if {0} {
 [fr]
 a prototype of word completion
 instant command completion in the [iFile 1.1] console
 completion works on first word only in ComboBox entry
 the string appended is the longest common beginning of all possible endings
 clickable continuations are displayed in a toplevel widget
 start typing a character, then repeatedly invoke the created buttons to get the wished command

 usage:
 append this to the iFile script
 or save this as q.tcl in same dir as iFile.tcl
 append following line to iFile.tcl
 PC:
 source [file join [file dirname [info script]] q.tcl]
 on PDA (WinCE):
 source q.tcl
 additional requirements:
 font_ce, puts_ce
 known bug:
 continuations not up to date when using the keyboard (e.g. tk_messageBox, open, option)
 }
 
 namespace eval ::q {
   variable tracedvar
   variable entry
   variable pp ""
   variable pattern ""
   variable temp [list]
   variable suffixlist [list]
   variable packages [lsort [package names]]
   variable added_prefixes [list]
 }
 proc ::q::qcoco {entryname varname x mode} {
 #	puts varname=$varname; puts x=$x; puts mode=$mode
   # completion for the first word
   if {$::q::ok} {
   	set v ::
   	append v $varname\($x\)
   	set v [subst $$v]
   	if {![regexp {^\S+\s} $v]} {
   		set pos 0
   		# only first word is assumed to be a command
   		set ns ""
   		set colon ""
   		set ::q::pattern ""
   		regexp -nocase {(^[^:]*)(::)*([a-z0-9_:]*)} $v {&1&2&3} ns colon ::q::pattern
   		if {$colon == ""} {
   			set ::q::pattern $ns
   			set ns ::
   		} else {
   			# learn used package names
   			if {[lsearch -sorted $::q::added_prefixes $ns] < 0} {
   				if {[lsearch -sorted $::q::packages $ns] >=0} {
   					lappend ::q::added_prefixes $ns
   					set ::q::added_prefixes [lsort $::q::added_prefixes]
   				}
   			} 
   		}
   		incr pos [string length $::q::pattern]
   		set pa ^$::q::pattern
   		set ::q::pp $::q::pattern*
   		set l [list]
   		if {[::q::isnopackage $ns]} {
   			namespace eval $ns {set ::q::commands [info command $::q::pp]}
   			foreach x $::q::commands {
   				lappend l [string range $x $pos end]
   			}
   			foreach idx [lsearch -all -sorted -regexp $::q::added_prefixes $pa] {
   				lappend l [string range [lindex $::q::added_prefixes $idx] $pos end]
   			}
   			if {0} {
   			# package names
   				foreach x $::q::packages {
   					if {[regexp $pa $x]} {
   						lappend l [string range $x $pos end]
   					}
   				}
   			}
   		} else {
   			set n ::
   			append n $ns
   			append n ::
   			append n $::q::pattern
   			set len [string length $n]
   			append n *
   			foreach x [info proc $n] {
   				lappend l [string range $x $len end]
   			}
   		}
   		::q::conti [lsort -unique -dictionary $l]
   		set add ""
   		foreach ff [split [lindex $::q::suffixlist 0] {}] ll [split [lindex $::q::suffixlist end] {}] {
   			expr {$ff==$ll ? [append add $ff] : [break] }
   		}
   		append v $add
   		set xl [llength $l]
   		if {[llength $l] == 1} {
   			# no alternatives exist
                        #append add { }
   			$entryname insert insert $add
   			set ::q::suffixlist [list]  ;# no need to display
   		} else {
   			if {[llength $l]==0} {
   			# invalid character entered
   				if {![string equal $v :]} {
   					set prev [$entryname index insert]
   					incr prev -1
   					$entryname selection range $prev end
   				}
   			} else {
   				$entryname insert insert $add
   				# display continuations as buttons
   			}
   		}
   	} else {
   		set ::q::text ""
   		set ::q::suffixlist [list]
   	}
   } else {
   	set ::q::ok 1
   }
   ::q::topcon $entryname $varname
 }
 proc ::q::insertpos {entryname x y} {
   # todo
   # calculate position below insert mark of entry
   # add +y positions of .n (notebook).n.f5 (frame) .n.f5.e (ComboBox)
   # plus height of ComboBox
   upvar $x X
   upvar $y Y
   set X 20
   set Y 110
 }
 
