1Snit's Not Incr Tcl README.txt
2-----------------------------------------------------------------
3
4Snit is pure-Tcl object and megawidget framework. See snit.html
5for full details.
6
7Snit is part of "tcllib", the standard Tcl Library.
8
9Snit lives in "tcllib" now, but it is available separately at
10http://www.wjduquette.com/snit. If you have any questions, bug
11reports, suggestions, or comments, feel free to contact me, Will
12Duquette, at will@wjduquette.com; or, join the Snit mailing list (see
13http://www.wjduquette.com/snit for details).
14
15Differences Between Snit 2.1 and Snit 1.x
16--------------------------------------------------------------------
17
18V2.0 and V1.x are being developed in parallel.
19
20 Version 2.1 takes advantage of some new Tcl/Tk 8.5 commands
21 ([dict], [namespace ensemble], and [namespace upvar]) to improve
22 Snit's run-time efficiency. Otherwise, it's intended to be
23 feature-equivalent with V1.x. When running with Tcl/Tk 8.5, both
24 V2.0 and V1.x are available; when running with Tcl/Tk 8.3 or Tcl/Tk
25 8.4, only V1.x is available.
26
27 Snit 1.x is implemented in snit.tcl; Snit 2.1 in snit2.tcl.
28
29V2.1 includes the following enhancements over V1.x:
30
31* A type's code (methods, type methods, etc.) can now call commands
32 from the type's parent namespace without qualifying or importing
33 them, i.e., type ::parentns::mytype's code can call
34 ::parentns::someproc as just "someproc".
35
36 This is extremely useful when a type is defined as part of a larger
37 package, and shares a parent namespace with the rest of the package;
38 it means that the type can call other commands defined by the
39 package without any extra work.
40
41 This feature depends on the new Tcl 8.5 [namespace path] command,
42 which is why it hasn't been implemented for V1.x. V1.x code can
43 achieve something similar by placing
44
45 namespace import [namespace parent]::*
46
47 in a type constructor. This is less useful, however, as it picks up
48 only those commands which have already been exported by the parent
49 namespace at the time the type is defined.
50
51There are four incompatibilities between V2.1 and V1.x:
52
53* Implicit naming of objects now only works if you set
54
55 pragma -hastypemethods 0
56
57 in the type definition. Otherwise,
58
59 set obj [mytype]
60
61 will fail; you must use
62
63 set obj [mytype %AUTO%]
64
65* In Snit 1.x and earlier, hierarchical methods and type methods
66 could be called in two ways:
67
68 snit::type mytype {
69 method {foo bar} {} { puts "Foobar!"}
70 }
71
72 set obj [mytype %AUTO%]
73 $obj foo bar ;# This is the first way
74 $obj {foo bar} ;# This is the second way
75
76 In Snit 2.1, the second way no longer works.
77
78* In Snit 1.x and earlier, [$obj info methods] and
79 [$obj info typemethods] returned a complete list of all known
80 hierarchical methods. In the example just above, for example,
81 the list returned by [$obj info methods] would include
82 "foo bar". In Snit 2.1, only the first word of a hierarchical
83 method name is returned, [$obj info methods] would include
84 "foo" but not "foo bar".
85
86* Because a type's code (methods, type methods, etc.) can now
87 call commands from the type's parent namespace without qualifying
88 or importing them, this means that all commands defined in the
89 parent namespace are visible--and can shadow commands defined
90 in the global namespace, including the standard Tcl commands.
91 There was a case in Tcllib where the Snit type ::tie::std::file
92 contained a bug with Snit 2.1 because the type's own name
93 shadowed the standard [file] command in the type's own code.
94
95
96Changes in V1.2
97--------------------------------------------------------------------
98
99* Defined a family of validation types. Validation types are used
100 to validate data values; for example, snit::integer and its
101 subtypes can validate a variety of classes of integer value, e.g.,
102 integers between 3 and 9 or integers greater than 0.
103
104Changes in V1.1
105--------------------------------------------------------------------
106
107* It's now explicitly an error to call an object's "destroy" method
108 in the object's constructor. (If you need to do it, just throw
109 an error; construction will fail and the object will be cleaned
110 up.
