Citizendia

Qt

The Qt designer used for GUI designing
Developed byTrolltech
Latest release4. A software developer is a person or organization concerned with facets of the software development process wider than design and coding a somewhat broader scope of A software release is the distribution whether public or private of an initial or new and upgraded version of a Computer software product 4. 0 / May 6, 2008 (2008-05-06); 38 days ago
Written inC++
OSCross-platform
GenreWidget toolkit
LicenseGPL 2/3
Q Public License
Proprietary
Websitehttp://trolltech.com/products/qt/

Qt (pronounced "cute"[1]) is a cross-platform application development framework, widely used for the development of GUI programs (in which case it is known as a Widget toolkit), and also used for developing non-GUI programs such as console tools and servers. Events 1527 - Spanish and German troops sack Rome; some consider this the end of the Renaissance. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common A programming language is an Artificial language that can be used to write programs which control the behavior of a machine particularly a Computer. C++ (" C Plus Plus " ˌsiːˌplʌsˈplʌs is a general-purpose Programming language. An operating system (commonly abbreviated OS and O/S) is the software component of a Computer system that is responsible for the management and coordination In computing cross-platform (also known as multi-platform) is a term used to refer to Computer software or computing methods and concepts that are implemented Computer software can be organized into categories based on common function type or field of use A widget toolkit, widget library, or GUI toolkit is a set of widgets for use in designing applications with Graphical user interfaces (GUIs A software license (or software licence in commonwealth usage is a Legal instrument governing the usage or redistribution of copyright protected software The Q Public License ( QPL) is a non- Copyleft Free software license created by Trolltech for its free edition of the Qt toolkit Proprietary software is Computer software on which the producer has set restrictions on use private modification copying, or republishing. A website (alternatively web site or Web site, a back-construction from the Proper noun World Wide Web) is a collection of Web pages In computing cross-platform (also known as multi-platform) is a term used to refer to Computer software or computing methods and concepts that are implemented A widget toolkit, widget library, or GUI toolkit is a set of widgets for use in designing applications with Graphical user interfaces (GUIs Qt is most notably used in KDE, the web browser Opera, Google Earth, Skype, Qtopia, Photoshop Elements and OPIE. KDE ( K Desktop Environment) (ˌkeɪdiːˈiː is a Free software project which aims to be a powerful system for an easy-to-use Desktop environment. Opera is a Web browser and Internet suite developed by the Opera Software company Google Earth is a Virtual globe program that was originally called Earth Viewer and was created by Keyhole Inc, a company acquired by Google in 2004 Skype (skaɪp is Software that allows users to make telephone calls over the Internet. Adobe Photoshop Elements is the consumer version of the Adobe Photoshop Raster image editing product sold at a fraction (roughly 1/6th of the cost of the professional OPIE (Open Palmtop Integrated Environment is a completely Open source based Graphical user interface for PDAs and other devices running Linux It is produced by the Norwegian company Trolltech. Norway ( Norwegian: Norge ( Bokmål) or Noreg ( Nynorsk) officially the Kingdom of Norway, is a Constitutional Nokia made an offer to acquire Trolltech on January 28, 2008[2] and Trolltech has accepted that offer [3]. Nokia Corporation (pronunciation /'nɔkiɑ/),,) is a Finnish multinational Communications Corporation, headquartered Events 1077 - Walk to Canossa: The Excommunication of Henry IV Holy Roman Emperor is lifted 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common

Qt uses C++ with several non-standard extensions implemented by an additional pre-processor that generates standard C++ code before compilation. C++ (" C Plus Plus " ˌsiːˌplʌsˈplʌs is a general-purpose Programming language. Qt can also be used in several other programming languages; bindings exist for Ada[4], C#[5], Java[6], Pascal, Perl, PHP (PHP-Qt), Ruby (RubyQt), and Python (PyQt). In computing a binding from a language to a library or OS service is an API providing that service in the language Ada is a structured, Statically typed, imperative, and object-oriented high-level computer Programming language C# (pronounced C Sharp is a Multi-paradigm Pascal is an influential imperative and procedural Programming language, designed in 1968/9 and published in 1970 by Niklaus Wirth as a small NOTES FOR EDITORS "Perl" is not an acronym (read the "Name" section below PHP is a computer Scripting language. Originally designed for producing Dynamic web pages it has evolved to include a Command line interface capability Matz's Ruby Interpreter or Ruby MRI is the reference implementation of the Ruby programming language. Python is a general-purpose High-level programming language. Its design philosophy emphasizes programmer productivity and code readability PyQt is the Python binding of the GUI toolkit Qt. PyQt is developed by the British firm Riverbank Computing It runs on all major platforms, and has extensive internationalization support. In Computing, Internationalization and localization (also spelled internationalisation and localisation, see spelling differences) are means of adapting Non-GUI features include SQL database access, XML parsing, thread management, network support and a unified cross-platform API for file handling. Don't change "Extensible" A thread in Computer science is short for a thread of execution.

