Source code for qtpyvcp.widgets.base_widgets.base_widget

Base Widgets

This file contains the definitions of the fundamental widgets upon which
all other QtPyVCP widgets are based.

import os
import json

from qtpy.QtCore import Property, Slot
from qtpy.QtWidgets import QPushButton

from qtpyvcp.plugins import getPlugin
from qtpyvcp.utilities.logger import getLogger

LOG = getLogger(__name__)

[docs]class ChanList(list): """Channel value list. This list is intended to hold lambda functions for retrieving the current data channel values. When the list is indexed the function is called and the resulting value is returned. """ def __getitem__(self, index): return super(ChanList, self).__getitem__(index)()
[docs]class VCPPrimitiveWidget(object): """VCPPrimitiveWidget. Class on which all QtPyVCP widgets should be based. """ def __init__(self, parent=None): super(VCPPrimitiveWidget, self).__init__()
[docs] def initialize(self): """This method is called right before the main application starts.""" pass
[docs] def terminate(self): """This method is called right before the main application ends.""" pass
[docs]class VCPBaseWidget(VCPPrimitiveWidget): """QtPyVCP Base Widget. This class handles the rules and other things that apply to QtPyVCP widgets regardless of use. """ IN_DESIGNER = os.getenv('DESIGNER') != None DEFAULT_RULE_PROPERTY = 'None' RULE_PROPERTIES = { 'None': ['None', None], 'Enable': ['setEnabled', bool], 'Visible': ['setVisible', bool], 'Style Class': ['setStyleClass', str], 'Style Sheet': ['setStyleSheet', str], } def __init__(self, parent=None): super(VCPBaseWidget, self).__init__() self._rules = '[]' self._style = '' self._data_channels = [] self._security_level = 0 # # Security implementation # @Property(int) def security(self): """ Security level An integer representing the security level for a widget. The higher the integer value the higher the operator access level needs to be to be able to interact with the widget. Example: security = 0 requires an operator to have an assigned security value of 0 or more. This is essentially the lowest security rating. Negative numbers having no effect. security = 5 requires an operator to have an assigned security level of 5 or more to interact with the widget. So an operator with a rating of 2 will not be able to interact with the widget. The widget will be represented as "disabled" to them. returns: int """ return self._security_level @security.setter def security(self, security): self._security_level = security # # Style Rules implementation #
[docs] def setStyleClass(self, style_class): """Set the QSS style class for the widget""" self.setProperty('style', style_class)
@Property(str, designable=False) def style(self): """QSS style class selector property. This property can be changed dynamically to update the QSS style applied to the widget. Example: The ``style`` property can be used as a selector in QSS to apply different styles depending on the value. :: /* This will be applied when the `style` is set to "error" */ WidgetClass[style="error"] { color: red; } /* This will be applied when the `style` is not set */ WidgetClass { color: black; } Returns: str """ return self._style @style.setter def style(self, style): self._style = style @Property(str, designable=False) def rules(self): """JSON formatted list of dictionaries, defining the widget rules. Returns: str """ return self._rules @rules.setter def rules(self, rules): self._rules = rules or '[]' self.registerRules() def registerRules(self): rules = json.loads(self._rules) for rule in rules: # print(rule) ch = ChanList() triggers = [] for chan in rule['channels']: try: url = chan['url'].strip() protocol, sep, item = url.partition(':') chan_obj, chan_exp = getPlugin(protocol).getChannel(item) ch.append(chan_exp) if chan.get('trigger', False): triggers.append(chan_obj.notify) except Exception: LOG.exception("Error evaluating rule: {}" .format(chan.get('url', ''))) return prop = self.RULE_PROPERTIES[rule['property']] if prop[1] is None: # donothing self._data_channels = ch continue eval_env = {'ch': ch, 'widget': self} eval_exp = 'lambda: widget.{}({})'.format( prop[0], rule['expression']).encode('utf-8') exp = eval(eval_exp, eval_env) # initial call to update try: exp() except: LOG.exception('Error calling rules expression:') continue for trigger in triggers: trigger(exp)
[docs]class VCPWidget(VCPBaseWidget): """VCP Widget This is a general purpose widget for displaying data and other uses that do not involve user interaction. """ def __init__(self, parent=None): super(VCPWidget, self).__init__()
[docs]class CMDWidget(VCPBaseWidget): """Command Widget This widget should be used as the base class for all widgets that control the machine. Eventually additional functionality will be added to this class. """ def __init__(self, parent=None): super(CMDWidget, self).__init__()
[docs]class HALWidget(VCPBaseWidget): """HAL Widget This widget should be used as the base class for HAL widgets. ToDo: Implement HAL functionality. """ def __init__(self, parent=None): super(HALWidget, self).__init__() self._hal_object_name = None @Property(str) def pinBaseName(self): """The base name to use for the generated HAL pins. If not specified the widgets objectName will be used. Returns: str """ if self._hal_object_name is None: return str(self.objectName()).replace('_', '-') return self._hal_object_name @pinBaseName.setter def pinBaseName(self, name): # ToDO: Validate HAL pin name self._hal_object_name = name @Slot() def getPinBaseName(self): return self.pinBaseName
[docs]class VCPButton(QPushButton, CMDWidget): """VCP Button Widget This is a general purpose button widget for displaying data and other uses that do not involve user interaction. """ DEFAULT_RULE_PROPERTY = 'Enable' RULE_PROPERTIES = CMDWidget.RULE_PROPERTIES.copy() RULE_PROPERTIES.update({ 'Text': ['setText', str], 'Checked': ['setChecked', bool] }) def __init__(self, parent=None): super(VCPButton, self).__init__(parent)