Dessy, 17 september 2007 Tango Meeting Development of Tango Client Applications in Python Tiago Coutinho and Josep Ribas

Dessy, 17 september 2007 Tango Meeting

Development of Tango Client Applications in Python

Tiago Coutinho and Josep Ribas

Tango MeetingDessy, 17 september 2007

Outline

PyTauico Goals of PyTauico Software Architecture

PyTauiwi Custom tango widgets in QtDesigner Application development Example

Current Status Future Work Conclusions


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


PyTango

Tango

PyTauico

'IPyTauico'

IPython

PyTauiwi

PyQT4

'WxTango'

WxPython

CORBA

Architecture


Architecture (II)

Device and Attribute Factories

PyTango accessed through DeviceProxy

Model and Listener

Polling management


PyTauico

Device<<sup>>

Attribute<<Position>>

Attribute<<Acceleration>>

Attribute<<Simulation>>

Listener<<LineEditPos>>

Listener<<LineEditAcc>>

Listener<<LineEditSim>>

Listener<<CheckBoxSim>>

AttributeFactoryDeviceFactory

Tango

Device ServerMotor

<<sup>>

Listeners


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

PyTango

Tango

PyTauico

CORBA

PyTauiwi

PyQT4


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.


Custom Widget Development

1. Design the widget using QtDesigner

2. Convert Design into Python Code using pyuic4

3. Implement widget functionality1. Inherit from tauico model2. Add Widget Properties, Signals and

Slots3. Implement the connection with

PyTauico.

4. Defining the Widget's Plugin Interface Describes our custom widget and tells

Qt Designer how to instantiate it.


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

@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("QString", getDevice, setDevice)

def eventReceived(self, EventSource, EventType, EventValue):

self.emit(QtCore.SIGNAL('changeText(QString)'), str(EventValue.value))

@QtCore.pyqtSignature("setState(QString)")

def setState(self, value):

self.setText(value)

self.changeColor(value)


Application Development

1. Design your application design using QtDesigner using the PyTauwi widgets.

2. Covert yout application to python code.3. Implement extra functionalities like

widget interconnection.4. Enjoy it.


Example. Libera UI


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.


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.


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,

…)


Acknowledgments

Fulvio Becheri

Documents

Dessy, 17 september 2007 Tango Meeting Development of Tango Client Applications in Python Tiago Coutinho and Josep Ribas