Tutorials Archives - Page 7 of 19

2016-09-232019-05-03

Full Featured VNC Client Widget for Qt

In this post I am going to share a Qt widget that allows full control (view and control) of VNC servers over TCP/IP. Using it is as simple as dropping a QWidget on your user interface and then promoting it to QVNCClientWidget. I needed this recently but was not able to find a Qt widget or any other Qt/C++ code for that matter, that supports VNC Authentication and can be used in a real cross-platform way. So I had to gather and write this widget piece by piece and make sure it build on all platforms supported by Qt.

2016-09-222019-05-03

How to Build Qt 5.7 Statically Using MSVC14 (Microsoft Visual Studio 2015)

In this post I will describe how to build Qt 5.7 statically for Windows using MSVC 14 compiler or in other words Microsoft Visual C++ 2015 which is included in Microsoft Visual Studio 2015. Quite obviously you need to install Microsoft Visual Studio 2015 (Community edition is free) before continuing with this guide. You can find it here: https://www.visualstudio.com/

2016-09-192019-05-03

How to Configure Qt to Use OpenCV Static Build in Linux

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
}

2016-09-192019-05-03

Build Qt Statically for Linux

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.

2016-09-192019-06-22

Build OpenCV 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.

2016-09-012019-05-03

Hello Qt, Hello OpenGL, Hello World

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.

2016-09-012019-05-03

Supported Operating Systems and Definitions in Qt

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:

2016-08-172019-05-03

How to Check if Windows is Locked in Qt/C++

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.

2016-08-052019-05-03

How to Update Your Qt Application’s Taskbar Icon at Runtime

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.

2016-08-022019-05-03

How to make a 32-bit and 16-bit integers using 16-bit and 8-bit integers

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.