Development of Tango Client Applications in Python

1
Development of Tango Client Applications in Python

• Tiago Coutinho and Josep Ribas

2
Outline

• PyTauico
• Goals of PyTauico
• Software Architecture
• PyTauiwi
• Custom tango widgets in QtDesigner
• Application development
• Example
• Current Status
• Future Work
• Conclusions

3
Goals of PyTauico

• PyTauico Python Tango User Interface Core
• Add Python and PyTango as an option for client
  applications
• Abstraction layer for PyTango Client Applications
• Simplify the application development using
  PyTango
• Reduce development time in Python
• Standarize PyTango client applications
• Improve performance of applications
• Efficient management of Devices and Attributes

4
Architecture
CORBA
Tango
PyTango
PyTauico
5
Architecture (II)

• Device and Attribute Factories
• PyTango accessed through DeviceProxy
• Model and Listener
• Polling management

6
Listeners
Device Server
Motor ltltsupgtgt
Tango
PyTauico
Listener ltltCheckBoxSimgtgt
Listener ltltLineEditPosgtgt
Listener ltltLineEditAccgtgt
Listener ltltLineEditSimgtgt
Device ltltsupgtgt
Attribute ltltPositiongtgt
Attribute ltltAccelerationgtgt
Attribute ltltSimulationgtgt
AttributeFactory
DeviceFactory
7
PyTauiwi

• Python Tango User Interface Widgets
• PyQt4 layer for PyTauico
• QtDesigner as a main tool.
• Provide a set of widgets for application
  development
• Standarize the look and feel
• Extensible
• Easy development of new widgets
• Complex widgets as a subset of basic widgets

CORBA
Tango
PyTango
PyTauico
PyQT4
PyTauiwi
8
Custom Widgets for PyTango

• PyQt4.2
• Full range of standard Qt widgets
• All the power of Qt, but exploit it with the
  simplicity of Python.
• QtDesigner. Graphical User Interface Designer.
• Own pure Python custom widgets
• All the signals, slots and properties defined in
  Python are accessible in Designer's user
  interface.

9
Custom Widget Development

• Design the widget using QtDesigner
• Convert Design into Python Code using pyuic4
• Implement widget functionality
• Inherit from tauico model
• Add Widget Properties, Signals and Slots
• Implement the connection with PyTauico.
• Defining the Widget's Plugin Interface
• Describes our custom widget and tells Qt Designer
  how to instantiate it.

10
Custom Widget development (II)

• Our widget is a Listener in the PyTauico Layer.
• Widget Code must include.
• A property defining the Tango attribute or device
  name.
• Subscription management to PyTauico Device or
  attribute objects.
• Implementation of the eventReceived() function
  defined in the TauicoListener abstract class.
• How the widget shows to the user the received
  events.
• Add signals and slots to the widget.
• Define the interaction of the widget with the
  other components.

from PyQt4 import QtCore, QtGui, Qt import
PyTauico class PyStateLabel(QtGui.QLabel,
PyTauico.TauicoListener) ...
def getDevice(self) return self._device
_at_QtCore.pyqtSignature("setDevice(QString)")
def setDevice(self, devname) self.dev
devfactory.getDevice(self._device) self.attr
self.dev.subscribeAttribute(self._device"/State",
self) self.setState(str(self.attr.read()
.value)) Device QtCore.pyqtProperty("QSt
ring", getDevice, setDevice)
def eventReceived(self, EventSource, EventType,
EventValue) self.emit(QtCore.SIGNAL('chan
geText(QString)'), str(EventValue.value))
_at_QtCore.pyqtSignature("setState(QString)")
def setState(self, value) self.setText(value)
self.changeColor(value)
11
Application Development

• Design your application design using QtDesigner
  using the PyTauwi widgets.
• Covert yout application to python code.
• Implement extra functionalities like widget
  interconnection.
• Enjoy it.

12
Example. Libera UI
13
Current Status

• PyTauico Layer
• Basic support for devices and attributes.
• Events for attributes
• Basic polling
• Core factory components
• Efficient object management (Devices and
  Attributes)
• Basic widget interface defined.
• PyTauwi Layer
• Basic widgets for testing.

14
Future work

• Documentation
• Guidelines for developing widgets
• Define widgets interface
• Error tracking
• Deal with tango exceptions
• Polling lists
• Widget for choosing polling periods for
  attributes
• Commnads
• Polling for Void commands
• Properties
• Multiple DB connection.
• Add the DB on the device name.
• Extend the widget library.

15
Conclusions

• PyTango and PyQt4.
• Mixing the power of Qt with the Python simplicity
• A good use for PyTango
• Abstraction layer
• Fast and easy development of python client
  applications
• Extensible.
• Possibility to create more complex and dedicated
  widgets. (A widget that represents a motor)
• Use other Python GUI technologies. (wxPython, )

16
Acknowledgments

• Fulvio Becheri

17
PyTauico
Listener ltltLineEditPosgtgt
Listener ltltLineEditAccgtgt
Listener ltltLineEditSimgtgt
AttributeFactory
Attribute ltltPositiongtgt
Attribute ltltAccelerationgtgt
Attribute ltltSimulationgtgt
PollingTimer ltlt3sgtgt
PollingTimer ltlt10sgtgt
T2
T1