Building Applications with Oratcl and BLT
As promised, before we leave the world of Tk, we’ll create our own small application for measuring Oracle table space usage. Building this tool, which we’ll call TableSpacer, will extend our use of Tk beyond using downloaded applications as is. This example builds on two excellent Tcl/Tk products: George Howlett’s BLT, described in this section, and Tom Poindexter’s Oratcl, already described in Chapter 3.
BLT
BLT is an extension to Tcl/Tk that adds combinations of plotting widgets (graphs, barcharts, etc.) to Tk canvases, saving you hundreds—possibly thousands—of lines of code when creating a typical on-the-fly graph within a Tk canvas object. (Not only is BLT one of the best chart-making packages around, but also the letters BLT can apparently stand for anything you want them to.)
The following are the main web sites for BLT:
- http://www.tcltk.com/blt
General information on the BLT package, upgrades, latest news, and so on.
- ftp://ftp.tcltk.com/pub/blt/
Central download site for the latest BLT code releases and self-installing pre-compiled Windows executable files.
- ftp://tcltk.sourceforge.net/pub/tcltk/blt/
SourceForge site for all things Tcl/Tk. In this directory you will find two very useful PDF tutorial files (it’s the same tutorial in different layouts), handouts.pdf and slides.pdf.
BLT is also described in Paul Raines and Jeff Tranter’s Tcl/Tk in a Nutshell, referenced in Appendix C.
Installing BLT on Unix
Before you can install BLT, ...