[rt.cpan.org #99607] Issue using wxTextEntryBox

Mon Oct 27 15:05:08 2014: Request 99607 was acted upon.
Transaction: Correspondence added by MDOOTSON
       Queue: Wx
     Subject: Issue using wxTextEntryBox
   Broken in: (no value)
    Severity: (no value)
       Owner: Nobody
  Requestors: [email protected]
      Status: open
 Ticket <URL: https://rt.cpan.org/Ticket/Display.html?id=99607 >


Hi,

Your issue with Wx::TextEntryBox arises from the basic way wxWidgets handles applications and windows.

The basic rule is that the main application loop will exit when no more instances of Wx::TopLevelWindow ( e.g. Wx::Frame and Wx::Dialog ) exist in the application.

Top level windows (Frames and Dialogs) must be explicitly destroyed.

$dialog_>Destroy;

unless your code causes them to be destroyed by some other method (such as being a child of another TopLevelWindow when it is destroyed or the automatic behaviour when you close the window using system menus / buttons).

In your example, none of these things happens so the application loop never exits. Your Wx::TextEntryDialog has no parent so continues to exist after you close your Frame.

Dialogs designed for modal usage, such as Wx::TextEntryDialog, need to have a valid parent to work properly, or be created as  a special case without a parent.

When you create the dialog and pass in the Wx::Panel as the parent the following things happen.

Dialogs need top level parents so the wxWidgets code determines the parent of Wx::Panel - your frame - and checks if that is a valid parent. It isn't - a parent top level window needs to be visible on the display to be a valid parent for a dialog. So the dialog is created without a parent. When you close the $frame, the TextEntryDialog is left hanging around so the main application loop never exits.

In this situation, wxWidgets will use anything you have set as the top window (wxTheApp->SetTopWindow) but your example does not do this.

In standard usage you would always do:

my $dialog = Wx::textEntryDialog->new(....);
my $result = $dialog->ShowModal;
# .. get stuff from dialog
$dialog->Destroy;

so your particular issue would not arise.

With regard to the different in implementation between Wx:TextEntryDialog and Wx::SingleChoiceDialog, it is indeed because of the use of client data. The wxPerl implementation allows you to pass a reference to an array of anything (so maybe references to objects) so a C++ class is required to maintain the correct reference counts on the Perl SVs for the array ref.

Hope it helps

Mark