A feature that has been requested the most over the past few months is the code generator. I have personally received several emails from VTK Designer 2 users asking about the code generator that existed in the 1.x series but has magically disappeared in the 2.x series. Since then we invested some efforts in getting the code generator design right. All the wrong design choices in the first code generator (written for 1.x) were discarded and a new design was engineered from scratch.

Adithya, an Intern at our company, and I set out on this task. Over the past 2 months the code generator has taken good shape. The CodeGenerator is implemented as a whole new component (thanks very much to GCF). It hooks into exposed interfaces from the canvas and visualization network components of VTK Designer and uses hints provided by nodes and connections to automatically generate the code. We still dont have the whole thing ready, but the results are showing up.

There is still a lot of work left, which I am sure Adithya will complete by the time his internship gets over at VCL. Right now we are only concentrating on a simple VTK/C++ code generator; however we have plans to provide Python and a pure OpenGL code generator as well.

The next version (2.3) of GCF should (ideally) have a plugin for Qt Creator that will make creation and maintenance of GCF applications with Qt Creator easy. We started our progress towards that end by studying Qt Creator and understanding how plugins for it can be written. The result of that effort is a small document that explains a Qt Creator newbie how to write plugins. The document is a work in progress, but I am sure that it will be a useful starting point for Qt Creator plugin developers. Have a look at if for yourself, we would love to hear feedback from you.

URL: http://www.vcreatelogic.com/resources/downloads/. Click on the “Other Downloads” tab.

5th September Update: Added a chapter on providing editors for new file types in Qt Creator

11th September Update: Added a section (2.6) on building plugins located outside Qt Creator source. [Thanks to Eike Ziller for helping with this one]

How easy it is to make signal/slot connections between local and remote objects ?

GCF::RemoteAppAccessPoint* rap = ....
GCF::RemoteObject* remoteObject
            = rap->getRemoteObject("ComponentName.ObjectName");

GCF::connect(remoteObject, SIGNAL(someSignal(int,char,QString,QPixmap)),
             localObjectPtr, SLOT(someSlot(int,char,QString,QPixmap)));

Isnt this sweet

Qt provides a QDirModel class that makes it easy to display directory structures in a view. For a project that we are working on, we needed a model that would make it easy to display the structure of a FTP directory. Thats exactly what we have in FtpDirModel right now. Using the FtpDirModel class is very simple,

#include <QApplication>
#include <QTreeView>

#include "FtpDirModel.h"

int main(int argc, char** argv)
{
    QApplication a(argc, argv);

    FtpDirModel model;
    model.setUrl(QUrl("ftp://ftp.trolltech.com"));

    QTreeView view;
    view.setModel(&model);
    view.show();

    return a.exec();
}

Upon executing the above program, you will see a QTreeView that shows the directory structure of ftp.trolltech.com.

While the model is fetching data for a directory, it shows a nice “Fetching…” text in the first column :-).

Take a look at the code. You can checkout a copy from here: https://svn2.hosted-projects.com/vcreatelogic/FtpDirModel. Username and password is anonymous.

The article on “Adding Components for VTK Designer” has now been updated to provide information about how new components can be provided via VTK Designer’s “Software Updater”, which is designed using GCF.

Grab your copy from here now: http://www.vcreatelogic.com/resources/downloads/

GCF introduced a tool called CreateAppTemplate in version 1.6.3 (released in March of 2008). The tool basically helped in quickly creating new GCF based applications. By providing the tool with some basic information, developers could expect a fully compilable application to be generated. Once the template was generated, developers only had to fill in the details to get their ‘functional application’ up and running.

With time, CreateAppTemplate became a maintenance nightmare. Whenever new components got added, it became difficult to add support for them. More over CreateAppTemplate was not handling dependencies between components. Hence we thought that it was time to let go of CreateAppTemplate.

Enter CreateAppTemplateWizard.

CreateAppTemplateWizard is a new tool that developers can now use to generate code for GCF applications.

The tool, as the name suggests, is a wizard that asks a series of simple questions and generates a customized GCF application for you.

The wizard also knows how to configure your applications for using the “automatic updates” feature in the next version of GCF.

Later this year, we have plans to support GCF applications in Qt Creator. This wizard will, I am sure, prove to be very useful there.