111
112* The Tile "ttk::frame" widget is now a valid hulltype for
113 snit::widgets. Any widget with a -class option can be used
114 as a hulltype; lappend the widget name to
115 snit::hulltypes to enable its use as a hulltype.
116
117* The TK labelframe widget and the Tile ttk::labelframe widget are
118 now valid hulltypes for snit::widgets.
119
120Changes in V1.0
121--------------------------------------------------------------------
122
123Functionally, V1.0 is identical to version V0.97.
124
125* Added a number of speed optimizations provided by Jeff Hobbs.
126 (Thanks, Jeff!)
127
128* Returned to the name "Snit's Not Incr Tcl".
129
130* Fixed SourceForge Tcllib Bug 1161779; it's no longer an error
131 if the destructor is defined before the constructor.
132
133* Fixed SourceForge Tcllib Bug 1106375; the hull widget is now
134 destroyed properly if there's an error in the constructor of
135 a widget or widgetadaptor.
136
137Changes in V0.97
138--------------------------------------------------------------------
139
140The changes listed here were actually made over time in Snit V0.96;
141now that they are complete, the result has been renumbered Snit V0.97.
142
143* Bug fix: methods called via [mymethod] can now return exotic
144 return codes (e.g., "return -code break").
145
146* Added the -hasinfo pragma, which controls whether there's an
147 "info" instance method or not. By default, there is.
148
149* POSSIBLE INCOMPATIBILITY: If no options are defined for a type, neither
150 locally nor delegated, then Snit will not define the "configure",
151 "configurelist", and "cget" instance methods or the "options"
152 instance variable.
153
154* If a snit::type's command is called without arguments, AND the type
155 can have instances, then an instance is created using %AUTO% to
156 create its name. E.g., the following commands are all equivalent:
157
158 snit::type dog { ... }
159
160 set mydog [dog create %AUTO%]
161 set mydog [dog %AUTO%]
162 set mydog [dog]
163
164 This doesn't work for widgets, for obvious reasons.
165
166* Added pragma -hastypemethods. If its value is "yes" (the
167 default), then the type has traditional Snit behavior with
168 respect to typemethods. If its value is "no", then the type
169 has no typemethods (even if typemethods were included
170 explicitly in the type definition). Instead, the first argument
171 of the type proc is the name of the object to create. As above,
172 the first argument defaults to "%AUTO%" for snit::types but not
173 for snit::widgets.
174
175* Added pragma -simpledispatch. This pragma is intended to make
176 simple, heavily used types (e.g. stacks or queues) more efficient.
177 If its value is "no" (the default), then the type has traditional
178 Snit behavior with respect to method dispatch. If its value is
179 "yes", then a simpler, faster scheme is used; however, there are
180 corresponding limitations. See the man page for details.
181
182* Bug fix: the "pragma" statement now throws an error if the specified
183 pragma isn't defined, e.g., "pragma -boguspragma yes" is now an
184 error.
185
186* Bug fix: -readonly options weren't. Now they are.
187
188* Added support for hierarchical methods, like the Tk text widget's
189 tag, mark, and image methods. You define the methods like so:
190
191 method {tag add} {args} {...}
192 method {tag configure} {args} {...}
193 method {tag cget} {args} {...}
194
195 and call them like so:
196
197 $widget tag add ....
198
199 The "delegate method" statement also supports hierarchical methods.
200 However, hierarchical methods cannot be used with -simpledispatch.
201
202* Similarly, added support for hierarchical typemethods.
203
204Changes in V0.96
205--------------------------------------------------------------------
206
207V0.96 was the development version in which most of the V0.97 changes
208were implemented. The name was changed to V0.97 when the changes
209were complete, so that the contents of V0.97 will be stable.
210
211Changes in V0.95
212--------------------------------------------------------------------
213
214The changes listed here were actually made over time in Snit V0.94;
215now that they are complete, the result has been renumbered Snit V0.95.
216
217* Snit method invocation (both local and delegated) has been
218 optimized by the addition of a "method cache". The primary
219 remaining cost in method invocation is the cost of declaring
220 instance variables.
221
222* Snit typemethod invocation now also uses a cache.
223
224* Added the "myproc" command, which parallels "mymethod". "codename"
225 is now deprecated.
226
227* Added the "mytypemethod" command, which parallels "mymethod".
228
229* Added the "myvar" and "mytypevar" commands. "varname" is now
230 deprecated.
