#------------------------------------------------------------------------------
# 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 Typed, ForwardTyped, Property, Bool, Int, set_default
from enaml.core.declarative import d_, observe
from .control import Control, ProxyControl
class ProxyProgressBar(ProxyControl):
""" The abstract definition of a proxy ProgressBar object.
"""
#: A reference to the ProgressBar declaration.
declaration = ForwardTyped(lambda: ProgressBar)
def set_minimum(self, minimum):
raise NotImplementedError
def set_maximum(self, maximum):
raise NotImplementedError
def set_value(self, value):
raise NotImplementedError
def set_text_visible(self, visible):
raise NotImplementedError
[docs]
class ProgressBar(Control):
""" A control which displays a value as a ticking progress bar.
"""
#: The minimum progress value. If the minimum value is changed such
#: that it becomes greater than the current value or the maximum
#: value, then those values will be adjusted. The default is 0.
minimum = d_(Int(0))
#: The maximum progress value. If the maximum value is changed such
#: that it becomes smaller than the current value or the minimum
#: value, then those values will be adjusted. The default is 100.
maximum = d_(Int(100))
#: The position value of the Slider. The value will be clipped to
#: always fall between the minimum and maximum.
value = d_(Int(0))
#: A read only cached property which computes the integer percentage.
percentage = d_(Property(cached=True), writable=False)
#: Whether or not to display progress percentage on the control.
#: This may not be supported by all toolkits and platforms.
text_visible = d_(Bool(False))
#: How strongly a component hugs it's content. ProgressBars expand
#: to fill the available horizontal space by default.
hug_width = set_default('ignore')
#: A reference to the ProxyProgressBar object.
proxy = Typed(ProxyProgressBar)
[docs]
@percentage.getter
def get_percentage(self):
""" The getter function for the read only percentage property.
"""
minimum = self.minimum
maximum = self.maximum
value = self.value
dy = maximum - minimum
if dy == 0:
res = 0
elif value == maximum:
res = 100
else:
dx = float(value - minimum)
res = int(round(100.0 * dx / dy))
# We already excluded the case where the value was exactly
# the maximum, so we can't really be at 100%, so round this
# down to 99% if necessary.
res = min(res, 99)
return res
#--------------------------------------------------------------------------
# Observers
#--------------------------------------------------------------------------
@observe('minimum', 'maximum', 'value', 'text_visible')
def _update_proxy(self, change):
""" An observer which sends state change to the proxy.
This observer also resets the 'percentage' property.
"""
# The superclass handler implementation is sufficient.
super(ProgressBar, self)._update_proxy(change)
@observe('minimum', 'maximum', 'value')
def _reset_percentage(self, change):
""" An observer which resets the percentage property.
"""
if change['type'] == 'update':
self.get_member('percentage').reset(self)
#--------------------------------------------------------------------------
# PostSetAttr Handlers
#--------------------------------------------------------------------------
def _post_setattr_minimum(self, old, new):
""" Post setattr the minimum value for the progress bar.
If the new minimum is greater than the current value or maximum,
those values are adjusted up.
"""
if new > self.maximum:
self.maximum = new
if new > self.value:
self.value = new
def _post_setattr_maximum(self, old, new):
""" Post setattr the maximum value for the progress bar.
If the new maximum is less than the current value or the minimum,
those values are adjusted down.
"""
if new < self.minimum:
self.minimum = new
if new < self.value:
self.value = new
#--------------------------------------------------------------------------
# PostValidate Handlers
#--------------------------------------------------------------------------
def _post_validate_value(self, old, new):
""" Post validate the value for the progress bar.
The value is clipped to minimum and maximum bounds.
"""
return max(self.minimum, min(new, self.maximum))