Görsel programlama teknikleri ve bir kalıp tasarım uygulaması

Abstract

Anahtar Kelimeler: Görsel Programlama Ortamları, MFC, Kalıp, Visual C++, Nesne Yönelimli Programlama Bu çalışmada Microsoft Windows görsel kullanıcı arayüzü özelliklerinin ve bu işletim sistemi altında kullanılan görsel programlama ortamlarının tanıtımı yapılmış, bu ortamlarda uygulama geliştirme metodolojisi verilirken görsel bir uygulamanın temel oluşturma adımlan ve bu aşamalarda geliştiriciye getirilen kolaylıklar incelenmiştir. Grafik ortamlarına tipik bir örnek olan tekstil kalıp tasarım sisteminde bu metodolojinin uygulaması yapılmıştır.

Keywords: Visual Development Environments, MFC, Pattern, Visual C++, Object Oriented Programming Starting in early 90's, MS Windows, has so far successfully conquered the PC software market, ending an era of DOS predominance. The user friendly interface of Windows has encouraged and helped many hesitant end users to become more acquainted with computers and applications. When more users started using software applications, the need for programs with better and more intuitive user interfaces became far more evident. This necessity led toward the birth of new programming techniques and environments. Many companies, but Microsoft in particular, invested heavily for development of visual user interfaces. In this new visual market Visual Basic and Visual C++ have become the most popular programming environments. Introduction of these visual programming tools based on object oriented programming concepts has substantially changed programming styles and habits of many software developers. MS Windows Windows has become extremely popular among users and consequently grew to be the market leader through the ease of use it provided with its user interface. The most important feature of the Windows interface is that most visual components are based on metaphores which the users are able to relate to objects they use in their daily lives. (Eg: A command button with a raised effect to start a process.) One of the many other attractive features of Windows is its multitasking capability. This allows a user to switch among many applications and exchange data without having to close any of them. In classical DOS based applications users had to close an application and then start a new one. This feature improved the vision of many users and drastically boosted the utilization of the software. In the previous DOS based systems the use of peripheral devices like Printers, Plotters was highly constrained since these devices required their drivers to be incorporated within applications. The use of a new device meant a modification in source code and recompilation. Windows on the other hand, provides a standard interface for all applications allowing a program to prepare a device independent output, leaving Windows to take care of device specific details to format the output and send to the device. Visual Basic Visual Basic is the most widely used programming system to develop software to run under Windows. Being a product with features for both the programmers and end users it improved its market shares sharply. In 1995 only, Visual Basic was sold more than 2.000.000 copies. Visual Basic is preferred especially for database applications. Visual Basic is an event-driven and document-centered application. With these orientations, Visual Basic can use some features of Object Oriented Programming Philosophy. But Visual Basic is not a real Object Oriented Programming environment. You cannot create new objects and cannot modify existing ones. Development environment of new objects is Visual C++. The Visual C++ environment is fully object-oriented. Visual C++ In programming market, Visual C++ is the most powerful and efficient programming environment. Most application programs (for Windows) have been developed with Visual C++. Some advantages of Visual C++ are as follows:. Handling of Huge Projects. With increases in project sizes, handling application code becomes too difficult with classical programming environments such as C or FORTRAN. In Visual C++, programmers can easily handle applications with more than 25.000 program lines.. Visual C++ codes are expandable and reusable.. Full Object Oriented Programming Environment.. Access to low level functions.. Speed With Visual C++, programmers are able to construct the below software pieces:. Windows EXE. Windows DLL. Windows Static Library. DOS EXE, COM. Visual Basic VBX (Custom Controls) In addition to these types, Visual C++ supports both 16 bit and 32 bit operating environments. Due to newer requirements from computer users, new design and programming philosophies were developed by computer scientists. One of the leading examples of these philosophies is Object Oriented Programming. Object Oriented Programming In ancient times users loaded their programs using switches on the control panels. This was an appropriate way for programs of small size. With the increases in program sizes other and more efficient methods were needed. High level languages such as Assembler and FORTRAN satisfied these requirements. In the meantime the advent of structured methodologies followed by the first structured languages, provided the developers with better and tighter control over program XI code; but when program sizes began to exceed 20.000-25.000 lines maintenance and modification of existing code became an unbearable task. Upon facing such challenge software scientists came up with a different approach which was built on logical grouping of concepts and flow of data among these logical objects through inter-object communication, namely Object Oriented Methodology. Object Oriented Programming Languages have three major features:. Encapsulation. Polymorphism. Inheritance In the design phase of the project, the first task is to determine which objects are needed in the application. This phase is the longest period of the project development phase. In general these projects have an accelerating nature. When the correct objects are in place, it is a rather simplified task to proceed with the rest of the project. Although most software is built for rather varying purposes, the essence of all requires or comprises similar components, for this reason it is an awkward solution to rewrite these components. With such component reusability concerns programmers make use of object libraries which include base classes. The most popular class library is Microsoft Foundation Classes supplied by Microsoft Corporation. This library includes most of the needed base classes for developing a Windows application. Computers In Textile Industry In textile industry, people use computers for 3 different purposes :. Accounting. Inventory Control and Manufacturing. Pattern Design The last of these purposes falls within the scope of this thesis. Pattern design is a matter of computer graphics. Many of computer graphical algorithms are used for implementing pattern design and modification. Some important features in pattern design are stated below: Lines and curves Adding and removing points from pattern Symmetry of a pattern Cutting a pattern Joining two distinct patterns Rotating a pattern Zooming in and out Adding seams to a pattern Grading Sizing and deforming patterns Adding grain lines, notes and special signs to a pattern This thesis consists of four sections. First a brief introduction to graphical interfaces has been provided followed by comprehensive information on Visual xu C++ and Visual Basic. Succeeding section covers the design methodology and development steps of a an application with a visual interface. Finally, a graphical pattern design system has been provided to serve as an example of this methodology and the tools.