This is version 2.4 of the BLT library. It's an extension to the
Tcl/Tk toolkit. You simply compile and link with the Tcl/Tk
libraries. It does not require the Tcl or Tk source files.
BLT is available from
This release has been built and tested with the following Tcl/Tk
Tcl 7.5 / Tk 4.1
Tcl 7.6 / Tk 4.2
Tcl/Tk 8.4 thru 8.4.0
Avoid alpha and beta versions of Tcl/Tk. They probably won't work.
What is BLT?
BLT is an extension to Tcl/Tk. It adds plotting widgets (X-Y graph,
barchart, stripchart), a powerful geometry manager, a new canvas
item, and several new commands to Tk.
graph, barchart, stripchart
BLT has X-Y graph, barchart, and stripchart widgets that are
both easy to use and customize. All the widgets work with
BLT vector data objects, which makes it easy to manage data.
treeview Displays a general ordered tree which may be built
on-the-fly or all at once.
tree Tree data object.
tabset Can be used either as a tab notebook or simple tabset.
Multi-tiered and/or scrolled tabsets are available.
Notebook pages can be torn-off into separate windows and
later put back.
table A table-based geometry manager. Lets you specify widget
layouts by row and column positions in the table. Unlike the
packer or grid, you can finely control and constrain window
Vector Data Object:
vector Lets you manage a vector of floating point values in a
high-level fashion. Vectors inter-operate seamlessly with
the plotting widgets. The graphs will automatically redraw
themselves when the vector data changes. Vector's components
can be managed through a Tcl array variable, a Tcl command,
or the using its own C API.
Background Program Execution:
bgexec Like Tcl's "exec ... &", but collects the output, error, and
status of the detached UNIX subprocesses. Sets a Tcl variable
busy For preventing user-interactions when the application is
busy. Manages an invisible "busy" window which prevents
further user interactions (keyboard, mouse, button, etc.).
Also you can provide a busy cursor that temporarily
overrides those of the Tk widgets.
New Canvas Item:
eps An new item is added to the Tk canvas for handling
encapsulated PostScript. It lets you embed an EPS file into
the canvas displaying either an EPS preview image found in
the file, or a Tk image that you provide. When you print
the canvas the EPS item will automatically include the EPS
file, translating and scaling the PostScript. For example,
you could use "eps" items to tile several PostScript pages
into single page.
The "eps" item can also be used as a replacement for "image"
canvas items. Unlike "image" canvas items, the image of an
eps item can be printed and scaled arbitrarily.
Drag & Drop Facility:
drag&drop Adds drag-n-drop capabilities to Tk. It uses "send"-style
communication between drag-drop sources and targets. The
result is a much more powerful drag-and-drop mechanism than
is available with OpenLook or Motif.
bitmap Lets you read and write bitmaps from Tcl. You can define
bitmaps from ordinary text strings. Bitmaps can also be
scaled and rotated. For example, you can create a button
with rotated text by defining a bitmap from a text string
and rotating it. You can then use the bitmap in the button
winop Basic window operations. You can raise, lower, map, or,
unmap windows. Other operations let you move the pointer
or take photo image snapshots of Tk widgets.
bltdebug Lets you trace the execution of Tcl commands and procedures.
Prints out each Tcl command before it's executed.
watch Lets you specify Tcl procedures to be run before and/or
after every Tcl command. May be used for logging, tracing,
profiling, or debugging or Tcl code.
spline Computes a spline fitting a set of data points (x and y
vectors) and produces a vector of the interpolated images
(y-coordinates) at a given set of x-coordinates.
htext A simple hypertext widget. Allows text and Tk widgets to
be combined in a scroll-able text window. Any Tk widget
can be embedded and used to form hyper-links. Other
options allow for selections and text searches.
How to compile and test BLT?
See the file "INSTALL" for instructions.
Does BLT work under Windows?
Yes. Windows 95/98/ME/NT/2000/XP. I've compiled it with both
MS VC++ 5.0/6.0p4 and EGCS 1.1.1. Self-installing pre-compiled versions
What are the differences between the Windows and Unix releases?
All commands work: graphs, bgexec, busy, drag&drop etc. except
the "container", and "cutbuffer" widgets.
The "drag&drop" command still needs to use "send" to transfer
information between Tk applications. You can use
to imitate "send" using DDE. Just source the script and execute
to set up the new send command.
In general, I can't answer the "When will" questions, mostly out of
embarrassment. My estimates of when new features and releases will
occur usually turn out to be way way off.
What does BLT stand for?
Whatever you want it to.
Where to send bugs reports, suggestions, etc. ?
(best to send to both addresses) Make sure you include BLT
and the version number in the subject line.