function_tracing.enaml

#------------------------------------------------------------------------------
# Copyright (c) 2019, Nucleic Development Team.
#
# Distributed under the terms of the Modified BSD License.
#
# The full license is in the file COPYING.txt, distributed with this software.
#------------------------------------------------------------------------------
""" An example illustrating the tracing inside declarative function.

Declarative function body can be traced. When used as the right hand side of
the << operator it means that any change to dynamic variables used inside the
function body will trigger an update.

<< autodoc-me >>
"""
from __future__ import print_function
from collections import Mapping
from enaml.widgets.api import Window, Label, CheckBox, Container, PushButton
from enaml.core.funchelper import call_func


enamldef Main(Window): m:

    attr state1 : bool = False

    attr state2 : bool = False

    func active_states():
        if state1 and state2:
            return 'both'
        elif state1 or state2:
            return 'single'
        else:
            return 'none'

    Container:
        CheckBox:
            text = 'Enabled state 1'
            checked := state1
        CheckBox:
            text = 'Enabled state 2'
            checked := state2
        PushButton:
            text = 'Refresh'
            clicked ::
                lab.text = active_states()
        Label: lab:
            text << active_states()