Qt, Portable Infrastructure for Desktop and Mobile

Graphical interface for desktop and mobile devices, which can be found even on the facades of virtual 3D decor!

Qt (cute) is a graphical library for GUI development, a graphical user interface, multi-platform, which includes Linux, Windows, Android and iOS.
It offers graphical interface components, widgets, as well as others for accessing databases, processing XML files, and file system APIs.
A development tool, Qt Creator is offered free of charge to run Qt applications.

Qt creator
Qt Creator - specialized EDI for Qt applications

Among the main applications using Qt are Linux KDE, Opera browser (under Linux), VLC, Google Earth, Skype.

Version 5 includes the V8 compiler. The trend is to use C++ to create modules, while JavaScript is an interface language.

Version 5.4 makes the WebKit rendering engine obsolete, replaced by the Chromium-based WebEngine. With WebChannel, JavaScript and native code can communicate, and objects created in C++ can be used in an HTML application. WebSocket is also supported.

The Qt widget can be inserted into a 3D scene, as seen in the WolfenQt demo video. Using the classic Wolfenstein 3D game algorithm, you place a widget in the walls to display any application on the walls of the maze. Fast display is obtained by mixing the OpenGL graphics library with Qt code

Qt was developed by Trolltech, acquired in 2008 by Nokia. Trolltech becomes Qt Software. In August 2012, Nokia lost Qt to the Finnish company Digia, whose goal is to bring it to all platforms, including Android and Windows 8. In 2014, Digia decided to start a separate company dedicated entirely to Qt.

Qt и JavaScript

Is it possible to make a Qt program in JavaScript? This is not about using JavaScript in combination with Qt components, as Qt Quick does, but about writing JavaScript programs using Qt. This is in order to use the well-known scripting language, if you are a webmaster, at a local post with a graphical interface...

This is a node-qt module object that works with Node.js. This platform allows JavaScript to be used on the command line, and this module integrates Qt with the platform.
To use it, you must:

  1. Install Node.js.
  2. Install node-qt, with the command: npm install node-qt
    3. .
  3. Include module in script with statement:
    var qt = require('node-qt');
  4. Create an application using:
    var app = new qt.QApplication;
  5. Create a window using
    6. : 
    var window = new qt.QWidget;
  6. You can then add content to the window using the method:
    window.paintEvent(function() { ... }

All this is done by a simple text editor.

More details can be found in the node-qt material on Githube. Of course, integration into Node allows you to transfer programs of different origins to each other, since the Qt interface can coexist with HTML pages, PHP scripts, as shown in the JavaScript section of this site.

Qt and mobile devices

Nokia has developed Qt Quick for mobile and tablet PCs, a framework that offers components for creating interfaces. This lightweight version is suitable for touchscreens. It includes QML, JavaScript version, runtime for accessing system functions. The programmer can use it with Qt Creator.

After the announcement of the partnership between Nokia and Microsoft, as well as the choice of Windows Phone 7 as a preferential system for smartphones, developers are worried when Qt in the future.
However, Nokia confirmed support for Qt running on Symbian and Meego, decided to develop it by hiring new developers, but in 2012 completely split from the platform in favor of Digia.
After replacing Meego with Tizen, whose privileged interface is HTML 5, Qt becomes even more marginalized on mobile devices. However, since the interface has become compatible with Android and iOS (starting with version 5.1), it remains possible to develop for Qt for mobile devices next to the standard platform.

Knowing that Qt uses JavaScript for the interface and has embedded the V8 compiler, its interest seems to be declining on mobile devices, where you can also use Node in combination with HTML 5 to get a complete user interface (see the JavaScript section of this site).

Currently, you can run Qt applications for Android, iOS, Blackberry and it is a framework for native applications for Sailfish and Ubuntu Touch. However, the application outside Sailfish will be impressive in size.

To create Android applications with a commercial license and all included tools, a special package is offered in 2014. In fact, Qt can only really be used on mobile devices with this commercial license that the QML compiler provides.

See also

Links and Resources