Long live Qt!

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diff --git a/src/gui/graphicsview/qgraphicsview.cpp b/src/gui/graphicsview/qgraphicsview.cpp
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+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain
+** additional rights. These rights are described in the Nokia Qt LGPL
+** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
+** package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//#define QGRAPHICSVIEW_DEBUG
+
+static const int QGRAPHICSVIEW_REGION_RECT_THRESHOLD = 50;
+
+static const int QGRAPHICSVIEW_PREALLOC_STYLE_OPTIONS = 503; // largest prime < 2^9
+
+/*!
+    \class QGraphicsView
+    \brief The QGraphicsView class provides a widget for displaying the
+    contents of a QGraphicsScene.
+    \since 4.2
+    \ingroup multimedia
+    \ingroup graphicsview-api
+    \mainclass
+
+    QGraphicsView visualizes the contents of a QGraphicsScene in a scrollable
+    viewport. To create a scene with geometrical items, see QGraphicsScene's
+    documentation. QGraphicsView is part of \l{The Graphics View Framework}.
+
+    To visualize a scene, you start by constructing a QGraphicsView object,
+    passing the address of the scene you want to visualize to QGraphicsView's
+    constructor. Alternatively, you can call setScene() to set the scene at a
+    later point. After you call show(), the view will by default scroll to the
+    center of the scene and display any items that are visible at this
+    point. For example:
+
+    \snippet doc/src/snippets/code/src_gui_graphicsview_qgraphicsview.cpp 0
+
+    You can explicitly scroll to any position on the scene by using the
+    scroll bars, or by calling centerOn(). By passing a point to centerOn(),
+    QGraphicsView will scroll its viewport to ensure that the point is
+    centered in the view. An overload is provided for scrolling to a
+    QGraphicsItem, in which case QGraphicsView will see to that the center of
+    the item is centered in the view. If all you want is to ensure that a
+    certain area is visible, (but not necessarily centered,) you can call
+    ensureVisible() instead.
+
+    QGraphicsView can be used to visualize a whole scene, or only parts of it.
+    The visualized area is by default detected automatically when the view is
+    displayed for the first time (by calling
+    QGraphicsScene::itemsBoundingRect()). To set the visualized area rectangle
+    yourself, you can call setSceneRect(). This will adjust the scroll bars'
+    ranges appropriately. Note that although the scene supports a virtually
+    unlimited size, the range of the scroll bars will never exceed the range of
+    an integer (INT_MIN, INT_MAX). When the scene is larger than the scroll
+    bars' values, you can choose to use translate() to navigate the scene
+    instead.
+
+    QGraphicsView visualizes the scene by calling render(). By default, the
+    items are drawn onto the viewport by using a regular QPainter, and using
+    default render hints. To change the default render hints that
+    QGraphicsView passes to QPainter when painting items, you can call
+    setRenderHints().
+
+    By default, QGraphicsView provides a regular QWidget for the viewport
+    widget. You can access this widget by calling viewport(), or you can
+    replace it by calling setViewport(). To render using OpenGL, simply call
+    setViewport(new QGLWidget). QGraphicsView takes ownership of the viewport
+    widget.
+
+    QGraphicsView supports affine transformations, using QMatrix. You can
+    either pass a matrix to setMatrix(), or you can call one of the
+    convenience functions rotate(), scale(), translate() or shear(). The most
+    two common transformations are scaling, which is used to implement
+    zooming, and rotation. QGraphicsView keeps the center of the view fixed
+    during a transformation.
+
+    You can interact with the items on the scene by using the mouse and
+    keyboard. QGraphicsView translates the mouse and key events into \e scene
+    events, (events that inherit QGraphicsSceneEvent,), and forward them to
+    the visualized scene. In the end, it's the individual item that handles
+    the events and reacts to them. For example, if you click on a selectable
+    item, the item will typically let the scene know that it has been
+    selected, and it will also redraw itself to display a selection
+    rectangle. Similiary, if you click and drag the mouse to move a movable
+    item, it's the item that handles the mouse moves and moves itself.  Item
+    interaction is enabled by default, and you can toggle it by calling
+    setInteractive().
+
+    You can also provide your own custom scene interaction, by creating a
+    subclass of QGraphicsView, and reimplementing the mouse and key event
+    handlers. To simplify how you programmatically interact with items in the
+    view, QGraphicsView provides the mapping functions mapToScene() and
+    mapFromScene(), and the item accessors items() and itemAt(). These
+    functions allow you to map points, rectangles, polygons and paths between
+    view coordinates and scene coordinates, and to find items on the scene
+    using view coordinates.
+
+    \img graphicsview-view.png
+
+    \sa QGraphicsScene, QGraphicsItem, QGraphicsSceneEvent
+*/
+
+/*!
+    \enum QGraphicsView::ViewportAnchor
+
+    This enums describe the possible anchors that QGraphicsView can
+    use when the user resizes the view or when the view is
+    transformed.
+
+    \value NoAnchor No anchor, i.e. the view leaves the scene's
+                    position unchanged.
+    \value AnchorViewCenter The scene point at the center of the view
+                            is used as the anchor.
+    \value AnchorUnderMouse The point under the mouse is used as the anchor.
+
+    \sa resizeAnchor, transformationAnchor
+*/
+
+/*!
+    \enum QGraphicsView::ViewportUpdateMode
+
+    \since 4.3
+
+    This enum describes how QGraphicsView updates its viewport when the scene
+    contents change or are exposed.
+
+    \value FullViewportUpdate When any visible part of the scene changes or is
+    reexposed, QGraphicsView will update the entire viewport. This approach is
+    fastest when QGraphicsView spends more time figuring out what to draw than
+    it would spend drawing (e.g., when very many small items are repeatedly
+    updated). This is the preferred update mode for viewports that do not
+    support partial updates, such as QGLWidget, and for viewports that need to
+    disable scroll optimization.
+
+    \value MinimalViewportUpdate QGraphicsView will determine the minimal
+    viewport region that requires a redraw, minimizing the time spent drawing
+    by avoiding a redraw of areas that have not changed. This is
+    QGraphicsView's default mode. Although this approach provides the best
+    performance in general, if there are many small visible changes on the
+    scene, QGraphicsView might end up spending more time finding the minimal
+    approach than it will spend drawing.
+
+    \value SmartViewportUpdate QGraphicsView will attempt to find an optimal
+    update mode by analyzing the areas that require a redraw.
+
+    \value BoundingRectViewportUpdate The bounding rectangle of all changes in
+    the viewport will be redrawn. This mode has the advantage that
+    QGraphicsView searches only one region for changes, minimizing time spent
+    determining what needs redrawing. The disadvantage is that areas that have
+    not changed also need to be redrawn.
+
+    \value NoViewportUpdate QGraphicsView will never update its viewport when
+    the scene changes; the user is expected to control all updates. This mode
+    disables all (potentially slow) item visibility testing in QGraphicsView,
+    and is suitable for scenes that either require a fixed frame rate, or where
+    the viewport is otherwise updated externally.
+
+    \sa viewportUpdateMode
+*/
+
+/*!
+    \enum QGraphicsView::OptimizationFlag
+
+    \since 4.3
+
+    This enum describes flags that you can enable to improve rendering
+    performance in QGraphicsView. By default, none of these flags are set.
+    Note that setting a flag usually imposes a side effect, and this effect
+    can vary between paint devices and platforms.
+
+    \value DontClipPainter QGraphicsView sometimes clips the painter when
+    rendering the scene contents. This can generally improve performance
+    (e.g., rendering only small parts of a large pixmap), and protects against
+    rendering mistakes (e.g., drawing outside bounding rectangles, or outside
+    the exposed area). In some situations, however, the painter clip can slow
+    down rendering; especially when all painting is restricted to inside
+    exposed areas. By enabling this flag, QGraphicsView will completely
+    disable its implicit clipping. Note that rendering artifacts from using a
+    semi-transparent foreground or background brush can occur if clipping is
+    disabled.
+
+    \value DontSavePainterState When rendering, QGraphicsView protects the
+    painter state (see QPainter::save()) when rendering the background or
+    foreground, and when rendering each item. This allows you to leave the
+    painter in an altered state (i.e., you can call QPainter::setPen() or
+    QPainter::setBrush() without restoring the state after painting). However,
+    if the items consistently do restore the state, you should enable this
+    flag to prevent QGraphicsView from doing the same.
+
+    \value DontAdjustForAntialiasing Disables QGraphicsView's antialiasing
+    auto-adjustment of exposed areas. Items that render antialiased lines on
+    the boundaries of their QGraphicsItem::boundingRect() can end up rendering
+    parts of the line outside. To prevent rendering artifacts, QGraphicsView
+    expands all exposed regions by 2 pixels in all directions. If you enable
+    this flag, QGraphicsView will no longer perform these adjustments,
+    minimizing the areas that require redrawing, which improves performance. A
+    common side effect is that items that do draw with antialiasing can leave
+    painting traces behind on the scene as they are moved.
+*/
+
+/*!
+    \enum QGraphicsView::CacheModeFlag
+
+    This enum describes the flags that you can set for a QGraphicsView's cache
+    mode.
+
+    \value CacheNone All painting is done directly onto the viewport.
+
+    \value CacheBackground The background is cached. This affects both custom
+    backgrounds, and backgrounds based on the backgroundBrush property. When
+    this flag is enabled, QGraphicsView will allocate one pixmap with the full
+    size of the viewport.
+
+    \sa cacheMode
+*/
+
+/*!
+    \enum QGraphicsView::DragMode
+
+    This enum describes the default action for the view when pressing and
+    dragging the mouse over the viewport.
+
+    \value NoDrag Nothing happens; the mouse event is ignored.
+
+    \value ScrollHandDrag The cursor changes into a pointing hand, and
+    dragging the mouse around will scroll the scrolbars. This mode works both
+    in \l{QGraphicsView::interactive}{interactive} and non-interactive mode.
+
+    \value RubberBandDrag A rubber band will appear. Dragging the mouse will
+    set the rubber band geometry, and all items covered by the rubber band are
+    selected. This mode is disabled for non-interactive views.
+
+    \sa dragMode, QGraphicsScene::setSelectionArea()
+*/
+
+#include "qgraphicsview.h"
+#include "qgraphicsview_p.h"
+
+#ifndef QT_NO_GRAPHICSVIEW
+
+#include "qgraphicsitem.h"
+#include "qgraphicsitem_p.h"
+#include "qgraphicsscene.h"
+#include "qgraphicsscene_p.h"
+#include "qgraphicssceneevent.h"
+#include "qgraphicswidget.h"
+
+#include <QtCore/qdatetime.h>
+#include <QtCore/qdebug.h>
+#include <QtCore/qmath.h>
+#include <QtGui/qapplication.h>
+#include <QtGui/qdesktopwidget.h>
+#include <QtGui/qevent.h>
+#include <QtGui/qlayout.h>
+#include <QtGui/qtransform.h>
+#include <QtGui/qmatrix.h>
+#include <QtGui/qpainter.h>
+#include <QtGui/qscrollbar.h>
+#include <QtGui/qstyleoption.h>
+#ifdef Q_WS_X11
+#include <private/qt_x11_p.h>
+#endif
+
+QT_BEGIN_NAMESPACE
+
+inline int q_round_bound(qreal d) //### (int)(qreal) INT_MAX != INT_MAX for single precision
+{
+    if (d <= (qreal) INT_MIN)
+        return INT_MIN;
+    else if (d >= (qreal) INT_MAX)
+        return INT_MAX;
+    return d >= 0.0 ? int(d + 0.5) : int(d - int(d-1) + 0.5) + int(d-1);
+}
+
+/*!
+    \internal
+*/
+QGraphicsViewPrivate::QGraphicsViewPrivate()
+    : renderHints(QPainter::TextAntialiasing),
+      dragMode(QGraphicsView::NoDrag),
+      sceneInteractionAllowed(true), hasSceneRect(false),
+      connectedToScene(false),
+      mousePressButton(Qt::NoButton),
+      identityMatrix(true),
+      dirtyScroll(true),
+      accelerateScrolling(true),
+      leftIndent(0), topIndent(0),
+      lastMouseEvent(QEvent::None, QPoint(), Qt::NoButton, 0, 0),
+      useLastMouseEvent(false),
+      keepLastCenterPoint(true),
+      alignment(Qt::AlignCenter),
+      transforming(false),
+      transformationAnchor(QGraphicsView::AnchorViewCenter), resizeAnchor(QGraphicsView::NoAnchor),
+      viewportUpdateMode(QGraphicsView::MinimalViewportUpdate),
+      optimizationFlags(0),
+      scene(0),
+#ifndef QT_NO_RUBBERBAND
+      rubberBanding(false),
+      rubberBandSelectionMode(Qt::IntersectsItemShape),
+#endif
+      handScrolling(false), handScrollMotions(0), cacheMode(0),
+      mustAllocateStyleOptions(false),
+      mustResizeBackgroundPixmap(true),
+#ifndef QT_NO_CURSOR
+      hasStoredOriginalCursor(false),
+#endif
+      lastDragDropEvent(0),
+      fullUpdatePending(true),
+      dirtyRectCount(0),
+      updatingLater(false),
+      updateSceneSlotReimplementedChecked(false)
+{
+    styleOptions.reserve(QGRAPHICSVIEW_PREALLOC_STYLE_OPTIONS);
+}
+
+/*!
+    \internal
+*/
+void QGraphicsViewPrivate::recalculateContentSize()
+{
+    Q_Q(QGraphicsView);
+
+    QSize maxSize = q->maximumViewportSize();
+    int width = maxSize.width();
+    int height = maxSize.height();
+    QRectF viewRect = matrix.mapRect(q->sceneRect());
+
+    bool frameOnlyAround = (q->style()->styleHint(QStyle::SH_ScrollView_FrameOnlyAroundContents, 0, q));
+    if (frameOnlyAround) {
+        if (hbarpolicy == Qt::ScrollBarAlwaysOn)
+            height -= frameWidth * 2;
+        if (vbarpolicy == Qt::ScrollBarAlwaysOn)
+            width -= frameWidth * 2;
+    }
+
+    // Adjust the maximum width and height of the viewport based on the width
+    // of visible scroll bars.
+    int scrollBarExtent = q->style()->pixelMetric(QStyle::PM_ScrollBarExtent, 0, q);
+    if (frameOnlyAround)
+        scrollBarExtent += frameWidth * 2;
+
+    bool useHorizontalScrollBar = (viewRect.width() > width) && hbarpolicy != Qt::ScrollBarAlwaysOff;
+    bool useVerticalScrollBar = (viewRect.height() > height) && vbarpolicy != Qt::ScrollBarAlwaysOff;
+    if (useHorizontalScrollBar && !useVerticalScrollBar) {
+        if (viewRect.height() > height - scrollBarExtent)
+            useVerticalScrollBar = true;
+    }
+    if (useVerticalScrollBar && !useHorizontalScrollBar) {
+        if (viewRect.width() > width - scrollBarExtent)
+            useHorizontalScrollBar = true;
+    }
+    if (useHorizontalScrollBar && hbarpolicy != Qt::ScrollBarAlwaysOn)
+        height -= scrollBarExtent;
+    if (useVerticalScrollBar && vbarpolicy != Qt::ScrollBarAlwaysOn)
+        width -= scrollBarExtent;
+
+    // Setting the ranges of these scroll bars can/will cause the values to
+    // change, and scrollContentsBy() will be called correspondingly. This
+    // will reset the last center point.
+    QPointF savedLastCenterPoint = lastCenterPoint;
+
+    // Remember the former indent settings
+    qreal oldLeftIndent = leftIndent;
+    qreal oldTopIndent = topIndent;
+
+    // If the whole scene fits horizontally, we center the scene horizontally,
+    // and ignore the horizontal scroll bars.
+    int left =  q_round_bound(viewRect.left());
+    int right = q_round_bound(viewRect.right() - width);
+    if (left >= right) {
+        q->horizontalScrollBar()->setRange(0, 0);
+
+        switch (alignment & Qt::AlignHorizontal_Mask) {
+        case Qt::AlignLeft:
+            leftIndent = -viewRect.left();
+            break;
+        case Qt::AlignRight:
+            leftIndent = width - viewRect.width() - viewRect.left() - 1;
+            break;
+        case Qt::AlignHCenter:
+        default:
+            leftIndent = width / 2 - (viewRect.left() + viewRect.right()) / 2;
+            break;
+        }
+    } else {
+        q->horizontalScrollBar()->setRange(left, right);
+        q->horizontalScrollBar()->setPageStep(width);
+        q->horizontalScrollBar()->setSingleStep(width / 20);
+        leftIndent = 0;
+    }
+
+    // If the whole scene fits vertically, we center the scene vertically, and
+    // ignore the vertical scroll bars.
+    int top = q_round_bound(viewRect.top());
+    int bottom = q_round_bound(viewRect.bottom()  - height);
+    if (top >= bottom) {
+        q->verticalScrollBar()->setRange(0, 0);
+
+        switch (alignment & Qt::AlignVertical_Mask) {
+        case Qt::AlignTop:
+            topIndent = -viewRect.top();
+            break;
+        case Qt::AlignBottom:
+            topIndent = height - viewRect.height() - viewRect.top() - 1;
+            break;
+        case Qt::AlignVCenter:
+        default:
+            topIndent = height / 2 - (viewRect.top() + viewRect.bottom()) / 2;
+            break;
+        }
+    } else {
+        q->verticalScrollBar()->setRange(top, bottom);
+        q->verticalScrollBar()->setPageStep(height);
+        q->verticalScrollBar()->setSingleStep(height / 20);
+        topIndent = 0;
+    }
+
+    // Restorethe center point from before the ranges changed.
+    lastCenterPoint = savedLastCenterPoint;
+
+    // Issue a full update if the indents change.
+    // ### If the transform is still the same, we can get away with just a
+    // scroll instead.
