qtruby problems

[Martin DeMello]

I have both qtruby and qt4-qtruby installed (via the gentoo ebuilds),
and am trying to run the examples from qt4-qtruby-1.4.7. However, most
of them are failing with "Unresolved constructor call". Here's a
minimal failure case:

irb(main):001:0> require 'Qt'
=> true
irb(main):002:0> app = Qt::Application.new([])
=> #<Qt::Application:0xb6a24bec name="irb">
irb(main):003:0> button = Qt:ushButton.new("hello world")
ArgumentError: unresolved constructor call Qt:ushButton

from /usr/lib/ruby/site_ruby/1.8/Qt/qtruby.rb:1367:in `initialize'
from /usr/lib/ruby/site_ruby/1.8/Qt/qtruby.rb:1367:in `call'
from /usr/lib/ruby/site_ruby/1.8/Qt/qtruby.rb:1367:in `try_initialize'
from /usr/lib/ruby/site_ruby/1.8/Qt/qtruby.rb:1366:in `catch'
from /usr/lib/ruby/site_ruby/1.8/Qt/qtruby.rb:1366:in `try_initialize'
from (irb):3:in `new'
from (irb):3

martin

 

[richard.j.dale]

I have both qtruby and qt4-qtruby installed (via the gentoo ebuilds),
and am trying to run the examples from qt4-qtruby-1.4.7. However, most
of them are failing with "Unresolved constructor call". Here's a
minimal failure case:

irb(main):001:0> require 'Qt'
=> true
irb(main):002:0> app = Qt::Application.new([])
=> #<Qt::Application:0xb6a24bec name="irb">
irb(main):003:0> button = Qt:ushButton.new("hello world")
ArgumentError: unresolved constructor call Qt:ushButton

from /usr/lib/ruby/site_ruby/1.8/Qt/qtruby.rb:1367:in `initialize'
from /usr/lib/ruby/site_ruby/1.8/Qt/qtruby.rb:1367:in `call'
from /usr/lib/ruby/site_ruby/1.8/Qt/qtruby.rb:1367:in `try_initialize'
from /usr/lib/ruby/site_ruby/1.8/Qt/qtruby.rb:1366:in `catch'
from /usr/lib/ruby/site_ruby/1.8/Qt/qtruby.rb:1366:in `try_initialize'
from (irb):3:in `new'
from (irb):3

It's because you're picking up the Qt3 version of QtRuby which doesn't
have that constructor. If you install the Qt3 version after the Qt4
version the default when you do a require 'Qt' will be the Qt3 one. If
you install the Qt4 version of QtRuby after the Qt3 one, then the
default is Qt4 instead. Maybe use require 'Qt3' or require 'Qt4' to
make sure you get the right one.

In the Qt4 version 'qtruby.rb' was renamed 'qtruby4.rb', and so it is
easy to see from the trace above what went wrong.

-- Richard

 

[Martin DeMello]

It's because you're picking up the Qt3 version of QtRuby which doesn't
have that constructor. If you install the Qt3 version after the Qt4
version the default when you do a require 'Qt' will be the Qt3 one. If
you install the Qt4 version of QtRuby after the Qt3 one, then the
default is Qt4 instead. Maybe use require 'Qt3' or require 'Qt4' to
make sure you get the right one.

Thanks! requiring 'Qt4' fixed it. How do I make Qt go back to defaulting to Qt4?

martin

 

[Caleb Tennis]

Thanks! requiring 'Qt4' fixed it. How do I make Qt go back to
defaulting to Qt4?

I *think* this is a result of whichever you emerged last. If you
emerged Qt3 after Qt4, then require 'Qt' pulls it in instead.

I recommend just using 'Qt4' or 'Qt3' explicitly. Also you can check
via Qt::version to see which one is loaded.

Caleb

 

[richard.j.dale]

Thanks! requiring 'Qt4' fixed it. How do I make Qt go back to defaulting to Qt4?

Reinstall the Qt4 version of QtRuby so that the Qt.rb file from that
release replaces the current one.

-- Richard