BaseObject

The main objects in defcon all subclass these objects.

See also

NotificationCenter
The base object uses notifications to notify observers about changes. The API for subscribing/unsubscribing to notifications are detailed below. Some familiarity with the NotificationCenter might be helpful.

BaseObject

class defcon.objects.base.BaseObject

The base object in defcon from which all other objects should be derived.

This object posts the following notifications:

Name Note
BaseObject.Changed Posted when the dirty attribute is set.
BaseObject.BeginUndo Posted when an undo begins.
BaseObject.EndUndo Posted when an undo ends.
BaseObject.BeginRedo Posted when a redo begins.
BaseObject.EndRedo Posted when a redo ends.

Keep in mind that subclasses will not post these same notifications.

setParent(obj)

Set the parent of the object. This will reference the parent using weakref.

getParent()

Get the parent. Returns None if no parent is set. Note that because the reference to the parent is stored as a weakref, the parent can disappear if it is no longer referenced by any object other than this one.

dispatcher

The defcon.tools.notifications.NotificationCenter assigned to this object.

addObserver(observer, methodName, notification)

Add an observer to this object’s notification dispatcher.

  • observer An object that can be referenced with weakref.
  • methodName A string epresenting the method to be called when the notification is posted.
  • notification The notification that the observer should be notified of.

The method that will be called as a result of the action must accept a single notification argument. This will be a defcon.tools.notifications.Notification object.

This is a convenience method that does the same thing as:

dispatcher = anObject.dispatcher
dispatcher.addObserver(observer=observer, methodName=methodName,
    notification=notification, observable=anObject)
removeObserver(observer, notification)

Remove an observer from this object’s notification dispatcher.

  • observer A registered object.
  • notification The notification that the observer was registered to be notified of.

This is a convenience method that does the same thing as:

dispatcher = anObject.dispatcher
dispatcher.removeObserver(observer=observer,
    notification=notification, observable=anObject)
hasObserver(observer, notification)

Returns a boolean indicating is the observer is registered for notification.

This is a convenience method that does the same thing as:

dispatcher = anObject.dispatcher
dispatcher.hasObserver(observer=observer,
    notification=notification, observable=anObject)
holdNotifications(notification=None)

Hold this object’s notifications until told to release them.

  • notification The specific notification to hold. This is optional. If no notification is given, all notifications will be held.

This is a convenience method that does the same thing as:

dispatcher = anObject.dispatcher
dispatcher.holdNotifications(
    observable=anObject, notification=notification)
releaseHeldNotifications(notification=None)

Release this object’s held notifications.

  • notification The specific notification to hold. This is optional.

This is a convenience method that does the same thing as:

dispatcher = anObject.dispatcher
dispatcher.releaseHeldNotifications(
    observable=anObject, notification=notification)
disableNotifications(notification=None, observer=None)

Disable this object’s notifications until told to resume them.

  • notification The specific notification to disable. This is optional. If no notification is given, all notifications will be disabled.

This is a convenience method that does the same thing as:

dispatcher = anObject.dispatcher
dispatcher.disableNotifications(
    observable=anObject, notification=notification, observer=observer)
enableNotifications(notification=None, observer=None)

Enable this object’s notifications.

  • notification The specific notification to enable. This is optional.

This is a convenience method that does the same thing as:

dispatcher = anObject.dispatcher
dispatcher.enableNotifications(
    observable=anObject, notification=notification, observer=observer)
dirty

The dirty state of the object. True if the object has been changed. False if not. Setting this to True will cause the base changed notification to be posted. The object will automatically maintain this attribute and update it as you change the object.

undoManager

The undo manager assigned to this object.

BaseDictObject

class defcon.objects.base.BaseDictObject

A subclass of BaseObject that implements a dict API. Any changes to the contents of the object will cause the dirty attribute to be set to True.