Contents

Varieties

Qt is released by Trolltech on the following platforms:

Qt is also available for embedded devices as Qtopia. Windows CE (also known officially as Windows Embedded Compact post version 6

There are four editions of Qt available on each of these platforms, namely:

Qt is available under a dual license, the GPL v2 or v3 with special exception[9] and a proprietary commercial license on all supported platforms. Dual-licensing is the practice of distributing Software under two different sets of terms and conditions The commercial license allows the final application to be licensed under various free software/open source licenses such as the LGPL or the Artistic License, or a proprietary software license. A free software licence is a Software licence which grants recipients rights to modify and redistribute the Software which would otherwise be prohibited by Copyright An open source license is a copyright License for Computer software that makes the source code available under terms that allow for modification and redistribution The GNU Lesser General Public License (formerly the GNU Library General Public License) or LGPL is a Free software license published by the Free Software Artistic license (also known as dramatic license, poetic license, narrative license, licentia poetica, or simply license) is a colloquial Proprietary software is Computer software on which the producer has set restrictions on use private modification copying, or republishing.

All editions support a wide range of compilers, including the GCC C++ compiler and Visual Studio suite. The GNU Compiler Collection (usually shortened to GCC) is a set of Compilers produced for various Programming languages by the GNU Project Microsoft Visual Studio is the main Integrated Development Environment (IDE from Microsoft.

Current

Trolltech released Qt 4 on June 28, 2005 and introduced five new technologies in the framework:

Qt 4. 1, released on December 19, 2005, introduced integrated SVG Tiny support, a PDF backend to Qt's printing system, and a few other features. Events 324 - Licinius abdicates his position as Roman Emperor. Year 2005 ( MMV) was a Common year starting on Saturday (link displays full calendar of the Gregorian calendar.

Qt 4. 2, released on October 4, 2006, introduced Windows Vista support, introduced native CSS support for widget styling, as well as the QGraphicsView framework for efficient rendering of thousands of 2D objects onscreen, to replace Qt 3. Events 610 - Heraclius arrives by ship from Africa at Constantinople, overthrows Byzantine Emperor Phocas Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Windows Vista (ˈvɪstə is a line of Operating systems developed by Microsoft for use on Personal computers including home and business desktops x's QCanvas class.

Qt 4. 3, released on May 30, 2007, improved Windows Vista support, improved OpenGL engine, SVG file generation, added QtScript (ECMAScript scripting engine based on QSA). Events 1416 - The Council of Constance, called by the Emperor Sigismund a supporter of Antipope John XXIII burns Jerome of Prague following Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Windows Vista (ˈvɪstə is a line of Operating systems developed by Microsoft for use on Personal computers including home and business desktops OpenGL ( Open G raphics L ibrary is a standard specification defining a cross-language Cross-platform API for writing applications that produce ECMAScript is a Scripting language, standardized by Ecma International in the ECMA-262 specification. [10] The latest release is Qt 4.3.4.

Qt 4. 4, released on May 6, 2008. Events 1527 - Spanish and German troops sack Rome; some consider this the end of the Renaissance. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Features included are improved multimedia support using Phonon, enhanced XML support, a concurrency framework to ease the development of multi-threaded applications, an IPC framework with a focus on shared memory, and WebKit integration. Phonon is the multimedia API for KDE 4. Phonon was created to allow KDE 4 to be independent of any single multimedia framework such as GStreamer or Don't change "Extensible" A thread in Computer science is short for a thread of execution. Inter-Process Communication ( IPC) is a set of techniques for the exchange of data among two or more threads in one or more processes. WebKit is an Open source Application framework that provides a foundation upon which to build a Web browser.

