path: root/dist/changes-4.6.0

Qt 4.6 introduces many new features and improvements as well as bugfixes
over the 4.5.x series. For more details, refer to the online documentation
included in this distribution. The documentation is also available online:

  http://qt.nokia.com/doc/4.6

The Qt version 4.6 series is binary compatible with the 4.5.x series.
Applications compiled for 4.5 will continue to run with 4.6.

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

  http://qt.nokia.com/developer/task-tracker

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

****************************************************************************
*                           General                                        *
****************************************************************************

 - QtDBus
   * The minimum required version of the D-Bus reference library is
     now 0.93.

 - [MR#1742] Added new multimedia keys to the Qt::Key enum.

 - QMatrix4x4, QGenericMatrix, QVector2D, QVector3D, QVector4D, QQuaternion
    * New classes to support 3D applications.

 - QGLShaderProgram, QGLShader
    * New classes for using shader programs written in the GL Shading Language.

 - Boxes demo ported to use new 3D math and shader program classes.

 - OpenVG graphics system added.

 - Add 800x480 screen mode to qvfb configuration dialog.

 - Improved support for input methods in graphics view.

 - QAudioInput, QAudioOutput
    * New audio input and output classes.

 - QAbstractVideoSurface, QVideoFrame
    * New abstract video output classes.

Third party components
----------------------

 - Updated FreeType to version 2.3.9

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

    * [245219] Added QXmlQuery::setFocus(const QString &focus);

 - QGraphicsBlurEffect
    * Since the 4.6 beta Qt::RenderHint has been moved to
      QGraphicsBlurEffect::BlurHint.

    * Input contexts are not activated for disabled widgets anymore.

    * [250555] Data copied from Mozilla Firefox can now be pasted correctly to
      a Qt application.

QtCore

 - QByteArray
    * New overloads for QByteArray::insert() and QByteArray::prepend()

 - QObject
    * [259514] fixed a possible dead-lock in the destructor

 - QVariant
    * Many optimisations
    * Added QVariant::toFloat() and QVariant::toReal()
    * Added QVariant(float) constructor
    * qvariant_cast<QVariant> and qVariantFromValue<QVariant> are now
      identify functions
    * Added support for math3d types.

 - Qt::escape
    * now escape the double quote (&quot;)

 - QScopedPointer
    * New pointer class for cleaning up objects when leaving the
      current scope

 - QFile
    * Make QFile::resize() more robust when operating on buffered files

 - QObject
    * Added the possibility to pass the flag Qt::UniqueConnection to QObject::connect
    * Fixed race conditions that occured when moving object to threads while connecting

 - QPluginLoader
    * Improved performance of plugin loading by reusing the plugin cache instead of loading
      it every time.

- QTextStream
    * [221316] Fixed crash on large input.
    * Improved reading utf8/utf16/utf32 data by correctly skipping the
      ByteOrderMark when reading data by one character at a time.

- QXmlStreamWriter
    * [256468] fix comment indentation

QtGui
- QGraphicsAnchorLayout
    * Support for expanding size policy has been removed. (The Qt 4.6 Beta had support for it).

 - QCompleter
    * [246056] Fixed a possible assertion when setting the completer prefix

 - QFontDialog
    * [256466] fixed the dialog not always returning the selected style.

 - QGraphicsItem
    * Fixed bug and improved accuracy of QGraphicsItem::childrenBoundingRect().
    * Many optimizations.
    * Introduced QGraphicsItem::ItemHasNoContents
    * Introduced QGraphicsItem::ItemSendsGeometryChanges (see Behavioral Changes)
    * Introduced QGraphicsItem::focusProxy(), focus proxy support
    * Introduced QGraphicsItem::ItemNegativeZStacksBehindParent
    * Introduced QGraphicsItem::ItemIsPanel, light-weight window support
    * Introduced activation support.
    * Introduced QGraphicsItem::stackBefore()
    * Cached items are now always invalidated when update() is called.
    * Added input hints.

