#------------------------------------------------------------------------------
# Copyright (c) 2013, Nucleic Development Team.
#
# Distributed under the terms of the Modified BSD License.
#
# The full license is in the file LICENSE, distributed with this software.
#------------------------------------------------------------------------------
from atom.api import Enum, Range, Coerced, Typed, ForwardTyped
from enaml.core.declarative import d_, observe
from enaml.layout.geometry import Size
from .container import Container
from .widget import Widget, ProxyWidget
class ProxyFlowItem(ProxyWidget):
""" The abstract definition of a proxy FlowItem object.
"""
#: A reference to the FlowItem declaration.
declaration = ForwardTyped(lambda: FlowItem)
def set_preferred_size(self, size):
raise NotImplementedError
def set_align(self, align):
raise NotImplementedError
def set_stretch(self, stretch):
raise NotImplementedError
def set_ortho_stretch(self, stretch):
raise NotImplementedError
[docs]
class FlowItem(Widget):
""" A widget which can be used as an item in a FlowArea.
A FlowItem is a widget which can be used as a child of a FlowArea
widget. It can have at most a single child widget which is an
instance of Container.
"""
#: The preferred size of this flow item. This size will be used as
#: the size of the item in the layout, bounded to the computed min
#: and max size. A size of (-1, -1) indicates to use the widget's
#: size hint as the preferred size.
preferred_size = d_(Coerced(Size, (-1, -1)))
#: The alignment of this item in the direction orthogonal to the
#: layout flow.
align = d_(Enum('leading', 'trailing', 'center'))
#: The stretch factor for this item in the flow direction, relative
#: to other items in the same line. The default is zero which means
#: that the item will not expand in the direction orthogonal to the
#: layout flow.
stretch = d_(Range(low=0, value=0))
#: The stretch factor for this item in the orthogonal direction
#: relative to other items in the layout. The default is zero
#: which means that the item will not expand in the direction
#: orthogonal to the layout flow.
ortho_stretch = d_(Range(low=0, value=0))
#: A reference to the ProxyFlowItem object.
proxy = Typed(ProxyFlowItem)
#--------------------------------------------------------------------------
# Observers
#--------------------------------------------------------------------------
@observe('preferred_size', 'align', 'stretch', 'ortho_stretch')
def _update_proxy(self, change):
""" An observer which sends state change to the proxy.
"""
# The superclass handler implementation is sufficient.
super(FlowItem, self)._update_proxy(change)