Thou shalt programme
First of all I assume you have seen this post which describes how to build opencv statically for Linux. If that is the case then you can just add the following code to your qmake .PRO file to use opencv with Qt.
unix: {
CONFIG += link_pkgconfig
PKGCONFIG += opencv
}In this post I’ll describe how to build a static version of Qt under Linux (Ubuntu flavor) and I will use Qt 5.7.0 and Ubuntu 16.04 64-Bit for that matter. Static builds ease the process of app deployment under Linux cause it is quite complex (much more complex than Windows and Mac OS X) so without further ado, here it is.
Continue reading “Build Qt Statically for Linux”
This post describes how to build an static version of OpenCV for Linux operating systems. I am going to use OpenCV version 3.1.0 and Ubuntu 16.04 64-bit but the process should be more or less the same under CentOS or other flavors of Linux. So let’s start.
Continue reading “Build OpenCV Statically for Linux”
The example project that I am going to share in this post is the absolute beginner guide version of using OpenGL in Qt (Specially Qt5 and latest versions of OpenGL) which to my surprise I could not find anywhere. By checking the existing OpenGL examples in Qt I noticed they all make some assumptions about what you know about OpenGL and then go ahead and describe how to use in in Qt. [I hope, I really do] that is not what you’ll find here. So without further ado here is the most simple example.
Continue reading “Hello Qt, Hello OpenGL, Hello World”
Following is a list of Operating Systems and their codes (as Qt calls them) which can be used in #ifdef and #ifndef compiler directives. Note that it is taken from qsystemdetection.h and you should always refer to it for the most updated values:
Continue reading “Supported Operating Systems and Definitions in Qt”
Here is how you can check and see if Windows is locked in Qt/C++. This same function will also let you know if the user is switched to another. Note that this involves using some Win32 API functions.
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To update a Qt app’s taskbar icon you need to create a QIcon object and assign it using setWindowIcon of the QApplication. Here is very simple example:
qApp->setWindowIcon(QIcon("path-to-an-image-file"));Notice that you are not required to provide an icon file (*.ico , *.icns etc.) for this function to work and you can use any (standard) image file type such as *.jpg or *.png etc. This function can be called anywhere in the program. You can use this same method along with a QTimer to ANIMATE TASKBAR ICON.
You can use the following functions to merge 2 words (16-bit) or 4 bytes (8-bit) into a 32-bit integer. There is also a function which makes a word (16-bit) using two bytes (8-bit). I am using the in my Qt/C++ projects whenever I need them but with a slight change you can use them on your non-Qt projects too.
Continue reading “How to make a 32-bit and 16-bit integers using 16-bit and 8-bit integers”
There are many cases in every cross-platform development framework that you want your source code to be built differently under different operating systems. For example you might want a method to to use platform specific functions in Windows, Linux and Mac OS X but you don’t want to have different projects for each one of them. If you are in a similar situation then you can use the following approach to have a single integrated project for all operating systems that you are developing for.
Continue reading “How to Configure a Single Qt Project for Different Operating Systems”
Frame in a window is the part of window that is crated and managed by the OS. It contains usually contains all borders and title bar of the window. To remove the frame of any window using Qt you need to use the following piece of code:
setWindowFlags(Qt::Window | Qt::FramelessWindowHint);Note that this will also cause the title bar of the window to be removed which means there will be no “close”, “minimize” and “maximize” buttons. So, you can use this same piece of code to remove all buttons from the title bar.