The basic implementation of the progressBar widget allows the setting of the "fraction" property of the GtkProgressBar but using this options requires more on the Tcl-side than it needs to.
Combination of the new options
-range and
-steps along with the new sub-commands
step, incr and
reset help to simplify matters.
For simple lists use the
step subcommand along with the the
-steps option to indicate the progress of a small, known number of steps where feedback on the completion of each step is required. Setting the
-steps option to 10, for example, will set the widget "fraction" property to 0.1 (1/10, i.e. 10%). Following this each time the
step sub-command is called, the widget bar will expand in length by 10% until it reaches 100%. The
step sub-command accepts an additional argument which will set the text content of the bar.
set modules [list \
apple.tcl \
blackberry.tcl \
cherry.tcl \
damson.tcl \
elderberry.tcl \
fig.tcl \
gooseberry.tcl \
hawthorn.tcl]
proc do_progress { box modules } {
set steps [llength $modules]
set pb [gnocl::progressBar]
$pb configure
-steps $steps -showText 1
$box add $pb
$pb
reset
for {set i 0} {$i <= $steps} {incr i} {
after 300
$pb
step [lindex $modules $i]
}
if ( [$box class] == statusBar ) {
$box unpack $pb
} else {
$box remove $pb
}
}
In the above example, the
reset subcommand was used to set the display fraction to 0.0 and text to and empty string.
More complicated operations, such as sifting through a large number of database records, may only need indication of relative progress. In other words, specific feedback on each increment in the batch process is not required. In this case the
incr sub-command should be used. As with
step above, an optional string can be specified, but if this field is left empty and the widget
-showText option set to 1, the percentage completion of the bar will be displayed.
set range [ expr 1000 + round (rand() * 10000) ]
set steps 20
$pb3 configure
-steps $steps
-range $range -showText 1
for {set i 0 } {$i < $range} {incr i} {
# do something or delay
after 1
$pb3
incr
}
