Stepwise Approach for Introducing Object-Oriented Technique at Software Maintenance Stages

Software maintenance, including improvement and conversion, is becoming essential. It is repeated many times for the survival of software, but its cost is quite expensive [1]. Though it is said that the object-oriented technique is effective to lower the cost of software maintenance, in applying the object-oriented technique to the existing conventional software, many problems are reported such as time-consuming reeducation of software developers, high cost, or not so remarkable instantaneous effect. This paper discusses a methodology to apply object-oriented technique to software already developed by conventional technique at its maintenance stages.
In order to settle above-mentioned problems and easily realize the introduction of the object-oriented technique at its maintenance stages, we propose a step-wise approach dividing the process of applying object-oriented technique into 4 phases.
The first and second phases of this methodology were applied to a part (about 1/3 namely around 50 kilo-steps in C/C++ language) of a large-scale practical system for scheduling elevator maintenance engineers. The result showed the above expectation was true and the object-oriented technique must lower the cost of software maintenance since the number of bugs in the applied part was about one tenth of that of the unapplied part.

Experiments on the Effects of User's Direct Modification of GUI Layout Using Real Application Programs

We have proposed Metamer, a platform that allows users to interactively and visually modify GUI definitions during application runtime. Metamer is a GUI modifier that allows dynamical GUI transformation (metamorphosis) independently of the applications running on particular user environments.
In the current stage of our research, we focused our attention on the implementation of the GUI layout modification function. In order to evaluate this function, we conducted a series of experiments involving the manipulation of a browser, which actually is a Smalltalk standard tool.
For the evaluation, we asked the several individuals (testees) to collaborate in the experiment. The testees were asked to modify by themselves the layout pattern of the same application. Using the Metamer functions from the standard browser layout, the testees changed the current layout to a layout that suited their preferences.
After the experiment, all testees opined that the layout modified by themselves was the easiest to use. This demonstrates a substantial improvement in the degree of satisfaction of the GUI users, which is one of the basic objectives of this research. Practically all testees reduced the time required to perform search operations.

Dynamic GUI Layout Modification During Application Runtime

There exists a barrier between GUI development and GUI running which impedes GUI modification during runtime. We consider that the elimination of this barrier to allow end-users to thoroughly modify GUI is of crucial importance.
We propose Metamer, a platform that allows users to interactively and visually modify GUI's appearance definitions and dialog definitions during application runtime. Metamer is a GUI modifier that allows dynamical GUI transformation (metamorphosis) independently of the applications running on particular user environments. Metamer objective is to enable GUI component modification, layout modification , and dialog modification.
In the current stage of our research, we focused our attention on the implementation of the GUI layout modification function, which must support effective visual communication functionality. This function is part of the GUI design component called appearance definition.
We have formerly proposed DEVO which allows dynamic modification of GUI objects layout and Tree structures. The layout modification function of Metamer is based on DEVO.
In this paper, we summarize the outline of Metamer which is being implemented currently on top of Smalltalk. We also explain the application runtime GUI object layout modification function and its evaluation.

Extended MVC Model on Smalltalk-80 and Its Application

We describe a method of extending the current MVC Model of Smalltalk-80. The existing View model which does not permit both the dynamically overlapping subviews and their free movement in the superview is extended. A pair of View-Controller for the management of these subviews is newly introduced. It also provides the capability of opening/closing subviews after the opening of superview.
A goal of the design is to produce a system, in which the visual-object can be constructed by the combination of M,V,C, and the object can have pictorial expression equiped with its own menu and control.
As an example of application of this method, we present Petri Net Editor in which a Petri Net can be designed, edited by drawing on the display, and can be executed.

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