231
232* Added ::snit::macro.
233
234* Added the "component" type definition statement. This replaces
235 "variable" for declaring components explicitly, and has two nifty
236 options, "-public" and "-inherit".
237
238* Reimplemented the "delegate method" and "delegate option"
239 statements; among other things, they now have more descriptive error
240 messages.
241
242* Added the "using" clause to the "delegate method" statement. The
243 "using" clause allows the programmer to specify an arbitrary command
244 prefix into which the component and method names (among other
245 things) can be automatically substituted. It's now possible to
246 delegate a method just about any way you'd like.
247
248* Added ::snit::compile.
249
250* Added the "delegate typemethod" statement. It's similar to
251 "delegate method" and has the same syntax, but delegates typemethods
252 to commands whose names are stored in typevariables.
253
254* Added the "typecomponent" type definition statement. Parallel to
255 "component", "typecomponent" is used to declare targets for the new
256 "delegate typemethod" statement.
257
258* "delegate method" can now delegate methods to components or
259 typecomponents.
260
261* The option definition syntax has been extended; see snit.man. You
262 can now define methods to handle cget or configure of any option; as
263 a result, The "oncget" and "onconfigure" statements are now deprecated.
264 Existing "oncget" and "onconfigure" handlers continue to function as
265 expected, with one difference: they get a new implicit argument,
266 "_option", which is the name of the option being set. If your
267 existing handlers use "_option" as a variable name, they will need
268 to be changed.
269
270* In addition, the "option" statement also allows you to define a
271 validation method. If defined, it will be called before the value
272 is saved; its job is to validate the option value and call "error"
273 if there's a problem.
274
275* In addition, options can be defined to be "-readonly". A readonly
276 option's value can be set at creation time (i.e., in the type's
277 constructor) but not afterwards.
278
279* There's a new type definition statement called "pragma" that
280 allows you to control how Snit generates the type from the
281 definition. For example, you can disable all standard typemethods
282 (including "create"); this allows you to use snit::type to define
283 an ensemble command (like "string" or "file") using typevariables
284 and typemethods.
285
286* In the past, you could create an instance of a snit::type with the
287 same name as an existing command; for example, you could create an
288 instance called "::info" or "::set". This is no longer allowed, as
289 it can lead to errors that are hard to debug. You can recover the
290 old behavior using the "-canreplace" pragma.
291
292* In type and widget definitions, the "variable" and "typevariable"
293 statements can now initialize arrays as well as scalars.
294
295* Added new introspection commands "$type info typemethods",
296 "$self info methods", and "$self info typemethods".
297
298* Sundry other internal changes.
299
300Changes in V0.94
301--------------------------------------------------------------------
302
303V0.94 was the development version in which most of the V0.95 changes
304were implemented. The name was changed to V0.95 when the changes
305were complete, so that the contents of V0.95 will be stable.
306
307Changes in V0.93
308--------------------------------------------------------------------
309
310* Enhancement: Added the snit::typemethod and snit::method commands;
311 these allow typemethods and methods to be defined (and redefined)
312 after the class already exists. See the Snit man page for
313 details.
314
315* Documentation fixes: a number of minor corrections were made to the
316 Snit man page and FAQ. Thanks to everyone who pointed them out,
317 especially David S. Cargo.
318
319* Bug fix: when using %AUTO% to create object names, the counter
320 will wrap around to 0 after it reaches (2^32 - 1), to prevent
321 integer overflow errors. (Credit Marty Backe)
322
323* Bug fix: in a normal Tcl proc, the command
324
325 variable ::my::namespace::var
326
327 makes variable "::my::namespace::var" available to the proc under the
328 local name "var". Snit redefines the "variable" command for use in
329 instance methods, and had lost this behavior. (Credit Jeff
330 Hobbs)
331
332* Bug fix: in some cases, the "info vars" instance method didn't
333 include the "options" instance variable in its output.
334
335* Fixed bug: in some cases the type command was created even if there
336 was an error defining the type. The type command is now cleaned
337 up in these cases. (Credit Andy Goth)
338
339
340Changes in V0.92
341--------------------------------------------------------------------
342
343* Bug fix: In type methods, constructors, and methods, the "errorCode"
344 of a thrown error was not propagated properly; no matter what it was
345 set to, it always emerged as "NONE".
