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INTRODUCTION to BIND code snippets:
As I develop more and more Tk GUI scripts in the FE 'tkGooies' subsystem
--- in the group of FE (Freedom Environment) subsystems, I find it extremely
helpful to copy 'snippets' of 'bind' code from an 'old' tkGooie script,
for use in a new 'tkGooie' --- and then make a few changes of variable names
and widget names, as needed.
As I publish a script of the 'tkGooies' system on the CODE pages that
are available via the
'tkGooies' Description page,
I hope that that particular 'tkGooie' script may help others
to learn to make Tcl-Tk scripts that are of interest to them.
In the course of these activities ('tkGooie' code development and
'tkGooie' code publishing), I realized that it will be of help to me
--- and to other potential
'Tclers' --- to have a web page that
points to sources of various kinds of Tcl-Tk code 'snippets'.
I quickly realized that, when I am looking for a Tcl-Tk code snippet,
I am usually looking for a snippet that is of one of 3 general kinds:
-
a WIDGET -
an example of DEFINITION (and packing) of a widget
-
a BINDING -
an example of an EVENT binding on a widget
-
a PROC -
an example to perform a SPECIFIC FUNCTION, such as file-reading,
or file-writing, or plotting lines/ovals/polygons on a canvas,
or plotting pixels in a photo-image on a canvas, or performing a
certain kind of calculation, or whatever.
It is the purpose of this page to provide examples of BIND STATEMENTS
--- via links to web pages that present Tcl-Tk code.
---
Most of the links (below) will be to the 'CODE pages' of my 'tkGooies' system
--- pages of this FE (Freedom Environment) web site, www.freedomenv.com.
But some links may be 'external' links --- to helpful pages at the
Tcler's wiki --- wiki.tcl.tk --- or elsewhere on the web.
Organization of the links below :
There are such a wide variety of 'code snippets', that it is difficult
to devise a single way of organizing the links.
There is a standardized Tk coding structure that I use in the
development of 'tkGooie' scripts.
I describe that coding structure on the page
A Canonical Structure for Tk Code --- and variations.
In that coding structure, I basically organize the code to include
3 main sections:
-
widget definitions
(the layout of the GUI) --- typically involving
defining 'frame' widgets, and then widgets within those frames ---
widgets like 'button' widgets, 'label' widgets, 'entry' widgets, etc.
-
'bind' statements,
if any are needed in addition to the default bindings
that are provided with the Tk widgets.
The 'bind' statements specify code to be executed when
certain 'events' occur, such as moving a mouse on
a Tk 'canvas' widget.
-
procs (procedures)
which may involve various kinds of algorithms to perform
calculations, to draw images, to read files, to write files,
to execute external programs, etc.
In providing the links below, I provide links for EVENT-BINDINGS.
A 'Table of Contents' section below can be used to take you to a section
of the page below --- where each section corresponds to an event-binding ---
like 'Release' or 'Press' events on a mouse button --- or 'Move' or 'Leave'
events with a mouse cursor --- or 'Home' or 'End' or 'PageDown' or 'PageUp'
keyboard events.
Note that the event types that are most commonly used in bindings are
those for user actions such as key presses (or releases)
or changes in the pointer position.
Examples of Tk event names:
-
'Button' or 'ButtonPress'
--- indicating a mouse button was pressed.
-
'ButtonRelease'
--- indicating a mouse button was released.
-
'Enter'
--- indicating the pointer moved into a window/widget.
-
'Leave'
--- indicating the pointer moved out of a window/widget.
-
'Motion'
--- indicating the pointer moved from one point to another
within a window/widget.
-
'Key' or 'KeyPress'
--- indicating a key was pressed.
-
'KeyRelease'
--- indicating a key was released.
-
'Return'
--- indicating the Return/Enter key was pressed.
The coder usually has a widget-type in mind --- to which
an action will be 'bound', to respond to a particular
user action on the widget.
For example, the 'Return' event is usually bound to
an 'entry' widget.
So the items in the Table of Contents below will be specified by a
combination of a widget-name and an event-name.
If this organization by widget-and-event name does not work for you,
and it would be more helpful to seek 'bind' examples by a 'function'
that you want to perform, you can look at the
PROCS code-snippets page which is organized by 'function'.
The Tk GUI scripts which provide that function may also
have 'bind' statements that use procs to perform that function.
Enough of this introduction.
Below is the 'Table of Contents' --- a table of links.
The table of contents below provides links to
sections of THIS web page that contain links to take the reader
to locally-stored (or remotely-stored) code --- code that contains
snippets that may help in making more Tk GUI's.
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