Viewing file:  virtevents1.pl (2.62 KB) -rw-r--r--
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use strict;
sub virtevents1 {
my( $demo ) = @_;
my $mw = $MW->WidgetDemo(
-name => $demo,
-text => [ "This demonstration shows how you can use keysyms (keyboard symbols) to programmatically synthesize events that simulate a person typing on the keyboard. To learn about keyboard keysyms, run to previous demonstration, \"Show keyboard symbols\".
A virtual event named <<pTkRules>> is defined that is activated by pressing the \"caps lock\" key (go ahead, press \"caps lock\"). A callback is bound to that virtual event - the callback synthesizes physicals events that \"type\" into the Entry widget displayed below. Pressing the \"Synthesize\" Button calls eventGenerate(), which synthesizes the virtual event <<pTkRules>> directly.
Warning: it's easy to make this demonstration recurse indefinitely because synthesized physical events behave just like the real thing. So, it's possible for the <<pTkRules>> callback to eventGenerate() the keysym that activates the <<pTkRules>> virtual event, which invokes the <<pTkRules>> callback to eventGenerate() the keysym that activates the <<pTkRules>> virtual event, which ...", -wraplength => '6i' ],
-title => 'Simulate KeyPress events.',
-iconname => 'vevents1',
);
# Define a virtual event - <<pTkRules>> - that is activated when
# the physical event - pressing the "caps lock" key - occurs.
$mw->eventAdd( qw/ <<pTkRules>> <Caps_Lock> / );
# Alphabetics are their own keysyms. The %keysyms hash maps other
# characters to their keysym string. To see the keysyms associated
# with keyboard characters run the previous widget demonstration.
my %keysyms = (' ' => 'space', '/' => 'slash', '!' => 'exclam' );
# Create an Entry widget for a person or this program to type into.
# The Button explicitly generates the virtual event.
my $e = $mw->Entry->pack;
my $b = $mw->Button(
-command => sub { $mw->eventGenerate( '<<pTkRules>>' ) },
-text => 'Synthesize <<pTkRules>>',
)->pack;
# Now bind the virtual event to a callback that "types" for us.
$mw->bind( qw/ <<pTkRules>> / => sub {
# This subroutine is invoked whenever the "caps lock" key is
# pressed or the virtual event <<pTkRules>> is programatically
# generated via eventGenerate.
$e->focus;
$mw->update;
my $string_to_type = 'Perl/Tk rules!';
foreach ( split '', $string_to_type ) {
$_ = $keysyms{$_} if exists $keysyms{$_};
$e->eventGenerate( '<KeyPress>', -keysym => $_ );
$mw->idletasks;
$mw->after( 100 );
} # end sub type characters
} );
} # end virtevents1
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