GUI Setup with Tk, overly verbose, or maintainable?

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

Monks,

I come seeking your opinions on this subroutine, it takes a reference to a scalar holding the name of the client, and a reference to a hash of db login properties. It then constructs the gui by creating a hash of arrays to hold corresponding elements.... lemme know what you think.. is it overly verbose.. or does it add to maintainability.

sub guiStart
{
    my ($client,$login) = @_;
    
    my $mw = MainWindow->new(-borderwidth=>30,
                             -title=>"Duplicates: ".$$client);

    my %layout = ('frame'   => [],
                  'button'  => [],              
                  'label'   => [],
                  'callback'=> []);
    
    #Construct labels 
    $layout{'label'}->[0] = 'List Available Data';
    $layout{'label'}->[1] = 'Remove Data';
    $layout{'label'}->[2] = 'Add Data';
    $layout{'label'}->[3] = 'Identify Duplicates';
    $layout{'label'}->[4] = 'Change Client';
    $layout{'label'}->[5] = 'Exit Application';
    
    #Set callbacks
    $layout{'callback'}->[0] = \&listData;
    $layout{'callback'}->[1] = \&removeData;
    $layout{'callback'}->[2] = [\&addData,,$client,$login,$mw];
    $layout{'callback'}->[3] = \&identifyDuplicates;
    $layout{'callback'}->[4] = \&changeClient;
    $layout{'callback'}->[5] = \&exitApp;            
    
    for (0..5)
    {
        #Create the frames
        $layout{'frame'}->[$_]  = $mw->Frame();
    
        #Create the buttons
        $layout{'button'}->[$_] = $layout{'frame'}->[$_]->Button(-text
+   =>$layout{'label'}->[$_],
                                                                 -widt
+h  =>20,
                                                                 -comm
+and=>$layout{'callback'}->[$_])->pack();
        $layout{'frame'}->[$_]->pack();
    }
    
    MainLoop;
    
    return;
}
[download]

Grygonos

Comment on GUI Setup with Tk, overly verbose, or maintainable? Download Code

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Re: GUI Setup with Tk, overly verbose, or maintainable? by keszler (Priest) on Jul 02, 2004 at 17:38 UTC
I'd go with "overly verbose", unless you need references to the majority of the widgets for cgets or changes. If that is the case, then I'd suggest adding `use constant { LIST => 0, DEL => 1, ADD => 2, DUP => 3, CHG => 4, EXIT => 5, };` [download] so that you can refer to e.g. `$layout{'button'}->[ADD]` to modify the "Add Data" text.	[reply] [d/l] [select]
Re^2: GUI Setup with Tk, overly verbose, or maintainable? by Grygonos (Chaplain) on Jul 02, 2004 at 17:44 UTC
Looking back on it I don't need the refs to Button's to be stored... just the labels, callbacks and frames(so I can create a button on that frame via `$frame->Button(..);` Would that help you think? Grygonos	[reply] [d/l]
Re: GUI Setup with Tk, overly verbose, or maintainable? by saberworks (Curate) on Jul 02, 2004 at 21:00 UTC
Since you're asking a style question, I would typically do something like this: `my $labels = { 0 => 'List Available Data', 1 => 'Remove Data', 2 => 'Add Data', ... }; my $callbacks = { 0 => \&listData, 1 => \&removeData, ... } $layout{label} = $labels; $layout{callback} = $callbacks;` [download] It eliminates a whole lot of typing and seems to be just as clear.	[reply] [d/l]
Re: GUI Setup with Tk, overly verbose, or maintainable? by toma (Vicar) on Jul 03, 2004 at 23:07 UTC
I think that your style of code is good for maintainability. I like the `use constant` approach that keszler mentioned. There is a module that can do the counting for you; it is called enum::fields. You also have the opportunity to remove some redundancy from your array initializations. sub guiStart { my ($client,$login) = @_; my $mw = MainWindow->new(-borderwidth => 30, -title => "Duplicates: ".$client); use enum::fields qw{ LIST DEL ADD DUP CHG EXIT }; my %layout; $layout{label} = [ 'List Available Data', 'Remove Data', 'Add Data', 'Identify Duplicates', 'Change Client', 'Exit Application', ]; $layout{callback} = [ \&listData, \&removeData, [\&addData,,$client,$login,$mw], \&identifyDuplicates, \&changeClient, \&exitApp, ]; for my $btn (LIST..EXIT) { $layout{frame}->[$btn] = $mw->Frame(); $layout{button}->[$btn] = $layout{frame}->[$btn] ->Button(-text => $layout{label}->[$btn], -width => 20, -command => $layout{callback}->[$btn]) ->pack(); $layout{frame}->[$btn]->pack(); } MainLoop; return; } [download] It should work perfectly the first time! - toma	[reply] [d/l] [select]
Re^2: GUI Setup with Tk, overly verbose, or maintainable? by Grygonos (Chaplain) on Jul 04, 2004 at 14:14 UTC
Thanks, toma that's a neat module. Is there very much overhead involved with it? Is it fairly lightweight? Grygonos	[reply]
Re^3: GUI Setup with Tk, overly verbose, or maintainable? by toma (Vicar) on Jul 06, 2004 at 00:08 UTC
You can read the source or invent benchmarks to decide how lightweight it is. I haven't looked at it much. The CAVEATS section of the enum::fields POD explains the module limitations. The author suggests that Class::Delegate may be a better module, but I don't understand the suggestion. It should work perfectly the first time! - toma	[reply]