'''`[http://www.tcl.tk/man/tcl/TkCmd/bind.htm%|%bind]`''', a [TkCommands%|%built-in] [Tk] command, arranges for [X] events to invoke [Tcl] [script%|%scripts]. ** Documentation ** [http://www.tcl.tk/man/tcl/TkCmd/bind.htm%|%official reference]: `[keysyms]`: the keyboard symbols to which one can potentially bind things. Of course, the specific keysyms available to you on any particular platform/hardware depend on factors outside of Tk's control. (See below for a simple script for determining what the specific keysym for a character is.) ** Synopsis ** : '''bind''' ''tag'' : '''bind''' ''tag sequence'' : '''bind''' ''tag sequence script'' : '''bind''' ''tag sequence '''''+'''''script'' ** Description ** `bind` (part of [Tk]) is used to associate Tcl commands to execute upon the press of specific keys. Also, `bind` may be driven by other events, both real and virtual, such as enter, leave, focus in, focus out, etc. See the documentation for specific details. ''tag'' is formally a `[bindtags]` tag, but for most user code it is best to use widget names. The optional ''sequence'' says what event to work with; if omitted, `bind` returns what bindings are set on ''tag''. If ''script'' is given, it replaces (or deletes, if empty, or appends, if it starts with a “'''+'''”) the binding script, and if ''script'' is omitted (but ''sequence'' is given) then the current binding script is returned. Keyboard symbols are the Tk values associated with particular sequences of keyboard keys that one can press, such as Shift, or A or special function keys such as Page Up, etc. ** Examples ** [Only in tcl...]: A nice simple example of `bind` in action [Vogel spiral]: uses `[apply]` as the script for `bind` [Salvatore Sanfilippo]: has an example on his page of using a keyboard n "raw" mode ** Eggdrop ** If you are looking for the [eggdrop] `bind` command, try [http://www.eggheads.org/support/egghtml/1.6.17/tcl-commands.html#bind%|%bind%|%] <> Discussion ** Discussion ** ** Unanswered Questions ** '''Question''': Is there an introspective method that a Tk application can determine whether a keysym is currently available for it to use? ** Answered Questions ** * [Moving Canvas Window Items - Can someone tell me what's going on here?] ** `bind` Syntax Example ** [RS] writes on comp.lang.tcl: The `bind` syntax is actually very easy. With x set to a widget (e.g. .mytext) or a class (e.g. Text), call ====== bind $x ====== to get a list of defined bindings. This list contains which is the correct name for the Page Up key. To see what it is bound to, call ====== bind $x ====== To mirror this binding to another event, make that ====== bind $x [bind $x ] ====== like you tried, just with the incorrect name. BTW, you normally need not include variable names in braces - only if they contain characters other than `A-Z a-z 0-9 _`. ** Finding keysyms ** [KBK]: You can find the keysym for a key on an unfamiliar keyboard by running ''wish'' against the one-line script: ====== bind . {puts %K} ; focus . ====== directing focus at the (empty) ''wish'' window, and touching the key in question. On Windows, you'll need to add ====== console show ====== to the script so that you can see its output. [Arjen Markus]: You may also put up a text widget and display the keysym by the following script: ====== bind .textwidget { %W insert end "%K\n" } focus .textwidget ====== ** Specifying a Key to `bind` ** [Arjen Markus]: There are several ways to define a specific key, for instance: ====== (subtle differences here!) (if the character is plain ASCII) ====== For a space, you will need to use: ====== ====== anything else seems to give problems. Also note that keysyms are case-sensitive: "Down" for the downward arrow and "space" for a space ("down" and "Space" do ''not'' work; quotation marks for convenience only) ** `bind` to a Mouse Action ** [LV]: If you are wanting to `bind` actions to a mouse button action, rather than a keyboard press, then you appear to be able to use: ====== bind $x { puts "Unmodified button" } bind $x { puts "Shift button 1 release" } ====== ** Idea: event ** [Martin Lemburg] 2002-07-02: Why isn't there an event ''Invoke'' for invokeable widgets, like buttons? Wouldn't make it sense to have such an event? To `bind` widgets using the ''Invoke'' event, like to connect