History

Haavard Nord and Eirik Chambe-Eng (the original developers of Qt and the CEO and President, respectively, of Trolltech) began development of "Qt" in 1991, three years before the company was incorporated as Quasar Technologies, then changed the name to Troll Tech, and then to Trolltech. Year 1991 ( MCMXCI) was a Common year starting on Tuesday (link will display full calendar of the Gregorian Calendar.

The toolkit was called Qt because the letter Q looked appealing in Haavard's Emacs font, and "t" was inspired by Xt, the X toolkit. Q is the seventeenth letter of the modern Latin alphabet. Its name in English is spelled cue (kjuː Emacs is a class of feature-rich Text editors usually characterized by their extensibility Intrinsics (also known as Xt, for X toolkit is a library used in the X Window System. [11]

Controversy erupted around 1998 when it became clear that KDE was going to become one of the leading desktop environments for Linux. Year 1998 ( MCMXCVIII) was a Common year starting on Thursday (link will display full 1998 Gregorian calendar) In graphical computing a desktop environment ( DE) commonly refers to a style of Graphical user interface (GUI that is based on the Desktop metaphor which Linux (commonly pronounced ˈlɪnəks As KDE was based on Qt, many people in the free software movement worried that an essential piece of one of their major operating systems would be proprietary. The free software movement (also known as open source movement, free and open source software movement and abbreviated FSM OSM or FOSSM) is a relatively

This gave rise to two efforts: the Harmony toolkit, which sought to duplicate the Qt Toolkit under a free software license, and the GNOME desktop, which intended to supplant KDE entirely. The Harmony toolkit is a never-completed Free software Widget toolkit that aimed to be API compatible with the then- proprietary Qt A free software licence is a Software licence which grants recipients rights to modify and redistribute the Software which would otherwise be prohibited by Copyright A gnome is a Mythical creature characterized by its extremely small size and subterranean lifestyle The GNOME Desktop uses the GTK+ toolkit, which was originally written for the GIMP, and primarily uses the C programming language. GTK+, or The GIMP Toolkit, is a Cross-platform Widget toolkit for creating Graphical user interfaces It is one of the most popular toolkits The GNU Image Manipulation Program, or GIMP, is a free Raster graphics editor used to process digital graphics and photographs tags please moot on the talk page first! --> In Computing, C is a general-purpose cross-platform block structured

Until version 1. 45, source code for Qt was released under the FreeQt license — which was viewed as not compliant with the open source principle by the Open Source Initiative and the free software definition by Free Software Foundation, because while the source was available it did not allow the redistribution of modified versions. The Open Source Initiative is an organization dedicated to promoting Open-source software. The Free Software Foundation ( FSF) is a Non-profit corporation founded by Richard Stallman on 4 October 1985 to support the Free software movement With the release of version 2. 0 of the toolkit, the license was changed to the Q Public License (QPL), a free software license but one regarded by the Free Software Foundation as incompatible with the GPL. The Q Public License ( QPL) is a non- Copyleft Free software license created by Trolltech for its free edition of the Qt toolkit Free software or software libre is Software that can be used studied and modified without restriction and which can be copied and redistributed in modified or unmodified The Free Software Foundation ( FSF) is a Non-profit corporation founded by Richard Stallman on 4 October 1985 to support the Free software movement Compromises were sought between KDE and Trolltech whereby Qt would not be able to fall under a more restrictive license than the QPL, even if Trolltech was bought out or went bankrupt. This led to the creation of the KDE Free Qt foundation, which guarantees that Qt would fall under a BSD-style license should no free software/open source version of Qt be released during 12 months. BSD licenses represent a family of Permissive free software licences.

The first two versions of Qt had only two flavours: Qt/X11 for Unix and Qt/Windows for the Windows platform. The Windows platform was only available under the proprietary license which meant free/open source applications written in Qt for X11 could not be ported to Windows without purchasing the QPL edition. In the end of 2001, Trolltech released Qt 3. 0 which added support for the Mac OS X platform. The Mac OS X support was available only in the proprietary license, until June 2003, where Trolltech released Qt 3. 2 with Mac OS X support available under the GPL.

