Qt 5.2 introduces many new features and improvements as well as bugfixes
over the 5.1.x series. For more details, refer to the online documentation
included in this distribution. The documentation is also available online:

  http://qt-project.org/doc/qt-5.2

The Qt version 5.2 series is binary compatible with the 5.1.x series.
Applications compiled for 5.1 will continue to run with 5.2.

Some of the changes listed in this file include issue tracking numbers
corresponding to tasks in the Qt Bug Tracker:

  http://bugreports.qt-project.org/

Each of these identifiers can be entered in the bug tracker to obtain more
information about a particular change.

****************************************************************************
*                   Important Behavior Changes                             *
****************************************************************************

 - Qt is now compiled with qreal typedef'ed to double on all
   platforms. qreal was a float on ARM chipsets before. This guarantees more
   consistent behavior between all platforms Qt supports, but is binary
   incompatible to Qt 5.1 on ARM. The old behavior can be restored by
   passing -qreal float to configure.
 - The supported date range in QDateTime has been reduced to about +/- 292
   million years, the range supported by the number of msecs since the Unix
   epoch of 1 Jan 1970 as stored in a qint64, and as able to be used in the
   setMSecsSinceEpoch() and toMSecsSinceEpoch() methods.

 - QUrl and QUrlQuery:
   * [QTBUG-31660] QUrl no longer considers all delimiter characters
     equivalent to their percent-encoded forms. Now, both classes always
     keep all delimiters exactly as they were in the original URL text.
   * [QTBUG-31660] QUrl no longer decodes %7B and %7D to "{" and "}" in the
     output of toString()
   * QUrl no longer supports QUrl::FullyDecoded mode in authority() and
     userInfo(), nor QUrl::DecodedMode in setAuthority() and setUserInfo().
   * [QTBUG-31945] QUrl no longer decodes %23 found in the fragment to "#"
     in the output of toString(QUrl::FullyEncoded) or toEncoded()
   * QUrl now defaults to decoded mode in the getters and setters for
     userName, password, host, topLevelDomain, path and fileName. This
     means a '%' in one of those fields is now returned (or set) as '%'
     rather than "%25". In the unlikely case where the former behavior was
     expected, pass PrettyDecoded to the getter and TolerantMode to the
     setter.
   * QUrl now normalizes the path given in setPath, removing ./ and ../ and
     duplicate slashes.

****************************************************************************
*                          Library                                         *
****************************************************************************

QtCore
------

 - Added QCollator, a class to collate Unicode strings.
 - Added QCommandLineParser, a class to parse command lines.
 - Added QFileSelector, a class to select platform-specific file assets.
 - Added QLoggingCategory and related functions for logging
 - [QTBUG-23946] Fixed a bug that prevented Qt from being built in a
   namespace on Mac OS X.
 - Updated the locale database to CLDR 23.1
 - Added support for ARMv8 64-bit mode.

 - Metatype system (QMetaType & QVariant):
   * Qt now handles metatypes automatically for std::vector, std::list,
     std::pair and std::map
   * The metatype system now supports registering explicit conversion
     functions via QMetaType::registerConverter
   * The metatype system now supports iteration over a container type via
     QSequentialIterable and QAssociativeIterable
   * Registering the same type name twice will now print only a warning (as
     opposed to aborting the execution of the program)

 - Qt Containers:
   * In debug mode, the Qt containers will now verify whether the iterators
     passed to most mutating functions belong to the iterator in question.
   * Fixed a number of bugs that would modify shared containers when calling
     erase(), under corner-case conditions.

- QtAlgorithms
  With STL no longer being optional for building and using Qt, a number of parts
  of QtAlgorithms no longer make sense, and have therefore been deprecated.

  Replacements are available in the STL, and generally have much better
  performance, but are not instantly source-compatible in all cases. For
  instance, specialization of qLess or qSwap means that a direct port to
  std::sort from qSort may not be possible, as std::sort does not use any of
  them; a possible workaround is explicitly passing a qLess functor to
  std::sort:

      std::sort(container.begin(), container.end(), qLess<T>());

  The functions in QtAlgorithms that have been deprecated, along with their
  STL counterparts, are:
    - qBinaryFind (std::binary_search / std::lower_bound)
    - qCopy (std::copy)
    - qCopyBackward (std::copy_backward)
    - qEqual (std::equal)
    - qFill (std::fill)
    - qFind (std::find)
    - qCount (std::count)
    - qSort (std::sort)
    - qStableSort (std::stable_sort)
    - qLowerBound (std::lower_bound)
    - qUpperBound (std::upper_bound)
    - qLess (std::less)
    - qGreater (std::greater)

 - QByteArray:
   * Added QByteArray::Base64Url and QByteArray::OmitTrailingEquals flags
     for QByteArray::toBase64 and fromBase64.
   * [QTBUG-34694] Fixed a bug that would cause QByteArray to overflow some
     size calculations.

