projman/supertext.tcl

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2015-10-19 13:27:31 +03:00
# supertext.tcl v1.01
#
# Copyright (c) 1998 Bryan Oakley
# All Rights Reserved
#
# this code is freely distributable, but is provided as-is with
# no waranty expressed or implied.
# send comments to oakley@channelpoint.com
# What is this?
#
# This is a replacement for (or superset of , or subclass of, ...)
# the tk text widget. Its big feature is that it supports unlimited
# undo. It also has two poorly documented options: -preproc and
# -postproc.
# The entry point to this widget is supertext::text; it takes all of
# the same arguments as the standard text widget and exhibits all of
# the same behaviors. The proc supertext::overrideTextCommand may be
# called to have the supertext widget be used whenever the command
# "text" is used (ie: it imports supertext::text as the command "text").
# Use at your own risk...
# To access the undo feature, use ".widget undo". It will undo the
# most recent insertion or deletion. On windows and the mac
# this command is bound to <Control-z>; on unix it is bound to
# <Control-_>
# if you are lucky, you might find documentation here:
# http://www1.clearlight.com/~oakley/tcl/supertext.html
package provide supertext 1.01
namespace eval supertext {
variable undo
variable undoIndex
variable text "::text"
variable preProc
variable postProc
namespace export text
}
# this proc is probably attempting to be more clever than it should...
# When called, it will (*gasp*) rename the tk command "text" to "_text_",
# then import our text command into the global scope.
#
# Use at your own risk!
proc supertext::overrideTextCommand {} {
variable text
set text "::_text_"
rename ::text $text
uplevel #0 namespace import supertext::text
}
proc supertext::text {w args} {
variable text
variable undo
variable undoIndex
variable preProc
variable postProc
# this is what we will rename our widget proc to...
set original __$w
# do we have any of our custom options? If so, process them and
# strip them out before sending them to the real text command
if {[set i [lsearch -exact $args "-preproc"]] >= 0} {
set j [expr $i + 1]
set preProc($original) [lindex $args $j]
set args [lreplace $args $i $j]
} else {
set preProc($original) {}
}
if {[set i [lsearch -exact $args "-postproc"]] >= 0} {
set j [expr $i + 1]
set postProc($original) [lindex $args $j]
set args [lreplace $args $i $j]
} else {
set postProc($original) {}
}
# let the text command create the widget...
eval $text $w $args
# now, rename the resultant widget proc so we can create our own
rename ::$w $original
# here's where we create our own widget proc.
proc ::$w {command args} \
"namespace eval supertext widgetproc $w $original \$command \$args"
# set up platform-specific binding for undo; the only one I'm
# really sure about is winders; the rest will stay the same for
# now until someone has a better suggestion...
switch $::tcl_platform(platform) {
unix {
event add <<Undo>> <Control-z>
event add <<Undo>> <Control-Z>
}
windows {
event add <<Undo>> <Control-z>
event add <<Undo>> <Control-Z>
}
macintosh {
event add <<Undo>> <Control-z>
event add <<Undo>> <Control-Z>
}
}
bind $w <<Undo>> "$w undo"
set undo($original) {}
set undoIndex($original) -1
set clones($original) {}
return $w
}
# this is the command that we associate with a supertext widget.
proc supertext::widgetproc {this w command args} {
variable undo
variable undoIndex
variable preProc
variable postProc
# these will be the arguments to the pre and post procs
set originalCommand $command
set originalArgs $args
# is there a pre-proc? If so, run it. If there is a problem,
# die. This is potentially bad, because once there is a problem
# in a preproc the user must fix the preproc -- there is no
# way to unconfigure the preproc. Oh well. The other choice
# is to ignore errors, but then how will the caller know if
# the proc fails?
if {[info exists preProc($w)] && $preProc($w) != ""} {
if {[catch "$preProc($w) command args" error]} {
return -code error "error during processing of -preproc: $error"
}
}
# if the command is "undo", we need to morph it into the appropriate
# command for undoing the last item on the stack
if {$command == "undo"} {
if {$undoIndex($w) == ""} {
# ie: last command was anything _but_ an undo...
set undoIndex($w) [expr [llength $undo($w)] -1]
}
# if the index is pointing to a valid list element,
# lets undo it...
if {$undoIndex($w) < 0} {
# nothing to undo...
bell
} else {
# data is a list comprised of a command token
# (i=insert, d=delete) and parameters related
# to that token
set data [lindex $undo($w) $undoIndex($w)]
if {[lindex $data 0] == "d"} {
set command "delete"
} else {
set command "insert"
}
set args [lrange $data 1 end]
# adjust the index
incr undoIndex($w) -1
}
}
# now, process the command (either the original one, or the morphed
# undo command
switch $command {
reset_undo {
set undo($w) ""
set undoIndex($w) ""
