"Balloon help" is sometimes known as "[tooltips]". Effective Tcl's example code ( http://sf.net/projects/efftcl/ ) [http://www.awl.com/cseng/titles/0-201-63474-0/efftcl-ex.tar.Z] as well as [Jeffrey Hobbs]'s widget library [http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/tcllib/widget/library/balloonhelp.tcl] include a balloonhelp.tcl [[Where is its documentation?]] [Bwidgets] have balloons under the title of "Dynamic help", here's an example how simple that can be ([RS]): interp alias {} help {} DynamicHelp::register Button .f.open -image $im(open) -command {starDOM::openFile .t} help .f.open balloon "Open existing XML file" [Tix] has a ballon widget: see http://tix.sourceforge.net/man/html/TixCmd/tixBalloon.htm ---- [[Also describe the section in the M&M book.]] This [Wiki] also has a related page under the title "[Balloon]", and this was from the [bag of Tk algorithms]: Balloon help, (a.k.a. tooltips), minimalist version proc balloon {w help} { bind $w "after 1000 [list balloon:show %W [list $help]]" bind $w "destroy %W.balloon" } proc balloon:show {w arg} { if {[eval winfo containing [winfo pointerxy .]]!=$w} {return} set top $w.balloon catch {destroy $top} toplevel $top -bd 1 -bg black wm overrideredirect $top 1 if {$::tcl_platform(platform) == "macintosh"} { unsupported1 style $top floating sideTitlebar } pack [message $top.txt -aspect 10000 -bg lightyellow \ -font fixed -text $arg] set wmx [winfo rootx $w] set wmy [expr [winfo rooty $w]+[winfo height $w]] wm geometry $top \ [winfo reqwidth $top.txt]x[winfo reqheight $top.txt]+$wmx+$wmy raise $top } # Example: button .b -text Exit -command exit balloon .b "Push me if you're done with this" pack .b DAS - added an 'unsupported1' command to make this work on macs as well, otherwise raising the balloon window would immediately post a Leave event leading to the destruction of the balloon... The 'unsupported1' command makes the balloon window into a floating window which does not put the underlying window into the background and thus avoids the problem. (BTW, for this to work, appearance manager needs to be present, but that shouldn't be a problem for all except very old macs, otherwise you can try using the older 'unsupported1 style $top floatSideProc' although I had problems with it) [GPS]: I know from experience with earlier balloon code that the code has a problem. If the $help string contains % then you will probably experience weird problems. The way to fix this is to use string map to double % if they exist. tcl[ol]: # dont try this at home: balloon .b "hey \[you\] }{ )( $ %" I would rather do it using a global variable to store the help text. Generally I avoid having text in after or callback scripts. More, using a global can be useful for debugging or translating. I modified the balloons script above. Move the help/ folder in directory [lindex $tcl_pkgPath 0] # you can replace 'help' with 'balloon' # i keep the balloon for my quick black dog jumping over lazy foxes help/pkgIndex.tcl: package ifneeded help 1.0 [list source [file join $dir help.tcl]] help/help.tcl: namespace eval ::help { namespace export set variable delay 1000 } proc help::set {widget txt} { variable help ::set help($widget) $txt bind $widget {after $help::delay [list help::show %W]} bind $widget {destroy %W.help} } proc help::show {widget} { variable help if {[eval winfo containing [winfo pointerxy .]]!=$widget} {return} ::set w $widget.help catch {destroy $w} toplevel $w -bd 1 -bg black wm overrideredirect $w 1 if {$::tcl_platform(platform) == "macintosh"} { unsupported1 style $w floating sideTitlebar } pack [message $w.txt -aspect 10000 -bg lightyellow -font fixed -text $help($widget)] ::set wmx [winfo rootx $widget] ::set wmy [expr [winfo rooty $widget]+[winfo height $widget]] wm geometry $w [winfo reqwidth $w.txt]x[winfo reqheight $w.txt]+$wmx+$wmy #useless ? raise $w } package provide help 1.0 help/test.tcl: package require help interp alias {} help {} help::set button .b pack .b help .b "hey \[you\] }{ )( $ %" ---- [EKB] I made a couple of modest changes to the minimalist code (without the fixes for embedding %s and other characters). (And then later on I made modest changes to the modest changes. But when I came here to post the changes, I saw [MG]'s nicer version below. So now I have a dilemma -- use my existing code, or switch to the nicer version? :-) The main changes: * Created a namespace, "balloon" (The proc "set_balloon" is outside the namespace for my own purposes -- this way I keep the same interface in my existing programs.) * The "balloon delay" is adjusted so that the balloon pops up quickly if the user is scanning across sibling windows (e.g., scanning across a toolbar), and more slowly initially. * Adding a "+" to the start of the binding procs so that other actions that should take place as the widget is entered and exited can also take place. namespace eval balloon { variable long_delay 750 variable short_delay 50 variable delay $long_delay variable family {} } bind . { if {$balloon::family != ""} { if {[lsearch -exact $balloon::family %W] == -1} { set balloon::family {} set balloon::delay $balloon::long_delay } } } proc set_balloon {w help} { bind $w "+after \$balloon::delay [list balloon::show %W [list $help]]; \ set balloon::delay $balloon::short_delay; set balloon::family \[balloon::getwfamily %W\]" bind $w "+destroy %W.balloon" } # Add these to the namespace proc balloon::getwfamily {w} { return [winfo children [winfo parent $w]] } proc balloon::show {w arg} { if {[eval winfo containing [winfo pointerxy .]]