- QGraphicsLayout
    * Introduced QGraphicsLayout::addChildLayoutItem()

 - QGraphicsObject
    * New class; inherits QGraphicsItem and adds notification signals and property declarations.

 - QGraphicsProxyWidget
    * [251407] Fixed window flag handling. Now QGraphicsProxyWidget's flags win.
    * Fix Qt::ClickFocus policy

 - QGraphicsScene
    * [245317] Fixes to mouse grabbing behavior.
    * Fixed delivery of double-click events after explicit grab and then ungrab.
    * Rewrote the internal rendering to use a recursive instead of an iterative approach.
    * Many optimizations.
    * Ensure hover enter events are delivered when an item is pressed.
    * Introduced activation support.
    * Fixed bugs in initial focus support.

 - QGraphicsTextItem
    * Now inherits from QGraphicsObject instead

 - QGraphicsTransform
    * New class; eases animation of transformations for QGraphicsItem.

 - QGraphicsView
    * Fix mapToScene(QRect) to avoid extra unnecessary adjustments.
    * Many optimizations.
    * Introduced QGraphicsView::isTransformed()
    * [QTBUG-4151] Items with parent that sets ItemClipsChildrenToShape were sometimes invisible.

 - QGraphicsWidget
    * Now inherits from QGraphicsObject instead
    * Interactive resizing of top level windows now respects height-for-width constraints.
    * Reduced memory footprint.

 - QHeaderView
    * [208320] Make sure the sort indicator s taken into account for the size hint
    * [255574] Make sure the sizehint for the section depend on visible sections

 - QMainWindow
    * [226060] Adding actions to a toolbar would always make the next toolbar move

 - QMenuBar
    * [260873] Fix mouse interaction while undocking a widget from the main window
	* dock areas don't get a splitter if their dock widgets are not resizable

 - QColumnView
    * [246999] Fixed view not updating when the model is changed dynamically

 - QLineEdit
    * [248948] Clear selection when redoing a delete operation.

 - QListView
    * [243335] Fixed the visualRect to return correct values when the widget is not yet show

 - QTreeView
    * [234930] Be able to use :has-children and :has-sibillings in a stylesheet
    * [252616] Set QStyleOptionViewItemV4::OnlyOne flag when painting spanning columns
	* [245654] Fixed expandAll when deleting and recreating a mode for the tree
	* [239271] Fixed missing update when adding a row when the first column is hidden
	* [258225] Fixed scrollTo with center and bottom

 - QTreeWidget
    * [253109] Shows the widget when calling setItemWidget

 - QTableView
    * [191545] Selections work more similarly to well-known spreadsheets
    * [234926] Fixed sorting after changing QTableView header
    * [244651] [245327] [250193] [QTBUG-5062] Spans get plenty of love with
      speed-up, support for rows/columns insertion/removal, and better keyboard
      navigation

 - QTableWidget
    * [234641] Fixed takeItem to cause the view to be updated.

 - QTabBar
    * [196326] Fixed having a stylesheet on a QTabBar resulted in some tab names
      to be slightly clipped.
    * [241383] Added ability to style the close tab button with style sheet

 - QComboBox
    * [220195] Fixed keyboard search when current index is -1

 - QPixmap
    * Optimized width(), height(), isNull() and depth().

 - QRegion
    * Minor optimizations.

 - QSpinBox
    * [259226] Fixed setting a stylesheet on a QSpinBox to change the arrow possition
    * [255051] Fixed sizeHint update bug.

 - QStandardItemModel
    * [255652] Fixed crash while using takeRow with a QSortFilterProxyModel

 - QToolTip
    * Fixed a bug where tooltips were not shown in popups. (Windows only).

 - QGraphicsItem
    * Added a new set of properties to set a transformation on a item

 - QMenu
    * [252610] Fixed position of the shortcut text while setting a stylesheet on menu items

 - QSortFilterProxyModel
    * [251296] Fixed bugs in which filtered items could not be filtered.