set result {}
}
configure {
# we have to deal with configure specially, since the
# user could try to configure the -preproc or -postproc
# options...
if {[llength $args] == 0} {
# first, the case where they just type "configure"; lets
# get it out of the way
set list [$w configure]
lappend list [list -preproc preproc Preproc {} $preProc($w)]
lappend list [list -postproc postproc Postproc {} $postProc($w)]
set result $list
} elseif {[llength $args] == 1} {
# this means they are wanting specific configuration
# information
set option [lindex $args 0]
if {$option == "-preproc"} {
set result [list -preproc preproc Preproc {} $preProc($w)]
} elseif {$option == "-postproc"} {
set result [list -postproc postproc Postproc {} $postProc($w)]
} else {
if {[catch "$w $command $args" result]} {
regsub $w $result $this result
return -code error $result
}
}
} else {
# ok, the user is actually configuring something...
# we'll deal with our special options first
if {[set i [lsearch -exact $args "-preproc"]] >= 0} {
set j [expr $i + 1]
set preProc($w) [lindex $args $j]
set args [lreplace $args $i $j]
set result {}
}
if {[set i [lsearch -exact $args "-postproc"]] >= 0} {
set j [expr $i + 1]
set postProc($w) [lindex $args $j]
set args [lreplace $args $i $j]
set result {}
}
# now, process any remaining args
if {[llength $args] > 0} {
if {[catch "$w $command $args" result]} {
regsub $w $result $this result
return -code error $result
}
}
}
}
undo {
# if an undo command makes it to here, that means there
# wasn't anything to undo; this effectively becomes a
# no-op
set result {}
}
insert {
if {[catch {set index [text_index $w [lindex $args 0]]}]} {
set index [lindex $args 0]
}
# since the insert command can have an arbitrary number
# of strings and possibly tags, we need to ferret that out
# now... what a pain!
set myargs [lrange $args 1 end]
set length 0
while {[llength $myargs] > 0} {
incr length [string length [lindex $myargs 0]]
if {[llength $myargs] > 1} {
# we have a tag...
set myargs [lrange $myargs 2 end]
} else {
set myargs [lrange $myargs 1 end]
}
}
# now, let the real widget command do the dirty work
# of inserting the text. If we fail, do some munging
# of the error message so the right widget name appears...
if {[catch "$w $command $args" result]} {
regsub $w $result $this result
return -code error $result
}
# we need this for the undo stack; index2 couldn't be
# computed until after we inserted the data...
set index2 [text_index $w "$index + $length chars"]
if {$originalCommand == "undo"} {
# let's do a "see" so what we just did is visible;
# also, we'll move the insertion cursor to the end
# of what we just did...
$w see $index2
$w mark set insert $index2
} else {
# since the original command wasn't undo, we need
# to reset the undoIndex. This means that the next
# time an undo is called for we'll start at the
# end of the stack
set undoIndex($w) ""
}
# add a delete command on the undo stack.
lappend undo($w) "d $index $index2"
}
delete {
# this converts the insertion index into an absolute address
set index [text_index $w [lindex $args 0]]
# lets get the data we are about to delete; we'll need
# it to be able to undo it (obviously. Duh.)
set data [eval $w get $args]
# add an insert on the undo stack
lappend undo($w) [list "i" $index $data]
if {$originalCommand == "undo"} {
# let's do a "see" so what we just did is visible;
# also, we'll move the insertion cursor to a suitable
# spot
$w see $index
$w mark set insert $index
} else {
# since the original command wasn't undo, we need
# to reset the undoIndex. This means that the next
# time an undo is called for we'll start at the
# end of the stack
set undoIndex($w) ""
}
# let the real widget command do the actual deletion. If
# we fail, do some munging of the error message so the right
# widget name appears...
if {[catch "$w $command $args" result]} {
regsub $w $result $this result
return -code error $result
}
}
default {
# if the command wasn't one of the special commands above,
# just pass it on to the real widget command as-is. If
# we fail, do some munging of the error message so the right
# widget name appears...
if {[catch "$w $command $args" result]} {
regsub $w $result $this result
return -code error $result
}
}
}
# is there a post-proc? If so, run it.
if {[info exists postProc($w)] && $postProc($w) != ""} {
if {[catch "$postProc($w) originalCommand originalArgs" error]} {
return -code error "error during processing of -postproc: $error"
}
}
# we're outta here! (I think this is faster than a
# return, though I'm not 100% sure on this...)
set result $result
}
# this returns a normalized index (ie: line.column), with special
# handling for the index "end"; to undo something we pretty much
# _have_ to have a precise row and column number.
proc supertext::text_index {w i} {
if {$i == "end"} {
set index [$w index "end-1c"]
} else {
set index [$w index $i]
}
return $index
}