+    if (oldLeftIndent != leftIndent || oldTopIndent != topIndent) {
+        dirtyScroll = true;
+        q->viewport()->update();
+    } else if (q->isRightToLeft() && !leftIndent) {
+        // In reverse mode, the horizontal scroll always changes after the content
+        // size has changed, as the scroll is calculated by summing the min and
+        // max values of the range and subtracting the current value. In normal
+        // mode the scroll remains unchanged unless the indent has changed.
+        dirtyScroll = true;
+    }
+
+    if (cacheMode & QGraphicsView::CacheBackground) {
+        // Invalidate the background pixmap
+        mustResizeBackgroundPixmap = true;
+    }
+}
+
+/*!
+    \internal
+*/
+void QGraphicsViewPrivate::centerView(QGraphicsView::ViewportAnchor anchor)
+{
+    Q_Q(QGraphicsView);
+    switch (anchor) {
+    case QGraphicsView::AnchorUnderMouse: {
+        if (q->underMouse()) {
+            // Last scene pos: lastMouseMoveScenePoint
+            // Current mouse pos:
+            QPointF transformationDiff = q->mapToScene(q->viewport()->rect().center())
+                                         - q->mapToScene(q->mapFromGlobal(QCursor::pos()));
+            q->centerOn(lastMouseMoveScenePoint + transformationDiff);;
+        } else {
+            q->centerOn(lastCenterPoint);
+        }
+        break;
+    }
+    case QGraphicsView::AnchorViewCenter:
+        q->centerOn(lastCenterPoint);
+        break;
+    case QGraphicsView::NoAnchor:
+        break;
+    }
+}
+
+/*!
+    \internal
+*/
+void QGraphicsViewPrivate::updateLastCenterPoint()
+{
+    Q_Q(QGraphicsView);
+    lastCenterPoint = q->mapToScene(q->viewport()->rect().center());
+}
+
+/*!
+    \internal
+
+    Returns the horizontal scroll value (the X value of the left edge of the
+    viewport).
+*/
+qint64 QGraphicsViewPrivate::horizontalScroll() const
+{
+    if (dirtyScroll)
+        const_cast<QGraphicsViewPrivate *>(this)->updateScroll();
+    return scrollX;
+}
+
+/*!
+    \internal
+
+    Returns the vertical scroll value (the X value of the top edge of the
+    viewport).
+*/
+qint64 QGraphicsViewPrivate::verticalScroll() const
+{
+    if (dirtyScroll)
+        const_cast<QGraphicsViewPrivate *>(this)->updateScroll();
+    return scrollY;
+}
+
+/*!
+    \internal
+*/
+void QGraphicsViewPrivate::updateScroll()
+{
+    Q_Q(QGraphicsView);
+    scrollX = qint64(-leftIndent);
+    if (q->isRightToLeft()) {
+        if (!leftIndent) {
+            scrollX += q->horizontalScrollBar()->minimum();
+            scrollX += q->horizontalScrollBar()->maximum();
+            scrollX -= q->horizontalScrollBar()->value();
+        }
+    } else {
+        scrollX += q->horizontalScrollBar()->value();
+    }
+
+    scrollY = qint64(q->verticalScrollBar()->value() - topIndent);
+
+    dirtyScroll = false;
+}
+
+/*!
+    \internal
+*/
+void QGraphicsViewPrivate::replayLastMouseEvent()
+{
+    if (!useLastMouseEvent || !scene)
+        return;
+    mouseMoveEventHandler(&lastMouseEvent);
+}
+
+/*!
+    \internal
+*/
+void QGraphicsViewPrivate::storeMouseEvent(QMouseEvent *event)
+{
+    useLastMouseEvent = true;
+    lastMouseEvent = QMouseEvent(QEvent::MouseMove, event->pos(), event->globalPos(),
+                                 event->button(), event->buttons(), event->modifiers());
+}
+
+void QGraphicsViewPrivate::mouseMoveEventHandler(QMouseEvent *event)
+{
+    Q_Q(QGraphicsView);
+
+    storeMouseEvent(event);
+    lastMouseEvent.setAccepted(false);
+
+    if (!sceneInteractionAllowed)
+        return;
+    if (handScrolling)
+        return;
+    if (!scene)
+        return;
+
+    QGraphicsSceneMouseEvent mouseEvent(QEvent::GraphicsSceneMouseMove);
+    mouseEvent.setWidget(q->viewport());
+    mouseEvent.setButtonDownScenePos(mousePressButton, mousePressScenePoint);
+    mouseEvent.setButtonDownScreenPos(mousePressButton, mousePressScreenPoint);
+    mouseEvent.setScenePos(q->mapToScene(event->pos()));
+    mouseEvent.setScreenPos(event->globalPos());
+    mouseEvent.setLastScenePos(lastMouseMoveScenePoint);
+    mouseEvent.setLastScreenPos(lastMouseMoveScreenPoint);
+    mouseEvent.setButtons(event->buttons());
+    mouseEvent.setButton(event->button());
+    mouseEvent.setModifiers(event->modifiers());
+    lastMouseMoveScenePoint = mouseEvent.scenePos();
+    lastMouseMoveScreenPoint = mouseEvent.screenPos();
+    mouseEvent.setAccepted(false);
+    QApplication::sendEvent(scene, &mouseEvent);
+
+    // Remember whether the last event was accepted or not.
+    lastMouseEvent.setAccepted(mouseEvent.isAccepted());
+
+    if (mouseEvent.isAccepted() && mouseEvent.buttons() != 0) {
+        // The event was delivered to a mouse grabber; the press is likely to
+        // have set a cursor, and we must not change it.
+        return;
+    }
+
+#ifndef QT_NO_CURSOR
+    // Find the topmost item under the mouse with a cursor.
+    foreach (QGraphicsItem *item, scene->d_func()->cachedItemsUnderMouse) {
+        if (item->hasCursor()) {
+            _q_setViewportCursor(item->cursor());
+            return;
+        }
+    }
+
+    // No items with cursors found; revert to the view cursor.
+    if (hasStoredOriginalCursor) {
+        // Restore the original viewport cursor.
+        hasStoredOriginalCursor = false;
+        q->viewport()->setCursor(originalCursor);
+    }
+#endif
+}
+
+/*!
+    \internal
+*/
+#ifndef QT_NO_RUBBERBAND
+QRegion QGraphicsViewPrivate::rubberBandRegion(const QWidget *widget, const QRect &rect) const
+{
+    QStyleHintReturnMask mask;
+    QStyleOptionRubberBand option;
+    option.initFrom(widget);
+    option.rect = rect;
+    option.opaque = false;
+    option.shape = QRubberBand::Rectangle;
+
+    QRegion tmp;
+    tmp += rect;
+    if (widget->style()->styleHint(QStyle::SH_RubberBand_Mask, &option, widget, &mask))
+        tmp &= mask.region;
+    return tmp;
+}
+#endif
+
+/*!
+    \internal
+*/
+#ifndef QT_NO_CURSOR
+void QGraphicsViewPrivate::_q_setViewportCursor(const QCursor &cursor)
+{
+    Q_Q(QGraphicsView);
+    QWidget *viewport = q->viewport();
+    if (!hasStoredOriginalCursor) {
+        hasStoredOriginalCursor = true;
+        originalCursor = viewport->cursor();
+    }
+    viewport->setCursor(cursor);
+}
+#endif
+
+/*!
+    \internal
+*/
+#ifndef QT_NO_CURSOR
+void QGraphicsViewPrivate::_q_unsetViewportCursor()
+{
+    Q_Q(QGraphicsView);
+    foreach (QGraphicsItem *item, q->items(lastMouseEvent.pos())) {
+        if (item->hasCursor()) {
+            _q_setViewportCursor(item->cursor());
+            return;
+        }
+    }
+
+    // Restore the original viewport cursor.
+    hasStoredOriginalCursor = false;
+    if (dragMode == QGraphicsView::ScrollHandDrag)
+        q->viewport()->setCursor(Qt::OpenHandCursor);
+    else
+        q->viewport()->setCursor(originalCursor);
+}
+#endif
+
+/*!
+    \internal
+*/
+void QGraphicsViewPrivate::storeDragDropEvent(const QGraphicsSceneDragDropEvent *event)
+{
+    delete lastDragDropEvent;
+    lastDragDropEvent = new QGraphicsSceneDragDropEvent(event->type());
+    lastDragDropEvent->setScenePos(event->scenePos());
+    lastDragDropEvent->setScreenPos(event->screenPos());
+    lastDragDropEvent->setButtons(event->buttons());
+    lastDragDropEvent->setModifiers(event->modifiers());
+    lastDragDropEvent->setPossibleActions(event->possibleActions());
+    lastDragDropEvent->setProposedAction(event->proposedAction());
+    lastDragDropEvent->setDropAction(event->dropAction());
+    lastDragDropEvent->setMimeData(event->mimeData());
+    lastDragDropEvent->setWidget(event->widget());
+    lastDragDropEvent->setSource(event->source());
+}
+
+/*!
+    \internal
+*/
+void QGraphicsViewPrivate::populateSceneDragDropEvent(QGraphicsSceneDragDropEvent *dest,
+                                                      QDropEvent *source)
+{
+#ifndef QT_NO_DRAGANDDROP
+    Q_Q(QGraphicsView);
+    dest->setScenePos(q->mapToScene(source->pos()));
+    dest->setScreenPos(q->mapToGlobal(source->pos()));
+    dest->setButtons(source->mouseButtons());
+    dest->setModifiers(source->keyboardModifiers());
+    dest->setPossibleActions(source->possibleActions());
+    dest->setProposedAction(source->proposedAction());
+    dest->setDropAction(source->dropAction());
+    dest->setMimeData(source->mimeData());
+    dest->setWidget(q->viewport());
+    dest->setSource(source->source());
+#else
+    Q_UNUSED(dest)
+    Q_UNUSED(source)
+#endif
+}
+
+/*!
+    \internal
+*/
+QRect QGraphicsViewPrivate::mapToViewRect(const QGraphicsItem *item, const QRectF &rect) const
+{
+    Q_Q(const QGraphicsView);
+    if (dirtyScroll)
+        const_cast<QGraphicsViewPrivate *>(this)->updateScroll();
+
+    if (item->d_ptr->itemIsUntransformable()) {
+        QTransform itv = item->deviceTransform(q->viewportTransform());
+        return itv.mapRect(rect).toAlignedRect();
+    }
+
+    // Translate-only
+    QPointF offset;
+    const QGraphicsItem *parentItem = item;
+    const QGraphicsItemPrivate *itemd;
+    do {
+        itemd = parentItem->d_ptr;
+        if (itemd->hasTransform)
+            break;
+        offset += itemd->pos;
+    } while ((parentItem = itemd->parent));
+
+    QRectF baseRect = rect.translated(offset.x(), offset.y());
+    if (!parentItem) {
+        if (identityMatrix) {
+            baseRect.translate(-scrollX, -scrollY);
+            return baseRect.toAlignedRect();
+        }
+        return matrix.mapRect(baseRect).translated(-scrollX, -scrollY).toAlignedRect();
+    }
+
+    QTransform tr = parentItem->sceneTransform();
+    if (!identityMatrix)
+        tr *= matrix;
+    QRectF r = tr.mapRect(baseRect);
+    r.translate(-scrollX, -scrollY);
+    return r.toAlignedRect();
+}
+
+/*!
+    \internal
+*/
+QRegion QGraphicsViewPrivate::mapToViewRegion(const QGraphicsItem *item, const QRectF &rect) const
+{
+    Q_Q(const QGraphicsView);
+    if (dirtyScroll)
+        const_cast<QGraphicsViewPrivate *>(this)->updateScroll();
+
+    // Accurate bounding region
+    QTransform itv = item->sceneTransform() * q->viewportTransform();
+    return item->boundingRegion(itv) & itv.mapRect(rect).toAlignedRect();
+}
+
+/*!
+    \internal
+*/
+void QGraphicsViewPrivate::itemUpdated(QGraphicsItem *item, const QRectF &rect)
+{
+    if (fullUpdatePending || viewportUpdateMode == QGraphicsView::NoViewportUpdate)
+        return;
+    if (item->d_ptr->dirty)
+        updateLater();
+
+    QRectF updateRect = rect;
+    if (item->isClipped()) {
+        // Minimize unnecessary redraw.
+        QGraphicsItem *p = item;
+        while ((p = p->d_ptr->parent)) {
+            if (p->flags() & QGraphicsItem::ItemClipsChildrenToShape) {
+                updateRect &= p->itemTransform(item).mapRect(p->boundingRect());
+                if (updateRect.isNull())
+                    return;
+            }
+
+            if (!(p->d_ptr->ancestorFlags & QGraphicsItemPrivate::AncestorClipsChildren))
+                break;
+        }
+
+        if (updateRect.isNull())
+            return;
+    }
+
+    // Map the rect to view coordinates.
+    QRect vr = viewport->rect();
+
+    if (!item->d_ptr->hasBoundingRegionGranularity) {
+        QRect r = mapToViewRect(item, updateRect) & vr;
+        if (r.isNull())
+            return;
+        this->updateRect(r);
+    } else {
+        QRegion r = mapToViewRegion(item, updateRect) & vr;
+        if (r.isEmpty())
+            return;
+        updateRegion(r);
+    }
+}
+
+void QGraphicsViewPrivate::updateLater()
+{
+    Q_Q(QGraphicsView);
+    if (updatingLater)
+        return;
+    updatingLater = true;
+    QMetaObject::invokeMethod(q, "_q_updateLaterSlot", Qt::QueuedConnection);
+}
+
+void QGraphicsViewPrivate::_q_updateLaterSlot()
+{
+    Q_Q(QGraphicsView);
+    if (!scene)
+        return;
+
+    QRect vr = viewport->rect();
+    QTransform viewTransform = q->viewportTransform();
+    const QList<QGraphicsItem *> &dirtyItems = scene->d_func()->dirtyItems;
+    for (int i = 0; i < dirtyItems.size(); ++i) {
+        const QGraphicsItem *item = dirtyItems.at(i);
+        QTransform x = item->sceneTransform() * viewTransform;
+        QRect viewRect = x.mapRect(item->boundingRect()).toAlignedRect() & vr;
+        if (!viewRect.isNull())
+            updateRect(viewRect);
+    }
+
+    dirtyRectCount += dirtyRects.size();
+
+    bool noUpdate = !fullUpdatePending && viewportUpdateMode == QGraphicsView::FullViewportUpdate;
+    if ((dirtyRectCount > 0 || !dirtyBoundingRect.isNull()) && !fullUpdatePending && !noUpdate) {
+        if (viewportUpdateMode == QGraphicsView::BoundingRectViewportUpdate
+            || (viewportUpdateMode == QGraphicsView::SmartViewportUpdate
+                && dirtyRectCount >= QGRAPHICSVIEW_REGION_RECT_THRESHOLD)) {
+            if (!(optimizationFlags & QGraphicsView::DontAdjustForAntialiasing)) {
+                viewport->update(dirtyBoundingRect.adjusted(-2, -2, 2, 2));
+            } else {
+                viewport->update(dirtyBoundingRect);
+            }
+        } else {
+            // ### Improve this block, which is very slow for complex regions. We
+            // need to strike the balance between having an accurate update
+            // region, and running fast. The below approach is the simplest way to
+            // create a region from a bunch of rects, but we might want to use
+            // other approaches; e.g., a grid of a fixed size representing
+            // quadrants of the viewport, which we mark as dirty depending on the
+            // rectangles in the list. Perhaps this should go into a
+            // QRegion::fromRects(rects, how) function.
+            QRegion region;
+            if (!(optimizationFlags & QGraphicsView::DontAdjustForAntialiasing)) {
+                for (int i = 0; i < dirtyRegions.size(); ++i) {
+                    QVector<QRect> rects = dirtyRegions.at(i).rects();
+                    for (int j = 0; j < rects.size(); ++j)
+                        region += rects.at(j).adjusted(-2, -2, 2, 2);
+                }
+                for (int i = 0; i < dirtyRects.size(); ++i)
+                    region += dirtyRects.at(i).adjusted(-2, -2, 2, 2);
+            } else {
+                for (int i = 0; i < dirtyRegions.size(); ++i)
+                    region += dirtyRegions.at(i);
+                for (int i = 0; i < dirtyRects.size(); ++i)
+                    region += dirtyRects.at(i);
+            }
+
+            viewport->update(region);
+        }
+    }
+
+    dirtyRegions.clear();
+    dirtyRects.clear();
+    dirtyRectCount = 0;
+    dirtyBoundingRect = QRect();
+    updatingLater = false;
+}
+
+void QGraphicsViewPrivate::updateAll()
+{
+    Q_Q(QGraphicsView);
+    q->viewport()->update();
+    fullUpdatePending = true;
+    dirtyRectCount = 0;
+    dirtyBoundingRect = QRect();
+    updatingLater = false;
+}
+
+void QGraphicsViewPrivate::updateRegion(const QRegion &r)
+{
+    Q_Q(QGraphicsView);
+
+    // Rect intersects viewport - update everything?
+    switch (viewportUpdateMode) {
+    case QGraphicsView::FullViewportUpdate:
+        fullUpdatePending = true;
+        q->viewport()->update();
+        break;
+    case QGraphicsView::BoundingRectViewportUpdate:
+        dirtyBoundingRect |= r.boundingRect();
+        if (dirtyBoundingRect == q->viewport()->rect()) {
+            fullUpdatePending = true;
+            q->viewport()->update();
+        } else {
+            updateLater();
+        }
+        break;
+    case QGraphicsView::SmartViewportUpdate:
+        dirtyBoundingRect |= r.boundingRect();
+        if ((dirtyRectCount + r.numRects()) < QGRAPHICSVIEW_REGION_RECT_THRESHOLD)
+            dirtyRegions << r;
+        dirtyRectCount += r.numRects();
+        updateLater();
+        break;
+    case QGraphicsView::MinimalViewportUpdate:
+        dirtyRegions << r;
+        dirtyRectCount += r.numRects();
+        updateLater();
+        break;
+    case QGraphicsView::NoViewportUpdate:
+        // Unreachable
+        break;
+    }
+
+    // Compress the regions...