In 2002 members of the KDE on Cygwin project began porting the GPL licensed Qt/X11 code base to Windows[12]. KDE on Cygwin is the port of Qt and KDE Desktop environment (both of which are commonly distributed natively in Linux Operating systems This was in response to Trolltech's refusal to license Qt/Windows under the GPL on the grounds that Windows was not a free software/open source platform[13][14]. The project achieved reasonable success although it never reached production quality.

This was resolved when Trolltech released Qt/Windows 4 under the GPL in June 2005. Qt 4 now supports the same set of platforms in the free software/open source editions as in the proprietary edition, so it is now possible to create GPL-licensed free/open source applications using Qt on all supported platforms.

Design

The innovation of Qt when it was first released relied on a few key concepts.

Use of native UI-rendering APIs

Qt used to emulate the native look of its intended platforms, which occasionally led to slight discrepancies where that emulation wasn't perfect. Recent versions of Qt use the native APIs of the different platforms to draw the Qt controls, and so do not suffer from such issues. (See also wxWidgets, which relies on native APIs for most widget functionality. )

Meta object compiler

Known as the moc, this is a tool that is run on the sources of a Qt program prior to compiling it. The tool will generate "Meta Information" about the classes used in the program. This meta information is used by Qt to provide programming features not available in C++: The signal/slot system, introspection and asynchronous function calls. Signals and slots is a language construct introduced in Qt, which makes it easy to implement the Observer pattern while avoiding boilerplate code. In Computing, type introspection is a capability of some Object-oriented programming languages to determine the type of an object at Runtime

The use of an additional tool has been criticized for making Qt programming different from pure C++ programming. In particular, the choice of an implementation based on macros has been criticized for its absence of type safety and pollution of the namespace. This is viewed by Trolltech as a necessary trade-off to provide introspection and the dynamically generated slot and signal mechanism.

QtScript JavaScript interpreter

Qt Script for Applications is a cross-platform toolkit that allows developers to make their Qt/C++ applications scriptable using an interpreted scripting language: Qt Script (based on ECMAScript/JavaScript). JavaScript is a Scripting language most often used for Client-side web development

From Qt 4. 3. 0 onward, the scripting API [15], which is based on QSA [16] is integrated as a core part of Qt and is no longer a separate library.

Applications built using Qt

Popular examples of applications which use Qt include:

See also

References

  1. ^ Interview with Trolltech president Eirik Eng on dot. Low-level widget toolkits Integrated in the Operating system The Mac OS toolbox, or Macintosh APIs formerly located kde. org
  2. ^ News release announcing Nokia's offer to acquire Qt-developer Trolltech
  3. ^ Nokia to acquire Trolltech to accelerate software strategy (en) (2008-01-28). 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1077 - Walk to Canossa: The Excommunication of Henry IV Holy Roman Emperor is lifted Retrieved on 2008-01-28. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1077 - Walk to Canossa: The Excommunication of Henry IV Holy Roman Emperor is lifted
  4. ^ QtAda, Ada 2005 bindings for Qt
  5. ^ The Qyoto / Kimono Project, a . Net and C# bindings for Qt
  6. ^ Qt Jambi, Java bindings for Qt from Trolltech
  7. ^ Qt for Windows CE Technology Preview Download — Trolltech
  8. ^ The ActiveQt class for ActiveX on Windows, for example, is not available in the Open Source Edition
  9. ^ Trolltech GPL Exception version 1.2
  10. ^ Trolltech: What’s New in Qt 4.3
  11. ^ A Brief History of Qt. ActiveX is a Component object model (COM developed by Microsoft for Windows. Retrieved on 2007-12-20. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 69 - Vespasian, formerly a general under Nero, enters Rome to claim the title of Emperor.
  12. ^ Q../Windows Edition history, 5 June 2006
  13. ^ E-mail to the kde-cygwin mailing list by Chris January, 4 February 2003
  14. ^ Qt Non-commercial FAQ, 5 October 2003
  15. ^ Qt 4.3: QtScript Module
  16. ^ QSA 1.2: Qt Script for Applications
  17. ^ Opera is not based on Qt. Retrieved on 2008-05-20. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 325 - The First Council of Nicaea &ndash the first Ecumenical Council of the Christian Church is held
  18. ^ TOra uses the Qt library

External links

© 2009 citizendia.org; parts available under the terms of GNU Free Documentation License, from http://en.wikipedia.org
 Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic