class AbstractFlowWidget(with_metaclass(ABCMeta, object)):
""" An abstract base class which defines the interface for widgets
which can be used in a QFlowLayout.
Users of QFlowLayout must register their custom QWidget classes with
this class in order to use the QFlowLayout.
"""
@abstractmethod
def layoutData(self):
""" An abstractmethod which must be implemented by subclasses.
Returns
-------
result : FlowLayoutData
The FlowLayoutData instance to use for this widget. The
same data layout data instance should be returned for
each call to this method.
"""
raise NotImplementedError
class _DockLayoutItem(with_metaclass(_DockLayoutItemMeta, object)):
""" A private class which performs type checking for dock layouts.
class _AreaLayoutItem(with_metaclass(_AreaLayoutItemMeta, object)):
""" A private class which performs type checking for area layouts.
class _SplitLayoutItem(with_metaclass(_SplitLayoutItemMeta, object)):
""" A private class which performs type checking for split layouts.
class LinearSymbolic(with_metaclass(ABCMeta, object)):
""" An abstract base class for testing linear symbolic interfaces.
class Constrainable(with_metaclass(ABCMeta, object)):
""" An abstract base class for defining constrainable objects.
class Declarative(with_metaclass(DeclarativeMeta, Object)):
""" The most base class of the Enaml declarative objects.
This class provides the core functionality required of declarative
Enaml types. It can be used directly in a declarative Enaml object
tree to store and react to state changes. It has no concept of a
visual representation; that functionality is added by subclasses.
"""
#: Export the 'name' attribute as a declarative member.
name = d_(Unicode())
#: An event fired when an object is initialized. It is triggered
#: once during the object lifetime, at the end of the initialize
#: method.
initialized = d_(Event(), writable=False)
#: A property which gets and sets the initialized flag. This should
#: not be manipulated directly by user code.
is_initialized = flag_property(INITIALIZED_FLAG)
#: Storage space for the declarative runtime. This value should not
#: be manipulated by user code.
_d_storage = Typed(sortedmap, ())
#: Storage space for the declarative engine. This value should not
#: be manipulated by user code.
_d_engine = Typed(ExpressionEngine)
def initialize(self):
""" Initialize this object all of its children recursively.
This is called to give the objects in the tree the opportunity
to initialize additional state which depends upon the object
tree being fully built. It is the responsibility of external
code to call this method at the appropriate time. This will
emit the `initialized` signal after all of the children have
been initialized.
"""
# Iterate over a copy since the children add and remove
# other children during initialization.
for child in self.children[:]:
if isinstance(child, Declarative):
child.initialize()
self.is_initialized = True
self.initialized()
def destroy(self):
""" An overridden destructor method for declarative cleanup.
"""
self.is_initialized = False
del self._d_storage
del self._d_engine
super(Declarative, self).destroy()
def child_added(self, child):
""" An overridden child added event handler.
This handler will automatically initialize a declarative child
if this object itself has already been initialized.
"""
super(Declarative, self).child_added(child)
if isinstance(child, Declarative):
if self.is_initialized and not child.is_initialized:
child.initialize()