Source code for enaml.widgets.stack

# 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 Atom, Enum, Int, Range, Typed, ForwardTyped, set_default

from enaml.core.declarative import d_, observe

from .constraints_widget import ConstraintsWidget, ProxyConstraintsWidget
from .stack_item import StackItem

[docs] class Transition(Atom): """ An object representing an animated transition. Once a transition is created, it should be considered read-only. """ #: The type of transition effect to use. type = Enum('slide', 'wipe', 'iris', 'fade', 'crossfade') #: The direction of the transition effect. Some transition types #: will ignore the direction if it doesn't apply to the effect. direction = Enum( 'left_to_right', 'right_to_left', 'top_to_bottom', 'bottom_to_top' ) #: The duration of the transition, in milliseconds. duration = Range(low=0, value=250)
class ProxyStack(ProxyConstraintsWidget): """ The abstract definition of a proxy Stack object. """ #: A reference to the Stack declaration. declaration = ForwardTyped(lambda: Stack) def set_index(self, index): raise NotImplementedError def set_transition(self, transition): raise NotImplementedError def set_size_hint_mode(self, mode): raise NotImplementedError
[docs] class Stack(ConstraintsWidget): """ A component which displays its children as a stack of widgets, only one of which is visible at a time. """ #: The index of the visible widget in the stack. The widget itself #: does not provide a means to changing this index. That control #: must be supplied externally. If the given index falls outside of #: the range of stack items, no widget will be visible. index = d_(Int(0)) #: The item transition to use when changing between stack items. transition = d_(Typed(Transition)) #: The size hint mode for the stack. The default is 'union' and #: means that the size hint of the stack is the union of all the #: stack item size hints. 'current' means the size hint of the #: stack will be the size hint of the current stack item. size_hint_mode = d_(Enum('union', 'current')) #: A Stack expands freely in height and width by default hug_width = set_default('ignore') hug_height = set_default('ignore') #: A reference to the ProxyStack widget. proxy = Typed(ProxyStack)
[docs] def stack_items(self): """ Get the stack items defined on the stack """ return [c for c in self.children if isinstance(c, StackItem)]
#-------------------------------------------------------------------------- # Observers #-------------------------------------------------------------------------- @observe('index', 'transition', 'size_hint_mode') def _update_proxy(self, change): """ An observer which sends state change to the proxy. """ # The superclass handler implementation is sufficient. super(Stack, self)._update_proxy(change)