Re: NoMethodError: private method `load' called for Qt::UiLoader (was: Re: Qt::UiLoader -> uninitialized constant Qt::QUiLoader)

On Sunday 26 September 2010, Markus Fischer wrote:
> |Hi,
> |
> |On 26.09.2010 22:50, Stefano Crocco wrote:
> |> require 'Qt'
> |> require 'qtuitools'
> |> 
> |> app = Qt::Application.new []
> |> ui = Qt::UiLoader.new
> |
> |That helps a bit! I'm only one step further however:
> |
> |$ irb
> |ruby-1.9.2-p0 > require 'Qt'
> | => true
> |ruby-1.9.2-p0 > require 'qtuitools'
> | => true
> |ruby-1.9.2-p0 >
> |ruby-1.9.2-p0 >   app = Qt::Application.new []
> | => #<Qt::Application:0x000000026b7590 objectName="irb">
> |ruby-1.9.2-p0 > ui = Qt::UiLoader.new
> | => #<Qt::UiLoader:0x000000026a81a8 objectName="">
> |ruby-1.9.2-p0 > ui.load
> |NoMethodError: private method `load' called for
> |#<Qt::UiLoader:0x000000026a81a8 objectName="">
> |	from (irb):6:in `method_missing'
> |	from (irb):6
> |	from /home/mfischer/.rvm/rubies/ruby-1.9.2-p0/bin/irb:17:in `<main>'

You're calling the load method with the wrong arguments. I think that, due to 
the way the qt bindings work, this ends up calling Kernel#load, which is a 
private method and therefore can't be called with a receiver. To have your 
code work, you just need to follow the example you posted in your previous 
mail:

require 'Qt'
require 'qtuitools'
app = Qt::Application.new []
loader = Qt::UiLoader.new
#Create a file pointing to the .ui file you want to load. Unfortunately, you
#can't use a ruby file here
file = Qt::File.new '/path/to/ui/file.ui'
#open the file
file.open Qt::File::ReadOnly
#At last, load the ui file. If the widget contained in the ui file should be
#a child of another widget, pass that widget as secon argument instead of nil
widget = loader.load file, nil
#Close the file
file.close
#Now do whatever you like with the widget. For example,
widget.show
app.exec

> |It's a bit hard currently to not get lost with these different QT ruby
> |ports.
> |
> |So there's the qtruby4 gem which only contains binaries for mswin32 (and
> |it's not mingw32, either). If you want qtruby4 anywhere else, manual
> |source compilation is required.
> |
> |Then we've the gem "qtbindings" which attempts to address the
> |shortcoming of qtruby4 not available on non-windows platforms, which is
> |fairly new and which I'm using.
> |
> |Sometimes skimming through the docs I also find references to korundum
> |(e.g. http://rubyforge.org/projects/korundum/ ) which I've no clue what
> |it is.
> |
> |Is the rubyforge project related to the qtruby4 gem or is it something
> |different?
> |
> |That's all really confusing.

Actually, there's only one qt ruby bindings. The situation is the following. 
The Qt ruby bindings have been born as a part of the ruby bindings for KDE (in 
case you don't know, KDE is a desktop environment born for Linux and based on 
the Qt libraries). This is "korundum".

Since KDE is based on Qt, korundum also contains bindings for all of the Qt 
classes, so the developers decided to allow users who don't have KDE to 
install only the parts of korundum containing the bindings to Qt. This is Qt 
ruby (or qtruby).

Originally, the build system of qtruby was the same as the KDE one, based on 
the cmake utility. This wasn't very easy, expecially on windows (this also 
happened because new releases of qtruby weren't released very often, so to 
obtain a newer version, you often needed to start from the korundum sources 
and modify the build system to remove anythig related to KDE before starting 
compiling). To make things easier for windows users, a windows binary gem of 
qtruby was created and  called qtruby4.

Now, it seems, the korundum developers have decided to create a proper gem for 
qtruby, which is what you're using. I can't say much on this, as I didn't know 
about it until I read your mail

> |Stefano: if I may ask, in which environment are you developing?

I'm using the ruby bindings for KDE (that is, korundum) on gentoo linux
> |thanks,
> |- Markus

I hope this helps

Stefano