346
347Changes in V0.91
348--------------------------------------------------------------------
349
350* Bug fix: On a system with both 0.9 and 0.81 installed,
351 "package require snit 0.9" would get snit 0.81. Here's why: to me
352 it was clear enough that 0.9 is later than 0.81, but to Tcl the
353 minor version number 9 is less than minor version number 81.
354 From now on, all pre-1.0 Snit version numbers will have two
355 digits.
356
357* Bug fix: If a method or typemethod had an argument list which was
358 broken onto multiple lines, the type definition would fail. It now
359 works as expected.
360
361* Added the "expose" statement; this allows you to expose an entire
362 component as part of your type's public interface. See the man page
363 and the Snit FAQ list for more information.
364
365* The "info" type and instance methods now take "string match"
366 patterns as appropriate.
367
368Changes in V0.9
369--------------------------------------------------------------------
370
371For specific changes, please see the file ChangeLog in this directory.
372Here are the highlights:
373
374* Snit widgets and widget adaptors now support the Tk option database.
375
376* It's possible set the hull type of a Snit widget to be either a
377 frame or a toplevel.
378
379* It's possible to explicitly set the widget class of a Snit widget.
380
381* It's possible to explicitly set the resource and class names for
382 all locally defined and explicitly delegated options.
383
384* Option and method names can be excluded from "delegate option *" by
385 using the "except" clause, e.g.,
386
387 delegate option * to hull except {-borderwidth -background}
388
389* Any Snit type or widget can define a "type constructor": a body of
390 code that's executed when the type is defined. The type constructor
391 is typically used to initialize array-valued type variables, and to
392 add values to the Tk option database.
393
394* Components should generally be created and installed using the new
395 "install" command.
396
397* snit::widgetadaptor hulls should generally be created and installed
398 using the new "installhull using" form of the "installhull" command.
399
400See the Snit man page and FAQ list for more information on these new
401features.
402
403
404Changes in V0.81
405--------------------------------------------------------------------
406
407* All documentation errors people e-mailed to me have been fixed.
408
409* Bug fix: weird type names. In Snit 0.8, type names like
410 "hyphenated-name" didn't work because the type name is used as a
411 namespace name, and Tcl won't parse "-" as part of a namespace name
412 unless you quote it somehow. Kudos to Michael Cleverly who both
413 noticed the problem and contributed the patch.
414
415* Bug fix: Tcl 8.4.2 incompatibility. There was a bug in Tcl 8.4.1
416 (and in earlier versions, likely) that if the Tcl command "catch"
417 evaluated a block that contained an explicit "return", "catch"
418 returned 0. The documentation evidently indicated that it should
419 return 2, and so this was fixed in Tcl 8.4.2. This broke a bit
420 of code in Snit.
421
422Changes in V0.8
423--------------------------------------------------------------------
424
425* Note that there are many incompatibilities between Snit V0.8 and
426 earlier versions; they are all included in this list.
427
428* Bug fix: In Snit 0.71 and Snit 0.72, if two instances of a
429 snit::type are created with the same name, the first instance's
430 private data is not destroyed. Hence, [$type info instances] will
431 report that the first instance still exists. This is now fixed.
432
433* Snit now requires Tcl 8.4, as it depends on the new command
434 tracing facility.
435
436* The snit::widgettype command, which was previously deprecated, has
437 now been deleted.
438
439* The snit::widget command has been renamed snit::widgetadaptor; its
440 usage is unchanged, except that the idiom "component hull is ..."
441 is no longer used to define the hull component. Instead, use the
442 "installhull" command:
443
444 constructor {args} {
445 installhull [label $win ...]
446 $self configurelist $args
447 }
448
449* The "component" command is now obsolete, and has been removed.
450 Instead, the "delegate" command implicitly defines an instance
451 variable for the named component; the constructor should assign an
452 object name to that instance variable. For example, whereas you
453 used to write this:
454
455 snit::type dog {
456 delegate method wag to tail
457
458 constructor {args} {
459 component tail is [tail $self.tail -partof self]
460 }
461
462 method gettail {} {
463 return [component tail]
464 }
465 }
466
467 you now write this:
468
469 snit::type dog {
470 delegate method wag to tail
471
472 constructor {args} {
473 set tail [tail $self.tail -partof self]
474 }
475
476 method gettail {} {
477 return $tail
478 }
479 }
480
481* There is a new snit::widget command; unlike snit::widgetadaptor,
482 snit::widget automatically creates a Tk frame widget as the hull
483 widget; the constructor doesn't need to create and set a hull component.