 - QCoreApplication:
   * [QTBUG-15379][QTBUG-30628] Fixed a bug that caused Qt to mis-parse a
     command-line argument like -DKEY=\"VALUE\" on Windows.

 - QDateTime:
   * [QTBUG-26161][QTBUG-29666] Fully implement support for Qt::TimeSpec of
     Qt::OffsetFromUTC, added new methods for offsetFromUTC(),
     toTimeSpec(), and toOffsetFromUTC().
   * Added convenience methods for fromMSecsSinceEpoch() and fromTime_t()
     to take time spec to be used in returned datetime.
   * Add method timeZoneAbbreviation() to return effective time zone
     abbreviation.
   * The debug datastream is now an ISO-like format instead of Qt::TextDate
   * The Standard Time to Daylight Time transition for Qt::LocalTime is now
     handled correctly. Any date set in the "missing" hour is now
     considered invalid. All date math results that fall into the missing
     hour will be automatically adjusted to a valid time in the following
     hour.
   * Added new method isDaylightTime() to return if the datetime is in
     Daylight Time or not.
   * Added support for a new Qt::TimeZone spec to be used with QTimeZone to
     define times in a specific time zone.
   * Added Qt::RFC2822Date format that can be passed to QDateTime and
     QLocale formatters and parsers.
   * Fixed a bug that caused QDate::toString() to return empty for dates
     with years beyond 9999.

 - QFileSystemWatcher:
   * [QTBUG-33211] Fixed a bug that caused QFileSystemWatcher to emit change
     notifications with the wrong path on Linux.

 - QJson:
   * [QTBUG-33229] The Writer and the Parser now fully accept non-character
     unicode points.
   * The Writer will no longer write inf, -inf and nan for infinites and NaN
     values, which resulted in parsing back as strings. Instead, it will now
     output null.
   * The Writer now emits numeric values with full numeric precision. This
     also allows QJson to support integer values with no loss of precision
     up to 2^53.

 - QJsonValue:
   * Added QJsonValue::toInt(). QJsonValue can store 32-bit signed integers
     with no loss of precision.

 - QObject:
   * New-style signal connections to functors, lambdas, and static functions
     now works with a receiver object. The connection will be removed when
     the either the sender or receiver objects are destroyed.

 - QPluginLoader:
   * QPluginLoader will no longer load the plugins on Mac OS X and iOS
     systems when scanning for valid plugins.
   * Added QPluginLoader::staticPlugins(), which returns the list of
     built-in plugins (linked to the executable and any loaded libraries).

 - QProcess:
   * [QTBUG-32958] Fixed a bug that would cause QProcess to crash if
     waitForStarted() were called after an unsuccessful start()
   * Added QProcess::nullDevice(), which returns the platform's "blackhole"
     device (/dev/null on Unix, NUL on Windows). This can be used with
     QProcess::setStandardOutputFile.
   * Added enum values QProcess::ForwardedOutputChannel and
     QProcess::ForwardedErrorChannel, which allow for more fine-grained
     control over which channel is forwarded and which one is captured.
   * Added QProcess::ForwardedInputChannel, which allows for stdin to be
     forwarded to this process's input.
   * [QTBUG-32979] On Unix, QProcess now correctly forwards the siginfo_t
     and context parameters of the signal handler to the previous handler.

 - QScopedPointer:
   * Added QScopedPointerDeleteLater, a new class that can be used as the
     second template to QScopedPointer and will call deleteLater() on the
     pointer when it goes out of scope.

 - QSocketNotifier:
   * Fixed a bug that caused socket notifiers not to be re-enabled after
     they had been activated on BlackBerry.

 - QStandardPaths:
   * QStandardPaths::enableTestMode is deprecated and is replaced by
     QStandardPaths::setTestModeEnabled.
   * Added QStandardPaths::GenericConfigLocation, which refers to a location
     where applications can store config files to be shared with other
     applications.

 - QThread:
   * Added an advisory interrupt mechanism (QThread::requestInterruption and
     QThread::isInterruptionRequested).

 - QThreadPool:
   * Added method clear() to remove any queued QRunnables.
   * Fixed a number of race conditions.