 - QSplitter
    * [206494] Added ability to style pressed slided with stylesheet

 - QWidget
    * [201649] Added QWidget::previousInFocusChain
    * [254563] Fixed a crash when setting a focus in a widget tree that
      contains invisible widgets

 - QFontEngineQPF
    * Make alphaMapForGlyph() generate the correct color table for
      Indexed8 and Mono glyph images.  Fixed the "all glyphs are white
      boxes" problem in OpenGL1 paint engine.

 - QPaintDevice
    * New qt_paint_device_metric() function to replace the friend
      declarations for window surface classes that need to access metric().

 - QPushButton
    * [255581] Fixed sizeHint recalculation bug.

 - QApplication
   * [QTBUG-739] Removed internal widgets from QApplication::topLevelWidgets().

QtNetwork

 - QAbstractSocket
    * only disconnect from host when all bytes have been written
    * New setSocketOption method.

 - QHttp
    * Do not buffer the complete POST data anymore when HTTPS is used.
    * QHttp is now obsolete and replaced by QNetworkAccessManager.

 - QLocalServer
    * fix timeout when waiting for a connection on Unix

 - QNativeSocketEngine
    * Do not set the OS socket send and receive buffer size. The OS
      should auto tune these values for us.

 - QNetworkAcessManager
    * [242916] add possibility to send HTTP DELETE requests
    * Connection count per HTTP server increased to 6 on Desktop, 3 on Symbian.
    * Optional HTTP pipelining support.
    * General HTTP performance improvements.

 - QNetworkReply
    * [257322] add possibility to ignore specific SSL errors
    * New isFinished() method.

 - QSslCertificate
    * [251830] fix version() and serialNumber() methods

 - QSslSocket
    * [257322] add possibility to ignore specific SSL errors
    * Fix build with openssl 1.0.0 betas
    * Trigger a SSL transmission when reading from the socket. In certain
      cases the connection stalled when a buffer limit was used.

QtOpenGL

 - QGLFormat
    * Increase unit test coverage and fix some long-standing issues.
    * Improve performance of code that tests QGLFormat options.
    * operator==() now tests for equality on all fields.

 - QGLColormap
    * setEntry() was inserting entries instead of replacing them.
    * Clarified documentation for isEmpty().

 - QGLFramebufferObject
    * Add support for the ARB_framebuffer_object, OES_framebuffer_object,
      and OES_packed_depth_stencil extensions.
    * Unbind the texture after it is initialized.
    * Don't destroy the texture target on cleanup if one wasn't created.

 - QGLFramebufferObjectFormat
    * New class for controlling fbo options.

 - Improvements to context sharing and object cleanup logic.

 - QGLContext
    * Fix RGB565 mode in bindTexture().
    * Map mipmaps work on OpenGL/ES 2.0 systems in bindTexture().
    * Improve performance of QGLContext::currentContext().

 - QGLGradientCache
   * [249919] Clean up the gradient cache in the right context.

 - OpenGL (ES) 2.0 Paint Engine
    * Re-written the OpenGL (ES) 2.0 Paint Engine's shader manager to use new
      shader API and to allow custom code from E.g. Pixmap Filters to be
      instered into the fragment "pipeline".
    * Fixed conical gradients.

 - Cleaned up usage of OpenGL extensions. QtOpenGL now uses the OpenGL 2.0
   names of methods rather than using the EXT postfix. However, when resolving
   extensions, QtOpenGL will also try postfixing EXT if the OpenGL 2.0 name is
   not found.

 - Fix QGLWidget::showFullscreen() on EGL platforms

 - Added lots of OpenGL autotests.