+    if (dirtyRectCount > QGRAPHICSVIEW_REGION_RECT_THRESHOLD && dirtyRegions.size() > 1) {
+        QRegion masterRegion;
+        for (int i=0; i<dirtyRegions.size(); ++i) {
+            masterRegion |= dirtyRegions.at(i);
+        }
+        dirtyRectCount = masterRegion.numRects();
+        dirtyRegions.clear();
+        dirtyRegions << masterRegion;
+    }
+}
+
+void QGraphicsViewPrivate::updateRect(const QRect &r)
+{
+    Q_Q(QGraphicsView);
+
+    // Rect intersects viewport - update everything?
+    switch (viewportUpdateMode) {
+    case QGraphicsView::FullViewportUpdate:
+        fullUpdatePending = true;
+        q->viewport()->update();
+        break;
+    case QGraphicsView::BoundingRectViewportUpdate:
+        dirtyBoundingRect |= r;
+        if (dirtyBoundingRect == q->viewport()->rect()) {
+            fullUpdatePending = true;
+            q->viewport()->update();
+        } else {
+            updateLater();
+        }
+        break;
+    case QGraphicsView::SmartViewportUpdate:
+        dirtyBoundingRect |= r;
+        if ((dirtyRectCount + dirtyRects.size()) < QGRAPHICSVIEW_REGION_RECT_THRESHOLD)
+            dirtyRects << r;
+        updateLater();
+        break;
+    case QGraphicsView::MinimalViewportUpdate:
+        dirtyRects << r;
+        updateLater();
+        break;
+    case QGraphicsView::NoViewportUpdate:
+        // Unreachable
+        break;
+    }
+}
+
+QStyleOptionGraphicsItem *QGraphicsViewPrivate::allocStyleOptionsArray(int numItems)
+{
+    if (mustAllocateStyleOptions || (numItems > styleOptions.capacity()))
+        // too many items, let's allocate on-the-fly
+        return new QStyleOptionGraphicsItem[numItems];
+
+    // expand only whenever necessary
+    if (numItems > styleOptions.size())
+        styleOptions.resize(numItems);
+
+    mustAllocateStyleOptions = true;
+    return styleOptions.data();
+}
+
+void QGraphicsViewPrivate::freeStyleOptionsArray(QStyleOptionGraphicsItem *array)
+{
+    mustAllocateStyleOptions = false;
+    if (array != styleOptions.data())
+        delete [] array;
+}
+
+extern QPainterPath qt_regionToPath(const QRegion &region);
+
+QList<QGraphicsItem *> QGraphicsViewPrivate::findItems(const QRegion &exposedRegion,
+                                                       const QTransform &worldTransform,
+                                                       bool *allItems) const
+{
+    Q_Q(const QGraphicsView);
+    QList<QGraphicsItem *> itemList;
+    QSet<QGraphicsItem *> tmp;
+    bool simpleTransform = worldTransform.type() <= QTransform::TxScale;
+
+    QPainterPath path = qt_regionToPath(exposedRegion);
+    *allItems = path.contains(q->mapFromScene(scene->d_func()->growingItemsBoundingRect).boundingRect());
+    QList<QRectF> exposedRects;
+    QList<QPolygonF> exposedPolys;
+
+    // Transform the exposed viewport rects to scene rects or polygons
+    foreach (const QRect &rect, exposedRegion.rects()) {
+        QPolygonF exposedPoly = q->mapToScene(rect.adjusted(-1, -1, 1, 1));
+        QRectF exposedRect = exposedPoly.boundingRect();
+        if (!simpleTransform)
+            exposedPolys << exposedPoly;
+        exposedRects << exposedRect;
+    }
+
+    // Find which items need to be drawn.
+    if (*allItems) {
+        // All items are guaranteed within the exposed region, don't bother using the index.
+        foreach (QGraphicsItem *item, scene->items()) {
+            // But we only want to include items that are visible
+            if (item->isVisible())
+                itemList << item;
+        }
+    } else if (simpleTransform) {
+        // Simple rect lookups will do.
+        if (exposedRects.size() > 1) {
+            foreach (const QRectF &rect, exposedRects) {
+                foreach (QGraphicsItem *item, scene->d_func()->items_helper(rect, Qt::IntersectsItemBoundingRect, Qt::SortOrder(-1) /* don't sort */)) {
+                    if (!tmp.contains(item)) {
+                        tmp << item;
+                        itemList << item;
+                    }
+                }
+            }
+        } else {
+            itemList += scene->d_func()->items_helper(exposedRects[0], Qt::IntersectsItemBoundingRect, Qt::SortOrder(-1) /* don't sort */);
+        }
+    } else {
+        // Polygon lookup is necessary.
+        if (exposedRects.size() > 1) {
+            foreach (const QPolygonF &poly, exposedPolys) {
+                foreach (QGraphicsItem *item, scene->d_func()->items_helper(poly, Qt::IntersectsItemBoundingRect, Qt::SortOrder(-1) /* don't sort */)) {
+                    if (!tmp.contains(item)) {
+                        tmp << item;
+                        itemList << item;
+                    }
+                }
+            }
+        } else {
+            itemList += scene->d_func()->items_helper(exposedPolys[0], Qt::IntersectsItemBoundingRect, Qt::SortOrder(-1) /* don't sort */);
+        }
+    }
+
+    // Check for items that ignore inherited transformations, and add them if
+    // necessary.
+    QRectF untr = scene->d_func()->largestUntransformableItem;
+    if (!*allItems && !untr.isNull()) {
+        // Map the largest untransformable item subtree boundingrect from view
+        // to scene coordinates, and use this to expand all exposed rects in
+        // search for untransformable items.
+        QRectF ltri = matrix.inverted().mapRect(untr);
+        ltri.adjust(-untr.width(), -untr.height(), untr.width(), untr.height());
+
+        foreach (const QRect &rect, exposedRegion.rects()) {
+            QRectF exposed = q->mapToScene(rect.adjusted(-1, -1, 1, 1)).boundingRect();
+            exposed.adjust(-ltri.width(), -ltri.height(), ltri.width(), ltri.height());
+
+            foreach (QGraphicsItem *item, scene->d_func()->estimateItemsInRect(exposed)) {
+                if (item->d_ptr->itemIsUntransformable()) {
+                    if (!tmp.contains(item)) {
+                        QPainterPath rectPath;
+                        rectPath.addRect(rect);
+                        QPainterPath path = item->deviceTransform(q->viewportTransform()).inverted().map(rectPath);
+                        if (item->collidesWithPath(path, Qt::IntersectsItemBoundingRect)) {
+                            itemList << item;
+                            tmp << item;
+                        }
+                    }
+                }
+            }
+        }
+    }
+    tmp.clear();
+
+    // Sort the items.
+    QGraphicsScenePrivate::sortItems(&itemList, Qt::DescendingOrder,
+                                     scene->d_func()->sortCacheEnabled);
+
+    return itemList;
+}
+
+void QGraphicsViewPrivate::generateStyleOptions(const QList<QGraphicsItem *> &itemList,
+                                                QGraphicsItem **itemArray,
+                                                QStyleOptionGraphicsItem *styleOptionArray,
+                                                const QTransform &worldTransform,
+                                                bool allItems,
+                                                const QRegion &exposedRegion) const
+{
+    // Two unit vectors.
+    QLineF v1(0, 0, 1, 0);
+    QLineF v2(0, 0, 0, 1);
+    QTransform itemToViewportTransform;
+    QRectF brect;
+    QTransform reverseMap;
+
+    for (int i = 0; i < itemList.size(); ++i) {
+        QGraphicsItem *item = itemArray[i] = itemList[i];
+
+        QStyleOptionGraphicsItem &option = styleOptionArray[i];
+        brect = item->boundingRect();
+        option.state = QStyle::State_None;
+        option.rect = brect.toRect();
+        option.exposedRect = QRectF();
+        if (item->d_ptr->selected)
+            option.state |= QStyle::State_Selected;
+        if (item->d_ptr->enabled)
+            option.state |= QStyle::State_Enabled;
+        if (item->hasFocus())
+            option.state |= QStyle::State_HasFocus;
+        if (scene->d_func()->hoverItems.contains(item))
+            option.state |= QStyle::State_MouseOver;
+        if (item == scene->mouseGrabberItem())
+            option.state |= QStyle::State_Sunken;
+
+        // Calculate a simple level-of-detail metric.
+        // ### almost identical code in QGraphicsScene::render()
+        //     and QGraphicsView::render() - consider refactoring
+        if (item->d_ptr->itemIsUntransformable()) {
+            itemToViewportTransform = item->deviceTransform(worldTransform);
+        } else {
+            itemToViewportTransform = item->sceneTransform() * worldTransform;
+        }
+
+        if (itemToViewportTransform.type() <= QTransform::TxTranslate) {
+            // Translation and rotation only? The LOD is 1.
+            option.levelOfDetail = 1;
+        } else {
+            // LOD is the transformed area of a 1x1 rectangle.
+            option.levelOfDetail = qSqrt(itemToViewportTransform.map(v1).length() * itemToViewportTransform.map(v2).length());
+        }
+        option.matrix = itemToViewportTransform.toAffine(); //### discards perspective
+
+        if (!allItems) {
+            // Determine the item's exposed area
+            reverseMap = itemToViewportTransform.inverted();
+            foreach (const QRect &rect, exposedRegion.rects()) {
+                option.exposedRect |= reverseMap.mapRect(QRectF(rect.adjusted(-1, -1, 1, 1)));
+                if (option.exposedRect.contains(brect))
+                    break;
+            }
+            option.exposedRect &= brect;
+        } else {
+            // The whole item is exposed
+            option.exposedRect = brect;
+        }
+    }
+}
+
+/*!
+    Constructs a QGraphicsView. \a parent is passed to QWidget's constructor.
+*/
+QGraphicsView::QGraphicsView(QWidget *parent)
+    : QAbstractScrollArea(*new QGraphicsViewPrivate, parent)
+{
+    setViewport(0);
+    setAcceptDrops(true);
+    setBackgroundRole(QPalette::Base);
+
+    // ### Ideally this would be enabled/disabled depending on whether any
+    // widgets in the current scene enabled input methods. We could do that
+    // using a simple reference count. The same goes for acceptDrops and mouse
+    // tracking.
+    setAttribute(Qt::WA_InputMethodEnabled);
+}
+
+/*!
+    Constructs a QGraphicsView and sets the visualized scene to \a
+    scene. \a parent is passed to QWidget's constructor.
+*/
+QGraphicsView::QGraphicsView(QGraphicsScene *scene, QWidget *parent)
+    : QAbstractScrollArea(*new QGraphicsViewPrivate, parent)
+{
+    setScene(scene);
+    setViewport(0);
+    setAcceptDrops(true);
+    setBackgroundRole(QPalette::Base);
+    setAttribute(Qt::WA_InputMethodEnabled);
+}
+
+/*!
+  \internal
+ */
+QGraphicsView::QGraphicsView(QGraphicsViewPrivate &dd, QWidget *parent)
+  : QAbstractScrollArea(dd, parent)
+{
+    setViewport(0);
+    setAcceptDrops(true);
+    setBackgroundRole(QPalette::Base);
+    setAttribute(Qt::WA_InputMethodEnabled);
+}
+
+/*!
+    Destructs the QGraphicsView object.
+*/
+QGraphicsView::~QGraphicsView()
+{
+    Q_D(QGraphicsView);
+    if (d->scene)
+        d->scene->d_func()->views.removeAll(this);
+    delete d->lastDragDropEvent;
+}
+
+/*!
+    \reimp
+*/
+QSize QGraphicsView::sizeHint() const
+{
+    Q_D(const QGraphicsView);
+    if (d->scene) {
+        QSizeF baseSize = d->matrix.mapRect(sceneRect()).size();
+        baseSize += QSizeF(d->frameWidth * 2, d->frameWidth * 2);
+        return baseSize.boundedTo((3 * QApplication::desktop()->size()) / 4).toSize();
+    }
+    return QAbstractScrollArea::sizeHint();
+}
+
+/*!
+    \property QGraphicsView::renderHints
+    \brief the default render hints for the view
+
+    These hints are
+    used to initialize QPainter before each visible item is drawn. QPainter
+    uses render hints to toggle rendering features such as antialiasing and
+    smooth pixmap transformation.
+
+    QPainter::TextAntialiasing is enabled by default.
+
+    Example:
+
+    \snippet doc/src/snippets/code/src_gui_graphicsview_qgraphicsview.cpp 1
+*/
+QPainter::RenderHints QGraphicsView::renderHints() const
+{
+    Q_D(const QGraphicsView);
+    return d->renderHints;
+}
+void QGraphicsView::setRenderHints(QPainter::RenderHints hints)
+{
+    Q_D(QGraphicsView);
+    if (hints == d->renderHints)
+        return;
+    d->renderHints = hints;
+    viewport()->update();
+}
+
+/*!
+    If \a enabled is true, the render hint \a hint is enabled; otherwise it
+    is disabled.
+
+    \sa renderHints
+*/
+void QGraphicsView::setRenderHint(QPainter::RenderHint hint, bool enabled)
+{
+    Q_D(QGraphicsView);
+    QPainter::RenderHints oldHints = d->renderHints;
+    if (enabled)
+        d->renderHints |= hint;
+    else
+        d->renderHints &= ~hint;
+    if (oldHints != d->renderHints)
+        viewport()->update();
+}
+
+/*!
+    \property QGraphicsView::alignment
+    \brief the alignment of the scene in the view when the whole
+    scene is visible.
+
+    If the whole scene is visible in the view, (i.e., there are no visible
+    scroll bars,) the view's alignment will decide where the scene will be
+    rendered in the view. For example, if the alignment is Qt::AlignCenter,
+    which is default, the scene will be centered in the view, and if the
+    alignment is (Qt::AlignLeft | Qt::AlignTop), the scene will be rendered in
+    the top-left corner of the view.
+*/
+Qt::Alignment QGraphicsView::alignment() const
+{
+    Q_D(const QGraphicsView);
+    return d->alignment;
+}
+void QGraphicsView::setAlignment(Qt::Alignment alignment)
+{
+    Q_D(QGraphicsView);
+    if (d->alignment != alignment) {
+        d->alignment = alignment;
+        d->recalculateContentSize();
+    }
+}
+
+/*!
+    \property QGraphicsView::transformationAnchor
+    \brief how the view should position the scene during transformations.
+
+    QGraphicsView uses this property to decide how to position the scene in
+    the viewport when the transformation matrix changes, and the coordinate
+    system of the view is transformed. The default behavior, AnchorViewCenter,
+    ensures that the scene point at the center of the view remains unchanged
+    during transformations (e.g., when rotating, the scene will appear to
+    rotate around the center of the view).
+
+    Note that the effect of this property is noticeable when only a part of the
+    scene is visible (i.e., when there are scroll bars). Otherwise, if the
+    whole scene fits in the view, QGraphicsScene uses the view \l alignment to
+    position the scene in the view.
+
+    \sa alignment, resizeAnchor
+*/
+QGraphicsView::ViewportAnchor QGraphicsView::transformationAnchor() const
+{
+    Q_D(const QGraphicsView);
+    return d->transformationAnchor;
+}
+void QGraphicsView::setTransformationAnchor(ViewportAnchor anchor)
+{
+    Q_D(QGraphicsView);
+    d->transformationAnchor = anchor;
+}
+
+/*!
+    \property QGraphicsView::resizeAnchor
+    \brief how the view should position the scene when the view is resized.
+
+    QGraphicsView uses this property to decide how to position the scene in
+    the viewport when the viewport widget's size changes. The default
+    behavior, NoAnchor, leaves the scene's position unchanged during a resize;
+    the top-left corner of the view will appear to be anchored while resizing.
+
+    Note that the effect of this property is noticeable when only a part of the
+    scene is visible (i.e., when there are scroll bars). Otherwise, if the
+    whole scene fits in the view, QGraphicsScene uses the view \l alignment to
+    position the scene in the view.
+
+    \sa alignment, transformationAnchor, Qt::WNorthWestGravity
+*/
+QGraphicsView::ViewportAnchor QGraphicsView::resizeAnchor() const
+{
+    Q_D(const QGraphicsView);
+    return d->resizeAnchor;
+}
+void QGraphicsView::setResizeAnchor(ViewportAnchor anchor)
+{
+    Q_D(QGraphicsView);
+    d->resizeAnchor = anchor;
+}
+
+/*!
+    \property QGraphicsView::viewportUpdateMode
+    \brief how the viewport should update its contents.
+
+    \since 4.3
+
+    QGraphicsView uses this property to decide how to update areas of the
+    scene that have been reexposed or changed. Usually you do not need to
+    modify this property, but there are some cases where doing so can improve
+    rendering performance. See the ViewportUpdateMode documentation for
+    specific details.
+
+    The default value is MinimalViewportUpdate, where QGraphicsView will
+    update as small an area of the viewport as possible when the contents
+    change.
+
+    \sa ViewportUpdateMode, cacheMode
+*/
+QGraphicsView::ViewportUpdateMode QGraphicsView::viewportUpdateMode() const
+{
+    Q_D(const QGraphicsView);
+    return d->viewportUpdateMode;
+}
+void QGraphicsView::setViewportUpdateMode(ViewportUpdateMode mode)
+{
+    Q_D(QGraphicsView);
+    d->viewportUpdateMode = mode;
+}
+
+/*!
+    \property QGraphicsView::optimizationFlags
+    \brief flags that can be used to tune QGraphicsView's performance.
+
+    \since 4.3
+
+    QGraphicsView uses clipping, extra bounding rect adjustments, and certain
+    other aids to improve rendering quality and performance for the common
+    case graphics scene. However, depending on the target platform, the scene,
+    and the viewport in use, some of these operations can degrade performance.
+
+    The effect varies from flag to flag; see the OptimizationFlags
+    documentation for details.
+
+    By default, no optimization flags are enabled.
+
+    \sa setOptimizationFlag()
+*/
+QGraphicsView::OptimizationFlags QGraphicsView::optimizationFlags() const
+{
+    Q_D(const QGraphicsView);
+    return d->optimizationFlags;
+}
+void QGraphicsView::setOptimizationFlags(OptimizationFlags flags)
+{
+    Q_D(QGraphicsView);
+    d->optimizationFlags = flags;
+}
+
+/*!
+    Enables \a flag if \a enabled is true; otherwise disables \a flag.
+
+    \sa optimizationFlags
+*/
+void QGraphicsView::setOptimizationFlag(OptimizationFlag flag, bool enabled)
+{
+    Q_D(QGraphicsView);
+    if (enabled)
+        d->optimizationFlags |= flag;
+    else
+        d->optimizationFlags &= ~flag;
+}
+
+/*!
+    \property QGraphicsView::dragMode
+    \brief the behavior for dragging the mouse over the scene while
+    the left mouse button is pressed.
+
+    This property defines what should happen when the user clicks on the scene
+    background and drags the mouse (e.g., scrolling the viewport contents
+    using a pointing hand cursor, or selecting multiple items with a rubber
+    band). The default value, NoDrag, does nothing.
+
+    This behavior only affects mouse clicks that are not handled by any item.
+    You can define a custom behavior by creating a subclass of QGraphicsView
+    and reimplementing mouseMoveEvent().
+*/
+QGraphicsView::DragMode QGraphicsView::dragMode() const
+{
+    Q_D(const QGraphicsView);
+    return d->dragMode;
+}
+void QGraphicsView::setDragMode(DragMode mode)
+{
+    Q_D(QGraphicsView);
+    if (d->dragMode == mode)
+        return;
+
+#ifndef QT_NO_CURSOR
+    if (d->dragMode == ScrollHandDrag)
+        viewport()->unsetCursor();
+#endif
+
+    // If dragMode is unset while dragging, e.g. via a keyEvent, we
+    // don't unset the handScrolling state. When enabling scrolling
+    // again the mouseMoveEvent will automatically start scrolling,
+    // without a mousePress
+    if (d->dragMode == ScrollHandDrag && mode == NoDrag && d->handScrolling)
+        d->handScrolling = false;
+
+    d->dragMode = mode;
+
+#ifndef QT_NO_CURSOR
+    if (d->dragMode == ScrollHandDrag) {
+        // Forget the stored viewport cursor when we enter scroll hand drag mode.
+        d->hasStoredOriginalCursor = false;
+        viewport()->setCursor(Qt::OpenHandCursor);
+    }
+#endif
+}
+
+#ifndef QT_NO_RUBBERBAND
+/*!
+    \property QGraphicsView::rubberBandSelectionMode
+    \brief the behavior for selecting items with a rubber band selection rectangle.
+    \since 4.3
+
+    This property defines how items are selected when using the RubberBandDrag
+    drag mode.
+
+    The default value is Qt::IntersectsItemShape; all items whose shape
+    intersects with or is contained by the rubber band are selected.
+
+    \sa dragMode, items()
+*/
+Qt::ItemSelectionMode QGraphicsView::rubberBandSelectionMode() const
+{
+    Q_D(const QGraphicsView);
+    return d->rubberBandSelectionMode;
+}
+void QGraphicsView::setRubberBandSelectionMode(Qt::ItemSelectionMode mode)
+{
+    Q_D(QGraphicsView);
+    d->rubberBandSelectionMode = mode;
+}
+#endif
+
+/*!
+    \property QGraphicsView::cacheMode
+    \brief which parts of the view are cached
+
+    QGraphicsView can cache pre-rendered content in a QPixmap, which is then
+    drawn onto the viewport. The purpose of such caching is to speed up the
+    total rendering time for areas that are slow to render.  Texture, gradient
+    and alpha blended backgrounds, for example, can be notibly slow to render;
+    especially with a transformed view. The CacheBackground flag enables
+    caching of the view's background. For example:
+
+    \snippet doc/src/snippets/code/src_gui_graphicsview_qgraphicsview.cpp 2
+
+    The cache is invalidated every time the view is transformed. However, when
+    scrolling, only partial invalidation is required.
+
+    By default, nothing is cached.
+
+    \sa resetCachedContent(), QPixmapCache
+*/
+QGraphicsView::CacheMode QGraphicsView::cacheMode() const
+{
+    Q_D(const QGraphicsView);
+    return d->cacheMode;
+}
+void QGraphicsView::setCacheMode(CacheMode mode)
+{
+    Q_D(QGraphicsView);
+    if (mode == d->cacheMode)
+        return;
+    d->cacheMode = mode;
+    resetCachedContent();
+}
+
+/*!
+    Resets any cached content. Calling this function will clear
+    QGraphicsView's cache. If the current cache mode is \l CacheNone, this
+    function does nothing.
+
+    This function is called automatically for you when the backgroundBrush or
+    QGraphicsScene::backgroundBrush properties change; you only need to call
+    this function if you have reimplemented QGraphicsScene::drawBackground()
+    or QGraphicsView::drawBackground() to draw a custom background, and need
+    to trigger a full redraw.
+
+    \sa cacheMode()
+*/
+void QGraphicsView::resetCachedContent()
+{
+    Q_D(QGraphicsView);
+    if (d->cacheMode == CacheNone)
+        return;
+
+    if (d->cacheMode & CacheBackground) {
+        // Background caching is enabled.
+        d->mustResizeBackgroundPixmap = true;
+        viewport()->update();
+    } else if (d->mustResizeBackgroundPixmap) {
+        // Background caching is disabled.
+        // Cleanup, free some resources.
+        d->mustResizeBackgroundPixmap = false;
+        d->backgroundPixmap = QPixmap();
+        d->backgroundPixmapExposed = QRegion();
+    }
+}
+
+/*!
+    Invalidates and schedules a redraw of \a layers inside \a rect. \a rect is
+    in scene coordinates. Any cached content for \a layers inside \a rect is
+    unconditionally invalidated and redrawn.
+
+    You can call this function to notify QGraphicsView of changes to the
+    background or the foreground of the scene. It is commonly used for scenes
+    with tile-based backgrounds to notify changes when QGraphicsView has
+    enabled background caching.
+
+    Note that QGraphicsView currently supports background caching only (see
+    QGraphicsView::CacheBackground). This function is equivalent to calling update() if any
+    layer but QGraphicsScene::BackgroundLayer is passed.
+
+    \sa QGraphicsScene::invalidate(), update()
+*/
+void QGraphicsView::invalidateScene(const QRectF &rect, QGraphicsScene::SceneLayers layers)
+{
+    Q_D(QGraphicsView);
+    if ((layers & QGraphicsScene::BackgroundLayer) && !d->mustResizeBackgroundPixmap) {
+        QRect viewRect = mapFromScene(rect).boundingRect();
+        if (viewport()->rect().intersects(viewRect)) {
+            // The updated background area is exposed; schedule this area for
+            // redrawing.
+            d->backgroundPixmapExposed += viewRect;
+            if (d->scene)
+                d->scene->update(rect);
+        }
+    }
+}
+
+/*!
+    \property QGraphicsView::interactive
+    \brief whether the view allowed scene interaction.
+
+    If enabled, this view is set to allow scene interaction. Otherwise, this
+    view will not allow interaction, and any mouse or key events are ignored
+    (i.e., it will act as a read-only view).
+
+    By default, this property is true.
+*/
+bool QGraphicsView::isInteractive() const
+{
+    Q_D(const QGraphicsView);
+    return d->sceneInteractionAllowed;
+}
+void QGraphicsView::setInteractive(bool allowed)
+{
+    Q_D(QGraphicsView);
+    d->sceneInteractionAllowed = allowed;
+}
+
+/*!
+    Returns a pointer to the scene that is currently visualized in the
+    view. If no scene is currently visualized, 0 is returned.
+
+    \sa setScene()
+*/
+QGraphicsScene *QGraphicsView::scene() const
+{
+    Q_D(const QGraphicsView);
+    return d->scene;
+}
+
+/*!
+    Sets the current scene to \a scene. If \a scene is already being
+    viewed, this function does nothing.
+
+    When a scene is set on a view, the QGraphicsScene::changed() signal
+    is automatically connected to this view's updateScene() slot, and the
+    view's scroll bars are adjusted to fit the size of the scene.
+*/
+void QGraphicsView::setScene(QGraphicsScene *scene)
+{
+    Q_D(QGraphicsView);
+    if (d->scene == scene)
+        return;
+
+    // Always update the viewport when the scene changes.
+    viewport()->update();
+
+    // Remove the previously assigned scene.
+    if (d->scene) {
+        disconnect(d->scene, SIGNAL(changed(QList<QRectF>)),
+                   this, SLOT(updateScene(QList<QRectF>)));
+        disconnect(d->scene, SIGNAL(sceneRectChanged(QRectF)),
+                   this, SLOT(updateSceneRect(QRectF)));
+        d->scene->d_func()->views.removeAll(this);
+    }
+
+    // Assign the new scene and update the contents (scrollbars, etc.)).
+    if ((d->scene = scene)) {
+        connect(d->scene, SIGNAL(sceneRectChanged(QRectF)),
+                this, SLOT(updateSceneRect(QRectF)));
+        d->updateSceneSlotReimplementedChecked = false;
+        d->scene->d_func()->views << this;
+        d->recalculateContentSize();
+        d->lastCenterPoint = sceneRect().center();
+        d->keepLastCenterPoint = true;
+    } else {
+        d->recalculateContentSize();
+    }
+}
+
+/*!
+    \property QGraphicsView::sceneRect
+    \brief the area of the scene visualized by this view.
+
+    The scene rectangle defines the extent of the scene, and in the view's case,
+    this means the area of the scene that you can navigate using the scroll
+    bars.
+
+    If unset, or if a null QRectF is set, this property has the same value as
+    QGraphicsScene::sceneRect, and it changes with
+    QGraphicsScene::sceneRect. Otherwise, the view's scene rect is unaffected
+    by the scene.
+
+    Note that, although the scene supports a virtually unlimited size, the
+    range of the scroll bars will never exceed the range of an integer
+    (INT_MIN, INT_MAX). When the scene is larger than the scroll bars' values,
+    you can choose to use translate() to navigate the scene instead.
+
+    By default, this property contains a rectangle at the origin with zero
+    width and height.
+
+    \sa QGraphicsScene::sceneRect
+*/
+QRectF QGraphicsView::sceneRect() const
+{
+    Q_D(const QGraphicsView);
+    if (d->hasSceneRect)
+        return d->sceneRect;
+    if (d->scene)
+        return d->scene->sceneRect();
+    return QRectF();
+}
+void QGraphicsView::setSceneRect(const QRectF &rect)
+{
+    Q_D(QGraphicsView);
+    d->hasSceneRect = !rect.isNull();
+    d->sceneRect = rect;
+    d->recalculateContentSize();
+}
+
+/*!
+    Returns the current transformation matrix for the view. If no current
+    transformation is set, the identity matrix is returned.
+
+    \sa setMatrix(), rotate(), scale(), shear(), translate()
+*/
+QMatrix QGraphicsView::matrix() const
+{
+    Q_D(const QGraphicsView);
+    return d->matrix.toAffine();
+}
+
+/*!
+    Sets the view's current transformation matrix to \a matrix.
+
+    If \a combine is true, then \a matrix is combined with the current matrix;
+    otherwise, \a matrix \e replaces the current matrix. \a combine is false
+    by default.
+
+    The transformation matrix tranforms the scene into view coordinates. Using
+    the default transformation, provided by the identity matrix, one pixel in
+    the view represents one unit in the scene (e.g., a 10x10 rectangular item
+    is drawn using 10x10 pixels in the view). If a 2x2 scaling matrix is
+    applied, the scene will be drawn in 1:2 (e.g., a 10x10 rectangular item is
+    then drawn using 20x20 pixels in the view).
+
+    Example:
+
+    \snippet doc/src/snippets/code/src_gui_graphicsview_qgraphicsview.cpp 3
+
+    To simplify interation with items using a transformed view, QGraphicsView
+    provides mapTo... and mapFrom... functions that can translate between
+    scene and view coordinates. For example, you can call mapToScene() to map
+    a view coordinate to a floating point scene coordinate, or mapFromScene()
+    to map from floating point scene coordinates to view coordinates.
+
+    \sa matrix(), rotate(), scale(), shear(), translate()
+*/
+void QGraphicsView::setMatrix(const QMatrix &matrix, bool combine)
+{
+    setTransform(QTransform(matrix), combine);
+}
+
+/*!
+    Resets the view transformation matrix to the identity matrix.
+*/
+void QGraphicsView::resetMatrix()
+{
+    resetTransform();
+}
+
+/*!
+    Rotates the current view transformation \a angle degrees clockwise.
+
+    \sa setMatrix(), matrix(), scale(), shear(), translate()
+*/
+void QGraphicsView::rotate(qreal angle)
+{
+    Q_D(QGraphicsView);
+    QTransform matrix = d->matrix;
+    matrix.rotate(angle);
+    setTransform(matrix);
+}
+
+/*!
+    Scales the current view transformation by (\a sx, \a sy).
+
+    \sa setMatrix(), matrix(), rotate(), shear(), translate()
+*/
+void QGraphicsView::scale(qreal sx, qreal sy)
+{
+    Q_D(QGraphicsView);
+    QTransform matrix = d->matrix;
+    matrix.scale(sx, sy);
+    setTransform(matrix);
+}
+
+/*!
+    Shears the current view transformation by (\a sh, \a sv).
+
+    \sa setMatrix(), matrix(), rotate(), scale(), translate()
+*/
+void QGraphicsView::shear(qreal sh, qreal sv)
+{
+    Q_D(QGraphicsView);
+    QTransform matrix = d->matrix;
+    matrix.shear(sh, sv);
+    setTransform(matrix);
+}
+
+/*!
+    Translates the current view transformation by (\a dx, \a dy).
+
+    \sa setMatrix(), matrix(), rotate(), shear()
+*/
+void QGraphicsView::translate(qreal dx, qreal dy)
+{
+    Q_D(QGraphicsView);
+    QTransform matrix = d->matrix;
+    matrix.translate(dx, dy);
+    setTransform(matrix);
+}
+
+/*!
+    Scrolls the contents of the viewport to ensure that the scene
+    coordinate \a pos, is centered in the view.
+
+    Because \a pos is a floating point coordinate, and the scroll bars operate
+    on integer coordinates, the centering is only an approximation.
+
+    \note If the item is close to or outside the border, it will be visible
+    in the view, but not centered.
+
+    \sa ensureVisible()
+*/
+void QGraphicsView::centerOn(const QPointF &pos)
+{
+    Q_D(QGraphicsView);
+    qreal width = viewport()->width();
+    qreal height = viewport()->height();
+    QPointF viewPoint = d->matrix.map(pos);
+    QPointF oldCenterPoint = pos;
+
+    if (!d->leftIndent) {
+        if (isRightToLeft()) {
+            qint64 horizontal = 0;
+            horizontal += horizontalScrollBar()->minimum();
+            horizontal += horizontalScrollBar()->maximum();
+            horizontal -= int(viewPoint.x() - width / 2.0);
+            horizontalScrollBar()->setValue(horizontal);
+        } else {
+            horizontalScrollBar()->setValue(int(viewPoint.x() - width / 2.0));
+        }
+    }
+    if (!d->topIndent)
+        verticalScrollBar()->setValue(int(viewPoint.y() - height / 2.0));
+    d->lastCenterPoint = oldCenterPoint;
+}
+
+/*!
+    \fn QGraphicsView::centerOn(qreal x, qreal y)
+    \overload
+
+    This function is provided for convenience. It's equivalent to calling
+    centerOn(QPointF(\a x, \a y)).
+*/
+
+/*!
+    \overload
+
+    Scrolls the contents of the viewport to ensure that \a item
+    is centered in the view.
+
+    \sa ensureVisible()
+*/
+void QGraphicsView::centerOn(const QGraphicsItem *item)
+{
+    centerOn(item->sceneBoundingRect().center());
+}
+
+/*!
+    Scrolls the contents of the viewport so that the scene rectangle \a rect
+    is visible, with margins specified in pixels by \a xmargin and \a
+    ymargin. If the specified rect cannot be reached, the contents are
+    scrolled to the nearest valid position. The default value for both margins
+    is 50 pixels.
+
+    \sa centerOn()
+*/
+void QGraphicsView::ensureVisible(const QRectF &rect, int xmargin, int ymargin)
+{
+    Q_D(QGraphicsView);
+    Q_UNUSED(xmargin);
+    Q_UNUSED(ymargin);
+    qreal width = viewport()->width();
+    qreal height = viewport()->height();
+    QRectF viewRect = d->matrix.mapRect(rect);
+
+    qreal left = d->horizontalScroll();
+    qreal right = left + width;
+    qreal top = d->verticalScroll();
+    qreal bottom = top + height;
+
+    if (viewRect.left() <= left + xmargin) {
+        // need to scroll from the left
+        if (!d->leftIndent)
+            horizontalScrollBar()->setValue(int(viewRect.left() - xmargin - 0.5));
+    }
+    if (viewRect.right() >= right - xmargin) {
+        // need to scroll from the right
+        if (!d->leftIndent)
+            horizontalScrollBar()->setValue(int(viewRect.right() - width + xmargin + 0.5));
+    }
+    if (viewRect.top() <= top + ymargin) {
+        // need to scroll from the top
+        if (!d->topIndent)
+            verticalScrollBar()->setValue(int(viewRect.top() - ymargin - 0.5));
+    }
+    if (viewRect.bottom() >= bottom - ymargin) {
+        // need to scroll from the bottom
+        if (!d->topIndent)
+            verticalScrollBar()->setValue(int(viewRect.bottom() - height + ymargin + 0.5));
+    }
+}
+
+/*!
+    \fn QGraphicsView::ensureVisible(qreal x, qreal y, qreal w, qreal h,
+    int xmargin, int ymargin)
+    \overload
+
+    This function is provided for convenience. It's equivalent to calling
+    ensureVisible(QRectF(\a x, \a y, \a w, \a h), \a xmargin, \a ymargin).
+*/
+
+/*!
+    \overload
+
+    Scrolls the contents of the viewport so that the center of item \a item is
+    visible, with margins specified in pixels by \a xmargin and \a ymargin. If
+    the specified point cannot be reached, the contents are scrolled to the
+    nearest valid position. The default value for both margins is 50 pixels.
+
+    \sa centerOn()
+*/
+void QGraphicsView::ensureVisible(const QGraphicsItem *item, int xmargin, int ymargin)
+{
+    ensureVisible(item->sceneBoundingRect(), xmargin, ymargin);
+}
+
+/*!
+    Scales the view matrix and scrolls the scroll bars to ensure that the
+    scene rectangle \a rect fits inside the viewport. \a rect must be inside
+    the scene rect; otherwise, fitInView() cannot guarantee that the whole
+    rect is visible.
+
+    This function keeps the view's rotation, translation, or shear. The view
+    is scaled according to \a aspectRatioMode. \a rect will be centered in the
+    view if it does not fit tightly.
+
+    It's common to call fitInView() from inside a reimplementation of
+    resizeEvent(), to ensure that the whole scene, or parts of the scene,
+    scales automatically to fit the new size of the viewport as the view is
+    resized. Note though, that calling fitInView() from inside resizeEvent()
+    can lead to unwanted resize recursion, if the new transformation toggles
+    the automatic state of the scrollbars. You can toggle the scrollbar
+    policies to always on or always off to prevent this (see
+    horizontalScrollBarPolicy() and verticalScrollBarPolicy()).
+
+    If \a rect is empty, or if the viewport is too small, this
+    function will do nothing.
+
+    \sa setMatrix(), ensureVisible(), centerOn()
+*/
+void QGraphicsView::fitInView(const QRectF &rect, Qt::AspectRatioMode aspectRatioMode)
+{
+    Q_D(QGraphicsView);
+    if (!d->scene || rect.isNull())
+        return;
+
+    // Reset the view scale to 1:1.
+    QRectF unity = d->matrix.mapRect(QRectF(0, 0, 1, 1));
+    if (unity.isEmpty())
+        return;
+    scale(1 / unity.width(), 1 / unity.height());
+
+    // Find the ideal x / y scaling ratio to fit \a rect in the view.
+    int margin = 2;
+    QRectF viewRect = viewport()->rect().adjusted(margin, margin, -margin, -margin);
+    if (viewRect.isEmpty())
+        return;
+    QRectF sceneRect = d->matrix.mapRect(rect);
+    if (sceneRect.isEmpty())
+        return;
+    qreal xratio = viewRect.width() / sceneRect.width();
+    qreal yratio = viewRect.height() / sceneRect.height();
+
+    // Respect the aspect ratio mode.
+    switch (aspectRatioMode) {
+    case Qt::KeepAspectRatio:
+        xratio = yratio = qMin(xratio, yratio);
+        break;
+    case Qt::KeepAspectRatioByExpanding:
+        xratio = yratio = qMax(xratio, yratio);
+        break;
+    case Qt::IgnoreAspectRatio:
+        break;
+    }
+
+    // Scale and center on the center of \a rect.
+    scale(xratio, yratio);
+    centerOn(rect.center());
+}
+
+/*!
+    \fn void QGraphicsView::fitInView(qreal x, qreal y, qreal w, qreal h,
+    Qt::AspectRatioMode aspectRatioMode = Qt::IgnoreAspectRatio)
+
+    \overload
+
+    This convenience function is equivalent to calling
+    fitInView(QRectF(\a x, \a y, \a w, \a h), \a aspectRatioMode).
+
+    \sa ensureVisible(), centerOn()
+*/
+
+/*!
+    \overload
+
+    Ensures that \a item fits tightly inside the view, scaling the view
+    according to \a aspectRatioMode.
+
+    \sa ensureVisible(), centerOn()
+*/
+void QGraphicsView::fitInView(const QGraphicsItem *item, Qt::AspectRatioMode aspectRatioMode)
+{
+    QPainterPath path = item->isClipped() ? item->clipPath() : item->shape();
+    fitInView(item->sceneTransform().map(path).boundingRect(), aspectRatioMode);
+}
+
+/*!
+    Renders the \a source rect, which is in view coordinates, from the scene
+    into \a target, which is in paint device coordinates, using \a
+    painter. This function is useful for capturing the contents of the view
+    onto a paint device, such as a QImage (e.g., to take a screenshot), or for
+    printing to QPrinter. For example:
+
+    \snippet doc/src/snippets/code/src_gui_graphicsview_qgraphicsview.cpp 4
+
+    If \a source is a null rect, this function will use viewport()->rect() to
+    determine what to draw. If \a target is a null rect, the full dimensions
+    of \a painter's paint device (e.g., for a QPrinter, the page size) will be
+    used.
+
+    The source rect contents will be transformed according to \a
+    aspectRatioMode to fit into the target rect. By default, the aspect ratio
+    is kept, and \a source is scaled to fit in \a target.
+
+    \sa QGraphicsScene::render()
+*/
+void QGraphicsView::render(QPainter *painter, const QRectF &target, const QRect &source,
+                           Qt::AspectRatioMode aspectRatioMode)
+{
+    Q_D(QGraphicsView);
+    if (!d->scene || !(painter && painter->isActive()))
+        return;
+
+    // Default source rect = viewport rect
+    QRect sourceRect = source;
+    if (source.isNull())
+        sourceRect = viewport()->rect();
+
+    // Default target rect = device rect
+    QRectF targetRect = target;
+    if (target.isNull()) {
+        if (painter->device()->devType() == QInternal::Picture)
+            targetRect = sourceRect;
+        else
+            targetRect.setRect(0, 0, painter->device()->width(), painter->device()->height());
+    }
+
+    // Find the ideal x / y scaling ratio to fit \a source into \a target.
+    qreal xratio = targetRect.width() / sourceRect.width();
+    qreal yratio = targetRect.height() / sourceRect.height();
+
+    // Scale according to the aspect ratio mode.
+    switch (aspectRatioMode) {
+    case Qt::KeepAspectRatio:
+        xratio = yratio = qMin(xratio, yratio);
+        break;
+    case Qt::KeepAspectRatioByExpanding:
+        xratio = yratio = qMax(xratio, yratio);
+        break;
+    case Qt::IgnoreAspectRatio:
+        break;
+    }
+
+    // Find all items to draw, and reverse the list (we want to draw
+    // in reverse order).
+    QPolygonF sourceScenePoly = mapToScene(sourceRect.adjusted(-1, -1, 1, 1));
+    QList<QGraphicsItem *> itemList = d->scene->items(sourceScenePoly,
+                                                      Qt::IntersectsItemBoundingRect);
+    QGraphicsItem **itemArray = new QGraphicsItem *[itemList.size()];
+    int numItems = itemList.size();
+    for (int i = 0; i < numItems; ++i)
+        itemArray[numItems - i - 1] = itemList.at(i);
+    itemList.clear();
+
+    // Setup painter matrix.
+    QTransform moveMatrix;
+    moveMatrix.translate(-d->horizontalScroll(), -d->verticalScroll());
+    QTransform painterMatrix = d->matrix * moveMatrix;
+    painterMatrix *= QTransform()
+                     .translate(targetRect.left(), targetRect.top())
+                     .scale(xratio, yratio)
+                     .translate(-sourceRect.left(), -sourceRect.top());
+
+    // Two unit vectors.
+    QLineF v1(0, 0, 1, 0);
+    QLineF v2(0, 0, 0, 1);
+
+    // Generate the style options
+    QStyleOptionGraphicsItem *styleOptionArray = d->allocStyleOptionsArray(numItems);
+    QStyleOptionGraphicsItem* option = styleOptionArray;
+    for (int i = 0; i < numItems; ++i, ++option) {
+        QGraphicsItem *item = itemArray[i];
+
+        option->state = QStyle::State_None;
+        option->rect = item->boundingRect().toRect();
+        if (item->isSelected())
+            option->state |= QStyle::State_Selected;
+        if (item->isEnabled())
+            option->state |= QStyle::State_Enabled;
+        if (item->hasFocus())
+            option->state |= QStyle::State_HasFocus;
+        if (d->scene->d_func()->hoverItems.contains(item))
+            option->state |= QStyle::State_MouseOver;
+        if (item == d->scene->mouseGrabberItem())
+            option->state |= QStyle::State_Sunken;
+
+        // Calculate a simple level-of-detail metric.
+        // ### almost identical code in QGraphicsScene::render()
+        //     and QGraphicsView::paintEvent() - consider refactoring
+        QTransform itemToViewportTransform;
+        if (item->d_ptr->itemIsUntransformable()) {
+            itemToViewportTransform = item->deviceTransform(painterMatrix);
+        } else {
+            itemToViewportTransform = item->sceneTransform() * painterMatrix;
+        }
+
+        option->levelOfDetail = qSqrt(itemToViewportTransform.map(v1).length() * itemToViewportTransform.map(v2).length());
+        option->matrix = itemToViewportTransform.toAffine();
+
+        option->exposedRect = item->boundingRect();
+        option->exposedRect &= itemToViewportTransform.inverted().mapRect(targetRect);
+    }
+
+    painter->save();
+
+    // Clip in device coordinates to avoid QRegion transformations.
+    painter->setClipRect(targetRect);
+    QPainterPath path;
+    path.addPolygon(sourceScenePoly);
+    path.closeSubpath();
+    painter->setClipPath(painterMatrix.map(path), Qt::IntersectClip);
+
+    // Transform the painter.
+    painter->setTransform(painterMatrix, true);
+
+    // Render the scene.
+    QRectF sourceSceneRect = sourceScenePoly.boundingRect();
+    drawBackground(painter, sourceSceneRect);
+    drawItems(painter, numItems, itemArray, styleOptionArray);
+    drawForeground(painter, sourceSceneRect);
+
+    delete [] itemArray;
+    d->freeStyleOptionsArray(styleOptionArray);
+
+    painter->restore();
+}
+
+/*!
+    Returns a list of all the items in the associated scene.
+
+    \sa QGraphicsScene::items()
+*/
+QList<QGraphicsItem *> QGraphicsView::items() const
+{
+    Q_D(const QGraphicsView);
+    if (!d->scene)
+        return QList<QGraphicsItem *>();
+    return d->scene->items();
+}
+
+/*!
+    Returns all items in the area \a path, which is in viewport coordinates,
+    also taking untransformable items into consideration. This function is
+    considerably slower than just checking the scene directly. There is
+    certainly room for improvement.
+*/
+QList<QGraphicsItem *> QGraphicsViewPrivate::itemsInArea(const QPainterPath &path,
+                                                         Qt::ItemSelectionMode mode) const
+{
+    Q_Q(const QGraphicsView);
+
+    // Determine the size of the largest untransformable subtree of children
+    // mapped to scene coordinates.
+    QRectF untr = scene->d_func()->largestUntransformableItem;
+    QRectF ltri = matrix.inverted().mapRect(untr);
+    ltri.adjust(-untr.width(), -untr.height(), untr.width(), untr.height());
+
+    QRectF rect = path.controlPointRect();
+
+    // Find all possible items in the relevant area.
+    // ### Improve this algorithm; it might be searching a too large area.
+    QRectF adjustedRect = q->mapToScene(rect.adjusted(-1, -1, 1, 1).toRect()).boundingRect();
+    adjustedRect.adjust(-ltri.width(), -ltri.height(), ltri.width(), ltri.height());
+
+    // First build a (potentially large) list of all items in the vicinity
+    // that might be untransformable.
+    QList<QGraphicsItem *> allCandidates = scene->d_func()->estimateItemsInRect(adjustedRect);
+
+    // Then find the minimal list of items that are inside \a path, and
+    // convert it to a set.
+    QList<QGraphicsItem *> regularCandidates = scene->items(q->mapToScene(path), mode);
+    QSet<QGraphicsItem *> candSet = QSet<QGraphicsItem *>::fromList(regularCandidates);
+
+    QTransform viewMatrix = q->viewportTransform();
+
+    QList<QGraphicsItem *> result;
+
+    // Run through all candidates and keep all items that are in candSet, or
+    // are untransformable and collide with \a path. ### We can improve this
+    // algorithm.
+    QList<QGraphicsItem *>::Iterator it = allCandidates.begin();
+    while (it != allCandidates.end()) {
+        QGraphicsItem *item = *it;
+        if (item->d_ptr->itemIsUntransformable()) {
+            // Check if this untransformable item collides with the
+            // original selection rect.
+            QTransform itemTransform = item->deviceTransform(viewMatrix);
+            if (QGraphicsScenePrivate::itemCollidesWithPath(item, itemTransform.inverted().map(path), mode))
+                result << item;
+        } else {
+            if (candSet.contains(item))
+                result << item;
+        }
+        ++it;
+    }
+
+    // ### Insertion sort would be faster.
+    QGraphicsScenePrivate::sortItems(&result, Qt::AscendingOrder,
+                                     scene->d_func()->sortCacheEnabled);
+    return result;
+}
+
+/*!
+    Returns a list of all the items at the position \a pos in the view. The
+    items are listed in descending Z order (i.e., the first item in the list
+    is the top-most item, and the last item is the bottom-most item). \a pos
+    is in viewport coordinates.
+
+    This function is most commonly called from within mouse event handlers in
+    a subclass in QGraphicsView. \a pos is in untransformed viewport
+    coordinates, just like QMouseEvent::pos().
+
+    \snippet doc/src/snippets/code/src_gui_graphicsview_qgraphicsview.cpp 5
+
+    \sa QGraphicsScene::items(), QGraphicsItem::zValue()
+*/
+QList<QGraphicsItem *> QGraphicsView::items(const QPoint &pos) const
+{
+    Q_D(const QGraphicsView);
+    if (!d->scene)
+        return QList<QGraphicsItem *>();
+    if (d->scene->d_func()->largestUntransformableItem.isNull()) {
+        if ((d->identityMatrix || d->matrix.type() <= QTransform::TxScale)) {
+            QTransform xinv = viewportTransform().inverted();
+            return d->scene->items(xinv.mapRect(QRectF(pos.x(), pos.y(), 1, 1)));
+        }
+        return d->scene->items(mapToScene(pos.x(), pos.y(), 2, 2));
+    }
+
+    QPainterPath path;
+    path.addRect(QRectF(pos.x(), pos.y(), 1, 1));
+    return d->itemsInArea(path);
+}
+
+/*!
+    \fn QGraphicsView::items(int x, int y) const
+
+    This function is provided for convenience. It's equivalent to calling
+    items(QPoint(\a x, \a y)).
+*/
+
+/*!
+    \overload
+
+    Returns a list of all the items that, depending on \a mode, are either
+    contained by or intersect with \a rect. \a rect is in viewport
+    coordinates.
+
+    The default value for \a mode is Qt::IntersectsItemShape; all items whose
+    exact shape intersects with or is contained by \a rect are returned.
+
+    \sa itemAt(), items(), mapToScene()
+*/
+QList<QGraphicsItem *> QGraphicsView::items(const QRect &rect, Qt::ItemSelectionMode mode) const
+{
+    Q_D(const QGraphicsView);
+    if (!d->scene)
+        return QList<QGraphicsItem *>();
+    if (d->scene->d_func()->largestUntransformableItem.isNull())
+        return d->scene->items(mapToScene(rect), mode);
+
+    QPainterPath path;
+    path.addRect(rect);
+    return d->itemsInArea(path);
+}
+
+/*!
+    \fn QList<QGraphicsItem *> QGraphicsView::items(int x, int y, int w, int h, Qt::ItemSelectionMode mode) const
+    \since 4.3
+
+    This convenience function is equivalent to calling items(QRectF(\a x, \a
+    y, \a w, \a h), \a mode).
+*/
+
+/*!
+    \overload
+
+    Returns a list of all the items that, depending on \a mode, are either
+    contained by or intersect with \a polygon. \a polygon is in viewport
+    coordinates.
+
+    The default value for \a mode is Qt::IntersectsItemShape; all items whose
+    exact shape intersects with or is contained by \a polygon are returned.
+
+    \sa itemAt(), items(), mapToScene()
+*/
+QList<QGraphicsItem *> QGraphicsView::items(const QPolygon &polygon, Qt::ItemSelectionMode mode) const
+{
+    Q_D(const QGraphicsView);
+    if (!d->scene)
+        return QList<QGraphicsItem *>();
+    if (d->scene->d_func()->largestUntransformableItem.isNull())
+        return d->scene->items(mapToScene(polygon), mode);
+
+    QPainterPath path;
+    path.addPolygon(polygon);
+    path.closeSubpath();
+    return d->itemsInArea(path);
+}
+
+/*!
+    \overload
+
+    Returns a list of all the items that, depending on \a mode, are either
+    contained by or intersect with \a path. \a path is in viewport
+    coordinates.
+
+    The default value for \a mode is Qt::IntersectsItemShape; all items whose
+    exact shape intersects with or is contained by \a path are returned.
+
+    \sa itemAt(), items(), mapToScene()
+*/
+QList<QGraphicsItem *> QGraphicsView::items(const QPainterPath &path, Qt::ItemSelectionMode mode) const
+{
+    Q_D(const QGraphicsView);
+    if (!d->scene)
+        return QList<QGraphicsItem *>();
+    if (d->scene->d_func()->largestUntransformableItem.isNull())
+        return d->scene->items(mapToScene(path), mode);
+    return d->itemsInArea(path);
+}
+
+/*!
+    Returns the item at position \a pos, which is in viewport coordinates.
+    If there are several items at this position, this function returns
+    the topmost item.
+
+    Example:
+
+    \snippet doc/src/snippets/code/src_gui_graphicsview_qgraphicsview.cpp 6
+
+    \sa items()
+*/
+QGraphicsItem *QGraphicsView::itemAt(const QPoint &pos) const
+{
+    Q_D(const QGraphicsView);
+    if (!d->scene)
+        return 0;
+    QList<QGraphicsItem *> itemsAtPos = items(pos);
+    return itemsAtPos.isEmpty() ? 0 : itemsAtPos.first();
+}
+
+/*!