 - QTime:
   * [QTBUG-30250] When calling QTime::toString(Qt::TextDate) and
     QTime::toString(Qt::ISODate), milliseconds are now included in
     the returned string. This also applies to
     QDateTime::toString(Qt::TextDate) and
     QDateTime::toString(ISODate).
   * Added new methods fromMSecsSinceStartOfDay() to create a new QTime
     from an msecs value, and msecsSinceStartOfDay() to return the QTime as
     the number of msecs since the start of the day.

 - QTimeZone:
   * Added new QTimeZone class to support time tone calculations using the
     host platform time zone database and the Olsen time zone ID's.

 - QUrl:
   * [QTBUG-33229] QUrl now fully accepts non-character unicode points;
     they are encoded as percent characters; they can also be pretty
     decoded
   * Added QUrl::RemoveFilename flag which can be passed to path(),
     authority() and toString() and will cause the filename part of the path
     (the contents after the last '/') to be removed.
   * Added QUrl::fileName(), which returns just the filename part of the
     path.
   * Added QUrl::NormalizePathSegments flag, which will cause QUrl to
     remove "/./" or "/../" sequences as much as possible. It will not
     remove "/../" from the beginning of the path.
   * Added QUrl::adjusted(), which returns a new QUrl with certain parts of
     the original URL removed or normalized.
   * Added QUrl::matches(), which can be used to compare parts of two URLs
     or to compare two URLs after normalization.

 - QUtf8:
   * [QTBUG-33229] UTF-8 now accepts non-character unicode points; these
     are not replaced by the replacement character anymore

 - QVariant:
   * Fixed QVariant::canConvert with longlong
   * Variant containing enum types can now be converted to integer
   * [QTBUG-33981] Fixed a bug that would cause QPolygonF to be saved or
     loaded incorrectly in QDataStream.

QtDBus
------

 - Improved error handling so as to give more feedback to the developer when
   certain marshalling or demarshalling actions fail.
 - [QTBUG-27809] Fixed some race conditions related to delivering method
   reply deliveries.
 - Fixed a bug that made non-slot invokables not get listed in the
   auto-generated introspections.

QtDeclarative
-------------

 - ColorDialog:
   * Added currentColor property.

 - [QTBUG-32928] ShortcutOverride events now work for QQuickItem
   subclasses

QtGui
-----

 - Accessibility classes are now public allowing accessibility
   information for custom widgets/QQuickItems

 - Session Management:
   * [QTBUG-28228] The new QPlatformSessionManager class brings back
     the session management functionality. It allows the
     implementation of platform specific behavior related to session
     management. For platform that don't support this feature the
     default behavior has not changed.  Both X11 and Windows session
     management are supported.

 - QPolygonF:
   * When a QVariant holds a QPolygonF() then it will be correctly seen as
     a null QVariant.

 - [QTBUG-27349] Reintroduced command line argument for positioning
   windows (-geometry on X11, -qwindowgeometry on other platforms)

QtNetwork
---------

 - API was added to store and resume TLS session tickets.
 - The minimum support openssl version has been increased to openssl
   1.0. The code to support older versions has not been removed, but is no
   longer supported.
 - An off-by-one error in NTLM proxy authentication has been fixed.
 - Various improvements to reduce the memory used by qtnetwork have been
   made.
 - Improved support for HTTP proxy authentication.
 - Support for preconnecting to servers before making HTTP and HTTPS
   connections. This allows for much reduced latency when the hosts to be
   connected to are known.

QtPrintSupport
--------------

 - QPrintDialog:
   * Added support for setting CUPS job options in the print dialog.
   * Added support for setting CUPS Banner pages in the print dialog.
   * Added support for setting CUPS Page Set (even/odd pages only) in the
     print dialog.
   * Added support for setting CUPS Pages Per Sheet and Pages Per Sheet
     Layout options
   * Added CUPS server-side print range support for apps that can't support
     print range option themselves

QtSql
-----

Changes in Qt 5.1.0 (missing from released changelog dist/changes-5.1.0)
 - [QTBUG-28088] Remove dependency of DB driver headers on qsqlcachedresult_p.h.
 - Deprecate QSqlError setters. The constructor is sufficient, since it has
   a parameter for each member variable.
 - Rename the SQL driver header files to _p.h (make private)
   The drivers were never public API. They were exposed by mistake in
   public headers. What's more, they have #include'd a private header
   (qsqlcachedresult_p.h) since at least Qt 4.5.1. That means no one used
   those headers in Qt 4 (private headers weren't installed then) and
   it's unlikely anyone did in 5.0.
 - ODBC: Implemented lastInsertId() for some ODBC compatible databases.
 - PSQL: Make lastInsertID work for tables without OIDs.
 - [QTBUG-14904] SQLITE: Fix for Sql query aliases with dots
 - [QTBUG-2192] ODBC: fix loss of milliseconds when binding QDateTime
 - [QTBUG-30076] PSQL: escape backslashes only when server requires it
   IMPORTANT: Applications that implemented their own workarounds must be
   updated to avoid misbehavior and SQL injection vulnerabilities.
 - [QTBUG-10569] ODBC: fixed QODBCResult::exec() return value for DELETE
   operations when no rows are affected.
 - ODBC: Fixed loss of column metadata on SQL_NO_DATA.
 - QSqlTableModel: expose methods for getting primary values.
 - ODBC: Fixed possible cause of spurious errors (commit af35ee291a1bbbc8)

