[wxruby-users] Wx::Bitmap causes segfaults

[Alex Fenton]

Hi Andreas

Sorry for the delay in replying.

Andreas Garnæs wrote:
> Instantiating a Wx::Bitmap with width and height causes a segmentation
> fault. This is the minimal example I could find where the behaviour is
> exhibited:
>
> require 'rubygems'
> require 'wx'
> Wx::Bitmap.new(1, 1)

The problem here is not that Wx::Bitmap.new(width, height) segfault, but 
that you can't instantiate Bitmap (or similarly, Font, I guess) outside 
of the main loop. In other words, you can't call Bitmap.new until after 
you've called App.run or App.main_loop. It works fine otherwise (tested 
SVN HEAD on GTK).

This restriction is inherited from Wx, unfortunately. Bitmap is a 
platform-specific representation of an image, and wraps a C++ native gui 
object. These can't be created  until various setup steps have been done.

The no-argument version is an exception because no real resource is created.

There are different ways round this - ArtProvider provides a way of 
retrieving and caching standard images.

Following this I've added a note to the documentation of Bitmap and Font 
to say they shouldn't be created outside of main_loop.

cheers
alex