QtSql
   * [QTBUG-3162] Views for Sql table models should not reset state on failed queries.
   * [QTBUG-5251] Fix retrieval of SQL  'TIME' information for PostgreSQL.
   * Better error checking for in case of failed query.
   * [QTBUG-5179] Fixed Floating point number truncation in qsqlpsql plugin.
   * [QTBUG-551] Fixed Oracle batchExec using strings as out params.
   * Updated sqlite to 3.6.19 + readded our patches.
   * [QTBUG-3736] ODBC: Retrieved in ascii, should be stored in ascii.
   * Fixed issue with multiple lookups to same table/field in QSqlRelationalTableModel
   * Updated documentation of setForwardOnly
   * [QT-754] TDS: Fixed improper formatting of date values
   * TDS: Fixed missing field/table name escaping.
   * ODBC: Fixed setForwardOnly not being reset on when the query is reset.
   * [QTBUG-4510] Add reconnection option to the mysql driver.
   * [222678] Fixed QSqlTableModel: trying to delete the wrong row.
   * Interbase: Fixed crash when calling numRows on unknown query type.
   * DB2: Don't return an error when the table is just empty.
   * [17327] Added OCI support for synonyms to tables created by another user.
   * [176267] Fixed mysql driver not knowing the difference between tables and views.
   * Fixed determination of end of ODBC string on deficient drivers.
   * Added ability to open sqlite databases readonly.
   * Fixed race condition on reopening an ODBC connection.
   * Fixed invalid use of statics in the defaultCasing code.
   * Fixed proper quoting under odbc.
   * [252450 & 246125] Fixed failed queries due to MySql driver auto-preparing.
   * QSqlDatabase now has a database level precisionPolicy. Queries now default to this.
   * Add proper iODBC linking support.

QtXml

- QDomDocument
    * set the codec to UTF-8 if codec not present or unknown

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

 - Added community supported Qt ports for QNX and VxWorks. See platform
   notes in the Qt documentation for details.

Qt for Linux/X11
----------------

 - KDE Integration: Improved the integration into KDE desktop (loading of KDE
   palette, usage of KColorDialog and KFileDialog) using the GuiPlatformPlugin

 - Fixed pasting the clipboard content to non-Qt application on X11 when the
   requested format is image/ppm. Patch by Ritt.K

 - On X11 Qt now supports the _NET_WM_SYNC protocol.

 - On X11 Qt now supports the SAVE_TARGET protocol that allows to keep
   clipboard contents if the application that owns the clipboards exits

 - [QTBUG-4652] On X11 clipboard content can be properly retrieved even when an
   application asks the unsupported target. This fixes copying and pasting data
   when using Synergy.
 - [MR#797] Fixed a crash when using QX11EmbedContainer/Widget on x86_64.
 - [MR#1111] Emit workAreaResized when _NET_WORKAREA is changed on X11.

 - Improved EGL integration on X11 (including better visual selection).

 - Support Qt::WA_TranslucentBackground on top-level QGLWidgets on X11, both 
   (EGL & glX). This allows OpenGL (& ES) rendering to semi-transparent widgets
   if a compositing window manager is running.

 - Support OpenGL texture_from_pixmap extension on X11 (EGL & glX) when
   calling QPainter::drawPixmap() with the OpenGL paint engine, or calling
   QGLContext::bindTexture() on an X11 QPixmap. If the 
   GLX_EXT_texture_from_pixmap or EGL_NOKIA_texture_from_pixmap extensions are
   present, Qt will attempt to use glXBindTexImageEXT or eglBindTexImage to
   bind the pixmap to a texture, rather than copying the pixel data.

 - Add new experimental QX11GLPixmapData backend for QPixmap. This pixmap
   backend uses regular X11 pixmaps to store the image data, however it uses
   OpenGL to render into them.

Qt for Windows
--------------

 - Significant external contribution from Milan Burda for planned removal
   of (non-unicode) Windows 9x/ME support.

 - QRegion is no longer a GDI object by default. This means it is no
   longer subject to gui-thread only nor does it potentially impact
   the 10.000 GDI object limit per process. By explicitly calling
   .handle() a GDI object will be created and memory managed by
   QRegion. The native handle is for reading out only. Any GDI calls
   made on the HRGN handle will not affect the QRegion.

 - The reading code of QLocalSocket on Windows has been rewritten to improve
   reading performance.

