WikiDbImage htext.jpg

Usage sample:

set docu(htext) {
[Richard Suchenwirth] 2001-07-20 - 
Here's an update to [a little hypertext system] that you might use for online help. It exports a single command:
 htext::htext (widget) ?title?  
brings up a toplevel showing the specified page
(or an alphabetic index of titles, if not specified). Thus you can use it
for context-sensitive help. You create help pages by just assigning 
to the global [[::docu]] array.
Links are displayed underlined and blue (or purple if they have been 
visited before), and change the cursor to a
pointing hand. Clicking on a link of course brings up that page. In
addition, you get "Index", "Search" (case-insensitive regexp in titles and
full text), "History", and "Back" links at the bottom of pages.
In a nutshell, you get a tiny browser, an information server, and a search
engine ;-) See also [[htext format]].
 set {docu(htext format)} {
The [htext] hypertext pages stored in the [[::docu]] array are in a subset 
of Wiki format:
   * indented lines come in fixed font without evaluation;
   * blank lines break paragraphs
   * all lines without leading blanks are displayed without explicit linebreak (but possibly word-wrapped)
   * a link is the title of another page in brackets (see examples at end).
 set docu(::docu) {
This global array is used for storing [htext] pages. The advantage is that
source files can be documented just by assigning to ::docu fields, without
creating a dependency on [htext]. After creating a [htext] widget, all 
''docu'' documentation is instantly available.

If you wish to have spaces in title, brace the whole thing:
 set {docu(An example)} {...}


 package require msgcat
 namespace eval htext {
    namespace export htext
    variable history {} seen {}
    proc htext {w args} {
        variable historyLabel
        variable searchLabel
        variable indexLabel
        variable backLabel
        if ![winfo exists $w] {
            wm title [toplevel $w] Help
            text $w.t -border 5 -relief flat -wrap word \
                    -state disabled -font {Times 9}
            pack $w.t -fill both -expand 1
            set w $w.t
        if ![info exists historyLabel] {
            set historyLabel [msgcat::mc "History"]
            set searchLabel [msgcat::mc "Search"]
            set indexLabel [msgcat::mc "Index"]
            set backLabel [msgcat::mc "Back"]
        $w tag config centered -justify center
        $w tag config link -foreground blue -underline 1
        $w tag config seen -foreground purple4 -underline 1
        $w tag bind link <Enter> "$w config -cursor hand2"
        $w tag bind link <Leave> "$w config -cursor {}"
        $w tag bind link <1> "[namespace current]::click $w %x %y"
        $w tag config hdr -font {Times 16}
        $w tag config fix -font {Courier 9}
        raise $w
        if ![llength [array names ::docu $args]] {set args Index}
        show $w $args
    proc click {w x y} {
        variable historyLabel
        variable searchLabel
        variable indexLabel
        variable backLabel
        set range [$w tag prevrange link [$w index @$x,$y]]
        set link [eval $w get $range]
        if {[string equal $link $historyLabel]} {
            set link History
        }  elseif {[string equal $link $searchLabel]} {
            set link Search
        }  elseif {[string equal $link $indexLabel]} {
            set link Index
        }  elseif {[string equal $link $backLabel]} {
            set link Back
        if [llength $range] {show $w $link}
    proc back w {
        variable history
        set l [llength $history]
        set last [lindex $history [expr $l-2]]
        set history [lrange $history 0 [expr $l-3]]
        show $w $last
    proc listpage {w list} {
        foreach i $list {$w insert end \n; showlink $w $i}
    proc search w {
        $w insert end "\n" {} [msgcat::mc "Search phrase:"] {} "  " {}
        entry $w.e -textvar [namespace current]::search
        $w window create end -window $w.e
        focus $w.e
        $w.e select range 0 end
        bind $w.e <Return> "htext::dosearch $w"
        button $w.b -text [msgcat::mc "Search!"] -command "htext::dosearch $w" -pady 0
        $w window create end -window $w.b
    proc dosearch w {
        variable search
        $w config -state normal
        $w insert end "\n\n" {} [msgcat::mc "Search results for '%s':" $search] {} \n {}
        foreach i [lsort [array names ::docu]] {
            if [regexp -nocase $search $i] {
                $w insert end \n; showlink $w $i ;# found in title
            } elseif [regexp -nocase -indices -- $search $::docu($i) pos] {
                regsub -all \n [string range $::docu($i) \
                    [expr [lindex $pos 0]-20] [expr [lindex $pos 1]+20]] \
                        " " context
                $w insert end \n
                showlink $w $i
                $w insert end " - ...$context..."
        $w config -state disabled
    proc showlink {w link} {
        if {[regexp "^image\\://(.*)\$" $link "" imgname]} {
            set end0 [$w index end]
            $w insert end "\n"
            $w image create end -image $imgname
            $w insert end "\n"
            $w tag add centered $end0 end-1c
        variable seen
        set tag link
        if {[lsearch -exact $seen $link]>-1} {
            lappend tag seen
        } else {lappend seen $link}
        if {[string equal $link History]} {
            set link $historyLabel
        }  elseif {[string equal $link Search]} {
            set link $searchLabel
        }  elseif {[string equal $link Index]} {
            set link $indexLabel
        }  elseif {[string equal $link Back]} {
            set link $backLabel
        $w insert end $link $tag
    proc show {w title} {
        variable historyLabel
        variable searchLabel
        variable indexLabel
        variable backLabel
        variable history
        $w config -state normal
        $w delete 1.0 end
        $w insert end $title hdr \n
        switch -- $title {
        Back    {back $w; return}
        History {listpage $w $history}
        Index   {listpage $w [lsort -dic [array names ::docu]]}
        Search  {search $w}
        default {
            if {![info exists ::docu($title)]} {
                $w insert end [msgcat::mc "This page was referenced but not written yet."]
            } else {
                set var 1
                foreach i [split $::docu($title) \n] {
                    if [regexp {^[ \t]+} $i] {
                        if $var {$w insert end \n\n; set var 0}
                        $w insert end $i\n fix
                    set i [string trim $i]
                    if ![string length $i] {$w insert end \n\n; continue}
                    if !$var {$w insert end \n}
                    set var 1
                    while {[regexp {([^[]*)[[]([^]]+)[]](.*)} $i \
                        -> before link after]} {
                        $w insert end "$before " {}
                        showlink $w $link
                        set i $after
                    $w insert end "$i "
      $w insert end \n------\n {} $indexLabel link " - " {} $searchLabel link
      if [llength $history] {
          $w insert end " - " {} $historyLabel link " - " {} $backLabel link
      $w insert end \n
      lappend history $title
      $w config -state disabled
 } ;# end namespace htext

