Add QDeclarativeGraphicsWidget, a QGraphicsWidget version of QmlView

Could use to be renamed. Possibly to
-QDeclarativeViewGraphicsWidget
-QGraphicsDeclarativeViewWidget (Or QGraphicsD20, in the spirit of i18n)
But those aren't any shorter.

Task-number: QTBUG-7067

4 files changed, 584 insertions, 2 deletions

diff --git a/doc/src/declarative/integrating.qdoc b/doc/src/declarative/integrating.qdoc
index c685d3d..09ed178 100644
--- a/doc/src/declarative/integrating.qdoc
+++ b/doc/src/declarative/integrating.qdoc
@@ -86,6 +86,9 @@ QGraphicsObject *object =
 scene->addItem(object);
 \endcode
 
+There is a convenience QGraphicsWidget subclass, QDeclarativeGraphicsWidget, which takes care of the engine
+and component instantiation for you.
+
 The following QGraphicsView options are recommended for optimal performance
 of QML UIs:
 
@@ -95,6 +98,13 @@ of QML UIs:
 \o QGraphicsScene::setItemIndexMethod(QGraphicsScene::NoIndex);
 \endlist
 
+And the following QGraphicsView options are required for QML key handling to work:
+
+\list
+\o QGraphicsView::viewport()->setFocusPolicy(Qt::NoFocus);
+\o QGraphicsScene::setStickyFocus(true);
+\endlist
+
 \section1 Using existing QGraphicsWidgets in QML
 Another way of integrating with a QGraphicsView based UI is to expose your
 existing QGraphicsWidgets to QML, and constructing your scene in QML. Note that
diff --git a/src/declarative/util/qdeclarativegraphicswidget.cpp b/src/declarative/util/qdeclarativegraphicswidget.cpp
new file mode 100644
index 0000000..1d0d468
--- /dev/null
+++ b/src/declarative/util/qdeclarativegraphicswidget.cpp
@@ -0,0 +1,457 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtDeclarative 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 Technology Preview License Agreement accompanying
+** this package.
+**
+** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qdeclarativegraphicswidget.h"
+
+#include "qperformancelog_p_p.h"
+#include "qfxperf_p_p.h"
+
+#include <qdeclarative.h>
+#include <qdeclarativeitem.h>
+#include <qdeclarativeengine.h>
+#include <qdeclarativecontext.h>
+#include <qdeclarativedebug_p.h>
+#include <qdeclarativedebugservice_p.h>
+#include <qdeclarativeglobal_p.h>
+#include <qdeclarativeerror.h>
+
+#include <qscriptvalueiterator.h>
+#include <qdebug.h>
+#include <qtimer.h>
+#include <qevent.h>
+#include <qdir.h>
+#include <qcoreapplication.h>
+#include <qfontdatabase.h>
+#include <qicon.h>
+#include <qurl.h>
+#include <qboxlayout.h>
+#include <qbasictimer.h>
+#include <QtCore/qabstractanimation.h>
+#include <private/qguard_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QDeclarativeGraphicsWidgetSharedQDeclarativeEngine
+{
+public:
+    QDeclarativeGraphicsWidgetSharedQDeclarativeEngine(){}
+
+    static QDeclarativeEngine* sharedEngine(){
+        if(!references)
+            return 0;
+        return &QDeclarativeGraphicsWidgetSharedQDeclarativeEngine::m_instance->engine;
+    }
+    static void attach(){
+        if(!references++)
+            m_instance = new QDeclarativeGraphicsWidgetSharedQDeclarativeEngine();
+    }
+
+    static void detach(){
+        if(!--references)
+            delete m_instance;
+    }
+
+private:
+    static QDeclarativeGraphicsWidgetSharedQDeclarativeEngine* m_instance;
+    static int references;
+    QDeclarativeEngine engine;
+};
+
+int QDeclarativeGraphicsWidgetSharedQDeclarativeEngine::references = 0;
+QDeclarativeGraphicsWidgetSharedQDeclarativeEngine* QDeclarativeGraphicsWidgetSharedQDeclarativeEngine::m_instance = 0;
+
+class QDeclarativeGraphicsWidgetPrivate
+{
+public:
+    QDeclarativeGraphicsWidgetPrivate()
+        : root(0), component(0),
+          resizeMode(QDeclarativeGraphicsWidget::SizeViewToRootObject) 
+    {
+        QDeclarativeGraphicsWidgetSharedQDeclarativeEngine::attach();
+        engine = QDeclarativeGraphicsWidgetSharedQDeclarativeEngine::sharedEngine();
+    }
+
+    ~QDeclarativeGraphicsWidgetPrivate()
+    {
+        QDeclarativeGraphicsWidgetSharedQDeclarativeEngine::detach();
+    }
+
+    QGuard<QGraphicsObject> root;
+    QGuard<QDeclarativeItem> declarativeRoot;
+
+    QUrl source;
+
+    QDeclarativeEngine* engine;
+    QDeclarativeComponent *component;
+    QBasicTimer resizetimer;
+
+    mutable QSize initialSize;
+    QDeclarativeGraphicsWidget::ResizeMode resizeMode;
+
+    void init();
+
+};
+
+/*!