a widget with the ''-command'' option to an event handler? Than ... ====== button .b -text exit -command {cmdProc .b [clock seconds]}; ====== ... would be equal to ... ====== bind .b {cmdProc %W %t}; ====== It shouldn't be a problem to use the substitution capabilities during the usage of a binding, like: ====== button .b -text exit -command {cmdProc %W %t}; ====== Wouldn't that be nice and consequent? Wouldn't it be consequent (for example) to use bindings to scrollbars or entries too? ... ====== entry .e -textvariable filter; button .b -text "filter"; listbox .lb -listvar data -selectmode extended; scrollbar .sbx -orient horizontal; scrollbar .sby -orient vertical; bind .e {validateFilter %V %s}; bind .b {filter .e .lb}; bind .lb {.sbx set}; bind .lb {.sby set}; bind .sbx {.lb xview}; bind .sby {.lb yview}; ====== There would be the chance to elimate all (event)handlers from that code, that only builds up the GUI. The code to handle events could use now use bindings. ** Caution: Abbreviated `bind` Descriptions ** [Ken Jones] writes on [comp.lang.tcl], in response to a developer trying to `bind` actions on numeric keys using ====== bind .bu1 {focus .bu2} ====== What you're experiencing is one of those traps that people encounter when they use abbreviated binding descriptions. For many `KeyPress` events, you can get by with providing only the keysym. So, is equivalent to , and is equivalent to . On the other hand, Tcl also allows you to abbreviate ButtonPress events, so <1> is equivalent to . And through is equivalent to through . Solution? `bind` to `` and ``. And be very careful relying on abbreviated event descriptions in bindings. ** Keypad Keys ** [LV]: I am trying to get the following sample program to display the numbers 0-9 when pressed on the keypad: ====== #! /usr/tcl84/bin/tclsh package require Tk entry .e bind .e { puts 1 } pack .e focus .e ====== The expectation was that I would get an entry widget into which I could press the keys on the keypad and get, in this case, the number 1 into the entry widget. What I experience is that after I mouse into the widget and click, I can type alphas and the numbers on top row of the main keyboard, but the keypad keys are generating nothing... Peter Newman 2004-04-30: ''NumLock'' switches the keypad between numbers and cursor keys. I presume you tried both settings - and still no joy. If so, then it would appear that Tk doesn't support the keyboard properly. Pierre Coueffin 2004-04-12: Try `` Thomas Guettler 26 April 2006: Or Try `` You can query the bindings interactively with this: (See above) ====== bind . { puts %K } ; focus . ====== ** Canonicalize a `bind` Specification ** Q. Given a string specifying an event sequence, how to obtain some sort of "normal form" for that event sequence, so that, for example, `1` and `Mousebutton-1` (or whatever the long form is) both map to the same normal form indicating a single click of mouse button 1? A. [KBK]: Hmm, `bind` it to a nonexistent bindtag and then query the bindings on the tag? ======none % bind Nothing {;} % bind Nothing ====== ** Control Sequences ** [Dossy] 2005-03-29: I just spent a good hour only trying to understand `bind` only to discover that `bind . {script}` is NOT the same as `bind . {script}`. the former works, the latter doesn't. [RS]: would expect that `` is equivalent to `` ... case matters, doesn't it? [MG]: The bindings for this, after a little playing, seem slightly strange. Without Caps Lock on, Shift and the `a` (to get an upper-case A) fires the binding for Shift and (uppercase) A. The only way to fire a binding for Shift and (lowercase) a that I can find is to turn Caps Lock on, and -then- press the 'a' key with Shift held down. CJL The minimal example of this mildly unexpected behaviour is to switch Caps Lock on, then in a Wish console (I'm talking Windoze here) type something, highlight it and press Ctrl-C. Now try to paste your text somewhere else (e.g. Notepad) using Ctrl-V - you'll discover that the copy didn't happen, but even though Caps Lock is still on, Notepad will quite happily obey the paste request (by pasting whatever was already in the clipboard). To me 'Ctrl-C' means "the physical key labelled with a 'C' was pressed while ctrl was down", and should have nothing to do with the state of Caps