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diff --git a/doc/changes.doc b/doc/changes.doc new file mode 100644 index 000000000..0f79e217a --- /dev/null +++ b/doc/changes.doc @@ -0,0 +1,453 @@ +/**************************************************************************** +** +** Change documentation +** +** Copyright (C) 1992-2008 Trolltech ASA. All rights reserved. +** +** This file is part of the Qt GUI Toolkit. +** +** This file may be used under the terms of the GNU General +** Public License versions 2.0 or 3.0 as published by the Free +** Software Foundation and appearing in the files LICENSE.GPL2 +** and LICENSE.GPL3 included in the packaging of this file. +** Alternatively you may (at your option) use any later version +** of the GNU General Public License if such license has been +** publicly approved by Trolltech ASA (or its successors, if any) +** and the KDE Free Qt Foundation. +** +** Please review the following information to ensure GNU General +** Public Licensing retquirements will be met: +** http://trolltech.com/products/qt/licenses/licensing/opensource/. +** If you are unsure which license is appropriate for your use, please +** review the following information: +** http://trolltech.com/products/qt/licenses/licensing/licensingoverview +** or contact the sales department at [email protected]. +** +** This file may be used under the terms of the Q Public License as +** defined by Trolltech ASA and appearing in the file LICENSE.QPL +** included in the packaging of this file. Licensees holding valid Qt +** Commercial licenses may use this file in accordance with the Qt +** Commercial License Agreement provided with the Software. +** +** This file is provided "AS IS" with NO WARRANTY OF ANY KIND, +** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted +** herein. +** +**********************************************************************/ + +/*! +\page keyfeatures30.html + +\title Key Features in Qt 3.0 + +Qt 3.0 adds a lot of new features and improvements over the Qt 2.x +series. Some internals have undergone major redesign and new classes +and methods have been added. + +We have tried to keep the API of Qt 3.0 as compatible as possible with +the Qt 2.x series. For most applications only minor changes will be +needed to compile and run them successfully using Qt 3.0. + +One of the major new features that has been added in the 3.0 release +is a module allowing you to easily work with databases. The API is +platform independent and database neutral. This module is seamlessly +integrated into Qt Designer, greatly simplifying the process of +building database applications and using data aware widgets. + +\omit +Other major new features include a component architecture allowing you +to build cross platform components, 'plugins' with Qt. +\endomit +Other major new features include a plugin architecture. You can use +your own and third party plugins your own applications. +The Unicode support of Qt 2.x has been greatly enhanced, it now +includes full support for scripts written from right to left (e.g. +Arabic and Hebrew) and also provides improved support for Asian +languages. + +Many new classes have been added to the Qt Library. Amongst them are +classes that provide a docking architecture +(\l{QDockArea}/\l{QDockWindow}), a powerful rich text editor +(QTextEdit), a class to store and access application settings +(QSettings) and a class to create and communicate with processes +(QProcess). + +Apart from the changes in the library itself a lot has been done to +make the development of Qt applications with Qt 3.0 even easier than +before. Two new applications have been added: Qt Linguist is a tool to +help you translate your application into different languages; Qt +Assistant is an easy to use help browser for the Qt documentation that +supports bookmarks and can search by keyword. + +Another change concerns the Qt build system, which has been reworked +to make it a lot easier to port Qt to new platforms. You can use this +platform independent build system for your own applications. + + +\section1 The Qt Library + +A large number of new features has been added to Qt 3.0. The following +list gives an overview of the most important new and changed aspects +of the Qt library. A full list of every new method follows the +overview. + + +\section2 Database support + +One of the major new features in Qt 3.0 is the \link sql.html SQL +module\endlink that provides multiplatform access to SQL databases, +making database application programming with Qt seamless and portable. +The API, built with standard SQL, is database-neutral and software +development is independent of the underlying database. + +A collection of tightly focused C++ classes are provided to give the +programmer direct access to SQL databases. Developers can send raw SQL +to the database server or have the Qt SQL classes generate SQL queries +automatically. Drivers for Oracle, PostgreSQL, MySQL and ODBC are +available and writing new drivers is straightforward. + +Tying the results of SQL queries to GUI components is fully supported +by Qt's SQL widgets. These classes include a tabular data widget +(for spreadsheet-like data presentation