[Kde-bindings] Qt::StandardItemModel#item_prototype= causes crashe in qtruby

[Stefano Crocco]

On Tuesday 14 April 2009, Richard Dale wrote:
> |On Friday 10 April 2009 08:58:37 Stefano Crocco wrote:
> |> Using Qt::StandardItemModel#item_prototype= and
> |> Qt::StandardItemModel#horizontal_header= causes ruby to crash. Here's
> |> the code causing the crash:
> |>
> |> require 'Qt4'
> |>
> |> app = Qt::Application.new []
> |> m = Qt::StandardItemModel.new
> |> proto = Qt::StandardItem.new ''
> |> proto.flags = Qt::ItemIsEnabled
> |> m.set_item_prototype proto
> |> m.horizontal_header_labels = %w[x y]
> |> app.exec
> |>
> |> If I comment out the call to horizontal_header_labels=, everything works
> |> correctly.
> |>

> |The crash is because you need to implement the clone() method in your
> |Qt::StandardItem:
> |
> |require 'Qt4'
> |
> |class MyStandardItem < Qt::StandardItem
> |  def clone
> |    return MyStandardItem.new('')
> |  end
> |end
> |
> |app = Qt::Application.new []
> |m = Qt::StandardItemModel.new
> |proto = MyStandardItem.new ''
> |proto.flags = Qt::ItemIsEnabled
> |m.set_item_prototype proto
> |m.horizontal_header_labels = %w[x y]
> |app.exec
> |
> |-- Richard
> |

Sorry, I completely misunderstood what the prototype does and how it should be 
used. However, I still can't understand why my program crashes. After all, my 
prototype was an instance of QStandardItem, which does have a clone method. So 
why should it crash? Also, I tried writing the same program in C++, and it 
doesn't crash (of course, as I now understand, setting the prototype this way 
doesn't do anything, but now this is beside the point). Here's the C++ 
version:

#include <QApplication>
#include <QStandardItemModel>
#include <QStringList>

int main(int argc, char *argv[])
{
      QApplication app(argc, argv);
      QStandardItemModel * m = new QStandardItemModel;
      QStandardItem * proto = new QStandardItem;
      proto->setFlags(Qt::ItemIsEnabled);
      m -> setItemPrototype(proto);
      QStringList headers;
      headers << "x" << "y";
      m->setHorizontalHeaderLabels(headers);
      return app.exec();
}

Am I missing something else?

Stefano