._click_handlers:
             self._click_handlers.append(callback)
 
-
     def _handle_button_msg(self, content):
-        """Handle a msg from the front-end
+        """Handle a msg from the front-end.
 
         Parameters
         ----------
         content: dict
             Content of the msg."""
         if 'event' in content and content['event'] == 'click':
             self._handle_click()
 
-
     def _handle_click(self):
-        """Handles when the button has been clicked.  Fires on_click
-        callbacks when appropriate."""
-        
+        """Handles when the button has been clicked.
+
+        Fires on_click callbacks when appropriate."""
         for handler in self._click_handlers:
             if callable(handler):
                 argspec = inspect.getargspec(handler)
                 nargs = len(argspec[0])
 
                 # Bound methods have an additional 'self' argument
                 if isinstance(handler, types.MethodType):
                     nargs -= 1
 
                 # Call the callback
                 if nargs == 0:
                     handler()
                 elif nargs == 1:
                     handler(self)
                 else:
                     raise TypeError('ButtonWidget click callback must ' \
                         'accept 0 or 1 arguments.')
-        

IPython/html/widgets/widget_container.py

@@ -1,33 +1,34 b''
 """ContainerWidget class.  
 
 Represents a container that can be used to group other widgets.
 """
 #-----------------------------------------------------------------------------
 # Copyright (c) 2013, the IPython Development Team.
 #
 # Distributed under the terms of the Modified BSD License.
 #
 # The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from .widget import DOMWidget
 from IPython.utils.traitlets import Unicode, Bool, List, Instance
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 class ContainerWidget(DOMWidget):
     view_name = Unicode('ContainerView', sync=True)
 
     # Keys, all private and managed by helper methods.  Flexible box model
     # classes...
     children = List(Instance(DOMWidget), sync=True)
     
     description = Unicode(sync=True)
     button_text = Unicode(sync=True)
 
+
 class ModalWidget(ContainerWidget):
     view_name = Unicode('ModalView', sync=True)

IPython/html/widgets/widget_float_range.py

@@ -1,49 +1,49 b''
 """FloatRangeWidget class.  
 
 Represents a bounded float using a widget.
 """
 #-----------------------------------------------------------------------------
 # Copyright (c) 2013, the IPython Development Team.
 #
 # Distributed under the terms of the Modified BSD License.
 #
 # The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from .widget import DOMWidget
 from IPython.utils.traitlets import Unicode, CFloat, Bool, List, Enum
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 class BoundedFloatTextWidget(DOMWidget):
     view_name = Unicode('FloatTextView', sync=True)
     value = CFloat(0.0, help="Float value", sync=True) 
     max = CFloat(100.0, help="Max value", sync=True)
     min = CFloat(0.0, help="Min value", sync=True)
     disabled = Bool(False, help="Enable or disable user changes", sync=True)
     step = CFloat(0.1, help="Minimum step that the value can take (ignored by some views)", sync=True)
     description = Unicode(help="Description of the value this widget represents", sync=True)
 
     def __init__(self, *pargs, **kwargs):
         """Constructor"""
         DOMWidget.__init__(self, *pargs, **kwargs)
         self.on_trait_change(self._validate, ['value', 'min', 'max'])
 
     def _validate(self, name, old, new):
-        """Validate value, max, min"""
+        """Validate value, max, min."""
         if self.min > new or new > self.max:
             self.value = min(max(new, self.min), self.max)
 
 
 class FloatSliderWidget(BoundedFloatTextWidget):
     view_name = Unicode('FloatSliderView', sync=True)
     orientation = Enum([u'horizontal', u'vertical'], u'horizontal', 
         help="Vertical or horizontal.", sync=True)
 
 
 class FloatProgressWidget(BoundedFloatTextWidget):
     view_name = Unicode('ProgressView', sync=True)

IPython/html/widgets/widget_int_range.py

@@ -1,51 +1,51 b''
 """IntRangeWidget class.  
 
 Represents a bounded int using a widget.
 """
 #-----------------------------------------------------------------------------
 # Copyright (c) 2013, the IPython Development Team.
 #
 # Distributed under the terms of the Modified BSD License.
 #
 # The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from .widget import DOMWidget
 from IPython.utils.traitlets import Unicode, CInt, Bool, List, Enum
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 class BoundedIntTextWidget(DOMWidget):
     view_name = Unicode('IntTextView', sync=True)
 
