uk.ac.sheffield.vtts.client.pojo

Class ContactList

java.lang.Object

uk.ac.sheffield.vtts.client.pojo.ContactList

public class ContactList
extends java.lang.Object

ContactList is a correct POJO implementation of the ContactList.xml specification. It models a table of names, where names may be entered, selected and removed. This example was developed to mimic the behaviour of many GUIs, where the selected row can be either transferred or dropped, when a row is deleted. This leads to three different kinds of behaviour upon deletion, which are triggered by the filled-state and selection-state of the table, rather than by any condition on the inputs.

This uses the State Pattern (a Design Pattern from Gamma, et al.) for its implementation. All requests are delegated to an abstract State, which has concrete subclasses EmptyTable, NonEmptyTable and RowSelected, which respond to certain requests in different ways. Otherwise, the table is implemented as a List of SimpleEntry pairs, where each pair contains two Strings for the forename and surname. Pairs in the specification language are implemented as SimpleEntry in the Java code. We provide a top-level public type with this name, shadowing the inner class AbstractMap.SimpleEntry, which causes problems for SOAP and REST web service frameworks that cannot pass nested classes as parameters.

Indexing in the specification language runs from 1..n; this is observed in the values assigned to indicate the selected row, but indices are converted into the range 0..n-1 when accessing the underlying Java Lists.

Suggestions are given for how to modify the source code to seed faults deliberately, which will be detected during testing.

Version:

1.0

Author:

Anthony J H Simons

Constructor Summary

Constructors

Constructor and Description
ContactList() Creates a ContactList.

Method Summary

Methods

Modifier and Type	Method and Description
void	addEntry(java.lang.String forename, java.lang.String surname) Attempts to add a new entry to this ContactList.
java.lang.String	getScenario() Returns the last scenario that was enacted.
java.lang.String	getState() Returns the last state that was entered.
void	removeEntry() Attempts to remove an entry from this ContactList.
void	selectRow(int index) Attempts to select a row in this ContactList.
void	unselectRow() Attempts to unselect a row in this ContactList.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ContactList

public ContactList()

Creates a ContactList. Enacts the scenario create/ok and enters the EmptyTable state. Initialises the lists of forenames and surnames to empty lists, and sets the selected row to zero (logical indexing runs from 0..n).

Method Detail

getScenario

public java.lang.String getScenario()

Returns the last scenario that was enacted. This State Pattern implementation logs separately the request received and the response triggered (which is state-dependent). The name of the last scenario that was enacted is obtained by concatenating the request, "/" and the response.

Returns:

the last scenario that was enacted.

getState

public java.lang.String getState()

Returns the last state that was entered. This State Pattern implementation models the states explicitly as nested inner classes, which also have access to the ContactList' fields. The name of the current state is obtained by reflection on the class name.

Returns:

the name of the current State instance.

addEntry

public void addEntry(java.lang.String forename,
            java.lang.String surname)

Attempts to add a new entry to this ContactList. If the forename and surname are valid (non-empty) Strings, enacts addEntry/ok and inserts the forename and surname at the end of their respective lists; and, if the current state is EmptyTable, changes state to NonEmptyTable, otherwise remains in the same state (NonEmptyTable, or RowSelected). If one of the names is an empty String, enacts addEntry/error and remains in the same state.

Parameters:

forename - a forename.

surname - a surname.

selectRow

public void selectRow(int index)

Attempts to select a row in this ContactList. If in the NonEmptyTable or RowSelected state, such that there are 1..n rows to be selected, and a valid row index is chosen, enacts either selectRow/high, if row n was selected, or selectRow/low if a lower row was selected, and then enters the RowSelected state; otherwise enacts selectRow/error and remains in the same state.

Parameters:

index - the row selection index.

unselectRow

public void unselectRow()

Attempts to unselect a row in this ContactList. If in the RowSelected state, where a current row is selected, enacts unselectRow/ok, sets the selected row to zero and changes state to NonEmptyTable; otherwise enacts unselectRow/error and remains in the same state (EmptyTable, or NonEmptyTable).

removeEntry

public void removeEntry()

Attempts to remove an entry from this ContactList. If in the state RowSelected, enacts one of three scenarios, depending on the table's fill-level and the row selected. If there is only one entry in the table, enacts removeEntry/onlyEntry, deletes the names from their respective arrays, sets the row selected to zero and enters the EmptyTable state. If there are multiple entries and the highest entry was selected, enacts removeEntry/finalEntry, deletes the names from their respective arrays, sets the row selected to zero and enters the NonEmptyTable state. Otherwise, enacts removeEntry/medialEntry and deletes the names, but allows the selection to be transferred onto the next row, and remains in the RowSelected state. If in any other state, enacts removeEntry/error and remains in that state.