+    \overload
+    \fn QGraphicsItem *QGraphicsView::itemAt(int x, int y) const
+
+    This function is provided for convenience. It's equivalent to
+    calling itemAt(QPoint(\a x, \a y)).
+*/
+
+/*!
+    Returns the viewport coordinate \a point mapped to scene coordinates.
+
+    Note: It can be useful to map the whole rectangle covered by the pixel at
+    \a point instead of the point itself. To do this, you can call
+    mapToScene(QRect(\a point, QSize(2, 2))).
+
+    \sa mapFromScene()
+*/
+QPointF QGraphicsView::mapToScene(const QPoint &point) const
+{
+    Q_D(const QGraphicsView);
+    QPointF p = point;
+    p.rx() += d->horizontalScroll();
+    p.ry() += d->verticalScroll();
+    return d->identityMatrix ? p : d->matrix.inverted().map(p);
+}
+
+/*!
+    \fn QGraphicsView::mapToScene(int x, int y) const
+
+    This function is provided for convenience. It's equivalent to calling
+    mapToScene(QPoint(\a x, \a y)).
+*/
+
+/*!
+    Returns the viewport rectangle \a rect mapped to a scene coordinate
+    polygon.
+
+    \sa mapFromScene()
+*/
+QPolygonF QGraphicsView::mapToScene(const QRect &rect) const
+{
+    Q_D(const QGraphicsView);
+    if (!rect.isValid())
+        return QPolygonF();
+
+    QPointF scrollOffset(d->horizontalScroll(), d->verticalScroll());
+    QPointF tl = scrollOffset + rect.topLeft();
+    QPointF tr = scrollOffset + rect.topRight();
+    QPointF br = scrollOffset + rect.bottomRight();
+    QPointF bl = scrollOffset + rect.bottomLeft();
+
+    QPolygonF poly;
+    poly.resize(4);
+    if (!d->identityMatrix) {
+        QTransform x = d->matrix.inverted();
+        poly[0] = x.map(tl);
+        poly[1] = x.map(tr);
+        poly[2] = x.map(br);
+        poly[3] = x.map(bl);
+    } else {
+        poly[0] = tl;
+        poly[1] = tr;
+        poly[2] = br;
+        poly[3] = bl;
+    }
+    return poly;
+}
+
+/*!
+    \fn QGraphicsView::mapToScene(int x, int y, int w, int h) const
+
+    This function is provided for convenience. It's equivalent to calling
+    mapToScene(QRect(\a x, \a y, \a w, \a h)).
+*/
+
+/*!
+    Returns the viewport polygon \a polygon mapped to a scene coordinate
+    polygon.
+
+    \sa mapFromScene()
+*/
+QPolygonF QGraphicsView::mapToScene(const QPolygon &polygon) const
+{
+    QPolygonF poly;
+    foreach (const QPoint &point, polygon)
+        poly << mapToScene(point);
+    return poly;
+}
+
+/*!
+    Returns the viewport painter path \a path mapped to a scene coordinate
+    painter path.
+
+    \sa mapFromScene()
+*/
+QPainterPath QGraphicsView::mapToScene(const QPainterPath &path) const
+{
+    Q_D(const QGraphicsView);
+    QTransform moveMatrix;
+    moveMatrix.translate(d->horizontalScroll(), d->verticalScroll());
+    return (moveMatrix * d->matrix.inverted()).map(path);
+}
+
+/*!
+    Returns the scene coordinate \a point to viewport coordinates.
+
+    \sa mapToScene()
+*/
+QPoint QGraphicsView::mapFromScene(const QPointF &point) const
+{
+    Q_D(const QGraphicsView);
+    QPointF p = d->identityMatrix ? point : d->matrix.map(point);
+    p.rx() -= d->horizontalScroll();
+    p.ry() -= d->verticalScroll();
+    return p.toPoint();
+}
+
+/*!
+    \fn QGraphicsView::mapFromScene(qreal x, qreal y) const
+
+    This function is provided for convenience. It's equivalent to
+    calling mapFromScene(QPointF(\a x, \a y)).
+*/
+
+/*!
+    Returns the scene rectangle \a rect to a viewport coordinate
+    polygon.
+
+    \sa mapToScene()
+*/
+QPolygon QGraphicsView::mapFromScene(const QRectF &rect) const
+{
+    Q_D(const QGraphicsView);
+    QPointF tl;
+    QPointF tr;
+    QPointF br;
+    QPointF bl;
+    if (!d->identityMatrix) {
+        const QTransform &x = d->matrix;
+        tl = x.map(rect.topLeft());
+        tr = x.map(rect.topRight());
+        br = x.map(rect.bottomRight());
+        bl = x.map(rect.bottomLeft());
+    } else {
+        tl = rect.topLeft();
+        tr = rect.topRight();
+        br = rect.bottomRight();
+        bl = rect.bottomLeft();
+    }
+    QPointF scrollOffset(d->horizontalScroll(), d->verticalScroll());
+    tl -= scrollOffset;
+    tr -= scrollOffset;
+    br -= scrollOffset;
+    bl -= scrollOffset;
+
+    QPolygon poly;
+    poly.resize(4);
+    poly[0] = tl.toPoint();
+    poly[1] = tr.toPoint();
+    poly[2] = br.toPoint();
+    poly[3] = bl.toPoint();
+    return poly;
+}
+
+/*!
+    \fn QGraphicsView::mapFromScene(qreal x, qreal y, qreal w, qreal h) const
+
+    This function is provided for convenience. It's equivalent to
+    calling mapFromScene(QRectF(\a x, \a y, \a w, \a h)).
+*/
+
+/*!
+    Returns the scene coordinate polygon \a polygon to a viewport coordinate
+    polygon.
+
+    \sa mapToScene()
+*/
+QPolygon QGraphicsView::mapFromScene(const QPolygonF &polygon) const
+{
+    QPolygon poly;
+    foreach (const QPointF &point, polygon)
+        poly << mapFromScene(point);
+    return poly;
+}
+
+/*!
+    Returns the scene coordinate painter path \a path to a viewport coordinate
+    painter path.
+
+    \sa mapToScene()
+*/
+QPainterPath QGraphicsView::mapFromScene(const QPainterPath &path) const
+{
+    Q_D(const QGraphicsView);
+    QTransform moveMatrix;
+    moveMatrix.translate(-d->horizontalScroll(), -d->verticalScroll());
+    return (d->matrix * moveMatrix).map(path);
+}
+
+/*!
+    \reimp
+*/
+QVariant QGraphicsView::inputMethodQuery(Qt::InputMethodQuery query) const
+{
+    Q_D(const QGraphicsView);
+    if (!d->scene)
+        return QVariant();
+
+    QVariant value = d->scene->inputMethodQuery(query);
+    if (value.type() == QVariant::RectF)
+        value = mapFromScene(value.toRectF()).boundingRect();
+    else if (value.type() == QVariant::PointF)
+        value = mapFromScene(value.toPointF());
+    else if (value.type() == QVariant::Rect)
+        value = mapFromScene(value.toRect()).boundingRect();
+    else if (value.type() == QVariant::Point)
+        value = mapFromScene(value.toPoint());
+    return value;
+}
+
+/*!
+    \property QGraphicsView::backgroundBrush
+    \brief the background brush of the scene.
+
+    This property sets the background brush for the scene in this view. It is
+    used to override the scene's own background, and defines the behavior of
+    drawBackground(). To provide custom background drawing for this view, you
+    can reimplement drawBackground() instead.
+
+    By default, this property contains a brush with the Qt::NoBrush pattern.
+
+    \sa QGraphicsScene::backgroundBrush, foregroundBrush
+*/
+QBrush QGraphicsView::backgroundBrush() const
+{
+    Q_D(const QGraphicsView);
+    return d->backgroundBrush;
+}
+void QGraphicsView::setBackgroundBrush(const QBrush &brush)
+{
+    Q_D(QGraphicsView);
+    d->backgroundBrush = brush;
+    viewport()->update();
+
+    if (d->cacheMode & CacheBackground) {
+        // Invalidate the background pixmap
+        d->mustResizeBackgroundPixmap = true;
+    }
+}
+
+/*!
+    \property QGraphicsView::foregroundBrush
+    \brief the foreground brush of the scene.
+
+    This property sets the foreground brush for the scene in this view. It is
+    used to override the scene's own foreground, and defines the behavior of
+    drawForeground(). To provide custom foreground drawing for this view, you
+    can reimplement drawForeground() instead.
+
+    By default, this property contains a brush with the Qt::NoBrush pattern.
+
+    \sa QGraphicsScene::foregroundBrush, backgroundBrush
+*/
+QBrush QGraphicsView::foregroundBrush() const
+{
+    Q_D(const QGraphicsView);
+    return d->foregroundBrush;
+}
+void QGraphicsView::setForegroundBrush(const QBrush &brush)
+{
+    Q_D(QGraphicsView);
+    d->foregroundBrush = brush;
+    viewport()->update();
+}
+
+/*!
+    Schedules an update of the scene rectangles \a rects.
+
+    \sa QGraphicsScene::changed()
+*/
+void QGraphicsView::updateScene(const QList<QRectF> &rects)
+{
+    // ### Note: Since 4.5, this slot is only called if the user explicitly
+    // establishes a connection between the scene and the view, as the scene
+    // and view are no longer connected. We need to keep it working (basically
+    // leave it as it is), but the new delivery path is through
+    // QGraphicsScenePrivate::itemUpdate().
+    Q_D(QGraphicsView);
+    if (d->fullUpdatePending || d->viewportUpdateMode == QGraphicsView::NoViewportUpdate)
+        return;
+
+    // Extract and reset dirty scene rect info.
+    QVector<QRect> dirtyViewportRects;
+    for (int i = 0; i < d->dirtyRegions.size(); ++i)
+        dirtyViewportRects += d->dirtyRegions.at(i).rects();
+    d->dirtyRegions.clear();
+
+    bool fullUpdate = !d->accelerateScrolling || d->viewportUpdateMode == QGraphicsView::FullViewportUpdate;
+    bool boundingRectUpdate = (d->viewportUpdateMode == QGraphicsView::BoundingRectViewportUpdate)
+                              || (d->viewportUpdateMode == QGraphicsView::SmartViewportUpdate
+                                  && ((dirtyViewportRects.size() + rects.size()) >= QGRAPHICSVIEW_REGION_RECT_THRESHOLD));
+
+    QRegion updateRegion;
+    QRect boundingRect;
+    QRect viewportRect = viewport()->rect();
+    bool redraw = false;
+    QTransform transform = viewportTransform();
+
+    // Convert scene rects to viewport rects.
+    foreach (const QRectF &rect, rects) {
+        QRect xrect = transform.mapRect(rect).toRect();
+        if (!(d->optimizationFlags & DontAdjustForAntialiasing))
+            xrect.adjust(-2, -2, 2, 2);
+        if (!viewportRect.intersects(xrect))
+            continue;
+        dirtyViewportRects << xrect;
+    }
+
+    foreach (const QRect &rect, dirtyViewportRects) {
+        // Add the exposed rect to the update region. In rect update
+        // mode, we only count the bounding rect of items.
+        if (!boundingRectUpdate) {
+            updateRegion += rect;
+        } else {
+            boundingRect |= rect;
+        }
+        redraw = true;
+        if (fullUpdate) {
+            // If fullUpdate is true and we found a visible dirty rect,
+            // we're done.
+            break;
+        }
+    }
+
+    if (!redraw)
+        return;
+
+    if (fullUpdate)
+        viewport()->update();
+    else if (boundingRectUpdate)
+        viewport()->update(boundingRect);
+    else
+        viewport()->update(updateRegion);
+}
+
+/*!
+    Notifies QGraphicsView that the scene's scene rect has changed.  \a rect
+    is the new scene rect. If the view already has an explicitly set scene
+    rect, this function does nothing.
+
+    \sa sceneRect, QGraphicsScene::sceneRectChanged()
+*/
+void QGraphicsView::updateSceneRect(const QRectF &rect)
+{
+    Q_D(QGraphicsView);
+    if (!d->hasSceneRect) {
+        d->sceneRect = rect;
+        d->recalculateContentSize();
+    }
+}
+
+/*!
+    This slot is called by QAbstractScrollArea after setViewport() has been
+    called. Reimplement this function in a subclass of QGraphicsView to
+    initialize the new viewport \a widget before it is used.
+
+    \sa setViewport()
+*/
+void QGraphicsView::setupViewport(QWidget *widget)
+{
+    Q_D(QGraphicsView);
+
+    if (!widget) {
+        qWarning("QGraphicsView::setupViewport: cannot initialize null widget");
+        return;
+    }
+
+    const bool isGLWidget = widget->inherits("QGLWidget");
+
+    d->accelerateScrolling = !(isGLWidget
+                               || widget->testAttribute(Qt::WA_MSWindowsUseDirect3D)
+                               || qApp->testAttribute(Qt::AA_MSWindowsUseDirect3DByDefault));
+
+    widget->setFocusPolicy(Qt::StrongFocus);
+
+    if (!isGLWidget) {
+        // autoFillBackground enables scroll acceleration.
+        widget->setAutoFillBackground(true);
+    }
+
+    widget->setMouseTracking(true);
+    widget->setAcceptDrops(acceptDrops());
+}
+
+/*!
+    \reimp
+*/
+bool QGraphicsView::event(QEvent *event)
+{
+    Q_D(QGraphicsView);
+
+    if (d->sceneInteractionAllowed) {
+        switch (event->type()) {
+        case QEvent::ShortcutOverride:
+            if (d->scene)
+                return QApplication::sendEvent(d->scene, event);
+            break;
+        case QEvent::KeyPress:
+            if (d->scene) {
+                QKeyEvent *k = static_cast<QKeyEvent *>(event);
+                if (k->key() == Qt::Key_Tab || k->key() == Qt::Key_Backtab) {
+                    // Send the key events to the scene. This will invoke the
+                    // scene's tab focus handling, and if the event is
+                    // accepted, we return (prevent further event delivery),
+                    // and the base implementation will call QGraphicsView's
+                    // focusNextPrevChild() function. If the event is ignored,
+                    // we fall back to standard tab focus handling.
+                    QApplication::sendEvent(d->scene, event);
+                    if (event->isAccepted())
+                        return true;
+                    // Ensure the event doesn't propagate just because the
+                    // scene ignored it. If the event propagates, then tab
+                    // handling will be called twice (this and parent).
+                    event->accept();
+                }
+            }
+            break;
+        default:
+            break;
+        }
+    }
+
+    return QAbstractScrollArea::event(event);
+}
+
+/*!
+    \reimp
+*/
+bool QGraphicsView::viewportEvent(QEvent *event)
+{
+    Q_D(QGraphicsView);
+
+    if (!d->scene)
+        return QAbstractScrollArea::viewportEvent(event);
+
+    switch (event->type()) {
+    case QEvent::Enter:
+        QApplication::sendEvent(d->scene, event);
+        break;
+    case QEvent::WindowActivate:
+        QApplication::sendEvent(d->scene, event);
+        break;
+    case QEvent::WindowDeactivate:
+        // ### This is a temporary fix for until we get proper mouse
+        // grab events. mouseGrabberItem should be set to 0 if we lose
+        // the mouse grab.
+        // Remove all popups when the scene loses focus.
+        if (!d->scene->d_func()->popupWidgets.isEmpty())
+            d->scene->d_func()->removePopup(d->scene->d_func()->popupWidgets.first());
+        QApplication::sendEvent(d->scene, event);
+        break;
+    case QEvent::Leave:
+        // ### This is a temporary fix for until we get proper mouse grab
+        // events. activeMouseGrabberItem should be set to 0 if we lose the
+        // mouse grab.
+        if ((QApplication::activePopupWidget() && QApplication::activePopupWidget() != window())
+            || (QApplication::activeModalWidget() && QApplication::activeModalWidget() != window())
+            || (QApplication::activeWindow() != window())) {
+            if (!d->scene->d_func()->popupWidgets.isEmpty())
+                d->scene->d_func()->removePopup(d->scene->d_func()->popupWidgets.first());
+        }
+        d->useLastMouseEvent = false;
+        QApplication::sendEvent(d->scene, event);
+        break;
+#ifndef QT_NO_TOOLTIP
+    case QEvent::ToolTip: {
+        QHelpEvent *toolTip = static_cast<QHelpEvent *>(event);
+        QGraphicsSceneHelpEvent helpEvent(QEvent::GraphicsSceneHelp);
+        helpEvent.setWidget(viewport());
+        helpEvent.setScreenPos(toolTip->globalPos());
+        helpEvent.setScenePos(mapToScene(toolTip->pos()));
+        QApplication::sendEvent(d->scene, &helpEvent);
+        toolTip->setAccepted(helpEvent.isAccepted());
+        return true;
+    }
+#endif
+    case QEvent::Paint:
+        // Reset full update
+        d->fullUpdatePending = false;
+        if (d->scene) {
+            // Check if this view reimplements the updateScene slot; if it
+            // does, we can't do direct update delivery and have to fall back
+            // to connecting the changed signal.
+            if (!d->updateSceneSlotReimplementedChecked) {
+                d->updateSceneSlotReimplementedChecked = true;
+                const QMetaObject *mo = metaObject();
+                if (mo != &QGraphicsView::staticMetaObject) {
+                    if (mo->indexOfSlot("updateScene(QList<QRectF>)")
+                        != QGraphicsView::staticMetaObject.indexOfSlot("updateScene(QList<QRectF>)")) {
+                        connect(d->scene, SIGNAL(changed(QList<QRectF>)),
+                                this, SLOT(updateScene(QList<QRectF>)));
+                    }
+                }
+            }
+            d->scene->d_func()->updateAll = false;
+        }
+        break;
+    default:
+        break;
+    }
+
+    return QAbstractScrollArea::viewportEvent(event);
+}
+
+#ifndef QT_NO_CONTEXTMENU
+/*!
