Packages
Package	Description
fr.esrf.tangoatk.core	This package contains the model part of TangoATK.
fr.esrf.tangoatk.core.attribute
fr.esrf.tangoatk.core.command
fr.esrf.tangoatk.core.util
fr.esrf.tangoatk.util
fr.esrf.tangoatk.widget.attribute	Contains a set of class to display the most of tango attributes.
fr.esrf.tangoatk.widget.command
fr.esrf.tangoatk.widget.device
fr.esrf.tangoatk.widget.device.tree
fr.esrf.tangoatk.widget.dnd
fr.esrf.tangoatk.widget.icons
fr.esrf.tangoatk.widget.image	This package contains a simple image viewing facility.
fr.esrf.tangoatk.widget.jdraw	Provides classes for handling synoptic files generated by the ESRF home made tool JDraw.
fr.esrf.tangoatk.widget.properties
fr.esrf.tangoatk.widget.util	Contains various graphic components used in ATK.
fr.esrf.tangoatk.widget.util.chart	Contains a set of classes to handle 2D scientific plots.
fr.esrf.tangoatk.widget.util.chart.math
fr.esrf.tangoatk.widget.util.interlock	Contains a set of classes to handle a network graph viewer and its editor.
fr.esrf.tangoatk.widget.util.jdraw	Contains a set of classes to handle a vector drawing viewer and its editor.
fr.esrf.tangoatk.widget.util.jgl3dchart

Welcome to TangoATK.

Getting started

TangoATK is a collection of java-classes to help build applications which interact with Tango-devices.

This document does assumes some prior knowledge:

Tango - it is assumed that you already have a clear understanding of devices, their attributes and their commands.
Java - There are many excellent tutorials on java, please read them. O'Reilly have quite a few books on the subject.
JDK - The Java Development Kit. You are expected to know how to set up a class-path and how to compile and run a java-program.

Central concepts

TangoATK is not built in a device-centric way. What this means is that in terms of TangoATK, a device is something that lurks in the background, but very seldom something that is worked with directly.
Instead we have chosen to look at the attributes and the commands as the central building blocks. This means that you can get a reference to an attribute by asking for it. You do not need a reference to the attributes device to obtain the attribute. The same goes for commands.

Attributes and commands need to be stored somewhere, and for that we have supplied the AttributeList and the CommandList. These objects take the name of a command or attribute, fetch them and store them.

I've got a running device-server, what do I do?

First of all it is important to understand the ideas behind TangoATK. TangoATK is buildt using several standard patterns where the most prominent one is the Model View Controller , or MVC for short. TangoATK supplies the model and the view, and it is the task of the application programmer to create the controller.

The Model

The model-part of TangoATK is found in the fr.esrf.tangoatk.core package. What we find here are non-graphic classes which are used to get a hold of devices, attributes, and commands. The objects representing attributes, devices, and commands, are made to distribute events to listeners which connect to them. This means that when eg an attribute changes its value, an event is sent to all registered listeners of that attribute.

The View

The view-part of TangoATK is found in the packages under fr.esrf.tangoatk.widget. There are specific viewers for attributes, commands, and devices. There are also widgets for viewing errors and such.

The Controller

The job of the controller, which normally is the application, is to connect models and views, and responding to user input.

Connecting models and views

Connecting a view to a model is done by calling the setModel method on a view with the model you want to connect to it as argument:


INumberScalar      model;
SimpleScalarViewer viewer;
AttributeList      list;

list = new AttributeList();
// initialize the model and the viewer, more on that later...
model = (INumberScalar)list.add("my/device/name/numberscalar");

// connect them
viewer.setModel(model);

Normally the setModel method in a viewer takes care of adding the viewer to the list of listeners of the model.

Dependencies

TangoATK is a modular toolkit built on top of other packages. This means that you will need to have the following packages in your classpath:

TangORB.jar, a library implementing the underlying Tango infrastructure

In addition to this, you'll also need the two jars for TangoATK:

ATKCore.jar, the non graphical part of the toolkit
ATKWidget.jar, all the viewers and graphical stuff.

Normally you will find all these in your favourite lib/java directory in your tangodistribution, so assuming $TANGO is pointing to where you installed tango, this command should set up your CLASSPATH:

$ export CLASSPATH=$TANGO/lib/java/TangORB.jar:$TANGO/lib/java/ATKCore.jar:$TANGO/lib/java/ATKWidget.jar

It is also worth noting that TangoATK is for the moment made with and for jdk1.4, but we invite you to use jdk1.5 today because future releases of ATK will be built with jdk1.5 and might be incompatible with jdk1.4. So you better fetch that from http://java.sun.com/ while you're at it.

A simple example

TangoATK is attribute and command centric, that is, you can obtain attributes and commands from any device and mix them without having to know about their devices. The main entry-points into TangoATK are the CommandList and the AttributeList, they live in fr.esrf.TangoATK.Core


import fr.esrf.TangoATK.Core.*;


public class FirstExample {


    public static void main (String[] args) {
        AttributeList list = new AttributeList();
        IAttribute attribute;

        // add an attribute to the list
        // AttributeList returs the last attribute added as an
        // IEntity, so we need to cast it to an IAttribute.
        // The AttributeList can throw a ConnectionException if
        // it is not treated nicely, so you need to catch that.
        try {
            attribute = (IAttribute)list.add("eas/test-api/1/Short_attr");
            System.out.println("Attribute " + attribute + " added OK");
        } catch (ConnectionException connEx) {
            System.out.println("Failed to add attributes");
        } // end of try-catch
        

    } // end of main ()
    
}

AttributeList and CommandList also accept wildcard-entries and String-arrays as arguments to their add methods.

A graphic example


import fr.esrf.TangoATK.Core.AttributeList;
import fr.esrf.TangoATK.Core.INumberScalar;
import fr.esrf.TangoATK.Core.ConnectionException;
import fr.esrf.TangoATK.Widget.attribute.SimpleScalarViewer;
import javax.swing.JFrame;

public class SecondExample {

    public static void main (String[] args) {
        AttributeList list = new AttributeList();
        SimpleScalarViewer viewer = new SimpleScalarViewer();
        INumberScalar attribute ;

        try {
            // This time we need to know what kind of attribute AttributeList
            // returns. By prior knowledge, I know that the attribute
            // I'm adding is some sort of a numeric scalar, and therefore
            // I treat it as a INumberScalar, since all numeric scalars are
            // INumberScalars.
            attribute = (INumberScalar)list.add("eas/test-api/1/Att_sinus");

            // This is the fun part. Here my viewer is informed of who
            // its model is. The viewer then connects itself to the model,
            // and things start to happen.
            viewer.setModel(attribute);

            // Another fun part of the AttributeList is that it has a
            // refreshing mechanism, which automagically refreshes any
            // attributes in the list and makes them send out events.
            list.startRefresher();

            // Boring old swing stuff, add the viewer to a frames content-
            // pane and have the frame show itself.
            javax.swing.JFrame frame = new javax.swing.JFrame();
            frame.getContentPane().add(viewer);
            frame.pack();
            frame.show();
        } catch (ConnectionException e) {
            System.out.println("Couldn't add attribute: " + e);
        } // end of try-catch
    }
}