DESIGN
AND IMPLEMENTATION OF A JAVA BASED CANVAS GRAPHIC SYSTEM
CHAPTER
ONE
INTRODUCTION
1.1
Background of Study
Canvas’ origins date back to 1987.
The original idea for Canvas came from Jorge Miranda, one of the founders of Deneba Systems Inc. of Miami Florida, for Apple’s Macintosh computers, part of the
wave of programs that made the desktop
publishing revolution.The first version was unique in many ways; not
least because it was released as both an application and a desk
accessory. In the latter form, it could be used while another program, e.g.
PageMaker, was running simultaneously; very handy in that time of single
program operation.
Canvas provides tools for creating
and editing vector and raster
graphics. It is used for illustration, page layout, animation, presentations, and
publications in printed and World Wide Web formats.From its
inception, Canvas differed from other graphics applications because it combined
tools and file formats for both vector (line art) graphics, and raster
(photographic and other pixel-based) images, along with word-processing and
page-layout features such as multiple page documents and master pages. The user works in a window which is the
familiar “page on a pasteboard” analog used by many DTP and vector
graphics programs, but in that window, which might be a single illustration
page or one page of a multi-page magazine, book, web site, animation or
presentation, the user can create or edit and layout text, vector graphics and
raster images. Canvas also emphasized technical drawing in addition to artistic
illustration features.
While Canvas started out as a
prosumer program in the general graphics/DTP market, and continues to be the
first (even only) tool of many professionals in such fields as graphics design,
advertising, marketing, and DTP, it is less known in the consumer/prosumer market
today than programs marketed by larger companies, such as Adobe Illustrator,
Photoshop, and CorelDRAW. It has been
better known in academic and commercial enterprises.
A Canvas component represents a blank
rectangular area of the screen onto which the application can draw or from
which the application can trap input events from the user. An application must
subclass the Canvas class in order to get useful functionality such as creating
a custom component. The paint method must be overridden in order to perform
custom graphics on the canvas.
An essential part of programming in
Java requires you build exciting new user interfaces for yourselves. Components
that come built into the Java framework are regular UI elements, however for a
more rich experience, you need controls of your own. Take, for instance, a
charting application. No charting tool comes built into a Java API. You need to
manually draw the chart yourself.
Graphic design is the
presentation of ideas and information to your audience in a clear, visually
engaging manner. Graphic design lets you make a great first impression.
Consumers tend to gravitate to better-designed products. It provides a quality
anchor in their mind. Good design gives you instant credibility, inspires
confidence and trustworthiness, and clearly communicates its point to your
audience.
1.2 Statement of the Problem
Information technology is a trend today,
and as the volume of information increases, problem of storage arises. As time
is money, in the 21st century, people don’t have the time to read
huge number of pages or analyze numerous tables of data. Hence, there is need
to represent a huge database in picture-like forms like bar charts and pie
charts.
1.3 Aim and Objectives
of the Study
The aim of this project is to design a
graphics application that uses a Canvas to display graphic objects.
The objectives of the study are;
1. To design a canvas based application
using a canvas component
2. To develop an interface for graphics
design.
3. To implement the application using java
programming language.
1.4 Significance of the Study
This project work will help to provide a
better understanding on developing graphic applications in java. It will also
increase our knowledge in drawing programmatically as this involves trigonometric
calculations.
This project work can serve as:
1. A guide to anyone who wants to develop a
graphics system
2. Reference work for students carrying out
research on graphic application development.
1.5
Limitations of the study
Due
to some constraints, this research work will be limited to the following areas;
1. It does not allow drawing of complicated
diagrams and designs
2. It does not support full format editing
of shapes
3. It is limited to simple shapes like
lines, rectangles and circles.
1.6 Scope of Study
This
study’s intended user is all personal computer owners which cuts across
students, companies and business enterprises that hope to achieve high quality
graphics design in a java environment.
1.7 Definitions of Terms
CANVAS:
A container that holds various drawing elements
(lines, shapes, text, frames containing other elements, etc.).
AWT:
The Java Abstract Windowing Toolkit (AWT)
provides numerous classes that support window program development.
GRAPHICS:
Refers to any computerdevice
or program that makes a computer capable of
displaying and manipulating pictures.
GUI:
Graphical User
Interface.
JAVA
2D API: provides
advanced two dimensional graphics capabilities for detailed and complex
graphical manipulations.
SWING:
Swing is a set of
program component s for Java
programmers that provide the ability to create graphical user interface (GUI)
components, such as buttons and scroll bars, that are independent of the
windowing system for specific operating system.