Lock, only the combination of keys pressed. [WHD]: On both Windows and Mac OS X, normal apps accept both `` and `` (`` and ``) as the Paste key. For Tk, it appears that you need to bind both. On the other hand, if you bind both you'll find that all of the following combinations will paste: * `` * `` * `` * `` If you want to support Shift-Control sequences in your keyset, you need to bind both `` and ``. Here's a simple solution that results in CapsLock-independent letter key bindings: ====== proc bindletterkey {tag modifier letter binding} { set upper [string toupper $letter] set lower [string tolower $letter] bind $tag <$modifier-$upper> $binding bind $tag <$modifier-$lower> $binding } bindletterkey .text Control F {puts Control-F} bindletterkey .text Shift-Control F {puts Shift-Control-F} ====== ** Case Insensitive Binding ** [MG] 2005-06-06: And, where the bindings already exist (ie, for the Text widget) and you want to make them case-insensitive, something like this will help. ====== proc mirror {class {dir 1}} { if {$dir eq {1}} { set range a-z set case toupper } else { set range A-Z set case tolower } foreach x [bind $class] { if {[regexp "^<(.+-)?\[$range]>$" $x]} { set y [string range $x end-1 end-1] set y [string range $x 0 end-2][string $case $y]> if {[bind $class $y] ne {}} { continue } bind $class $y [bind $class $x] } } };# mirror ====== Then run, for instance: ====== mirror Text 1; # copy all lower-class bindings for the Text widget to upper-class versions mirror Text 0; # copy all upper-class bindings for the Text widget to lower-class versions mirror Entry 1; # copy all lower-class bindings for the Entry widget to upper-class versions ====== It's also careful not to overwrite bindings - if you have an and an binding for the Text widget, and run ''mirror Text 1'', will be left as it is, rather than being overwritten with 's binding. This raises one question for me, though - what's better practice? Should you bind to ====== bind Text [bind Text ] ====== and copy the binding, or use something like ====== bind Text {event generate %W } ====== to mirror 's state at the time the event happens? ** Unbound `bind` ** Some of the best `bind` coding doesn't involve '''bind''' at all. [DKF], for example, astutely remarked that ====== event add <> ====== trumps ====== bind $class [bind $type <>] bind $class [bind $type <>] ====== ... [[Correct; elaborate]] ** `bind` to a plain keystroke only (not modified by Ctrl or Alt) ** ====== proc bind'plainkey {tag key script} { bind $tag {} bind $tag {} bind $tag $key $script } ====== Example: ====== bind'plainkey all x {puts Hello} ====== ---- [RUJ]: If bind leave command to main window it is not (bindings) grabbing to its associated widgets. e.g.: ====== toplevel $wa -bd 1 -relief ridge wm geometry $wa 600x40+$mousex+$mousey wm resizable $wa 0 0 wm overrideredirect $wa yes wm iconname $wa "menu" wm group $wa . focus $wa grab set $wa entry $wa.ent01 -width 6 -background white bind $wa <1> [list after cancel destroy .base] bind $wa [list destroy .base] ====== But it is destroying base if cursor goes near to entry. Can anybody solve the problem. ** Disable Pasting ** 2008-03-17: How can I disable pasting into a text widget? I tried the following: ====== bind $theText <> {tk_messageBox -message {Paste Attempt}} bind $theText {tk_messageBox -message {Paste Attempt}} bind $theText {tk_messageBox -message {Paste Attempt}} bind $theText {tk_messageBox -message {Paste Attempt}} ====== The message boxes are shown, so the event handling works. But after the message box has been clicked away, the pasting takes place anyway - at least for Shift-Insert. Answer: You are adding bindings to the widget but aren't addressing the bindings associated with the widget class. Read up on `[bindtags]`. One solution is to add `;break` to each binding to prevent the class bindings from firing: ====== bind $theText <> {tk_messageBox -message "Paste Attempt"; break} ====== Of course, you can also just set the -state option to "disabled". *** Class binding, do they work? *** [Janic]: 2009-07-01T09:48:17: I tried to set a class binding but it never works. For example: ====== checkbutton .a -text test pack .a bind .a break ====== works fine (the widget is still active but you can't check it anymore), but if write ====== bind Checkbutton break ====== it doesn't work. Did I miss something in the class binding behavior? [MG]: Many different bindings are checked for a widget, based on its [bindtags]. The default order for a widget is: bindings on the widget itself, bindings on its class, its toplevel, and then on `all`. Also, bindings are checked from most specific match to least specific (so if you press the 'a' key, it checks for KeyPress-a before a more generic KeyPress, etc). That's why you're seeing what you see; first the widget's own bindings are checked, and the generic `` binding matches and is run; `[break]` stops further bindings being checked. When you `bind` that on the Checkbutton class, though, the default `` binding is more specific, and gets used instead of your `` binding. (You can see all the default bindings with `bind Checkbutton`, then see what a specific one does with `bind Checkbutton $binding`.) So, to override the default binding, you'd need to either replace the Button-1 binding, or add something higher up the `[bindtags]` chain. [DKF]: You are advised to be ''very'' careful with changing bindings of widget classes, as that affects ''all'' widgets of that type in the application. (It's most useful if you're adding more editing keys to the `[text]` [widget], or are making your own megawidget class.) It's far better to adjust the `[bindtags]` for the specific widgets in question as the results are a lot more predictable. [wdb]: Here an example: button `.b` has new binding tag, `Button1` instead of `Button`. Bindings are copied from `Button` to `lButton1`, then binding of `<1>` is modified: === % package require Tk 8.5.1 % pack [button .b -text Howdy] % # button appears % bindtags .b .b Button . all % bindtags .b {.b Button1 . all} % apply {{old new} { foreach p [bind $old] { bind $new $p [bind $old $p] } }} Button Button1 % % bind Button1 <1> "+puts yep!" % # now clicking on .b: % yep! % === From now on, you can change arbitrary buttons without side-effects to "normal" buttons. ---- [telgo] 2010-07-29 15:22:47: On a Mac [OSX 10.6.4] I have a program with a text widget, and the binding ====== bind . { Find break } ====== I also have a menu item that calls Find ====== $Test add command -label Find -accel Command-F -command Find ====== `Find` puts up a dialox box, but involves some sorting. However, it still takes less than a second to generate the data. Here it is: ====== proc Find {} { global body dict t set t1 [clock clicks -milliseconds] set f .dictdisplay #see if we want to restrict display set target {} if {[$t tag ranges sel] ne {}} { set term [$t get sel.first sel.last] set target [::soundex::soundex $term] } if [Dialog_Create $f Dictionary -borderwidth 10] { set text [Scrolled_Text $f.body -width 20 -font 16] set b [frame $f.buttons] #--------- convert the array to a list foreach index [array names dict] { lappend sort $index } set sorted [WolofSort $sort] foreach item $sorted { if {$target eq {} || $target eq [::soundex::soundex $item] } { $text insert end "$item : $dict($item)\n" } } pack $f.body $f.buttons -side top -fill x button $b.ok -text OK -command {set dictdisplay(ok) 1} pack $b.ok -side right } set t2 [clock clicks -milliseconds] puts "[expr {($t2-$t1)/1000.0}] seconds" set dictdisplay(ok) 0 Dialog_Wait $f dictdisplay(ok) set t3 [clock clicks -milliseconds] puts "[expr {($t3-$t2)/1000}] seconds" Dialog_Dismiss $f } ====== If I use the menu item, everything works as expected. If I use Command-f, there is a noticeable pause, then the dialog appears - undecorated - with the data in it and the ok button, but never returns from Dialog_Create. `Dialog_Create`, `Dialog_Wait` and `Dialog_Dismiss` are taken from Welch, Jones and Hobbs 2003 "Practical Programming in Tcl and Tk"p 606-607] Is there an issue with putting up a dialog box from within a key-binding? <> ** See Also ** [Bindings and why they are important]: [Bindings and variable substitution]: [Disable autorepeat under X11]: [mousewheel] bindings: [binding to a single mouse click]: [Key-press names]: [Portable keystate]: [uevent]: Functionality similar to `[bind]`, but written in [pure-Tcl%|%pure Tcl]. Allows scripts to generate and respond to events. <> Tk syntax help | Arts and Crafts of Tcl-Tk Programming | Command | Introspection | Category Characters