In this lab you will practice creating sequence diagrams with Violet, the same diagramming tool you used in the previous lab exercise.

This section describes most of the sequence diagram operations that you can perform in Violet.

You should try to replicate the operations described in this section before moving on to Your Job.

After launching Violet, either click sequence diagram on the opening screen or use the File → New menu option to get:

Under Diagram tools select Object lifeline and click in the drawing area to create an empty box.

Right click on the box to get a dialog that accepts the object's name.

In this case an object named aFoo of type Foo is being created:

An activation bar represents a method call on an object.

To create one select the Activation bar tool and click on an object's lifeline.

Below two objects with activation bars have been created.

Note that at this point it is assumed that aFoo's method exits before aBar's method starts.

Sequence diagram notes provide information and make diagrams easier to read.

They are created in the same way class diagram notes are created.

Select the Note tool and click where you want the note to appear in the diagram.

Right click the note to get a dialog accepting the text of the note. (Note that you can also change the note's background color.)

In this case we are indicating the Foo method that is represented by aFoo's activation bar:

To connect the note to a specific point in the diagram, select the Note connector tool and drag from the note to the specific point:

To show how objects collaborate to produce a result, sequence diagrams model method calls, which can be thought of as sending a message from one object to another.

This example will show aFoo calling aBar's method someBarMethod with value 1 being returned.

Select the Call / Create message tool and drag from the calling object's activation bar to the receiving object's activation bar:

Upon release of the mouse, Violet will realign the objects' activation bars:

Right click the connecting line to get a dialog that accepts the name of the method being called, with or without arguments:

Select the Return message tool and drag from the receiving object's activation bar to the sending object's activation bar.

Right click the connecting line to get a dialog that accepts the value being returned:

Sometimes it is necessary to model an object calling its own method.

In this example we show aFoo's method someFooMethod calling its own method anotherFooMethod.

There does not appear to be any good way to indicate the return value of a self call in Violet.

Start by creating a new activation bar for the object that is doing the self calling by using the Activation bar tool.

Hang the new activation bar on the activation bar of the method that is doing the self calling:

Select the Call / Create message tool and drag from the object's upper activation bar down to the lower activation bar that was just created:

Upon release of the mouse, Violet will redraw the connection as a self call:

Right click the self call connection to get a dialog accepting the name of the method being called:

To indicate conditional method calls, simply label the call line with a prefix "[condition]" where condition is a boolean valued expression.

Below, aFoo calls aBar's method anotherBarMethod only if value 1 is not equal to zero.

Note that a second activation bar has been added to aBar's lifeline before making the connection:

Sometimes a sequence diagram needs to model the creation of an object.

In this example the object aBaz of type Baz is created during execution of aBar's method anotherBarMethod.

First create the new object's lifeline using the Object lifeline tool.

Do not create an activation bar for the new object.

Using the Call / Create message tool connect the activation bar of the method that creates the new object directly to that object:

Upon release of the mouse, Violet will realign the object to indicate its creation.

It will also automatically label the connection with the «create» stereotype:

Draw a diagram that models the Console.processMoves() method from the problem solving framework provided in Assignment 2.

The framework.Console class is shown below.

You should show all calls except to System.exit().

Your calls should show all arguments and return values.

Save your diagram as CS2511_Lab_4.