PWQ 17 Feb 2004
Changed
Hack-O-Matic to create the canvas items once, and then use itemconfigure to change their values. In the scroll test applied, it gives a speed up to scrolling by a factor of 2.
Another optimisation would be to move the canvas items as a block by the number of lines scrolled and then move the rows that have moved off the screen back to the top or bottom. Then you would only have to configure the rows that are new.
W.r.t. that last comment, see also the virtual grid widget page.
#!/bin/sh
# Restart with tcl: -*- mode: tcl; tab-width: 8; -*- \
exec wish $0 ${1+"$@"}
##+##########################################################################
#
# Hack-O-Matic -- visual binary editor
# by Keith Vetter, September 2003
#
# Rob Kudla on http://wiki.tcl.tk/9505 complained about a utility for
# editing Atari graphic files called Hack-O-Matic, that he wrote in
# tcl was 10 times slower than a windows BASIC version and unstable.
#
# Taking that as a challenge, here's a version I wrote in a few hours
# that is quite fast.
# The speed up was not in nit-picking optimizations like bracing
# expressions but in a new algorithm. I don't care what language
# you're using but if you have a 32k file, drawing 32k * 8 boxes is
# going to take a long time. Instead, just draw as many boxes as will
# fit on the screen. The scrollbar command, instead of scrolling
# pixels, just changes which rows get displayed.
package require Tk
set S(title) "Hack-O-Matic"
set S(box) 20 ;# Size of each cell
set S(tm) 10 ;# Top margin
set S(lm) 10 ;# Left margin
set S(lm2) 45 ;# Left margin for the grid
set S(rows) 16 ;# How many rows to show
set S(max) 1048576 ;# Largest file we can handle
set S(top) 0 ;# First row of data to display
proc DoDisplay {} {
global S
wm title . $S(title)
menu .menu
. configure -menu .menu ;# Attach menu to main window
.menu add cascade -menu .menu.file -label "File" -underline 0
.menu add cascade -menu .menu.help -label "Help" -underline 0
menu .menu.file
menu .menu.help
.menu.file add command -label "Open" -command LoadFile
.menu.file add command -label "Save As..." -command SaveFile
.menu.file add command -label "Exit" -command exit
.menu.help add command -label "About..." -command About
label .title -textvariable S(fname) -bd 2 -relief sunken
scrollbar .sb -orient vertical -command ScrollProc
canvas .c -width 245 -highlightthickness 0
.c config -height [expr {$S(tm) + $S(rows)*$S(box)}]
pack .title -side top -fill x
pack .sb -fill y -expand 0 -side right
pack .c -fill both -expand 1 -side left
for {set i 0; set n 1} {$i < 8} {incr i} {
set ::S(pow,$i) $n
set n [expr {2*$n}]
}
# update
bind .c <Configure> {Resize %W %h %w} ;# Handle resizing
}
#
# ScrollProc -- called by the scrollbar. We need to determine what
# the new top of the page is.
#
proc ScrollProc {args} {
foreach {cmd perc} $args break
if {$cmd != "moveto"} return
set top [expr {round($perc * $::DATA(len))}]
if {$top == $::S(top)} return
DoPage $top
}
#
# DoPage -- display a screenful of data rows starting at TOP
#
proc MkPage {} {
global S DATA
.c delete all
puts "Make $S(rows)"
for {set i 0} {$i < $S(rows)} {incr i} {
MkRow $i
}
}
proc MkRow {srow} {
global S DATA
set x1 $S(lm2)
set x2 [expr {$x1 + $S(box)}]
set y1 [expr {$S(tm) + $S(box) * $srow}]
set y2 [expr {$y1 + $S(box)}]
set ym [expr {$y1 + $S(box)/2}]
.c create text $S(lm) $ym -tag d$srow -text ???? -anchor w
foreach i {7 6 5 4 3 2 1 0} {
set tag b$srow,$i
set xy [list $x1 $y1 $x2 $y1 $x2 $y2 $x1 $y2]
