Re: [Fxruby-users] catching exceptions in event handlers

[Emmanuel T. <emm...@wa...>]

> Emmanuel Touzery wrote:
>
> >     I'm having the problem that my GUI app might have some bugs; in that
> > case, instead of seeing it exiting violently, dumping the stack on the
> > command line (which will never be seen by the user in most cases), i
would
> > like to catch the exception and display a nice dialog box.
> >     Wrapping the app.run call (i don't remember how it's called, but
it's
> > something like that) in a begin/rescue block doesn't seem to catch this
> > exception.
>
> Is it a standard Ruby exception, or is the Ruby interpreter (ruby)
> seg-faulting? If it's the former (a regular exception), it /should/ be
> raised all the way to the "top" and get caught in your begin-rescue
> block around the call to FXApp#run.

standard exception. for an interpreter crash there is not much to display
anyway ;O)
i want a backtrace so that i can debug.
i'm happy to read that FXApp#run is going to "forward me" the exception. but
it doesn't seem to work here (see code snippet at the end of the mail).

> This sounds way too complicated, IMO. If wrapping the call to FXApp#run
> with a "last-chance" begin-rescue block is failing to catch exceptions,
> I would like to see that demonstrated and get it fixed. I think the best
> solution is to get a good group of testers and get them to help you find
> the bugs ;)

maybe i'm doing something wrong, but how about this code:
click on file->open

#!/usr/bin/env ruby

require 'fox'
include Fox

class GlossaryMainWindow < FXMainWindow

 include Responder

 ID_OPEN,
 ID_LAST = enum(FXMainWindow::ID_LAST, 2)

 def initialize(app)
  # Initialize base class first
  super(app, "Glossary", nil, nil, DECOR_ALL, 0, 0, 400, 300)

  FXMAPFUNC(SEL_COMMAND,            ID_OPEN,          :onCmdOpen)

  # Make main window; set myself as the target
#   setTarget(self)
#   setSelector(ID_TITLE)

  # Make menu bar
  dragshell1 = FXToolbarShell.new(self, FRAME_RAISED|FRAME_THICK)
  menubar = FXMenubar.new(self, dragshell1, LAYOUT_SIDE_TOP|LAYOUT_FILL_X)
  FXToolbarGrip.new(menubar, menubar, FXMenubar::ID_TOOLBARGRIP,
   TOOLBARGRIP_SINGLE)
  # File menu
  filemenu = FXMenuPane.new(self)
  FXMenuTitle.new(menubar, "&File", nil, filemenu)
  # File Menu entries
  FXMenuCommand.new(filemenu,
   "&Open...        \tCtl-O\tOpen document file.",
   @openicon, self, ID_OPEN)
 end

 def onCmdOpen(sender, sel, ptr)
  pouf  # <-- invalid code
 end


 # Create and show the main window
 def create
  super
  show(PLACEMENT_SCREEN)
 end
end

if $0 == __FILE__
 # Construct an application
 application = FXApp.new('Glossary', 'Emmanuel')

 # Construct the main window
 GlossaryMainWindow.new(application)

 # Create and show the application windows
 application.create

 # Run the application
 begin
  application.run
 rescue
  FXMessageBox.error(self, MBOX_OK, "Error", "Boom!")
 end
end