Source code for enaml.widgets.scroll_area
#------------------------------------------------------------------------------
# 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, Bool, Typed, ForwardTyped, set_default
from enaml.core.declarative import d_, observe
from .container import Container
from .frame import Frame, ProxyFrame, Border
class ProxyScrollArea(ProxyFrame):
""" The abstract definition of a proxy ScrollArea object.
"""
#: A reference to the ScrollArea declaration.
declaration = ForwardTyped(lambda: ScrollArea)
def set_horizontal_policy(self, policy):
raise NotImplementedError
def set_vertical_policy(self, policy):
raise NotImplementedError
def set_widget_resizable(self, resizable):
raise NotImplementedError
[docs]
class ScrollArea(Frame):
""" A Frame 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 = d_(Enum('as_needed', 'always_on', 'always_off'))
#: The vertical scrollbar policy.
vertical_policy = d_(Enum('as_needed', 'always_on', 'always_off'))
#: Whether to resize the scroll widget when possible to avoid the
#: need for scrollbars or to make use of extra space.
widget_resizable = d_(Bool(True))
#: A scroll area is free to expand in width and height by default.
hug_width = set_default('ignore')
hug_height = set_default('ignore')
#: A reference to the ProxyScrollArea object.
proxy = Typed(ProxyScrollArea)
[docs]
def scroll_widget(self):
""" Get the scroll widget child defined on the area.
The scroll widget is the last Container child.
"""
for child in reversed(self.children):
if isinstance(child, Container):
return child
#--------------------------------------------------------------------------
# Default Handlers
#--------------------------------------------------------------------------
def _default_border(self):
""" Get the default border for the scroll area.
The default value matches the default for Qt's QScrollArea.
"""
return Border(style='styled_panel', line_style='sunken')
#--------------------------------------------------------------------------
# Observers
#--------------------------------------------------------------------------
@observe('horizontal_policy', 'vertical_policy', 'widget_resizable')
def _update_proxy(self, change):
""" An observer which sends state change to the proxy.
"""
# The superclass handler implementation is sufficient.
super(ScrollArea, self)._update_proxy(change)