 - On Windows when a file cannot be accessed (stat()ed), we are now restoring
   the error mode to the original value.

 - [259221] QFileInfo::symLinkTarget() now supports NTFS symbolic links
   thanks to Konstantin Ritt (merge request 1217).
 - [251554] Fixed openUrl("mailto:") with Thunderbird on Windows.
 - [254501] QDestopServices now supports cyrillic file names.
 - Fixed an issue which prevents moving fixed size windows using titlebar.
 - [258087] Fixed an issue on Vista which returns incorrect file paths when using
   QFileDialog::getOpenFileNames()
 - [253763] Fixed a focus issue when using out-of-process ActiveQt controls.
 - [255912] Mouse move events will not be delivered to a blocked widget.
 - [225588] Enabled IME reconversion support.

 - Phonon on Windows
   * Now much more reliable when reading a file through a QIODevice.
   * If Video Mixing Renderer 9 is not available, falls back to software
     rendering.
   * Fixed a flicker issue when switching source with a transition time of 0

Qt for Mac OS X
---------------

 - Add support for GetURL events on Mac OS X
 - [123740] Fixed an issue with dead keys on Mac (cocoa) on French keyboard layout.
 - [252088] Drag Leave events will be delivered correctly on Cocoa.
 - [257661] Cocoa now uses the correct line ending for clipboard plain text.
 - [258438] Enabled Emacs style keyboard shortcuts.
 - [258173] Fixed an issue which caused "whatsthis" pointer to flicked on Cocoa.
 - [QTBUG-4418] Fixed maximizing and restoring a window on Mac.

General changes on Mac OS X:
 - Mac OS X version support: Support for 10.3(Panther) has been dropped, support for
   10.6(Snow Leopard) has been added.
 - The Cocoa port now supports static linking.
 - The Cocoa port now supports the Qt3Support library (with the exception of Q3FileDialog)
   to ease the transition from Carbon to Cocoa.
 - The Cocoa binary packages are now Intel only (universal i386 and x86_64).
 - Snow Leopard notes:
    - Gcc 4.2 is used by default. Configure with -platform macx-g++40 to select 4.0.
    - Using the 10.4u SDK requires gcc 4.0.
    - Configuring for the Cocoa port (-cocoa) produces 64-bit binaries by default.
      Use the -arch flags to override.
    - Building for ppc64 is no longer supported by the gcc tool chain.
    - Building for ppc is still supported.

Qt for Embedded Linux
---------------------

- Added QMAKE_LIBS_OPENGL_ES1, QMAKE_LIBS_OPENGL_ES1CL and
  QMAKE_LIBS_OPENGL_ES2 qmake variables for specifying OpenGL ES
  specific libraries.

- Compilation fixes for OpenGL/ES 1.0 and OpenGL/ES 1.1 Common Lite.

- EGL and OpenGL/ES
   * Protect the use of version-specific EGL symbols with #ifdef's.
   * Make sure an EGL context is current when resolving GL extensions.
   * Introduce "lazyDoneCurrent" for optimizing context switching in
     paint engines.
   * Separate EGLSurface from QEglContext so that the same context can
     be used with multiple surfaces.
   * Move common functions from system-specific files to qgl_egl.cpp.
   * Fix a memory leak of EGLSurface's in QGLContext.
   * Fix detection of pbuffers on OpenGL/ES systems.
   * EGL_SAMPLES was being set to the wrong value for multisampled surfaces.

- PowerVR
   * Make the code better at detecting MBX vs SGX header files.
   * Fix 32-bit screen support - some code was still assuming 16-bit.
   * Stop GL window surfaces double-flushing their contents.
   * Remove surface holder, which never worked all that well.
   * Implement screen rotations.

- Remove obsolete OpenGL/ES screen drivers: hybrid, ahigl.

