Source code for enaml.widgets.scroll_area

#  Copyright (c) 2012, Enthought, Inc.
#  All rights reserved.
from traits.api import Enum, Property, Bool, cached_property

from .constraints_widget import ConstraintsWidget
from .container import Container

#: Enum trait describing the scrollbar policies that can be assigned to
#: the horizontal and vertical scrollbars.
ScrollbarPolicy = Enum('as_needed', 'always_on', 'always_off')

[docs]class ScrollArea(ConstraintsWidget): """ A widget which displays a single child in a scrollable area. A ScrollArea has at most a single child Container widget. """ #: The horizontal scrollbar policy. horizontal_policy = ScrollbarPolicy #: The vertical scrollbar policy. vertical_policy = ScrollbarPolicy #: Whether to resize the scroll widget when possible to avoid the #: need for scrollbars or to make use of extra space. widget_resizable = Bool(True) #: A read only property which returns the scrolled widget. scroll_widget = Property(depends_on='children') #: How strongly a component hugs it's contents' width. Scroll #: areas do not hug their width and are free to expand. hug_width = 'ignore' #: How strongly a component hugs it's contents' height. Scroll #: areas do not hug their height and are free to expand. hug_height = 'ignore' #-------------------------------------------------------------------------- # Initialization #--------------------------------------------------------------------------
[docs] def snapshot(self): """ Return a dictionary which contains all the state necessary to initialize a client widget. """ snap = super(ScrollArea, self).snapshot() snap['horizontal_policy'] = self.horizontal_policy snap['vertical_policy'] = self.vertical_policy snap['widget_resizable'] = self.widget_resizable return snap
[docs] def bind(self): """ Bind the change handlers for this widget. """ super(ScrollArea, self).bind() attrs = ('horizontal_policy', 'vertical_policy', 'widget_resizable') self.publish_attributes(*attrs) #-------------------------------------------------------------------------- # Private API #--------------------------------------------------------------------------
@cached_property def _get_scroll_widget(self): """ The getter for the 'scroll_widget' property. Returns ------- result : Container or None The scroll widget for the ScrollArea, or None if not provided. """ widget = None for child in self.children: if isinstance(child, Container): widget = child return widget