+    \reimp
+*/
+void QGraphicsView::contextMenuEvent(QContextMenuEvent *event)
+{
+    Q_D(QGraphicsView);
+    if (!d->scene || !d->sceneInteractionAllowed)
+        return;
+
+    d->mousePressViewPoint = event->pos();
+    d->mousePressScenePoint = mapToScene(d->mousePressViewPoint);
+    d->mousePressScreenPoint = event->globalPos();
+    d->lastMouseMoveScenePoint = d->mousePressScenePoint;
+    d->lastMouseMoveScreenPoint = d->mousePressScreenPoint;
+
+    QGraphicsSceneContextMenuEvent contextEvent(QEvent::GraphicsSceneContextMenu);
+    contextEvent.setWidget(viewport());
+    contextEvent.setScenePos(d->mousePressScenePoint);
+    contextEvent.setScreenPos(d->mousePressScreenPoint);
+    contextEvent.setModifiers(event->modifiers());
+    contextEvent.setReason((QGraphicsSceneContextMenuEvent::Reason)(event->reason()));
+    contextEvent.setAccepted(event->isAccepted());
+    QApplication::sendEvent(d->scene, &contextEvent);
+    event->setAccepted(contextEvent.isAccepted());
+}
+#endif // QT_NO_CONTEXTMENU
+
+/*!
+    \reimp
+*/
+void QGraphicsView::dropEvent(QDropEvent *event)
+{
+#ifndef QT_NO_DRAGANDDROP
+    Q_D(QGraphicsView);
+    if (!d->scene || !d->sceneInteractionAllowed)
+        return;
+
+    // Generate a scene event.
+    QGraphicsSceneDragDropEvent sceneEvent(QEvent::GraphicsSceneDrop);
+    d->populateSceneDragDropEvent(&sceneEvent, event);
+
+    // Send it to the scene.
+    QApplication::sendEvent(d->scene, &sceneEvent);
+
+    // Accept the originating event if the scene accepted the scene event.
+    event->setAccepted(sceneEvent.isAccepted());
+    if (sceneEvent.isAccepted())
+        event->setDropAction(sceneEvent.dropAction());
+
+    delete d->lastDragDropEvent;
+    d->lastDragDropEvent = 0;
+
+#else
+    Q_UNUSED(event)
+#endif
+}
+
+/*!
+    \reimp
+*/
+void QGraphicsView::dragEnterEvent(QDragEnterEvent *event)
+{
+#ifndef QT_NO_DRAGANDDROP
+    Q_D(QGraphicsView);
+    if (!d->scene || !d->sceneInteractionAllowed)
+        return;
+
+    // Disable replaying of mouse move events.
+    d->useLastMouseEvent = false;
+
+    // Generate a scene event.
+    QGraphicsSceneDragDropEvent sceneEvent(QEvent::GraphicsSceneDragEnter);
+    d->populateSceneDragDropEvent(&sceneEvent, event);
+
+    // Store it for later use.
+    d->storeDragDropEvent(&sceneEvent);
+
+    // Send it to the scene.
+    QApplication::sendEvent(d->scene, &sceneEvent);
+
+    // Accept the originating event if the scene accepted the scene event.
+    if (sceneEvent.isAccepted()) {
+        event->setAccepted(true);
+        event->setDropAction(sceneEvent.dropAction());
+    }
+#else
+    Q_UNUSED(event)
+#endif
+}
+
+/*!
+    \reimp
+*/
+void QGraphicsView::dragLeaveEvent(QDragLeaveEvent *event)
+{
+#ifndef QT_NO_DRAGANDDROP
+    Q_D(QGraphicsView);
+    if (!d->scene || !d->sceneInteractionAllowed)
+        return;
+    if (!d->lastDragDropEvent) {
+        qWarning("QGraphicsView::dragLeaveEvent: drag leave received before drag enter");
+        return;
+    }
+
+    // Generate a scene event.
+    QGraphicsSceneDragDropEvent sceneEvent(QEvent::GraphicsSceneDragLeave);
+    sceneEvent.setScenePos(d->lastDragDropEvent->scenePos());
+    sceneEvent.setScreenPos(d->lastDragDropEvent->screenPos());
+    sceneEvent.setButtons(d->lastDragDropEvent->buttons());
+    sceneEvent.setModifiers(d->lastDragDropEvent->modifiers());
+    sceneEvent.setPossibleActions(d->lastDragDropEvent->possibleActions());
+    sceneEvent.setProposedAction(d->lastDragDropEvent->proposedAction());
+    sceneEvent.setDropAction(d->lastDragDropEvent->dropAction());
+    sceneEvent.setMimeData(d->lastDragDropEvent->mimeData());
+    sceneEvent.setWidget(d->lastDragDropEvent->widget());
+    sceneEvent.setSource(d->lastDragDropEvent->source());
+    delete d->lastDragDropEvent;
+    d->lastDragDropEvent = 0;
+
+    // Send it to the scene.
+    QApplication::sendEvent(d->scene, &sceneEvent);
+
+    // Accept the originating event if the scene accepted the scene event.
+    if (sceneEvent.isAccepted())
+        event->setAccepted(true);
+#else
+    Q_UNUSED(event)
+#endif
+}
+
+/*!
+    \reimp
+*/
+void QGraphicsView::dragMoveEvent(QDragMoveEvent *event)
+{
+#ifndef QT_NO_DRAGANDDROP
+    Q_D(QGraphicsView);
+    if (!d->scene || !d->sceneInteractionAllowed)
+        return;
+
+    // Generate a scene event.
+    QGraphicsSceneDragDropEvent sceneEvent(QEvent::GraphicsSceneDragMove);
+    d->populateSceneDragDropEvent(&sceneEvent, event);
+
+    // Store it for later use.
+    d->storeDragDropEvent(&sceneEvent);
+
+    // Send it to the scene.
+    QApplication::sendEvent(d->scene, &sceneEvent);
+
+    // Ignore the originating event if the scene ignored the scene event.
+    event->setAccepted(sceneEvent.isAccepted());
+    if (sceneEvent.isAccepted())
+        event->setDropAction(sceneEvent.dropAction());
+#else
+    Q_UNUSED(event)
+#endif
+}
+
+/*!
+    \reimp
+*/
+void QGraphicsView::focusInEvent(QFocusEvent *event)
+{
+    Q_D(QGraphicsView);
+    QAbstractScrollArea::focusInEvent(event);
+    if (d->scene)
+        QApplication::sendEvent(d->scene, event);
+    // Pass focus on if the scene cannot accept focus.
+    if (!d->scene || !event->isAccepted())
+        QAbstractScrollArea::focusInEvent(event);
+}
+
+/*!
+    \reimp
+*/
+bool QGraphicsView::focusNextPrevChild(bool next)
+{
+    return QAbstractScrollArea::focusNextPrevChild(next);
+}
+
+/*!
+    \reimp
+*/
+void QGraphicsView::focusOutEvent(QFocusEvent *event)
+{
+    Q_D(QGraphicsView);
+    QAbstractScrollArea::focusOutEvent(event);
+    if (d->scene)
+        QApplication::sendEvent(d->scene, event);
+}
+
+/*!
+    \reimp
+*/
+void QGraphicsView::keyPressEvent(QKeyEvent *event)
+{
+    Q_D(QGraphicsView);
+    if (!d->scene || !d->sceneInteractionAllowed) {
+        QAbstractScrollArea::keyPressEvent(event);
+        return;
+    }
+    QApplication::sendEvent(d->scene, event);
+    if (!event->isAccepted())
+        QAbstractScrollArea::keyPressEvent(event);
+}
+
+/*!
+    \reimp
+*/
+void QGraphicsView::keyReleaseEvent(QKeyEvent *event)
+{
+    Q_D(QGraphicsView);
+    if (!d->scene || !d->sceneInteractionAllowed)
+        return;
+    QApplication::sendEvent(d->scene, event);
+    if (!event->isAccepted())
+        QAbstractScrollArea::keyReleaseEvent(event);
+}
+
+/*!
+    \reimp
+*/
+void QGraphicsView::mouseDoubleClickEvent(QMouseEvent *event)
+{
+    Q_D(QGraphicsView);
+    if (!d->scene || !d->sceneInteractionAllowed)
+        return;
+
+    d->storeMouseEvent(event);
+    d->mousePressViewPoint = event->pos();
+    d->mousePressScenePoint = mapToScene(d->mousePressViewPoint);
+    d->mousePressScreenPoint = event->globalPos();
+    d->lastMouseMoveScenePoint = d->mousePressScenePoint;
+    d->lastMouseMoveScreenPoint = d->mousePressScreenPoint;
+    d->mousePressButton = event->button();
+
+    QGraphicsSceneMouseEvent mouseEvent(QEvent::GraphicsSceneMouseDoubleClick);
+    mouseEvent.setWidget(viewport());
+    mouseEvent.setButtonDownScenePos(d->mousePressButton, d->mousePressScenePoint);
+    mouseEvent.setButtonDownScreenPos(d->mousePressButton, d->mousePressScreenPoint);
+    mouseEvent.setScenePos(mapToScene(d->mousePressViewPoint));
+    mouseEvent.setScreenPos(d->mousePressScreenPoint);
+    mouseEvent.setLastScenePos(d->lastMouseMoveScenePoint);
+    mouseEvent.setLastScreenPos(d->lastMouseMoveScreenPoint);
+    mouseEvent.setButtons(event->buttons());
+    mouseEvent.setButtons(event->buttons());
+    mouseEvent.setAccepted(false);
+    mouseEvent.setButton(event->button());
+    mouseEvent.setModifiers(event->modifiers());
+    QApplication::sendEvent(d->scene, &mouseEvent);
+}
+
+/*!
+    \reimp
+*/
+void QGraphicsView::mousePressEvent(QMouseEvent *event)
+{
+    Q_D(QGraphicsView);
+
+    // Store this event for replaying, finding deltas, and for
+    // scroll-dragging; even in non-interactive mode, scroll hand dragging is
+    // allowed, so we store the event at the very top of this function.
+    d->storeMouseEvent(event);
+    d->lastMouseEvent.setAccepted(false);
+
+    if (d->sceneInteractionAllowed) {
+        // Store some of the event's button-down data.
+        d->mousePressViewPoint = event->pos();
+        d->mousePressScenePoint = mapToScene(d->mousePressViewPoint);
+        d->mousePressScreenPoint = event->globalPos();
+        d->lastMouseMoveScenePoint = d->mousePressScenePoint;
+        d->lastMouseMoveScreenPoint = d->mousePressScreenPoint;
+        d->mousePressButton = event->button();
+
+        if (d->scene) {
+            // Convert and deliver the mouse event to the scene.
+            QGraphicsSceneMouseEvent mouseEvent(QEvent::GraphicsSceneMousePress);
+            mouseEvent.setWidget(viewport());
+            mouseEvent.setButtonDownScenePos(d->mousePressButton, d->mousePressScenePoint);
+            mouseEvent.setButtonDownScreenPos(d->mousePressButton, d->mousePressScreenPoint);
+            mouseEvent.setScenePos(d->mousePressScenePoint);
+            mouseEvent.setScreenPos(d->mousePressScreenPoint);
+            mouseEvent.setLastScenePos(d->lastMouseMoveScenePoint);
+            mouseEvent.setLastScreenPos(d->lastMouseMoveScreenPoint);
+            mouseEvent.setButtons(event->buttons());
+            mouseEvent.setButton(event->button());
+            mouseEvent.setModifiers(event->modifiers());
+            mouseEvent.setAccepted(false);
+            QApplication::sendEvent(d->scene, &mouseEvent);
+
+            // Update the original mouse event accepted state.
+            bool isAccepted = mouseEvent.isAccepted();
+            event->setAccepted(isAccepted);
+
+            // Update the last mouse event accepted state.
+            d->lastMouseEvent.setAccepted(isAccepted);
+
+            if (isAccepted)
+                return;
+        }
+    }
+
+#ifndef QT_NO_RUBBERBAND
+    if (d->dragMode == QGraphicsView::RubberBandDrag && !d->rubberBanding) {
+        if (d->sceneInteractionAllowed) {
+            // Rubberbanding is only allowed in interactive mode.
+            event->accept();
+            d->rubberBanding = true;
+            d->rubberBandRect = QRect();
+            if (d->scene) {
+                // Initiating a rubber band always clears the selection.
+                d->scene->clearSelection();
+            }
+        }
+    } else
+#endif
+        if (d->dragMode == QGraphicsView::ScrollHandDrag && event->button() == Qt::LeftButton) {
+            // Left-button press in scroll hand mode initiates hand scrolling.
+            event->accept();
+            d->handScrolling = true;
+            d->handScrollMotions = 0;
+#ifndef QT_NO_CURSOR
+            viewport()->setCursor(Qt::ClosedHandCursor);
+#endif
+        }
+}
+
+/*!
+    \reimp
+*/
+void QGraphicsView::mouseMoveEvent(QMouseEvent *event)
+{
+    Q_D(QGraphicsView);
+
+#ifndef QT_NO_RUBBERBAND
+    if (d->dragMode == QGraphicsView::RubberBandDrag && d->sceneInteractionAllowed) {
+        d->storeMouseEvent(event);
+        if (d->rubberBanding) {
+            // Check for enough drag distance
+            if ((d->mousePressViewPoint - event->pos()).manhattanLength()
+                < QApplication::startDragDistance()) {
+                return;
+            }
+
+            // Update old rubberband
+            if (d->viewportUpdateMode != QGraphicsView::NoViewportUpdate && !d->rubberBandRect.isNull()) {
+                if (d->viewportUpdateMode != FullViewportUpdate)
+                    viewport()->update(d->rubberBandRegion(viewport(), d->rubberBandRect));
+                else
+                    viewport()->update();
+            }
+
+            // Stop rubber banding if the user has let go of all buttons (even
+            // if we didn't get the release events).
+            if (!event->buttons()) {
+                d->rubberBanding = false;
+                d->rubberBandRect = QRect();
+                return;
+            }
+
+            // Update rubberband position
+            const QPoint &mp = d->mousePressViewPoint;
+            QPoint ep = event->pos();
+            d->rubberBandRect = QRect(qMin(mp.x(), ep.x()), qMin(mp.y(), ep.y()),
+                                      qAbs(mp.x() - ep.x()) + 1, qAbs(mp.y() - ep.y()) + 1);
+
+            // Update new rubberband
+            if (d->viewportUpdateMode != QGraphicsView::NoViewportUpdate){
+                if (d->viewportUpdateMode != FullViewportUpdate)
+                    viewport()->update(d->rubberBandRegion(viewport(), d->rubberBandRect));
+                else
+                    viewport()->update();
+            }
+            // Set the new selection area
+            QPainterPath selectionArea;
+            selectionArea.addPolygon(mapToScene(d->rubberBandRect));
+            selectionArea.closeSubpath();
+            if (d->scene)
+                d->scene->setSelectionArea(selectionArea, d->rubberBandSelectionMode);
+            return;
+        }
+    } else
+#endif // QT_NO_RUBBERBAND
+    if (d->dragMode == QGraphicsView::ScrollHandDrag) {
+        if (d->handScrolling) {
+            QScrollBar *hBar = horizontalScrollBar();
+            QScrollBar *vBar = verticalScrollBar();
+            QPoint delta = event->pos() - d->lastMouseEvent.pos();
+            hBar->setValue(hBar->value() + (isRightToLeft() ? delta.x() : -delta.x()));
+            vBar->setValue(vBar->value() - delta.y());
+
+            // Detect how much we've scrolled to disambiguate scrolling from
+            // clicking.
+            ++d->handScrollMotions;
+        }
+    }
+
+    d->mouseMoveEventHandler(event);
+}
+
+/*!
+    \reimp
+*/
+void QGraphicsView::mouseReleaseEvent(QMouseEvent *event)
+{
+    Q_D(QGraphicsView);
+
+#ifndef QT_NO_RUBBERBAND
+    if (d->dragMode == QGraphicsView::RubberBandDrag && d->sceneInteractionAllowed && !event->buttons()) {
+        if (d->rubberBanding) {
+            if (d->viewportUpdateMode != QGraphicsView::NoViewportUpdate){
+                if (d->viewportUpdateMode != FullViewportUpdate)
+                    viewport()->update(d->rubberBandRegion(viewport(), d->rubberBandRect));
+                else
+                    viewport()->update();
+            }
+            d->rubberBanding = false;
+            d->rubberBandRect = QRect();
+        }
+    } else
+#endif
+    if (d->dragMode == QGraphicsView::ScrollHandDrag) {
+#ifndef QT_NO_CURSOR
+        // Restore the open hand cursor. ### There might be items
+        // under the mouse that have a valid cursor at this time, so
+        // we could repeat the steps from mouseMoveEvent().
+        viewport()->setCursor(Qt::OpenHandCursor);
+#endif
+        d->handScrolling = false;
+
+        if (d->scene && d->sceneInteractionAllowed && !d->lastMouseEvent.isAccepted() && d->handScrollMotions <= 6) {
+            // If we've detected very little motion during the hand drag, and
+            // no item accepted the last event, we'll interpret that as a
+            // click to the scene, and reset the selection.
+            d->scene->clearSelection();
+        }
+    }
+
+    d->storeMouseEvent(event);
+
+    if (!d->sceneInteractionAllowed)
+        return;
+
+    if (!d->scene)
+        return;
+
+    QGraphicsSceneMouseEvent mouseEvent(QEvent::GraphicsSceneMouseRelease);
+    mouseEvent.setWidget(viewport());
+    mouseEvent.setButtonDownScenePos(d->mousePressButton, d->mousePressScenePoint);
+    mouseEvent.setButtonDownScreenPos(d->mousePressButton, d->mousePressScreenPoint);
+    mouseEvent.setScenePos(mapToScene(event->pos()));
+    mouseEvent.setScreenPos(event->globalPos());
+    mouseEvent.setLastScenePos(d->lastMouseMoveScenePoint);
+    mouseEvent.setLastScreenPos(d->lastMouseMoveScreenPoint);
+    mouseEvent.setButtons(event->buttons());
+    mouseEvent.setButton(event->button());
+    mouseEvent.setModifiers(event->modifiers());
+    mouseEvent.setAccepted(false);
+    QApplication::sendEvent(d->scene, &mouseEvent);
+
+    // Update the last mouse event selected state.