484
485* Snit objects may now be renamed without breaking; many of the
486 specific changes which follow are related to this. However,
487 there are some new practices for type authors to follow if they wish
488 to write renameable types and widgets. In particular,
489
490 * In an instance method, $self will always contain the object's
491 current name, so instance methods can go on calling other instance
492 methods using $self.
493
494 * If the object is renamed, then $self's value will change. Therefore,
495 don't use $self for anything that will break if $self changes.
496 For example, don't pass a callback as "[list $self methodname]".
497
498 * If the object passes "[list $self methodname arg1 arg2]" as a callback,
499 the callback will fail when the object is renamed. Instead, the
500 object should pass "[mymethod methodname arg1 arg2]". The [mymethod]
501 command returns the desired command as a list beginning with a
502 name for the object that never changes.
503
504 For example, in Snit V0.71 you might have used this code to call a
505 method when a Tk button is pushed:
506
507 .btn configure -command [list $self buttonpress]
508
509 This still works in V0.8--but the callback will break if your
510 instance is renamed. Here's the safe way to do it:
511
512 .btn configure -command [mymethod buttonpress]
513
514 * Every object has a private namespace; the name of this namespace
515 is now available in method bodies, etc., as "$selfns". This value is
516 constant for the life the object. Use "$selfns" instead of "$self" if
517 you need a unique token to identify the object.
518
519 * When a snit::widget's instance command is renamed, its Tk window
520 name remains the same--and is still extremely important.
521 Consequently, the Tk window name is now available in snit::widget
522 method bodies, etc., as "$win". This value is constant for the
523 life of the object. When creating child windows, it's best to
524 use "$win.child" rather than "$self.child" as the name of the
525 child window.
526
527* The names "selfns" and "win" may no longer be used as explicit argument
528 names for typemethods, methods, constructors, or onconfigure
529 handlers.
530
531* procs defined in a Snit type or widget definition used to be able to
532 reference instance variables if "$self" was passed to them
533 explicitly as the argument "self"; this is no longer the case.
534
535* procs defined in a Snit type or widget definition can now reference
536 instance variables if "$selfns" is passed to them explicitly as the
537 argument "selfns". However, this usage is deprecated.
538
539* All Snit type and widget instances can be destroyed by renaming the
540 instance command to "".
541
542Changes in V0.72
543--------------------------------------------------------------------
544
545* Updated the pkgIndex.tcl file to references snit 0.72 instead of
546 snit 0.7.
547
548* Fixed a bug in widget destruction that caused errors like
549 "can't rename "::hull1.f": command doesn't exist".
550
551Changes in V0.71
552--------------------------------------------------------------------
553
554* KNOWN BUG: The V0.7 documentation implies that a snit::widget can
555 serve as the hull of another snit::widget. Unfortunately, it
556 doesn't work. The fix for this turns out to be extremely
557 complicated, so I plan to fix it in Snit V0.8.
558
559 Note that a snit::widget can still be composed of other
560 snit::widgets; it's only a problem when the hull component in
561 particular is a snit::widget.
562
563* KNOWN BUG: If you rename a Snit type or instance command (i.e., using
564 Tcl's [rename] command) it will no longer work properly. This is
565 part of the reason for the previous bug, and should also be fixed in
566 Snit V0.8.
567
568* Enhancement: Snit now preserves the call stack (i.e., the
569 "errorInfo") when rethrowing errors thrown by Snit methods,
570 typemethods, and so forth. This should make debugging Snit types
571 and widgets much easier. In Snit V0.8, I hope to clean up the
572 call stack so that Snit internals are hidden.
573
574* Bug fix: Option default values were being processed incorrectly. In
575 particular, if the default value contained brackets, it was treated
576 as a command interpolation. For example,
577
578 option -regexp {[a-z]+}
579
580 yield the error that "a-z" isn't a known command. Credit to Keith
581 Waclena for finding this one.
582
583* Bug fix: the [$type info instances] command failed to find
584 instances that weren't defined in the global namespace, and found
585 some things that weren't instances. Credit to Keith Waclena for
586 finding this one as well.