 if {[file tail [info script]]==[file tail $argv0]} {
     htext::htext .h htext
     wm withdraw .

The following procedure will load all files that end with one of the extensions .hlp, .htp or .txt and populate the docu array used by the help system above. I use it to keep all the files describing my applications in a single directory. While this has the drawback of separating the help text from the applications themselves, it allows for better and easier editing from your favorite editor. EF

 proc loadhelp { dir { f_ptn {*.{hlp,htp,txt}}} } {
     global docu 
     foreach fname [glob -nocomplain -tails -directory $dir $f_ptn] {
        if { [catch {open [file join $dir $fname]} fd] == 0 } {
            set idx [file rootname $fname]
            set docu(${idx}) [read $fd]
            close $fd

Implemented with Tk's versatile text widget.

Wojciech Kocjan I have put an image support - putting [image://anyphotoexistingintk] shows an image. I have also converted htext package to use msgcat. This is very useful for people like me who would like to supply documentation that looks Polish.

Here's how to plug htext into the menu of a console (tested on both Win XP and eTcl/PocketPC):

 console eval { add command -label Help \
               -command {consoleinterp eval {htext::htext .h}}}

MHo 2020-12-07: Klicking on history yields this error:

can't read "indexLabel": no such variable
can't read "indexLabel": no such variable
    while executing
"set link $indexLabel"
    (procedure "showlink" line 20)
    invoked from within
"showlink $w $i"
    (procedure "listpage" line 2)
    invoked from within
"listpage $w $history"
    (procedure "show" line 12)
    invoked from within
"show $w $link"
    invoked from within
"if [llength $range] {show $w $link}"
    (procedure "::htext::click" line 17)
    invoked from within
"::htext::click .h.t 101 278"
    (command bound to event)

See also htext as eTcl plugin.