+    d->lastMouseEvent.setAccepted(mouseEvent.isAccepted());
+
+#ifndef QT_NO_CURSOR
+    if (mouseEvent.isAccepted() && mouseEvent.buttons() == 0 && viewport()->testAttribute(Qt::WA_SetCursor)) {
+        // The last mouse release on the viewport will trigger clearing the cursor.
+        d->_q_unsetViewportCursor();
+    }
+#endif
+}
+
+#ifndef QT_NO_WHEELEVENT
+/*!
+    \reimp
+*/
+void QGraphicsView::wheelEvent(QWheelEvent *event)
+{
+    Q_D(QGraphicsView);
+    if (!d->scene || !d->sceneInteractionAllowed) {
+        QAbstractScrollArea::wheelEvent(event);
+        return;
+    }
+
+    event->ignore();
+
+    QGraphicsSceneWheelEvent wheelEvent(QEvent::GraphicsSceneWheel);
+    wheelEvent.setWidget(viewport());
+    wheelEvent.setScenePos(mapToScene(event->pos()));
+    wheelEvent.setScreenPos(event->globalPos());
+    wheelEvent.setButtons(event->buttons());
+    wheelEvent.setModifiers(event->modifiers());
+    wheelEvent.setDelta(event->delta());
+    wheelEvent.setOrientation(event->orientation());
+    wheelEvent.setAccepted(false);
+    QApplication::sendEvent(d->scene, &wheelEvent);
+    event->setAccepted(wheelEvent.isAccepted());
+    if (!event->isAccepted())
+        QAbstractScrollArea::wheelEvent(event);
+}
+#endif // QT_NO_WHEELEVENT
+
+/*!
+    \reimp
+*/
+void QGraphicsView::paintEvent(QPaintEvent *event)
+{
+    Q_D(QGraphicsView);
+    if (!d->scene) {
+        QAbstractScrollArea::paintEvent(event);
+        return;
+    }
+
+    // Set up painter state protection.
+    d->scene->d_func()->painterStateProtection = !(d->optimizationFlags & DontSavePainterState);
+
+    // Determine the exposed region
+    QRegion exposedRegion = event->region();
+    if (!d->accelerateScrolling)
+        exposedRegion = viewport()->rect();
+    else if (d->viewportUpdateMode == BoundingRectViewportUpdate)
+        exposedRegion = event->rect();
+    QRectF exposedSceneRect = mapToScene(exposedRegion.boundingRect().adjusted(0, 0, 1, 1)).boundingRect();
+
+    // Set up the painter
+    QPainter painter(viewport());
+    QTransform original = painter.worldTransform();
+#ifndef QT_NO_RUBBERBAND
+    if (d->rubberBanding && !d->rubberBandRect.isNull())
+        painter.save();
+#endif
+    // Set up render hints
+    painter.setRenderHints(painter.renderHints(), false);
+    painter.setRenderHints(d->renderHints, true);
+
+    // Set up viewport transform
+    const QTransform viewTransform = viewportTransform();
+    painter.setTransform(viewTransform, true);
+
+#ifdef QGRAPHICSVIEW_DEBUG
+    QTime stopWatch;
+    stopWatch.start();
+    qDebug() << "QGraphicsView::paintEvent(" << exposedRegion << ")";
+#endif
+
+    // Find all exposed items
+    bool allItems = false;
+    QList<QGraphicsItem *> itemList = d->findItems(exposedRegion, viewTransform, &allItems);
+
+#ifdef QGRAPHICSVIEW_DEBUG
+    int exposedTime = stopWatch.elapsed();
+#endif
+
+    if ((d->cacheMode & CacheBackground)
+#ifdef Q_WS_X11
+        && X11->use_xrender
+#endif
+        ) {
+        // Recreate the background pixmap, and flag the whole background as
+        // exposed.
+        if (d->mustResizeBackgroundPixmap) {
+            d->backgroundPixmap = QPixmap(viewport()->size());
+            QBrush bgBrush = viewport()->palette().brush(viewport()->backgroundRole());
+            if (!bgBrush.isOpaque())
+                d->backgroundPixmap.fill(Qt::transparent);
+            QPainter p(&d->backgroundPixmap);
+            p.fillRect(0, 0, d->backgroundPixmap.width(), d->backgroundPixmap.height(), bgBrush);
+            d->backgroundPixmapExposed = QRegion(viewport()->rect());
+            d->mustResizeBackgroundPixmap = false;
+        }
+
+        // Redraw exposed areas
+        if (!d->backgroundPixmapExposed.isEmpty()) {
+            QPainter backgroundPainter(&d->backgroundPixmap);
+            backgroundPainter.setClipRegion(d->backgroundPixmapExposed, Qt::ReplaceClip);
+            backgroundPainter.setTransform(viewportTransform());
+            backgroundPainter.setCompositionMode(QPainter::CompositionMode_Source);
+            drawBackground(&backgroundPainter, exposedSceneRect);
+            d->backgroundPixmapExposed = QRegion();
+        }
+
+        // Blit the background from the background pixmap
+        QTransform oldMatrix = painter.worldTransform();
+        painter.setWorldTransform(original);
+        painter.drawPixmap(QPoint(), d->backgroundPixmap);
+        painter.setWorldTransform(oldMatrix);
+    } else {
+        if (!(d->optimizationFlags & DontSavePainterState))
+            painter.save();
+        drawBackground(&painter, exposedSceneRect);
+        if (!(d->optimizationFlags & DontSavePainterState))
+            painter.restore();
+    }
+
+#ifdef QGRAPHICSVIEW_DEBUG
+    int backgroundTime = stopWatch.elapsed() - exposedTime;
+#endif
+
+    // Generate the style options
+    QGraphicsItem **itemArray = new QGraphicsItem *[itemList.size()];
+    QStyleOptionGraphicsItem *styleOptionArray = d->allocStyleOptionsArray(itemList.size());
+
+    d->generateStyleOptions(itemList, itemArray, styleOptionArray, viewTransform,
+                            allItems, exposedRegion);
+
+    // Items
+    drawItems(&painter, itemList.size(), itemArray, styleOptionArray);
+
+#ifdef QGRAPHICSVIEW_DEBUG
+    int itemsTime = stopWatch.elapsed() - exposedTime - backgroundTime;
+#endif
+
+    // Foreground
+    drawForeground(&painter, exposedSceneRect);
+
+    delete [] itemArray;
+    d->freeStyleOptionsArray(styleOptionArray);
+
+#ifdef QGRAPHICSVIEW_DEBUG
+    int foregroundTime = stopWatch.elapsed() - exposedTime - backgroundTime - itemsTime;
+#endif
+
+#ifndef QT_NO_RUBBERBAND
+    // Rubberband
+    if (d->rubberBanding && !d->rubberBandRect.isNull()) {
+        painter.restore();
+        QStyleOptionRubberBand option;
+        option.initFrom(viewport());
+        option.rect = d->rubberBandRect;
+        option.shape = QRubberBand::Rectangle;
+
+        QStyleHintReturnMask mask;
+        if (viewport()->style()->styleHint(QStyle::SH_RubberBand_Mask, &option, viewport(), &mask)) {
+            // painter clipping for masked rubberbands
+            painter.setClipRegion(mask.region, Qt::IntersectClip);
+        }
+
+        viewport()->style()->drawControl(QStyle::CE_RubberBand, &option, &painter, viewport());
+    }
+#endif
+
+    painter.end();
+
+#ifdef QGRAPHICSVIEW_DEBUG
+    qDebug() << "\tItem discovery....... " << exposedTime << "msecs (" << itemList.size() << "items,"
+             << (exposedTime > 0 ? (itemList.size() * 1000.0 / exposedTime) : -1) << "/ sec )";
+    qDebug() << "\tDrawing background... " << backgroundTime << "msecs (" << exposedRegion.numRects() << "segments )";
+    qDebug() << "\tDrawing items........ " << itemsTime << "msecs ("
+             << (itemsTime > 0 ? (itemList.size() * 1000.0 / itemsTime) : -1) << "/ sec )";
+    qDebug() << "\tDrawing foreground... " << foregroundTime << "msecs (" << exposedRegion.numRects() << "segments )";
+    qDebug() << "\tTotal rendering time: " << stopWatch.elapsed() << "msecs ("
+             << (stopWatch.elapsed() > 0 ? (1000.0 / stopWatch.elapsed()) : -1.0) << "fps )";
+#endif
+
+    // Restore painter state protection.
+    d->scene->d_func()->painterStateProtection = true;
+}
+
+/*!
+    \reimp
+*/
+void QGraphicsView::resizeEvent(QResizeEvent *event)
+{
+    Q_D(QGraphicsView);
+    // Save the last center point - the resize may scroll the view, which
+    // changes the center point.
+    QPointF oldLastCenterPoint = d->lastCenterPoint;
+
+    QAbstractScrollArea::resizeEvent(event);
+    d->recalculateContentSize();
+
+    // Restore the center point again.
+    if (d->resizeAnchor == NoAnchor && !d->keepLastCenterPoint) {
+        d->updateLastCenterPoint();
+    } else {
+        d->lastCenterPoint = oldLastCenterPoint;
+    }
+    d->centerView(d->resizeAnchor);
+    d->keepLastCenterPoint = false;
+
+    if (d->cacheMode & CacheBackground) {
+        // Invalidate the background pixmap
+        d->mustResizeBackgroundPixmap = true;
+    }
+}
+
+/*!
+    \reimp
+*/
+void QGraphicsView::scrollContentsBy(int dx, int dy)
+{
+    Q_D(QGraphicsView);
+    d->dirtyScroll = true;
+    if (d->transforming)
+        return;
+    if (isRightToLeft())
+        dx = -dx;
+
+    if (d->viewportUpdateMode != QGraphicsView::NoViewportUpdate
+        && d->viewportUpdateMode != QGraphicsView::FullViewportUpdate) {
+        for (int i = 0; i < d->dirtyRects.size(); ++i)
+            d->dirtyRects[i].translate(dx, dy);
+        for (int i = 0; i < d->dirtyRegions.size(); ++i)
+            d->dirtyRegions[i].translate(dx, dy);
+    }
+
+#ifndef QT_NO_RUBBERBAND
+    // Update old rubberband
+    if (d->viewportUpdateMode != QGraphicsView::NoViewportUpdate && !d->rubberBandRect.isNull()) {
+        if (d->viewportUpdateMode != FullViewportUpdate)
+            viewport()->update(d->rubberBandRegion(viewport(), d->rubberBandRect));
+        else
+            viewport()->update();
+    }
+#endif
+
+    if (d->viewportUpdateMode != QGraphicsView::NoViewportUpdate){
+        if (d->accelerateScrolling && d->viewportUpdateMode != FullViewportUpdate)
+            viewport()->scroll(dx, dy);
+        else
+            viewport()->update();
+    }
+    d->updateLastCenterPoint();
+
+    if ((d->cacheMode & CacheBackground)
+#ifdef Q_WS_X11
+        && X11->use_xrender
+#endif
+        ) {
+        // Scroll the background pixmap
+        QRegion exposed;
+        if (!d->backgroundPixmap.isNull())
+            d->backgroundPixmap.scroll(dx, dy, d->backgroundPixmap.rect(), &exposed);
+
+        // Invalidate the background pixmap
+        d->backgroundPixmapExposed.translate(dx, dy);
+        d->backgroundPixmapExposed += exposed;
+    }
+
+    // Always replay on scroll.
+    if (d->sceneInteractionAllowed)
+        d->replayLastMouseEvent();
+}
+
+/*!
+    \reimp
+*/
+void QGraphicsView::showEvent(QShowEvent *event)
+{
+    Q_D(QGraphicsView);
+    d->recalculateContentSize();
+    d->centerView(d->transformationAnchor);
+    QAbstractScrollArea::showEvent(event);
+}
+
+/*!
+    \reimp
+*/
+void QGraphicsView::inputMethodEvent(QInputMethodEvent *event)
+{
+    Q_D(QGraphicsView);
+    if (d->scene)
+        QApplication::sendEvent(d->scene, event);
+}
+
+/*!
+    Draws the background of the scene using \a painter, before any items and
+    the foreground are drawn. Reimplement this function to provide a custom
+    background for this view.
+
+    If all you want is to define a color, texture or gradient for the
+    background, you can call setBackgroundBrush() instead.
+
+    All painting is done in \e scene coordinates. \a rect is the exposed
+    rectangle.
+
+    The default implementation fills \a rect using the view's backgroundBrush.
+    If no such brush is defined (the default), the scene's drawBackground()
+    function is called instead.
+
+    \sa drawForeground(), QGraphicsScene::drawBackground()
+*/
+void QGraphicsView::drawBackground(QPainter *painter, const QRectF &rect)
+{
+    Q_D(QGraphicsView);
+    if (d->scene && d->backgroundBrush.style() == Qt::NoBrush) {
+        d->scene->drawBackground(painter, rect);
+        return;
+    }
+
+    painter->fillRect(rect, d->backgroundBrush);
+}
+
+/*!
+    Draws the foreground of the scene using \a painter, after the background
+    and all items are drawn. Reimplement this function to provide a custom
+    foreground for this view.
+
+    If all you want is to define a color, texture or gradient for the
+    foreground, you can call setForegroundBrush() instead.
+
+    All painting is done in \e scene coordinates. \a rect is the exposed
+    rectangle.
+
+    The default implementation fills \a rect using the view's foregroundBrush.
+    If no such brush is defined (the default), the scene's drawForeground()
+    function is called instead.
+
+    \sa drawBackground(), QGraphicsScene::drawForeground()
+*/
+void QGraphicsView::drawForeground(QPainter *painter, const QRectF &rect)
+{
+    Q_D(QGraphicsView);
+    if (d->scene && d->foregroundBrush.style() == Qt::NoBrush) {
+        d->scene->drawForeground(painter, rect);
+        return;
+    }
+
+    painter->fillRect(rect, d->foregroundBrush);
+}
+
+/*!
+    Draws the items \a items in the scene using \a painter, after the
+    background and before the foreground are drawn. \a numItems is the number
+    of items in \a items and options in \a options. \a options is a list of
+    styleoptions; one for each item. Reimplement this function to provide
+    custom item drawing for this view.
+
+    The default implementation calls the scene's drawItems() function.
+
+    \sa drawForeground(), drawBackground(), QGraphicsScene::drawItems()
+*/
+void QGraphicsView::drawItems(QPainter *painter, int numItems,
+                              QGraphicsItem *items[],
+                              const QStyleOptionGraphicsItem options[])
+{
+    Q_D(QGraphicsView);
+    if (d->scene)
+        d->scene->drawItems(painter, numItems, items, options, viewport());
+}
+
+/*!
+    Returns the current transformation matrix for the view. If no current
+    transformation is set, the identity matrix is returned.
+
+    \sa setTransform(), rotate(), scale(), shear(), translate()
+*/
+QTransform QGraphicsView::transform() const
+{
+    Q_D(const QGraphicsView);
+    return d->matrix;
+}
+
+/*!
+    Returns a matrix that maps viewport coordinates to scene coordinates.
+
+    \sa mapToScene(), mapFromScene()
+*/
+QTransform QGraphicsView::viewportTransform() const
+{
+    Q_D(const QGraphicsView);
+    QTransform moveMatrix;
+    moveMatrix.translate(-d->horizontalScroll(), -d->verticalScroll());
+    return d->identityMatrix ? moveMatrix : d->matrix * moveMatrix;
+}
+
+/*!
+    Sets the view's current transformation matrix to \a matrix.
+
+    If \a combine is true, then \a matrix is combined with the current matrix;
+    otherwise, \a matrix \e replaces the current matrix. \a combine is false
+    by default.
+
+    The transformation matrix tranforms the scene into view coordinates. Using
+    the default transformation, provided by the identity matrix, one pixel in
+    the view represents one unit in the scene (e.g., a 10x10 rectangular item
+    is drawn using 10x10 pixels in the view). If a 2x2 scaling matrix is
+    applied, the scene will be drawn in 1:2 (e.g., a 10x10 rectangular item is
+    then drawn using 20x20 pixels in the view).
+
+    Example:
+
+    \snippet doc/src/snippets/code/src_gui_graphicsview_qgraphicsview.cpp 7
+
+    To simplify interation with items using a transformed view, QGraphicsView
+    provides mapTo... and mapFrom... functions that can translate between
+    scene and view coordinates. For example, you can call mapToScene() to map
+    a view coordiate to a floating point scene coordinate, or mapFromScene()
+    to map from floating point scene coordinates to view coordinates.
+
+    \sa transform(), rotate(), scale(), shear(), translate()
+*/
+void QGraphicsView::setTransform(const QTransform &matrix, bool combine )
+{
+    Q_D(QGraphicsView);
+    QTransform oldMatrix = d->matrix;
+    if (!combine)
+        d->matrix = matrix;
+    else
+        d->matrix = matrix * d->matrix;
+    if (oldMatrix == d->matrix)
+        return;
+
+    d->identityMatrix = d->matrix.isIdentity();
+    d->transforming = true;
+    if (d->scene) {
+        d->recalculateContentSize();
+        d->centerView(d->transformationAnchor);
+    } else {
+        d->updateLastCenterPoint();
+    }
+
+    if (d->sceneInteractionAllowed)
+        d->replayLastMouseEvent();
+    d->transforming = false;
+
+    // Any matrix operation requires a full update.
+    viewport()->update();
+}
+
+/*!
+    Resets the view transformation to the identity matrix.
+
+    \sa transform(), setTransform()
+*/
+void QGraphicsView::resetTransform()
+{
+    setTransform(QTransform());
+}
+
+QT_END_NAMESPACE
+
+#include "moc_qgraphicsview.cpp"
+
+#endif // QT_NO_GRAPHICSVIEW