SEKE 2012 Proceedings - Knowledge Systems Institute

Coordination Model to Support Visualization of Aspect-Oriented Programs
Álvaro F. d’Arce, Rogério E. Garcia, Ronaldo C. M. Correia, Danilo M. Eler
Departamento de Matemática, Estatística e Computação
Faculdade de Ciências e Tecnologia – Universidade Estadual Paulista “Júlio de Mesquita Filho”
Rua Roberto Simonsen, 305 – CEP 19060-900 – Presidente Prudente - SP, Brazil
alvaro@darce.com, {rogerio,ronaldo,danilo}@fct.unesp.br
Abstract
Program Comprehension tasks represent a strategic role
in Software Engineering activities, demanding time and
effort, representing a considerable cost in maintenance.
Aspect-Oriented Programming has specific elements to
compose program behavior (e.g., aspects, pointcuts, join
points and advices). The cognitive process can be improved
by employing visual techniques to support source
code analysis of its structure and behavior. A Software
Visualization tool must be able to provide suitable visual
representations for the program. Particularly, visual exploration
of Aspect-Oriented programs requires some features
to map how aspects crosscut some program structures. In
this paper we propose a tool and an architecture to improve
Aspect-Oriented program understanding supported by three
coordinated visualization techniques.
Keywords: Program Understanding, Aspect-Oriented
Program, Software Visualization, Software Engineering.
1 Introduction
Program Comprehension involves individual programmers
understanding about what a program does and how
it does it, in order to make functional changes and extensions,
for example, without introducing defects [6]. Karahasanovic
and his partners argue that Program Comprehension
remains incomplete, requiring a deeper understanding
of employed strategies, and before any modification (e.g.,
maintenance tasks), understanding the underlying mechanisms
might improve the comprehension [13]. Acquiring
knowledge about large programs may delay Program Comprehension
tasks, which motivate the use of Software Visualization
as an alternative approach to improve the cognitive
process.
However, Aspect-Oriented programs comprehension can
become more complex to be done, because separated units
of code interfere in the behavior of other units. Aspect-
Oriented Programming (AOP) supports crosscut concerns
modularization, by structures that add behavior to selected
elements of the programming language semantics [14].
Thus, AOP isolates implementation that otherwise would
be spread and tangled throughout the base code. This new
feature increases the program structural complexity, making
harder to achieve the understanding of its architecture and
structure, bringing up challenges to Aspect-Oriented Program
Comprehension.
Based on that, Software Visualization can be an alternative
approach to help software engineers to cope with
structural complexity – due to fragmentation and the need
to compose fragments – since the visual representations are
able to work with an Aspect-Oriented program effectively,
having specific visual mappings for Aspect-Oriented programs
and mechanisms to gather and to organize data representing
AOP features.
Visualization techniques, some extensions and tools
have been proposed to support software visualization:
TreeMaps [12, 2, 18], Polymetric Views [15, 3] to visualize
hierarchical structures; Hyperbolic Trees [17] to visualize
large hierarchical structures; Bars and Stripes for interrelational
structures visualization [1]; UML 3D to visualize
packages, classes and methods [10]; and Dependence
Graphs for inter-dependency level visualization [19]. These
visualization techniques can be used to build visual representations
to support comprehension tasks, but when applied
to an Aspect-Oriented program as artifact, they are
able to represent only the aspects before the weaving process
– its fragmented code – and not the resulting code after
the weaver – its tangled and spread code.
In this paper we propose a tool and an architecture
supported by coordinated visual mappings which tackle
Aspect-Oriented programs. The proposed approach is capable
of analyzing a source code after the weaving process,
enabling a visual exploration of the software structure (i.e.,
methods, aspects, advices and pointcuts) and how it all is
related. Furthermore, our tool is able to visually show all
structures involved in structural tests’ results.
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