ldln has asked for the wisdom of the Perl Monks concerning the following question:

What is the correct way to determine if popup menu belonging to a Tk::Text widget is onscreen? "-postcommand"-option works when menu is displayed, but since there is no "unpostcommand" it doesn't help much..

Sample code:

    use strict;
    use Tk;
        
    my $mw = MainWindow->new();
    my $Text = $mw->Text()->pack;
    my $TextMenu = $Text->menu();
    my $timer = $mw->repeat(100,\&Loop);
    MainLoop;

sub Loop {
        #Try various ways to detect if PopUp-menu of Tk::Text is displ
+ayed..
        #Dont't work (no change when popup is displayed)
    my $IsMenuMapped = $TextMenu->ismapped();
        #Dont't work (no change when popup is displayed)
    my $IsMenuViewable = $TextMenu->viewable();
        #Dont't work (no change when popup is displayed)
    my $WhoGotFocus  = $mw->focusCurrent();
        #Dont't work (no change when popup is displayed)
    my $MenuRootY = $TextMenu->y;
        #Dont't work (no change when popup is displayed)
    my $MenuHeight = $TextMenu->height();    
}

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Replies are listed 'Best First'.
Re: Is Tk::Text-widget PopUp-menu onscreen?
by zentara (Cardinal) on Aug 14, 2005 at 13:20 UTC
    It was simpler than I thought above. This does it, but there still is a need to detect cascading submenus. 
    #!/usr/bin/perl
use warnings;
use strict;
use Tk;

my $mw = MainWindow->new();
my $Text = $mw->Text()->pack;
my $TextMenu = $Text->menu();

$TextMenu->bind("<Enter>",sub {print "1\n" });
$TextMenu->bind("<Leave>",sub {print "0\n" });
MainLoop;

    [download]
    I'm not really a human, but I play one on earth. flash japh
[reply]
[d/l]
      Hm, strange cos that was something I tried before posting here.

      Tried with different event-bindings on the Menu-widget. But Since <Motion>, <Enter> etc events didn't work (Win32/Tk800.024), I assumed that Menu-widgets didn't support bindings.. but the <Leave>-event acutally works (the event-sub is, for whatever reason, even called TWICE when the event triggers, hehe).

      Together with using the "-postcommand" option instead of the <Enter> event, I can achieve what I want.

      Thanks zentara!

[reply]
Re: Is Tk::Text-widget PopUp-menu onscreen?
by zentara (Cardinal) on Aug 14, 2005 at 11:54 UTC
    Hi, interesting question. What I did was run the following code, for the first 5 seconds with no menu, then a menu for the second 5 seconds. Then compare the output. It seems that when the menu is visible, Dumper has an Entry for '_XEvent_' , which contains some binary and font information.

    I'm not sure what is the best way to detect what '_XEVENT_' is. If you figure it out, please post the code. 

    #!/usr/bin/perl
use warnings;
use strict;
use Tk;
use Data::Dumper;


my $mw = MainWindow->new();
my $Text = $mw->Text()->pack;
my $TextMenu = $Text->menu();
my $timer = $mw->repeat(5000,\&Loop);
MainLoop;

sub Loop {

#print Dumper[(\$TextMenu)],"\n\n"; 
#print join ' ',keys %$TextMenu,"\n"; 
#print $TextMenu{'_XEvent_'},"\n"; 

my %hash = %$TextMenu;
print join ' ',keys %hash,"\n";
print $hash{'_XEvent_'},"\n";

}

    [download]
    I'm not really a human, but I play one on earth. flash japh
[reply]
[d/l]

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