Changes in Qt 5.2.0
 - [QTBUG-29261] IBASE: Construct a valid QTime when creating timestamps for
   iBase SQL driver.
 - [QTBUG-33389] PSQL: Format QDateTime following ISO8601.
 - Add QSQLITE_OPEN_URI option to QSQLITE driver

QtWidgets
---------

 - [QTBUG-30255] Fixed a bug where spans across empty cells in a grid
   layout got broken.
 - [QTBUG-32788] Properly handles Qt::WidgetWithChildrenShortcut
   shortcuts in MDI subwindows now.
 - [QTBUG-33078] QWidget::setWindowOpacity() now works when called
   before QWidget::show().
 - [QTBUG-33247] Changed accessible trees and tables to always expose
   hidden headers, instead of only exposing the visible headers.
 - [QTBUG-34007] Fixed a crash in tablet support.
 - Fixed a bug where the maximum size hint of a layout with spans was
   wrong.
 - Item delegates now cycle through all three states of tri-state
   checkboxes, the same way QCheckBox itself does.

 - QAbstractItemView:
   * [QTBUG-7232] In ItemViews scrollbars will now by default only
     scroll 1 pixel when scrollMode is set to scrollPerPixel. That is
     it will (when scrollMode is scrollPerPixel) do what is stated in
     the documentation, and no longer automatically adjust the
     scrollbar's singleStep. The user can now control that value.

 - QAbstractScrollArea:
   * QAbstractScrollArea now has a SizeAdjustPolicy. If it is set to
     AdjustToContents it will make use of the protected viewportSizeHint()
     virtual function. This function returns a suggested size based on
     contents. Note that although the viewportSizeHint() virtual function
     was reserved in 5.0, user code was not supposed to be overriding it
     (as the function was private and undocumented).  Code that was
     overriding viewportSizeHint() needs to be recompiled against 5.2 for
     this feature to work correctly.

 - QColorDialog:
   * Added a web color QLineEdit.
   * [QTBUG-14332] Added a screen color picker button.
   * [QTBUG-31998] Does no longer create widgets when using the
     platform dialog.

 - QComboBox:
   * Added currentData() convenience function which allows to retrieve
     the user data set for the current item.

 - QCompleter:
   * [QTBUG-3414] Added filterMode property.

 - QDesktopWidget:
   * [QTBUG-32567] Fixed emission of workAreaResized() signal.

 - QDialogButtonBox:
   * Added a (StandardButtons,QWidget*) constructor.

 - QDockWidget:
   * [QTBUG-31044] The position of a dock widget is now kept when
     undocking.
   * [QTBUG-32260] Fixed a bug where visibilityChanged was signaled
     wrongly in certain multi-screen setups.

 - QFileDialog:
   * setDefaultSuffix() now removes leading dot characters.
   * Introduced DontUseCustomDirectoryIcons. This improves the file
     dialog performance under Windows for the case where there are
     lots of folders. Went from taking 60 seconds to 2 seconds, on a
     SDCard with 10k folders.
   * Added setMimeTypeFilters() for mimetype-based filtering, as an
     alternative to pattern matching.
   * Fixed removing of directories containing hidden or system files.
   * Added QUrl-based API for remote files.
   * [QTBUG-13182] Improved performance on Windows by
     + not resolving NTFS symlinks (15x speedup on pessimistic
       workloads) and
     + using extensions over calling GetFileAttributesEx() in certain
       cases.
   * [QTBUG-29403] Fixed potential crash in destructor of
     ~QFileInfoGather in threaded applications.
   * [QTBUG-34132] QFileDialog does no longer instantiate widgets if a
     native dialog will be used instead.  Therefore some accessors
     which previously returned unused objects will now return null.
     As before, you can set the DontUseNativeDialog option to ensure
     that widgets will be created and used instead.
   * [QTBUG-33039] Does no longer create widgets when using the
     platform dialog.