     # Keys
     value = CInt(0, help="Int value", sync=True) 
     max = CInt(100, help="Max value", sync=True)
     min = CInt(0, help="Min value", sync=True)
     disabled = Bool(False, help="Enable or disable user changes", sync=True)
     step = CInt(1, help="Minimum step that the value can take (ignored by some views)", sync=True)
     description = Unicode(help="Description of the value this widget represents", sync=True)
 
     def __init__(self, *pargs, **kwargs):
         """Constructor"""
         DOMWidget.__init__(self, *pargs, **kwargs)
         self.on_trait_change(self._validate, ['value', 'min', 'max'])
 
     def _validate(self, name, old, new):
-        """Validate value, max, min"""
+        """Validate value, max, min."""
         if self.min > new or new > self.max:
             self.value = min(max(new, self.min), self.max)
 
 
 class IntSliderWidget(BoundedIntTextWidget):
     view_name = Unicode('IntSliderView', sync=True)
     orientation = Enum([u'horizontal', u'vertical'], u'horizontal', 
         help="Vertical or horizontal.", sync=True)
 
 
 class IntProgressWidget(BoundedIntTextWidget):
     view_name = Unicode('ProgressView', sync=True)

IPython/html/widgets/widget_selectioncontainer.py

@@ -1,60 +1,59 b''
 """SelectionContainerWidget class.  
 
 Represents a multipage container that can be used to group other widgets into
 pages.
 """
 #-----------------------------------------------------------------------------
 # Copyright (c) 2013, the IPython Development Team.
 #
 # Distributed under the terms of the Modified BSD License.
 #
 # The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from .widget import DOMWidget
 from IPython.utils.traitlets import Unicode, Dict, CInt, List, Instance
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 class AccordionWidget(DOMWidget):
     view_name = Unicode('AccordionView', sync=True)
 
     # Keys
     _titles = Dict(help="Titles of the pages", sync=True)
     selected_index = CInt(0, sync=True)
 
     children = List(Instance(DOMWidget), sync=True)
 
     # Public methods
     def set_title(self, index, title):
-        """Sets the title of a container page
+        """Sets the title of a container page.
 
         Parameters
         ----------
         index : int
             Index of the container page
         title : unicode
             New title"""
         self._titles[index] = title
         self.send_state('_titles')
 
-
     def get_title(self, index):
-        """Gets the title of a container pages
+        """Gets the title of a container pages.
 
         Parameters
         ----------
         index : int
             Index of the container page"""
         if index in self._titles:
             return self._titles[index]
         else:
             return None
 
 
 class TabWidget(AccordionWidget):
     view_name = Unicode('TabView', sync=True)

IPython/html/widgets/widget_string.py

@@ -1,94 +1,95 b''
 """StringWidget class.  
 
 Represents a unicode string using a widget.
 """
 #-----------------------------------------------------------------------------
 # Copyright (c) 2013, the IPython Development Team.
 #
 # Distributed under the terms of the Modified BSD License.
 #
 # The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 import inspect
 import types
 
 from .widget import DOMWidget
 from IPython.utils.traitlets import Unicode, Bool, List
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 class HTMLWidget(DOMWidget):
     view_name = Unicode('HTMLView', sync=True)
 
     # Keys
     value = Unicode(help="String value", sync=True)
     disabled = Bool(False, help="Enable or disable user changes", sync=True)
     description = Unicode(help="Description of the value this widget represents", sync=True)
 
 
 class LatexWidget(HTMLWidget):
     view_name = Unicode('LatexView', sync=True)
 
 
 class TextAreaWidget(HTMLWidget):
     view_name = Unicode('TextAreaView', sync=True)
 
     def scroll_to_bottom(self):
         self.send({"method": "scroll_to_bottom"})
 
 
 class TextBoxWidget(HTMLWidget):
     view_name = Unicode('TextBoxView', sync=True)
 
     def __init__(self, **kwargs):
         super(TextBoxWidget, self).__init__(**kwargs)
         self._submission_callbacks = []        
         self.on_msg(self._handle_string_msg)
 
     def _handle_string_msg(self, content):
-        """Handle a msg from the front-end
+        """Handle a msg from the front-end.
 
         Parameters
         ----------
         content: dict
             Content of the msg."""
         if 'event' in content and content['event'] == 'submit':
             for handler in self._submission_callbacks:
                 handler(self)
 
     def on_submit(self, callback, remove=False):
-        """Register a callback to handle text submission (triggered when the 
-        user clicks enter).
+        """(Un)Register a callback to handle text submission.
+
+        Triggered when the user clicks enter.
 
         Parameters
         callback: Method handle
             Function to be called when the text has been submitted.  Function
             can have two possible signatures:
             callback()
             callback(sender)
         remove: bool (optional)
             Whether or not to unregister the callback"""
         if remove and callback in self._submission_callbacks:
             self._submission_callbacks.remove(callback)
         elif not remove and not callback in self._submission_callbacks:
             if callable(callback):
                 argspec = inspect.getargspec(callback)
                 nargs = len(argspec[0])
 
                 # Bound methods have an additional 'self' argument
                 if isinstance(callback, types.MethodType):
                     nargs -= 1
 
                 # Call the callback
                 if nargs == 0:
                     self._submission_callbacks.append(lambda sender: callback())
                 elif nargs == 1:
                     self._submission_callbacks.append(callback)
                 else:
                     raise TypeError('TextBoxWidget submit callback must ' \
                         'accept 0 or 1 arguments.')