| EspressChart Components
The EspressChart toolkit is composed of four major components.
Chart Designer: Chart Designer is an interactive front-end application
that provides users with tools for generating a wide variety of charts based
on data from data files, Java classes, or from database queries. Its
point and click interface allows charts to be created quickly
with an almost infinite degree of flexibility.
It is written in 100% pure Java. It can run as an applet in any
Web browser with the Java plug-in. Chart Designer is also available
as an application version for running in a standalone environment. Chart
Designer allows you to view the chart from different viewpoints and to
position the chart at any desired angle.
Chart Designer can also be completely customized to run within different
application environments. A user-configurable Chart Designer can be
launched using the Chart API. Users can control the menu and toolbar
options, as well as the file i/o functions. In addition the Chart Designer
can be fully internationalized to support any foreign language.
A chart may be exported to a number of different binary formats for viewing
or printing as a static image. A chart can also be stored in the .tpl
format that saves the attributes of the chart (colors, size, etc.) but without
the associated data. Each time a template, .tpl, file is loaded into a browser,
the data is dynamically loaded from the data source. Hence charts can be continuously
updated without any programming. In addition, saving charts as templates
enables users to produce charts with a consistent look and feel. Charts
may also be stored using another proprietary format, .cht which stores chart
attributes as well as chart data. Charts saved in either .tpl or .cht formats
can be viewed through the Chart Viewer Java applet. EspressChart also
allows the generated charts to be saved/exported using standard formats such
as GIF, JPEG, PNG, WMF, BMP, SVG, Flash etc.
Chart Viewer: Chart Viewer is an lightweight applet that allows
charts to be viewed remotely. It enables viewers to rotate, resize,
zoom and pan a chart. Viewers can click on individual data points to
either recover the data associated with the data point, or link to another
chart. Essentially, Chart Viewer provides full user interaction on the
chart. EspressChart includes two other smaller applets for interactive
chart viewing: Mini Viewer and Micro Viewer. Each sacrifices some
functionality and has a successively smaller client footprint.
EspressManager: EspressManager serves as the "back-end" to the Chart Designer
and Viewer applets. When running as an applet, EspressManager handles the data
access and file i/o activities on the server side. In addition, EspressManager
provides database connection and data buffering.
Chart API: Chart API,written in 100% pure Java, provides a sophisticated
yet easy-to-use Java package to a set of advanced two and three-dimensional
charting library functions. High-performance three-dimensional graphics
algorithms are employed to allow visualization and manipulation of the
chart (pan, zoom, xyz-scale, rotate, translate etc.) in real time. You
can use as little as one line of code to plot a chart. It supports JDBC-ODBC
connectivity to retrieve data from any database directly. Chart API can
be used in applets as well as in servlets/JSP(JavaServer Pages) applications.
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