.c create poly $xy -tag [list b$srow $tag] \
-fill white -outline black
.c bind $tag <Button-1> [list CellClick $srow $i $srow]
set x1 $x2
incr x2 $S(box)
}
# Show the hex value and the character
.c create text $x1 $ym -tag e$srow -text ???? -anchor w
}
proc DoPage {{top ""}} {
global S DATA
if {$top == ""} {set top $S(top)}
set S(top) $top
for {set i 0} {$i < $S(rows)} {incr i} {
DoRow [expr {$S(top) + $i}] $i
}
# Adjust the scrollbar
set sb1 [expr {double($S(top)) / $DATA(len)}]
set sb2 [expr {double($S(top)+$S(rows)) / $DATA(len)}]
.sb set $sb1 $sb2
}
#
# DoRow -- shows one row of data at a given screen row
#
proc DoRow {row srow} {
global S DATA
if {$row >= $DATA(len)} return
set datum [lindex $DATA(bytes) $row]
set x1 $S(lm2)
set x2 [expr {$x1 + $S(box)}]
set y1 [expr {$S(tm) + $S(box) * $srow}]
set y2 [expr {$y1 + $S(box)}]
set ym [expr {$y1 + $S(box)/2}]
set num [format %04x $row]
.c itemconfig d$srow -text $num
for {set i 7} {$i >= 0} {incr i -1} {
set tag b$srow,$i
set xy [list $x1 $y1 $x2 $y1 $x2 $y2 $x1 $y2]
.c itemconfig $tag -fill [expr {$datum & $S(pow,$i) ? "black" : "white"}]
set x1 $x2
incr x2 $S(box)
}
# Show the hex value and the character
set ch [format %c $datum]
if {! [string is ascii $ch] || [string is control $ch]} {set ch "?"}
set extra [format " %02x %s" [expr {($datum + 0x100) % 0x100}] $ch]
.c itemconfig e$srow -text $extra
}
#
# CellClick -- handles clicking in a cell which toggles the bit
#
proc CellClick {row col srow} {
global S DATA
set datum [lindex $DATA(bytes) $row]
if {$datum & $S(pow,$col)} { ;# Bit is already set
.c itemconfig b$srow,$col -fill white
incr datum -$S(pow,$col)
} else { ;# Bit is off
.c itemconfig b$srow,$col -fill black
incr datum $S(pow,$col)
}
lset DATA(bytes) $row $datum
set ch [format %c $datum]
if {! [string is ascii $ch] || [string is control $ch]} {set ch "?"}
set extra [format " %02x %s" [expr {($datum + 0x100) % 0x100}] $ch]
.c itemconfig e$srow -text $extra
}
#
# LoadFile -- reads a file and converts to an integer list
#
proc LoadFile {{fname ""}} {
global S DATA
# Read in the data
if {$fname == ""} {
set fname [tk_getOpenFile]
if {$fname == ""} return
}
if {[file size $fname] >= $S(max)} {
tk_messageBox -message "File $fname is too big" -icon error
return
}
set S(fname) [file tail $fname]
set FIN [open $fname r]
fconfigure $FIN -translation binary
set bytes [read $FIN [file size $fname]]
close $FIN
binary scan $bytes c* DATA(bytes)
set DATA(len) [llength $DATA(bytes)]
DoPage 0
}
#
# SaveFile -- saves our binary data
#
proc SaveFile {} {
global DATA
set fname [tk_getSaveFile]
if {$fname == ""} return
set FOUT [open $fname w]
fconfigure $FOUT -translation binary
puts -nonewline $FOUT [binary format c* $DATA(bytes)]
close $FOUT
}
proc About {} {
tk_messageBox -message "$::S(title)\nby Keith Vetter, September 2003" \
-title "About $::S(title)"
}
proc Resize {W h w} {
global S
if {$W != ".c"} return
set rows [expr {1 + int(([winfo height .c] - $S(tm)) / $S(box))}]
if {$rows == $S(rows)} return
set S(rows) $rows
MkPage
DoPage
}
DoDisplay
proc test {} {
for {set i 0} {$i < 1000} {incr i} {
DoPage $i
update idletasks
}
}
set script [info script]
if {[file readable $script]} { ;# Use this script as a demo
LoadFile $script
### PWQ Time to scroll 1000 lines.
update
set x [time test]
puts "Time $x"
} else {
set txt "$S(title)\nby Keith Vetter" ;# Sample text to display
binary scan $txt c* DATA(bytes)
set DATA(len) [llength $DATA(bytes)] ;# Rows of data to display
DoPage 0
}