Code Jamming Everyday IT problems, solutions and discussions

Replacing QNetworkAccessManager for the great good

Everybody using Qt for networking for small tasks will sometimes face oddities of QNetworkAccessManager. This class aims to be useful and convenient while having few quite sensible drawbacks. First one of couse is inability to use it in blocking way. What you should do instead is to create instance of QEventLoop and connect it’s quit() signal wi... Read more

Resources to learn and understand parallel programming. The hard way

There’s no way other than the hard way. (c) Parallel programming is considered as not easy or even advanced topic by many programmers. It’s the starting point for even more advanced stuff like distributed computations, reliability, CAP theorem, consensus problems and much more. Besides, deep understanding of how CPU and operating system wor... Read more

Implementing spellchecking in desktop application in C++

When user is supposed to enter significant amount of text in your application, it’s better to help him/her to control it with checking spelling. Basically, to check spelling you need a dictionary with words and algorithm to order these words. Also it might be useful to provide user with possible corrections for any spelling error. Here where Hun... Read more

Classic Producer-Consumer in Qt/C++

Producer-Consumer is a classic pattern of interaction between two or more threads which share common tasks queue and workers who process that queue. When I came to similar task first I googled for standard approaches in Qt to solve this problem, but they were based on signals/slots plus synchronization primitives while I wanted simple and clear ... Read more

Implementing autocomplete for English in C++

When it comes to implementing autocompletion in C++ in some type of input field, the question is which algorithm to choose and where to get the source for completion. In this post I’ll try to answer both questions. As for the algorithm, SO gives us hints about tries, segment trees and others. You can find good article about them. Author has imp... Read more