Qt is a C++ class library for writing GUI applications that run on UNIX, Windows 95/98, and Windows NT platforms. Qt is much easier to use than the standard Motif toolkit for UNIX systems, but at the same time Qt emulates the look-and-feel of Motif. Best of all, after you have written an application with Qt, all you have to do is recompile it to have a version that works on Windows systems. Qt also emulates the look-and-feel of Windows, so you can provide all of your users with native-looking interfaces.Platform independence is not the only benefit of Qt. Qt uses an ingenious signal/slot mechanism for connecting user interaction with program functionality, providing an excellent framework for component-based programming. Graphical rendering in Qt is highly optimized due to its use of effective caching mechanisms -- rendering in Qt is often faster than with the similar native API. In addition to user interface classes, Qt features portable support for file system access, working with date and time values, and network programming. With Qt, you'll find that you need to write very little, if any, platform-dependent code because Qt already has what you need.Qt is popular with open-source and Linux developers because it can be used for free on UNIX systems for this type of development. For commercial development, you need a license for Qt, which is available from Troll Tech, the developers of Qt. In addition to open-source development, Qt is being used by several major companies and government and international agencies.While programming with Qt is straightforward and feels natural once you get the hang of it, the learning curve can be steep. Qt comes with excellent reference documentation, but beginners often find the included tutorial is not enough to really get started with Qt. That is where this book steps in. Programming with Qt guides you through the steps of writing a Qt application by showing you how to write a simple paint application. It also helps deepen your understanding of the topics with exercises and fully worked out answers. The book presents all of the GUI elements in Qt, along with advice about when and how to use them, so that you can make full use of the toolkit. There's also lots of information for seasoned Qt programmers, including material on advanced 2D transformations, drag-and-drop, and writing custom image file filters.Programming with Qt helps you get the most out of Qt. With it, you'll learn to take full advantage of this powerful, easy-to-use, cross-platform toolkit.
Programming with Qt offers an excellent introduction to the Qt toolkit, a powerful C++ graphical user interface (GUI) library that allows developers to create interfaces that run under both Unix and Windows. The book first looks at the strengths of the Qt library: it provides excellent cross-platform support, good performance, and ease of use for the C++ programmer.
After a basic application, the book moves onto the event model in Qt, which uses signals and slots to attach events to code. The author demonstrates that Qt is a remarkably sophisticated user interface library. Early sections examine programming menus, including pop-up menus, basic widgets, or controls (such as labels and listboxes), and more complex controls (such as sliders, progress bars, listviews, and tables).
Next the book presents material on Qt's built-in dialogs (for message boxes and opening and saving files) and layout managers. The author investigates Qt's container classes (such as arrays and dictionaries) and offers a lot of material on 2-D graphics, including printing, saving, and loading images.
Later chapters look at validating text and working with files and directories, with tips on important topics such as focus handling, internationalization, portability, and debugging. (The author even shows you how to work with Qt in Perl and reviews several Qt GUI builders that help automate design.)
Filled with expert advice and sample code, this guide makes a strong case that both Unix and Windows developers should try out Qt. --Richard Dragan