Qt for Windows CE
-----------------
 - On Windows CE the link time code generation has been disabled by default to
   be consistent with win32-msvc200x.
 - The default button size has been reduced in the Windows mobile style.
 - [QTBUG-3613] QWizard issues have been fixed on Windows mobile.
 - [254673] Restoring minimized widgets fixed for Windows mobile and
   Windows CE.
 - [255242] Seeking within large files (bigger than 0x80000000 bytes) fixed
   on Windows CE.
 - [257352] When configuring Qt for Windows CE, configure points the user to
   setcepaths, when its done.
 - [259850] Added a makespec template for Windows CE 6.

****************************************************************************
*                          Tools                                           *
****************************************************************************

- Designer

 - [233683] Promoted Widgets are now stored correctly in scratchpad.
 - [249823] Added search functionality to the resource browser.
 - [254282] Enabled the use of promoted widgets in form templates.
 - [254824] Made it possible to override the createAction()/createWidget()
            functions of QUiLoader.
 - [256332] Enabled deleting all pages of a QTabWidget or QStackedWidget.
 - [259238] Fixed menubar/menu editing in right-to-left mode.
 - [259918] Fixed setting of object names for container pages not to use
            localized strings.
 - [260658] Fixed saving of alpha values set in the palette editor.
 -          It is now possible to further specify the kind of custom widget
            string properties using XML tags.

- uic3

 - [128859] Fixed code generation of QLabel's wordWrap property.

 - lupdate
  - Fixed a bug in the java source code parser.

****************************************************************************
*                               DirectFB                                   *
****************************************************************************

 - When running Qt/DirectFB the DirectFB window id of a top level QWidget can
   be queried using property("_q_DirectFBWindowID")

 - Allow setting the background color of the primary layer in DirectFB with
   connect options. QWS_DISPLAY=directfb:bgcolor=red or
   QWS_DISPLAY=directfb:bgcolor=\#aabbccdd

 - Add support for rendering mouse cursor using a top level window when cursor
   support is not working in IDirectFBDisplayLayer. Define
   QT_DIRECTFB_WINDOW_AS_CURSOR to enable.

 - Add experimental support for optimized locking/unlocking of surfaces. Enable
   by defining QT_DIRECTFB_SUBSURFACE.

 - Fix a bug to conceptually allow using QDirectFBScreen as a subscreen of a
   proxy screen. Don't make QDirectFBScreen::instance() assume that
   QScreen::instance() is a QDirectFBScreen.

 - Optimize move/resize operations with DirectFB. With a properly configured
   DirectFB these operations are handled for us and we don't need to force a
   repaint of the window.

 - Support top level window opacity in DirectFB

 - Fix a bug when loading RGB32 images that would lead to rendering issues.

 - Fix a bug when painting with invalid pens/brushes.

 - Fix a bug that would show up when QWidget::scroll is called.

 - Implement support for loading pixmaps using IDirectFBImageProvider.

 - Disable color table support by default. This seems to work incorrectly on
   most boards and loading these images will generally require an image
   conversion anyway.

 - Fix a bug regarding QGraphicsProxyWidgets

 - Fix a crash when resizing windows

 - Compile with versions < 1.0. We still recommend using newer versions.

 - Considerable code cleanup

 - Various optimizations regarding painting, loading of images and creation of
   surfaces.

 - Allow forcibly falling back to raster engine for painting operations by
   exporting QT_DIRECTFB_FORCE_RASTER=1

 - Reenable support for RGB32 primary surface.


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

 - The experimental Direct3D paint engine has been removed. The reason for
   this is that Nokia focuses on OpenGL for desktop hardware accelerated
   rendering.

 - The default engine used to draw onto OpenGL buffers has changed in
   Qt 4.6. The QPaintEngine::OpenGL2 engine is now used as the default
   engine. This *may* cause compatibility problems for applications
   that use a mix of QPainter and native OpenGL calls to draw into a GL
   buffer. Use the QGL::setPreferredPaintEngine() function to enforce
   usage of the old GL paint engine.