with in-place editing), a +form-based data browser (which provides data navigation and edit +functions) and a form-based data viewer (which provides read-only +forms). This framework can be extended by using custom field editors, +allowing for example, a data table to use custom widgets for in-place +editing. The SQL module fully supports Qt's signal/slots mechanism, +making it easy for developers to include their own data validation and +auditing code. + +Qt Designer fully supports Qt's SQL module. All SQL widgets can be +laid out within Qt Designer, and relationships can be established +between controls visually. Many interactions can be defined purely in +terms of Qt's signals/slots mechanism directly in Qt Designer. + +\omit +\section2 Component model - plugins + +The QLibrary class provides a platform independent wrapper for runtime +loading of shared libraries. Access to the shared libraries uses a +COM-like interface. QPluginManager makes it trivial to implement +plugin support in applications. The Qt library is able to load +additional styles, database drivers and text codecs from plugins which +implement the relevant interfaces, e.g. QStyleFactoryInterface, +QSqlDriverInterface or QTextCodecInterface. It is possible to remove +unused components from the Qt library, and easy to extend any +application with 3rd party styles, database drivers or text codecs. + +Qt Designer supports custom widgets in plugins, and will use the +widgets both when designing and previewing forms. + +QComponentFactory makes it easy to register any kind of component in a +global database (e.g. the Windows Registry) and to use any registered +component. +\endomit +\section2 Plugins + +The QLibrary class provides a platform independent wrapper for runtime +loading of shared libraries. QPluginManager makes it trivial to implement +plugin support in applications. The Qt library is able to load +additional styles, database drivers and text codecs from plugins. + +Qt Designer supports custom widgets in plugins, and will use the +widgets both when designing and previewing forms. + +See the \link plugins-howto.html plugins documentation\endlink. + + +\section2 Rich text engine and editor + +The rich text engine originally introduced in Qt 2.0 has been further +optimized and extended to support editing. It allows editing formatted +text with different fonts, colors, paragraph styles, tables and +images. The editor supports different word wrap modes, command-based +undo/redo, multiple selections, drag and drop, and many other +features. The new QTextEdit engine is highly optimized for proccesing +and displaying large documents tquickly and efficiently. + + +\section2 Unicode + +Apart from the rich text engine, another new feature of Qt 3.0 that +relates to text handling is the greatly improved Unicode support. Qt +3.0 includes an implementation of the bidirectional algorithm (BiDi) +as defined in the Unicode standard and a shaping engine for Arabic, +which gives full native language support to Arabic and Hebrew speaking +people. At the same time the support for Asian languages has been +greatly enhanced. + +The support is almost transparent for the developer using Qt to +develop their applications. This means that developers who developed +applications using Qt 2.x will automatically gain the full support for +these languages when switching to Qt 3.0. Developers can rely on their +application to work for people using writing systems different from +Latin1, without having to worry about the complexities involved with +these scripts, as Qt takes care of this automatically. + + +\section2 Docked and Floating Windows + +Qt 3.0 introduces the concept of Dock Windows and Dock Areas. Dock +windows are widgets, that can be attached to, and detached from, dock +areas. The commonest kind of dock window is a tool bar. Any number of +dock windows may be placed in a dock area. A main window can have dock +areas, for example, QMainWindow provides four dock areas (top, left, +bottom, right) by default. The user can freely move dock windows and +place them at a convenient place in a dock area, or drag them out of +the application and have them float freely as top level windows in +their own right. Dock windows can also be minimized or hidden. + +For developers, dock windows behave just like ordinary widgets. QToolbar +for example is now a specialized subclass of a dock window. The API +of QMainWindow and QToolBar is source compatible with Qt 2.x, so +existing code which uses these classes will continue to work. + + +\section2 Regular Expressions + +Qt has always provided regular expression support, but that support +was pretty much limited to what was retquired in common GUI control +elements such as file dialogs. Qt 3.0 introduces a new regular +expression engine, QRegExp, that supports most of Perl's regex +features and is Unicode based. The most useful additions are support +for parentheses (capturing and non-capturing) and backreferences. + + +\section2 Storing application settings + +Most programs will need to store some settings between runs, for +example, user selected fonts, colors and other preferences, or a list +of recently used files. The