587
588* Internal Change: the naming convention for instance namespaces
589 within the type namespace has changed. But then, your code
590 shouldn't have depended on that anyway.
591
592* Bug fix: snit::widget destruction was seriously broken if the hull
593 component was itself a megawidget (e.g., a BWidget).
594 Each layer of megawidget code needs its opportunity
595 to clean up properly, and that wasn't happening. In addition, the
596 snit::widget destruction code was bound as follows:
597
598 bind $widgetName <Destroy> {....}
599
600 which means that if the user of a Snit widget needs to bind to
601 <Destroy> on the widget name they've just wiped out Snit's
602 destructor. Consequently, Snit now creates a bindtag called
603
604 Snit<widgettype>
605
606 e.g.,
607
608 Snit::rotext
609
610 and binds its destroy handler to that. This bindtag is inserted in
611 the snit::widget's bindtags immediately after the widget name.
612
613 Destruction is always going to be somewhat tricky when multiple
614 levels of megawidgets are involved, as you need to make sure that
615 the destructors are called in inverse order of creation.
616
617Changes in V0.7
618----------------------------------------------------------------------
619
620* INCOMPATIBILITY: Snit constructor definitions can now have arbitrary
621 argument lists, as methods do. That is, the type's create method
622 expects the instance name followed by exactly the arguments defined
623 in the constructor's argument list:
624
625 snit::type dog {
626 variable data
627 constructor {breed color} {
628 set data(breed) $breed
629 set data(color) $color
630 }
631 }
632
633 dog spot labrador chocolate
634
635 To get the V0.6 behavior, use the argument "args". That is, the
636 default constructor would be defined in this way:
637
638 snit::type dog {
639 constructor {args} {
640 $self configurelist $args
641 }
642 }
643
644* Added a "$type destroy" type method. It destroys all instances of
645 the type properly (if possible) then deletes the type's namespace
646 and type command.
647
648Changes in V0.6
649-----------------------------------------------------------------
650
651* Minor corrections to the man page.
652
653* The command snit::widgettype is deprecated, in favor of
654 snit::widget.
655
656* The variable "type" is now automatically defined in all methods,
657 constructors, destructors, typemethods, onconfigure handlers, and
658 oncget handlers. Thus, a method can call type methods as "$type
659 methodname".
660
661* The new standard instance method "info" is used for introspection on
662 type and widget instances:
663
664 $object info type
665 Returns the object's type.
666
667 $object info vars
668 Returns a list of the object's instance variables (excluding Snit
669 internal variables). The names are fully qualified.
670
671 $object info typevars
672 Returns a list of the object's type's type variables (excluding
673 Snit internal variables). The names are fully qualified.
674
675 $object info options
676 Returns a list of the object's option names. This always
677 includes local options and explicitly delegated options. If
678 unknown options are delegated as well, and if the component to
679 which they are delegated responds to "$object configure" like Tk
680 widgets do, then the result will include all possible unknown
681 options which could be delegated to the component.
682
683 Note that the return value might be different for different
684 instances of the same type, if component object types can vary
685 from one instance to another.
686
687* The new standard typemethod "info" is used for introspection on
688 types:
689
690 $type info typevars
691 Returns a list of the type's type variables (excluding Snit
692 internal variables).
693
694 $type info instances
695 Returns a list of the instances of the type. For non-widget
696 types, each instance will be the fully-qualified instance command
697 name; for widget types, each instance will be a widget name.
698
699* Bug fixed: great confusion resulted if the hull component of a
700 snit::widgettype was another snit::widgettype. Snit takes over the
701 hull widget's Tk widget command by renaming it to a known name, and
702 putting its own command in its place. The code made no allowance
703 for the fact that this might happen more than once; the second time,
704 the original Tk widget command would be lost. Snit now ensures that
705 the renamed widget command is given a unique name.
706
707* Previously, instance methods could call typemethods by name, as
708 though they were normal procs. The downside to this was that
709 if a typemethod name was the same as a standard Tcl command, the
710 typemethod shadowed the standard command in all of the object's
711 code. This is extremely annoying should you wish to define a
712 typemethod called "set". Instance methods must now call typemethods
713 using the type's command, as in "$type methodname".
714
715* Typevariable declarations are no longer required in
716 typemethods, methods, or procs provided that the typevariables are defined
717 in the main type or widget definition.
718
719* Instance variable declarations are no longer required in methods provided
720 that the instance variables are defined in the main type or widget
721 declaration.
722
723* Instance variable declarations are no longer required in procs,
724 provided that the instance variables are defined in the main type or
725 widget declaration. Any proc that includes "self" in its argument
726 list will pick up all such instance variables automatically.
727
728* The "configure" method now returns output consistent with Tk's when
729 called with 0 or 1 arguments, i.e., it returns information about one
730 or all options. For options defined by Snit objects, the "dbname"
731 and "classname" returned in the output will be {}. "configure" does
732 its best to do the right thing in the face of delegation.
733
734* If the string "%AUTO%" appears in the "name" argument to "$type create"
735 or "$widgettype create", it will be replaced with a string that
736 looks like "$type$n", where "$type" is the type name and "$n" is
737 a counter that's incremented each time a
738 widget of this type is created. This allows the caller to create
739 effectively anonymous instances:
740
741 widget mylabel {...}
742
743 set w [mylabel .pane.toolbar.%AUTO% ...]
744 $w configure -text "Some text"
745
746* The "create" typemethod is now optional for ordinary types so long
747 as the desired instance name is different than any typemethod name
748 for that type. Thus, the following code creates two dogs, ::spot
749 and ::fido.
750
751 type dog {...}
752
753 dog create spot
754 dog fido
755
756 If there's a conflict between the instance name and a typemethod,
757 either use "create" explicitly, or fully qualify the instance name:
758
759 dog info -color black ;# Error; assumes "info" typemethod.
760 dog create info -color black ;# OK
761 dog ::info -color black ;# also OK
762
763* Bug fix: If any Snit method, typemethod, constructor, or onconfigure
764 handler defines an explicit argument called "type" or "self", the type
765 definition now throws an error, preventing confusing runtime
766 behavior.
767
768* Bug fix: If a Snit type or widget definition attempts to define a
769 method or option locally and also delegate it to a component, the
770 type definition now throws an error, preventing confusing runtime
771 behavior.
772
773* Bug(?) Fix: Previously, the "$self" command couldn't be used in
774 snit::widget constructors until after the hull component was
775 defined. It is now possible to use the "$self" command to call
776 instance methods at any point in the snit::widget's
777 constructor--always bearing in mind that it's an error to configure
778 delegated options or are call delegated methods before creating the
779 component to which they are delegated.
780
781Changes in V0.5
782------------------------------------------------------------------
783
784* Updated the test suite so that Tk-related tests are only run if
785 Tk is available. Credit Jose Nazario for pointing out the problem.
786
787* For snit::widgettypes, the "create" keyword is now optional when
788 creating a new instance. That is, either of the following will
789 work:
790
791 ::snit::widgettype mylabel { }
792
793 mylabel create .lab1 -text "Using create typemethod"
794 mylabel .lab2 -text "Implied create typemethod"
795
796 This means that snit::widgettypes can be used identically to normal
797 Tk widgets. Credit goes to Colin McCormack for suggesting this.
798
799* Destruction code is now defined using the "destructor" keyword
800 instead of by defining a "destroy" method. If you've been
801 defining the "destroy" method, you need to replace it with
802 "destructor" immediately. See the man page for the syntax.
803
804* widgettype destruction is now handled properly (it was buggy).
805 Use the Tk command "destroy" to destroy instances of a widgettype;
806 the "destroy" method isn't automatically defined for widgettypes as
807 it is for normal types, and has no special significance even if it
808 is defined.
809
810* Added the "from" command to aid in parsing out specific option
811 values in constructors.
812
813Changes in V0.4
814------------------------------------------------------------------
815
816* Added the "codename" command, to qualify type method and private
817 proc names.
818
819* Changed the internal implementation of Snit types and widget types
820 to prevent an obscure kind of error and to make it easier to pass
821 private procs as callback commands to other objects. Credit to Rolf
822 Ade for discovering the hole.
823
824Changes in V0.3
825------------------------------------------------------------------
826
827* First public release.
828
829
830