 proc ::q::topcon {w var} {
   set name .qcon
   append name $w
   regsub -all -start 1 {\.} $name _ name
   #catch {destroy $name}
   #destroy & toplevel -> no more winhandle map slots
   set len [llength $::q::suffixlist]
   catch {wm withdraw $name}
   if {$len==0} {return}
   if {$len==1 && [lindex $::q::suffixlist] == { } } {return}
   if {![winfo exists $name]} {
   	set widget [toplevel $name]
   } else {
   	foreach x [winfo children $name.f] {
   		destroy $x
   	}
   	destroy $name.f
   	set widget $name
   }
   ::q::insertpos $w px py
   wm geometry $widget +$px+$py
   wm overrideredirect $widget 1
   
   set sw $widget
   set sf [frame $sw.f]
   $sf configure -bg bisque
   set ii 0
   foreach x $::q::suffixlist {
   	set j [button $sf.b$ii -text $x -justify left -border 0 -bg white -fg black -activebackground skyblue -activeforeground white -takefocus 0]
   	pack $j -side top -padx 2 -pady 1 -anchor w
   	$j configure -command [list ::q::button_invoke $w $x]
   	incr ii
   }
   pack $sf -fill both
   wm deiconify $name
 }
 proc ::q::button_invoke {entryname suffix} {
   global g
   set t [$entryname cget -text]
   append t $suffix
   $entryname insert insert $suffix
   focus $entryname
   set g(cmd) $t
 }
 proc ::q::isnopackage {v} {
   if {$v==""} {return 1}
   set pattern [format "^%s::" $v]
   foreach x $::q::packages {
   	if {[regexp $pattern $x]} {
   		return 0
   	}
   }
   return 1
 }
 proc ::q::off {} {
   #set k [trace info variable $::q::tracedvar]
   # trace vdelete ::g(cmd) [lindex $k {0 1}]
   trace vdelete $::q::tracedvar w [list ::q::qcoco $::q::entry]
   set ::q::text "::q::on ;# instant command" 
   bind $::q::entry <Key-BackSpace> {}
 }	
 proc ::q::about {} {
   set t {
 iFile command completion
 basic prototype
 Roland Frank, Aalen 2005
 www.deltadatentechnik.de
 }
   catch {destroy.qab}
   toplevel .qab
   wm title .qab contributors
   label .qab.l -justify center -text $t
   pack .qab.l -pady 10
 }
 
 proc ::q::on {{entryname .n.f5.e.e}} {
   # activate command completion in "iFile console"
   global g
   set g(cmd) ""
   set ::q::entry $entryname
   set ::q::tracedvar ::[$entryname cget -textvariable]
   set ::q::ok 1
   bind $entryname <Key-BackSpace> {
   	set ::q::ok 0
   	set ::q::suffixlist [list]
   }
   trace add variable $::q::tracedvar write [list ::q::qcoco $entryname]
   $entryname selection range 0 end
 }
 proc ::q::conti {inlist} {
   set ::q::temp [list]
   foreach x $inlist {
   	if {$x == ""} {
   		set x " "
   	}
   	::q::merge $x 0
   }
   set ::q::suffixlist $::q::temp
   set text ""
   set n 0
   foreach x $::q::temp {
   	incr n [string length $x]
   	if {$n>30} {
   		append text \n
   		set n 0
   	} else {
   		append text " "
   		incr n
   	}
   	append text $x
   }
   set ::q::text $text
 }
 proc ::q::merge {value minlen} {
   # merge value to common prefix with last element of list
   set last [lindex $::q::temp end]
   if {$last != ""} {
   	set lastlen [string length $last]
   	set c ""
   	foreach t1 [split $last ""] t2 [split $value ""] {
   		expr {$t1==$t2 ? [append c $t1] : [break]}
   	}
   	if {$c!=""} {
   		set clen [string length $c]
   		if {$clen>$minlen} {
   			if {$clen==$lastlen} {
   				# skip
   				#lappend ::q::temp $value
   			} else {
   				lset ::q::temp end $c
   			}
   		} else {
   			lappend ::q::temp $value
   		}
   	} else {
   		lappend ::q::temp $value
   	}
   } else {
   	set ::q::temp [list $value]
   }
 }
 
 .n.f5.e.e configure -text "::q::on ;# instant command, ::q::off" 
 $5.l configure -textvariable ::q::text