new QSettings class provides a platform +independent way to achieve this goal. The API makes it easy to store +and retrieve most of the basic data types used in Qt (such as basic +C++ types, strings, lists, colors, etc). The class uses the registry +on the Windows platform and traditional resource files on Unix. + + +\section2 Creating and controlling other processes + +QProcess is a class that allows you to start other programs from +within a Qt application in a platform independent manner. It gives you +full control over the started program, for example you can redirect +the input and output of console applications. + + +\section2 Accessibility + +Accessibility means making software usable and accessible to a wide +range of users, including those with disabilities. In Qt 3.0, most +widgets provide accessibility information for assistive tools that can +be used by a wide range of disabled users. Qt standard widgets like +buttons or range controls are fully supported. Support for complex +widgets, like e.g. QListView, is in development. Existing applications +that make use of standard widgets will become accessible just by using +Qt 3.0. + +Qt uses the Active Accessibility infrastructure on Windows, and needs +the MSAA SDK, which is part of most platform SDKs. With improving +standardization of accessibility on other platforms, Qt will support +assistive technologies on other systems, too. + + +\section2 XML Improvements + +The XML framework introduced in Qt 2.2 has been vastly improved. Qt +2.2 already supported level 1 of the Document Object Model (DOM), a +W3C standard for accessing and modifying XML documents. Qt 3.0 has +added support for DOM Level 2 and XML namespaces. + +The XML parser has been extended to allow incremental parsing of XML +documents. This allows you to start parsing the document directly +after the first parts of the data have arrived, and to continue +whenever new data is available. This is especially useful if the XML +document is read from a slow source, e.g. over the network, as it +allows the application to start working on the data at a very early +stage. + + +\section2 SVG support + +SVG is a W3C standard for "Scalable Vector Graphics". Qt 3.0's XML +support means that QPicture can optionally generate and import static +SVG documents. All the SVG features that have an equivalent in +QPainter are supported. + + +\section2 Multihead support + +Many professional applications, such as DTP and CAD software, are able +to display data on two or more monitors. In Qt 3.0 the QDesktopWidget +class provides the application with runtime information about the +number and geometry of the desktops on the different monitors and such +allows applications to efficiently use a multi-monitor setup. + +The virtual desktop of Mac OS X, Windows 98, and 2000 is supported, as well +as the traditional multi-screen and the newer Xinerama multihead setups on +X11. + + +\section2 X11 specific enhancements + +Qt 3.0 now complies with the NET WM Specification, recently adopted +by KDE 2.0. This allows easy integration and proper execution with +desktop environments that support the NET WM specification. + +The font handling on X11 has undergone major changes. QFont no longer +has a one-to-one relation with window system fonts. QFont is now a +logical font that can load multiple window system fonts to simplify +Unicode text display. This completely removes the burden of +changing/setting fonts for a specific locale/language from the +programmer. For end-users, any font can be used in any locale. For +example, a user in Norway will be able to see Korean text without +having to set their locale to Korean. + +Qt 3.0 also supports the new render extension recently added to +XFree86. This adds support for anti aliased text and pixmaps with +alpha channel (semi transparency) on the systems that support the +rendering extension (at the moment XFree 4.0.3 and later). + + +\section2 Printing + +Printing support has been enhanced on all platforms. The QPrinter +class now supports setting a virtual resolution for the painting +process. This makes WYSIWYG printing trivial, and also allows you to +take full advantage of the high resolution of a printer when painting +on it. + +The postscript driver built into Qt and used on Unix has been greatly +enhanced. It supports the embedding of true/open type and type1 fonts +into the document, and can correctly handle and display Unicode. +Support for fonts built into the printer has been enhanced and Qt now +knows about the most common printer fonts used for Asian languages. + + +\section2 QHttp + +This class provides a simple interface for HTTP downloads and uploads. + + +\section2 Compatibility with the Standard Template Library (STL) + +Support for the C++ Standard Template Library has been added to the +\link qt-template-lib.html Qt Template Library (QTL)\endlink. The QTL +classes now contain appropriate copy constructors and typedefs so that +they can be freely mixed with other STL containers and algorithms. In +addition, new member functions have been added to QTL template classes +which correspond to STL-style naming conventions (e.g., push_back()). + + +\section1 Qt Designer + +\link designer-manual.book Qt Designer\endlink was a pure dialog +editor in Qt 2.2 but has now been extended to provide the full +functionality of a GUI design tool. + +This includes the ability to lay out main windows with menus and +toolbars. Actions can be edited within Qt Designer and then plugged +into toolbars and menu bars via drag and drop. Splitters can now be +used in a way similar to layouts to group widgets horizontally or +vertically. + +In Qt 2.2, many of the dialogs created by Qt Designer had to be +subclassed to implement functionality beyond the predefined signal and +slot connections. Whilst the subclassing approach is still fully supported, +Qt Designer now offers an alternative: a plugin for editing +slots. The editor offers features such as syntax highlighting, +completion, parentheses matching and incremental search. + +The functionality of Qt Designer can now be extended via plugins. +Using Qt Designer's interface or by implementing one of the provided +interfaces in a plugin, a two way communication between plugin and Qt +Designer can be established. This functionality is used to implement +plugins for custom widgets, so that they can be used as real widgets +inside the designer. + +Basic support for project management has been added. This allows you +to read and edit *.pro files, add and remove files to/from the project +and do some global operations on the project. You can now open the +project file and have one-click access to all the *.ui forms in the +project. + +In addition to generating code via uic, Qt Designer now supports the +dynamic creation of widgets directly from XML user interface +description files (*.ui files) at runtime. This eliminates the need of +recompiling your application when the GUI changes, and could be used +to enable your customers to do their own customizations. Technically, +the feature is provided by a new class, QWidgetFactory in the +QResource library. + + +\section1 Qt Linguist + +\link linguist-manual.book Qt Linguist\endlink is a GUI utility to +support translating the user-visible text in applications written with +Qt. It comes with two command-line tools: lupdate and lrelease. + +Translation of a Qt application is a three-step process: + +\list + \i Run lupdate to extract user-visible text from the C++ source + code of the Qt application, resulting in a translation source file + (a *.ts file). + \i Provide translations for the source texts in the *.ts file using + Qt Linguist. + \i Run lrelease to obtain a light-weight message file (a *.qm file) + from the *.ts file, which provides very fast lookup for released + applications. +\endlist + +Qt Linguist is a tool suitable for use by translators. Each +user-visible (source) text is characterized by the text itself, a +context (usually the name of the C++ class containing the text), and +an optional comment to help the translator. The C++ class name will +usually be the name of the relevant dialog, and the comment will often +contain instructions that describe how to navigate to the relevant +dialog. + +You can create phrase books for Qt Linguist to provide common +translations to help ensure consistency and to speed up the +translation process. Whenever a translator navigates to a new text to +translate, Qt Linguist uses an intelligent algorithm to provide a list +of possible translations: the list is composed of relevant text from +any open phrase books and also from identical or similar text that has +already been translated. + +Once a translation is complete it can be marked as "done"; such +translations are included in the *.qm file. Text that has not been +"done" is included in the *.qm file in its original form. Although Qt +Linguist is a GUI application with dock windows and mouse control, +toolbars, etc., it has a full set of keyboard shortcuts to make +translation as fast and efficient as possible. + +When the Qt application that you're developing evolves (e.g. from +version 1.0 to version 1.1), the utility lupdate merges the source +texts from the new version with the previous translation source file, +reusing existing translations. In some typical cases, lupdate may +suggest translations. These translations are marked as unfinished, so +you can easily find and check them. + + +\section1 Qt Assistant + +Thanks to the positive feedback we received about the help system +built into \link designer-manual.book Qt Designer\endlink, we decided +to offer this part as a separate application called \link +assistant.book Qt Assistant\endlink. Qt Assistant can be used to +browse the Qt class documentation as well as the manuals for Qt +Designer and Qt Linguist. It offers index searching, a contents +overview, bookmarks history and incremental search. Qt Assistant is +used by both Qt Designer and Qt Linguist for browsing their help +documentation. + + +\section1 qmake + +To ease portability we now provide the \link qmake-manual.book +qmake\endlink utility to replace tmake. QMake is a C++ version of +tmake which offers additional functionallity that is difficult to +reproduce in tmake. Trolltech uses qmake in its build system for Qt +and related products and we have released it as free software. + +*/ |