.. include:: headings.inc



.. _NotifyEvent:

==========================================================================================================================================
|phoenix_title|  **NotifyEvent**
==========================================================================================================================================

This class is not used by the event handlers by itself, but is a base class for other event classes (such as :ref:`BookCtrlEvent`).          

It (or an object of a derived class) is sent when the controls state is being changed and allows the program to :meth:`NotifyEvent.Veto`   this change if it wants to prevent it from happening. 







         



.. seealso:: :ref:`BookCtrlEvent`    







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|class_hierarchy| Inheritance Diagram
=====================================

Inheritance diagram for class **NotifyEvent**

.. raw:: html

   <p class="graphviz">
   <img src="_static/images/inheritance/NotifyEvent_inheritance.png" alt="Inheritance diagram of NotifyEvent" usemap="#dummy" class="inheritance"/>
   <map id="dummy" name="dummy"> <area shape="rect" id="node1" href="Event.html" title="An event is a structure holding information about an event passed to a callback or member function." alt="" coords="125,5,197,35"/> <area shape="rect" id="node4" href="CommandEvent.html" title="This event class contains information about command events, which originate from a variety of simple controls." alt="" coords="245,5,381,35"/> <area shape="rect" id="node2" href="Object.html" title="This is the root class of many of the wxWidgets classes." alt="" coords="5,5,77,35"/> <area shape="rect" id="node6" href="NotifyEvent.html" title="This class is not used by the event handlers by itself, but is a base class for other event classes (such as BookCtrlEvent)." alt="" coords="429,5,533,35"/> </map> 
   </p>

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|sub_classes| Known Subclasses
==============================

`AuiToolBarEvent`, :ref:`BookCtrlEvent`, :ref:`dataview.DataViewEvent`, `GridEvent`, `GridRangeSelectEvent`, `GridSizeEvent`, `HeaderCtrlEvent`, :ref:`ListEvent`, `MediaEvent`, `RibbonBarEvent`, `RichTextEvent`, :ref:`SpinDoubleEvent`, :ref:`SpinEvent`, :ref:`SplitterEvent`, :ref:`TreeEvent`, `TreeListEvent`, `WebViewEvent`, `WizardEvent`

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|method_summary| Methods Summary
================================

================================================================================ ================================================================================
:meth:`~NotifyEvent.__init__`                                                    Constructor (used internally by wxWidgets only).
:meth:`~NotifyEvent.Allow`                                                       This is the opposite of :meth:`Veto` : it explicitly allows the event to be processed.
:meth:`~NotifyEvent.IsAllowed`                                                   Returns ``True`` if the change is allowed ( :meth:`Veto`   hasn't been called) or ``False`` otherwise (if it was).
:meth:`~NotifyEvent.Veto`                                                        Prevents the change announced by this event from happening.
================================================================================ ================================================================================


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|api| Class API
===============
   

.. class:: NotifyEvent(CommandEvent)

   This class is not used by the event handlers by itself, but is a base class for other event classes (such as BookCtrlEvent).
   
   **Possible constructors**::

       NotifyEvent(eventType=wxEVT_NULL, id=0)
       



   .. method:: __init__(self, eventType=wxEVT_NULL, id=0)

      Constructor (used internally by wxWidgets only).                  


      :param `eventType`: 
      :type `eventType`: EventType
      :param `id`: 
      :type `id`: int







   .. method:: Allow(self)

      This is the opposite of :meth:`Veto` : it explicitly allows the event to be processed.                  

      For most events it is not necessary to call this method as the events are allowed anyhow but some are forbidden by default (this will be mentioned in the corresponding event description).                   





   .. method:: IsAllowed(self)

      Returns ``True`` if the change is allowed ( :meth:`Veto`   hasn't been called) or ``False`` otherwise (if it was).                  

      :rtype: `bool`








   .. method:: Veto(self)

      Prevents the change announced by this event from happening.                  

      It is in general a good idea to notify the user about the reasons for vetoing the change because otherwise the applications behaviour (which just refuses to do what the user wants) might be quite surprising.