[perl-win32-gui-users] Drawing transparently.

[Giuseppe J. C. <msj...@ho...>]

Hi all,
I put together a smaller example to better show my issue.

<code>
#!/C/Perl/bin/perl.exe
use strict;
use warnings;
use Win32::GUI();
use Win32::GUI::DIBitmap;

$|++;

my $interval = 1000;

my $dib = newFromFile Win32::GUI::DIBitmap("Zapotec.bmp")
  or die "newFromFile";

my $main = Win32::GUI::Window->new(
    -name    => 'Main',
    -width   => 150,
    -height  => 100,
    -onTimer => \&redraw_Timer,
    -onPaint => \&Main_Paint,
    -text    => 'Transparent Label',
);

$main->AddTimer( "redraw_Timer", $interval );

my $label = $main->AddLabel(
    -text     => scalar(localtime),
    -addstyle => 11,                  # TRANSPARENT
);

#-------------------------------------------------------------------------------
$main->Show();
Win32::GUI::Dialog();
$main->Hide();
exit(0);

#-------------------------------------------------------------------------------

sub Main_Paint {
    printf( "[%s] Main Paint Event Fired.\n", scalar(localtime) );
    my $self = shift;
    my $dc   = shift;
    my ( $width, $height ) = ( $self->GetClientRect )[ 2 .. 3 ];
    $dib->StretchToDC( $dc, 0, 0, $width, $height );
    $dc->Validate();
    return 1;
}

sub Main_Terminate {
    -1;
}

sub redraw_Timer {
    my $temp = localtime;
    $main->InvalidateRect(1);    # Forces Redraw
    select( undef, undef, undef, 1 / 4 );
    $label->Text($temp);
}
</code>

If I remove the bitmap background (onPaint) and add a "-background => [0,255,0]," to the Main window I obtain the desired result. Unfortunately in my case I am dealing with a background obtained via DC cals.

Again, thank you in advance for any help.

Giuseppe