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(An example)} {...}} package require Tk
namespace eval htext {
variable history {} seen {}
proc htext {w args} {
if ![winfo exists $w] {
wm title [toplevel $w] Help
scrollbar $w.y -command "$w.t yview"
text $w.t -border 5 -relief flat -wrap word \
-state disabled -font {Tahoma 10} -yscr "$w.y set"
pack $w.y $w.t -side right -fill y -expand 1
wm geometry $w 240x268+0+26
bind $w <Up> [list event generate $w <Prior>]
bind $w <Down> [list event generate $w <Next>]
set w $w.t
}
$w tag config link -foreground blue -underline 1
$w tag config seen -foreground purple4 -underline 1
$w tag bind link <1> "[namespace current]::click $w %x %y"
$w tag config hdr -font {Tahoma 14}
$w tag config fix -font {Courier 9}
raise $w
if ![llength [array names ::docu $args]] {set args Index}
show $w $args
}
proc click {w x y} {
set range [$w tag prevrange link [$w index @$x,$y]]
if [llength $range] {show $w [eval $w get $range]}
}
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 "\nSearch phrase: "
entry $w.e -textvar [namespace current]::search -font {Tahoma 10}
$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 Search! -command "htext::dosearch $w" -pady 0
$w window create end -window $w.b
catch {wce sipshow} ;# eTcl/PPC only
}
proc dosearch w {
variable search
catch {wce siphide} ;# eTcl/PPC only
$w config -state normal
$w insert end "\n\nSearch results for '$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} {
variable seen
set tag link
if {[lsearch -exact $seen $link]>-1} {
lappend tag seen
} else {lappend seen $link}
$w insert end $link $tag
}
proc show {w title} {
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 "404 - 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
continue
}
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 {} Index link " - " {} Search link
if [llength $history] {
$w insert end " - " {} History link " - " {} Back link
}
$w insert end \n
lremove history $title ;# make sure it's in only once
lappend history $title
$w config -state disabled
}
} ;# end namespace htext
proc lremove {_list el} {
upvar 1 $_list list
set pos [lsearch -exact $list $el]
set list [lreplace $list $pos $pos]
}
if {[file tail [info script]]==[file tail $argv0]} {
htext::htext .h htext
wm withdraw .
bind .h <Escape> {exec tclsh $argv0 &; exit}
}This extra line adds the call to htext in eTcl's console menu:
console eval {.menubar.help add command -label Help \
-command {consoleinterp eval {htext::htext .h}}}For an editable alternative, see a pocket Wiki