 - When mixing OpenGL and QPainter calls you need to surround your
   custom OpenGL calls with QPainter::beginNativePainting() and
   QPainter::endNativePainting().
   This is to ensure that the paint engine flushes any pending drawing and sets
   up the GL modelview/projection matrices properly before you can issue custom
   OpenGL calls, and to let the paint engine synchronize to the painter state
   before resuming regular QPainter based drawing.

 - Graphics View has undergone heavy optimization work, and as a result of
   this work, the following behavior changes were introduced.

   a) QStyleOptionGraphicsItem::exposedRect now contains the item's bounding
      rectangle, and QStyleOptionGraphicsItem::matrix is uninitialized by
      default. You can enable an exact exposed rectangle and a correct matrix
      by enabling the flag QGraphicsItem::ItemUsesExtendedStyleOptions.

   b) QStyleOptionGraphicsItem::levelOfDetails is obsoleted and its value is
      always initialized to 1. Instead you can call
      QStyleOptionGraphicsItem::levelOfDetailFromTransform(const QTransform &)
      to determine the level of detail.

   c) QGraphicsView no longer calls QGraphicsView::drawItems(), and in turn
      QGraphicsScene::drawItems(), by default. You can get the old behavior
      back by enabling QGraphicsView::IndirectPainting.

   d) QGraphicsItem no longer calls itemChange() for position and
      transformation changes. If you want to receive notifications for changes
      to the item's position and transformation, you can set the flag
      QGraphicsItem::ItemSendsGeometryChanges (which is enabled by default by
      QGraphicsWidget and QGraphicsProxyWidget).

 - QDesktopWidget on X11 no longer emits the resized(int) signal when screens
   are added or removed. This was not done on other platforms. Use the
   screenCountChanged signal instead

 - QUrl's parser is more strict when for hostnames in URLs. QUrl now
   enforces STD 3 rules:

    * each individual hostname section (between dots) must be at most
      63 ASCII characters in length;

    * only letters, digits, and the hyphen character are allowed in the
      ASCII range; letters outside the ASCII range follow the normal
      IDN rules

   That means QUrl no longer accepts some URLs that were invalid
   before, but weren't interpreted as such.

 - The Unix configure-time check for STL is stricter now in Qt
   4.6.0. This means some legacy STL implementations may fail to pass
   the test and, therefore, Qt will automatically disable STL support.

   This is a binary-compatible change: existing code will continue to
   work without being recompiled. However, it affects the source code,
   since some STL-compatibility API will not be enabled.

   Platforms affected by this change:
     * solaris-cc-* with the default (Cstd) C++ STL library
       recommendation: use -library=stlport4
       See Sun Studio's documentation for the effects of this option

 - QVariant has now a new implicit constructor that takes a float. This
   means that code that assigned a float to a variant would create a
   variant with userType QMetaType::Float, instead of QVariant::Double.

 - QDataStream will now read and write all floating point numbers with the
   same precision, regardless of whether it's streamed into or out from a
   float or double. This is to maintain compatibility across platforms with
   a different default precision for qreal. The default is 64-bit precision
   for all floating point numbers, and this can be changed using the new
   function setFloatingPointPrecision(). Set Qt_4_5 as the version of the
   QDataStream to get the behavior of previous versions.

 - On Mac OS X, QDesktopServices::storageLocation(DataLocation) now includes
   QCoreApplication::organizationName() and QCoreApplication::applicationName()
   if those are set. This matches the behavior on the other platforms.

 - The Animation Framework
   * currentTime() now returns the complete current time including previous loops
   * currentLoopTime() returns the time inside the current loop
   * stateChanged signal sends the new state as first parameter and old state as
     the second
   * QAnimationGroup::clearAnimations() has been renames to clear()
   * QAnimationGroup::insertAnimationAt() has been renames to insertAnimation()
   * QAnimationGroup::takeAnimationAt() has been renames to takeAnimation()
   * QSequentialAnimationGroup::insertPauseAt() has been renames to insertPause()

- Refactoring in OpenGL examples to improve portability and utilize the
  Animation framework for animation.  The hellogl and overpainting examples
  now compile on OpenGL/ES 1.1.  Also common code is factored.