Storage B

(LGPL License Option Added to Qt)

Espoo, Finland — Nokia today announced that its Qt cross-platform User Interface (UI) and application framework for desktop and embedded platforms will be available under the Lesser General Public License (LGPL) version 2.1 license from the release of Qt 4.5, scheduled for March 2009. Previously, Qt has been made available to the open source community under the General Public License (GPL) license. In addition, Qt will now be available from the new domain, www.qtsoftware.com.

The move to LGPL licensing will provide open source and commercial developers with more permissive licensing than GPL and so increase flexibility for developers. In addition, Qt source code repositories will be made publicly available and will encourage contributions from desktop and embedded developer communities. With these changes, developers will be able to actively drive the evolution of the Qt framework.

Qt 4.5 will also be available under commercial licensing terms, while licensing for previous versions of Qt remains unchanged. In addition, service offerings for Qt will be expanded to ensure that all Qt development projects can have access to the same levels of support, independent of the selected license.

Good news for those of us too cheap to pay the $4950 per developer multi-platform license.

• X Windows Programming in C++: Part I
• X Windows Programming in C++: Part II

Continuing with our task of creating a C++ version of basicwin.c, we next look at XCreateSimpleWindow. Here’s some code snippets from basicwin.c showing the use of XCreateSimpleWindow:

• X Windows Programming in C++: Part I

Continuing with our task of creating a C++ version of basicwin.c, we next look at XOpenDisplay / XCloseDisplay. Here’s some code snippets from basicwin.c showing the use of these functions:

Years ago, I did quite a bit X Windows programming. When I started developing X Windows software, I was also learning C++ (this was a long time ago). Unfortunately , the X Windows system I was developing software for did not have a C++ compiler. This led to some frustration since using C++ would have made some of my tasks easier.

A fews years later, I worked on another project using X and Motif. It was mandated that this software be written in C leading to same frustration I experience when I first started learning X (by this time I was a seasoned C++ developer, so writing anything in C seemed like a step backward).

I’ve decided to revisit X Windows programming on my own for a few reasons:

• I’m a little rusty when it comes to X Windows programming.
  
  
• I want to use X in a project I’ve been contemplating for the past few years.
  
  
• I’m currently working on Microsoft Windows C++/C# project at work and I want to do some non-Microsoft programming on my own.

My first step in getting back into X Windows programming was to revist the book, Xlib Programming Manual, Rel. 5. The examples in this book are written in C (Kerninghan and Ritchie C, no less). One of these examples, basicwin.c, demonstrates the fundementals of programming with the X library. I figure coming up with a C++ version of basicwin.c would be a useful learning experience for myself and possibly others.

I’ll start out by taking pieces of basicwin.c and converting them to C++. I’ll start with following code fragments showing the use of the structures: XSizeHints, XWMHints, and XClassHint.