!=$w} {return} set top $w.balloon catch {destroy $top} toplevel $top -bd 1 -bg black wm overrideredirect $top 1 if {$::tcl_platform(platform) == "macintosh"} { unsupported1 style $top floating sideTitlebar } pack [message $top.txt -aspect 10000 -bg lightyellow -padx 1 -pady 0 \ -text $arg] set wmx [expr [winfo rootx $w]+5] set wmy [expr [winfo rooty $w]+[winfo height $w]+7] wm geometry $top \ [winfo reqwidth $top.txt]x[winfo reqheight $top.txt]+$wmx+$wmy raise $top } [MG] offers a slightly modified version of the above (the actual balloon code is basically identical). A few changes are: * The balloon code is all moved into a namespace, removing the global variables. * The bindings are no longer made on the widget itself - instead, they're made on a new class (if that's the right word), "Balloon", and the widget has this added at the start of its [[bindtags]]. That means broken bindings already set for the widget won't stop the tooltip running. * The text to be shown is stored in a variable (array), ::balloon::tips. * A few names (procs/variables) shortened, as the namespace should prevent their being overwritten by something else. The 'delay' proc is also laid out a little differently, to shorten it down. To clear the balloon text for any widget, just set it blank (i.e., balloon $widget ""). When a widget is destroyed, its balloon text is automatically cleared from the variable via the [trace] command, which means if you create a new widget with the same name, it won't be carried over by mistake. Here's the code, with a brief example script: namespace eval balloon {set last 0 ; namespace export balloon} proc ::balloon::balloon {w text} { variable last variable tips if { ![winfo exists $w] } { error "bad window path name \"$w\"" } if { $text == "" } { # turn off tooltip if { [set x [lsearch [bindtags $w] "Balloon"]] >= 0 } { bindtags $w [lreplace [bindtags $w] $x $x] } unset -nocomplain tips($w) trace remove command $w delete ::balloon::autoclear return; } # OK, set up a (new?) tooltip if { [lsearch [bindtags $w] "Balloon"] < 0 } { bindtags $w [linsert [bindtags $w] 0 "Balloon"] } if { [lsearch [trace info command $w] {delete ::balloon::autoclear}] < 0 } { trace add command $w delete ::balloon::autoclear } set tips($w) $text };# balloon::balloon proc ::balloon::show {w} { variable tips if { ![info exists tips($w)] } {return} if {[eval winfo containing [winfo pointerxy .]]!=$w} {return} set top $w.balloon catch {destroy $top} toplevel $top -bd 1 -bg black wm overrideredirect $top 1 if {$::tcl_platform(platform) == "macintosh"} { catch {unsupported1 style $top floating sideTitlebar} } pack [message $top.txt -aspect 10000 -bg lightyellow \ -text $tips($w)] set wmx [winfo rootx $w] set wmy [expr [winfo rooty $w]+[winfo height $w]] wm geometry $top \ [winfo reqwidth $top.txt]x[winfo reqheight $top.txt]+$wmx+$wmy raise $top };# balloon::show proc ::balloon::show8.5 {w} { variable tips if { ![info exists tips($w)] } {return} if {[winfo containing {expand}[winfo pointerxy .]]!=$w} {return} set top $w.balloon catch {destroy $top} toplevel $top -bd 1 -bg black bind $top [list destroy $top] wm overrideredirect $top 1 if {$::tcl_platform(platform) == "macintosh"} { catch {unsupported1 style $top floating sideTitlebar} } pack [message $top.txt -aspect 10000 -bg lightyellow \ -text $tips($w)] set wmx [winfo rootx $w] set wmy [expr [winfo rooty $w]+[winfo height $w]] wm geometry $top \ [winfo reqwidth $top.txt]x[winfo reqheight $top.txt]+$wmx+$wmy raise $top };# balloon::show8.5 if { [package vcompare [package require Tcl] 8.5] >= 0 } { rename ::balloon::show8.5 ::balloon::show } else { rename ::balloon::show8.5 {} } proc ::balloon::delay {} { variable last set then $last set last [clock seconds] if { [expr {$last - $then}] < 3} { return 50 } else { return 1000 } };# balloon::delay proc ::balloon::autoclear {old new op} { variable tips unset -nocomplain tips([namespace tail $old]); };# balloon::autoclear namespace import ::balloon::balloon bind Balloon {after [::balloon::delay] [list ::balloon::show %W]} bind Balloon {destroy %W.balloon} console show ############## # test script ############## button .b1 -text "First" ; balloon .b1 "1st" button .b2 -text "Second" ; balloon .b2 "2nd" button .b3 -text "Third" ; balloon .b3 "3rd" button .b4 -text "No tip" pack .b1 .b2 .b3 .b4 -side left -padx 4 # uncomment below to clear the tooltip for "Third" button # balloon .b3 "" ---- [Category GUI]