 - QFontDialog:
   * Now has finer-grained control over the types of fonts listed,
     similar to what QFontComboBox already had.

 - QGraphicsView etc
   * Fixed a crash in QGraphicsProxyWidget.
   * [QTBUG-8061] Allow handling of mouseDoubleClickEvent in
     QGraphicsItems.
   * [QTBUG-19036] Make QGraphicsScene::items(QPointF) work using
     Qt::{Contains,Intersets}ItemBoundingRect with items that contain
     the point in the bounding rectangle, but not their (custom)
     shape.

 - QHeaderView:
   * [QTBUG-4346] A maximumSize for sections has been introduced. The
     maximum section size is by default the largest possible section
     size which in Qt 5.2 has been limited to 1048575 pixels.

 - QInputDialog:
   * Added getMultiLineText static method.

 - QLineEdit:
   * Keep placeholderText visible when focused, until text is added.
   * Context-menu actions now have icons.
   * Made it possible to add side widgets.
   * Made it possible to add a clear button commonly used for item
     view filtering as a side widget

 - QListView:
   * [QTBUG-1180] Dragging an item outside the QListView in icon mode
     no longer loses the icon. Also fixed a bug where under certain
     conditions code overriding QAbstractItemView::viewOptions() would
     not be called.

 - QMenuBar:
   * [QTBUG-32807] Menus now close again on second click.

 - QMessageBox:
   * May use native message boxes on some platforms now.
   * [QTBUG-6731] It is now possible to select some or all text from a
     QMessageBox and copy it to the clipboard.

 - QSizePolicy:
   * Added a retainSizeWhenHidden attribute.

 - QSpinBox:
   * Values can now be displayed in different bases
     (cf. displayIntegerBase property)
   * [QTBUG-31602] Size calculation will now be fixed when stylesheets
     are used.

 - QSplitter:
   * Now gets the default value of opaqueResize property from (new)
     QStyle::SH_Splitter_OpaqueResize styleHint.

 - QSystemTrayIcon:
   * [QTBUG-31762] Fixed position of system tray icon on Linux/X11
     (except Unity).
   * [QTBUG-33461] Increased the maximum length of a system tray
     tooltip on Windows to what it was in Qt 4.

 - QTableView:
   * [QTBUG-4206] resizeToContents will now adjust to actual contents
     and not just visible area. QHeaderView::setAutoResizePrecision()
     has been introduced to control how precise the autoResize should
     be.

 - QTextEdit:
   * Added placeholderText akin to QLineEdit.
   * Context-menu actions now have icons.

 - QTreeView:
   * QTreeView now has setTreePosition to allow the treestructure to
     show data from other columns than logicalindex zero.

 - QWindowContainer:
   * [QTBUG-32177] Sets active window correctly now.

 - QWizard:
   * [QTBUG-29924] Gave all buttons an objectName().

****************************************************************************
*                      Platform Specific Changes                           *
****************************************************************************


Android
-------

 - Project structure and deployment has changed with the introduction of
   androiddeployqt. Source and build files are no longer mixed, and the
   build files for the APK package should not be touched. Customizing
   the build files is possible. Read the documentation for androiddeployqt
   for more information.
 - Status bar visibility is now controlled by Qt, so the window state will
   override settings in the AndroidManifest.xml. The default is still to
   show the status bar (QWindow::showMaximized()). Use
   QWindow::showFullScreen() to hide it.
 - Implemented support for accessibility on Android.

OS X
----

 - Qt for OS X is now identified by the macro Q_OS_OSX. This complements the
   existing Q_OS_DARWIN macro (which identifies the open source kernel and
   could identify non-Apple products) and Q_OS_MAC, which is defined for
   both OS X and iOS. The old macro Q_OS_MACX is now deprecated.
 - Qt no longer complains about new versions of OS X that haven't been
   released yet. This will allow Qt 5.2 and future versions to build on
   future versions yet to be released. Note that those versions are not
   supported until official announcement by the Qt Project.
 - Added a number of functions to QtCore to convert to and from
   CFString/NSString and QString, CFURL/NSURL and QUrl.

Windows
-------

 - [QTBUG-33409][QTBUG-8764][QTBUG-10032] Fixed virtual key mapping on
   Windows.
 - QCoreApplication::arguments() changed the handling of single quotes, double quotes
   and the backslash character, in order to match what argv[] contains.
   In particular, single quotes are no longer removed from the argument string.
   (QTBUG-15379, QTBUG-30628)

X11
---

 - [QTBUG-31762] Fix position of system tray icon (except Unity)
 - [QTBUG-27349] Reintroduced command line argument for positioning
   windows (-geometry)