$mainWindow->AddButton
  (
   -name => 'b1',
   -text => 'label 1',
   -pos => [100, 0],
   -onClick => sub {
     $mainWindow->label1->Hide;
     $mainWindow->label1->Animate
       (
        -show => 1, # !$mainWindow->label1->IsVisible(),
        -activate => 1,
        -time => 600,
        -direction => 'brtl',
        -animation => 'roll',
       );
   },
  );