C++ GUI Programming with Qt 3

william_lorenz writes: "With the recent release of KDE 3.2 and KDevelop 3.0, and with the forming of the KDE Quality team as mentioned on Slashdot just days ago, it was an opportune time to read my newest book, C++ GUI Programming with Qt 3. (Qt is of course TrollTech's multi-platform windowing toolkit -- Win32, Linux, UNIX, and the embedded space with Qt/Embedded -- upon which KDE is built. There's a free version licensed under the GPL for non-commercial use and also a commercial version.)" Read on for the rest of Lorenz' review. C++ GUI Programming with Qt 3 author Jasmin Blanchette, Mark Summerfield pages 464 publisher Prentice Hall rating 9 reviewer Bill Lorenz ISBN 0131240722 summary A smooth introduction to best practices for Qt 3 application development.

I didn't have to force myself to read this one: the book grabbed my interest from the beginning. It's filled with just enough technical details to whet my technical curiosity, keep me turning pages, and provide the important information, clearly and concisely. I don't have much Qt development experience (none at all yet), although I am experienced in other windowing toolkits. The book quickly provided me with everything I need to know to get up and developing an application, and now I know where to quickly start.

Who's it for? I am of course a novice Qt developer, yet one with a fair amount of IT experience, specifically with other windowing toolkits. I found this book not only a great introduction for those who want to get started with Qt, but it's also a trove of information for somewhat intermediate Qt developers. It's not for people who work for Trolltech or have already been developing feature-rich KDE applications; however, besides providing a great point of entry for new Qt developers, the book does touch on some more advanced topics. Technical books tend to age quickly, but I should note that the book is written by some of the people who brought us Qt 3 and are working on bringing us Qt 4, so this book should have a degree of forward compatibility. What can I expect to learn?

The book is divided into two sections: "Basic Qt" and "Intermediate Qt" development.

The basic Qt section covers everything that someone new to Qt would probably want to learn, beginning with a simple application and an explanation of signals and slots (signals and slots work much the same way as windowing events in Java, for example, and can help to tell when a button or key is pressed). Signals and slots help make the sample application functional. This section also introduces the Qt reference documentation, available online as a reference during development, and Qt Designer, for those who want to use a graphical user interface to create components such as dialog boxes. A quick overview of some of the available widgets is next (widgets are graphical elements such as dialog boxes and buttons), which helps to give someone brand new to Qt development a feel for some of the components that come ready-to-build-upon. This is all covered in the first 38 pages of the book.

I should point out that I think that knowledge of the C++ programming language is essential if one is to learn good things from this book (I'm a big proponent of learning through experience, and you'll need to play with C++ code), but learning Qt and C++ development at the same time might help one come up with some interesting project ideas for learning!

After a quick introduction to creating custom widgets and double buffering (used in some cases to prevent screen flicker), the intermediate section starts by hopping right into layout managers, intended to make graphical forms and components beautiful (and more usable), just like tables helped to make HTML beautiful before CSS came around; layout managers help do for graphical application components what the font and alignment settings do for a word processor. The managers included are very similar to those used in Java's JFC/Swing stuff, and they work well. Also covered are methods for creating 2D and 3D graphics, drag-and-drop, and event processing. Compared to signals and slots, event processing gives the developer more control, and becomes important when writing custom widgets or changing the way an existing widget behaves.

Following this are sections on internationalization, providing online help within an application, multithreading for responsive applications, and Qt's platform-specific features. Qt works with Microsoft's ActiveX, for example, although this apparently requires the Qt/Windows Enterprise Edition as opposed to the free edition of Qt. It's important to point out that Qt implements its own threading capabilities, and the section on threads covers this in depth.

Conclusion

This is a great book for those interested in Qt and KDE development, cross-platform C++ graphical application development, and just making beautiful, functional applications. The book provides information that can't be had from the Qt API alone, and it does so in a way that kept me turning pages. Blanchette and Summerfield organized their text well, with logical chapters that make finding tips for that first application possible. This book gets twelve thumbs up from me.

Bill Lorenz is Vice-President of the Linux Users Group of Cleveland and is helping to organize the Ohio LinuxFest, 2004 edition (call for submissions now in the wild!). You can purchase C++ GUI Programming with Qt 3 from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.

Comments

Re:Online Books

[Teh_monkeyCode]

GTK Tutorial
QT Tutorial

Re:GPL Version

[HuguesT]

What they mean like that is that you are not allowed to develop closed source apps, free (as in beer) or otherwise, with the GPL version of QT.

If you want to develop closed-source applications with QT you need to purchase the commercial version of QT, you can't use the GPL version.

This way of doing things is compatible with the GPL.

Some reasons to use an OS' native toolkit

[Rascasse]

Speaking as a relatively new Mac OS X user, I'd like to add the following reasons not to try to use cross-platform GUI toolkits. Looks are deceiving. Though they appear to look like native widgets, upon closer inspection some differences become apparent. Moreover, they may not act like native widgets. The keyboard shortcut equivalents may be different than what are available on the native OS' widgets. Scripting support may be available on the native OS' widgets, but unavailable on these cross-platform widgets. As minor as these differences may appear at first-glance, they add enough inconsistency to ruin the user experience - especially on OSes such as Mac OS X.

I used to be a big fan of cross-platform GUI programming, but having worked on all variations of Windows, Linux desktops, and Mac OS X, I am now against the idea. I now believe if you're going to support a platform, use the native toolkits as they bring a level of consistency that is just not there with cross-platform toolkits. Having to use a GTK or QT-based app on Mac OS X these days proves to be tremendously frustrating. Text boxes don't have spell-checking or auto-completion. The red dot in the window decoration does not change if the document does. In fact, there is often no document-based implementation whereas there would be one if a native solution was developed. On Windows and Linux, the differences may only be cosmetic, but on OSes such as Mac OS X looks are only the tip of the iceberg with the problem. Cocoa widgets look pretty, but they also bring with them a lot of functionality that I've yet to see replicated on these cross-platform toolkits.

So please, when in Rome do as the Romans do.

Re:Why to get this book

[Bruce Perens]

I also read the book is released under a special copyright license similar to the GPL ( the Perens License ), so that after a few months the electronic format of the book becomes legally distributable. Is that cool, or what?

Yes. It's the Open Content License. It applies to the printed version today, meaning that you can shove it in a copier if you want and sell the copy, and it will apply to the electronic version when that is released. We usually do that about 3 months after the books reach store shelves. Source and unencrypted PDF will be available as usual.

Unfortunately, I can't say the same for the CD. There is some proprietary software on the CD, I think a Windows version of Qt and some Borland stuff, which isn't really in line with the series policy. But I found out so late that it would have seriously messed things up for the Trolltech folks for me to insist on changes, so I let that go by this time (and made sure it would not happen again).

Next books: Understanding the Linux Virtual Memory Manager next month, and Samba 3 by Example next week! Those are books 9 and 10 in the series.

Thanks

Bruce

Re:Qt is not my favorite toolkit

[Gauchito]

often students would go way overboard in designing a solution, using 30 classes where 5 would suffice

You were their teacher? Guess who's fault this is.

wxWidgets - fully free Qt alternative

[georgevulov]

Those looking for a fully free C++ toolkit should consider wxWidgets. With its superb sizer layouting system, rich api, native look, and great support (You often get replies from the authors themselves on the mailing lists), it is one of the best free toolkits around.

Now, with the new partnership between wxWidgets and Borland, wxWidgets is likely to develop even more rapidly.

Though wxWindows is free, unlike the free version of Qt it is not GPL, thus it can be used for commercial software development without worry.