+    \class QDeclarativeGraphicsWidget
+    \brief The QDeclarativeGraphicsWidget class provides a QGraphicsWidget for displaying a Qt Declarative user interface.
+
+    Any QGraphicsObject or QDeclarativeGraphicsItem
+    created via Qt Declarative can be placed on a standard QGraphicsScene and viewed with a standard
+    QGraphicsView.
+
+    QDeclarativeGraphicsWidget is a convenience class which handles QDeclarativeComponent loading and object creation.
+    It shares the same QDeclarativeEngine between all QDeclarativeGraphicsWidgets in the application, to minimize overhead.
+
+    QDeclarativeGraphicsWidget is ideal for when you have many small components styled with Qt Declarative, and want to integrate
+    them into a larger QGraphicsItem based scene. If your interface is primarily Qt Declarative based, consider using QDeclarativeView
+    instead.
+
+    Note that the following settings on your QGraphicsScene/View are recommended for optimal performance with Qt Declarative:
+        \list
+        \o QGraphicsView::setOptimizationFlags(QGraphicsView::DontSavePainterState);
+        \o QGraphicsView::setViewportUpdateMode(QGraphicsView::BoundingRectViewportUpdate);
+        \o QGraphicsScene::setItemIndexMethod(QGraphicsScene::NoIndex);
+        \endlist
+    Also note that the following settings on your QGraphicsScene/View are required for key handling in Qt Declarative to work:
+        \list
+        \o QGraphicsView::viewport()->setFocusPolicy(Qt::NoFocus);
+        \o QGraphicsScene::setStickyFocus(true);
+        \endlist
+
+    To receive errors related to loading and executing declarative files with QDeclarativeGraphicsWidget,
+    you can connect to the statusChanged() signal and monitor for QDeclarativeGraphicsWidget::Error.
+    The errors are available via QDeclarativeGraphicsWidget::errors().
+*/
+
+
+/*! \fn void QDeclarativeGraphicsWidget::sceneResized(QSize size)
+  This signal is emitted when the view is resized to \a size.
+*/
+
+/*! \fn void QDeclarativeGraphicsWidget::statusChanged(QDeclarativeGraphicsWidget::Status status)
+    This signal is emitted when the component's current \l{QDeclarativeGraphicsWidget::Status} {status} changes.
+*/
+
+/*!
+  \fn QDeclarativeGraphicsWidget::QDeclarativeGraphicsWidget(QGraphicsItem *parent)
+
+  Constructs a QDeclarativeGraphicsWidget with the given \a parent.
+*/
+QDeclarativeGraphicsWidget::QDeclarativeGraphicsWidget(QGraphicsItem *parent)
+: QGraphicsWidget(parent), d(new QDeclarativeGraphicsWidgetPrivate)
+{
+    setSizePolicy(QSizePolicy::Preferred,QSizePolicy::Preferred);
+    d->init();
+}
+
+void QDeclarativeGraphicsWidgetPrivate::init()
+{
+}
+
+/*!
+  The destructor clears the view's \l {QGraphicsObject} {items} and
+  deletes the internal representation.
+ */
+QDeclarativeGraphicsWidget::~QDeclarativeGraphicsWidget()
+{
+    delete d->root;
+    delete d;
+}
+
+/*!
+    Sets the source to the \a url.
+
+    Will also load the QML file and instantiate the component.
+
+ */
+void QDeclarativeGraphicsWidget::setSource(const QUrl& url)
+{
+    d->source = url;
+
+    //Execute
+    if(d->root)
+        delete d->root;
+    if(d->component)
+        delete d->component;
+    d->component = new QDeclarativeComponent(d->engine, d->source, this);
+
+    if (!d->component->isLoading()) {
+        continueExecute();
+    } else {
+        connect(d->component, SIGNAL(statusChanged(QDeclarativeComponent::Status)), this, SLOT(continueExecute()));
+    }
+}
+
+/*!
+  Returns the source URL, if set.
+
+  \sa setSource()
+ */
+QUrl QDeclarativeGraphicsWidget::source() const
+{
+    return d->source;
+}
+
+/*!
+  Returns a pointer to the QDeclarativeEngine used for instantiating
+  Qt Declarative Components.
+ */
+QDeclarativeEngine* QDeclarativeGraphicsWidget::engine()
+{
+    return d->engine;
+}
+
+/*!
+  This function returns the root of the context hierarchy.  Each declarative
+  component is instantiated in a QDeclarativeContext.  QDeclarativeContext's are
+  essential for passing data to declarative components.  In Qt Declarative, contexts are
+  arranged hierarchically and this hierarchy is managed by the
+  QDeclarativeEngine.
+ */
+QDeclarativeContext* QDeclarativeGraphicsWidget::rootContext()
+{
+    return d->engine->rootContext();
+}
+
+
+/*!
+  \enum QDeclarativeGraphicsWidget::Status
+
+    Specifies the loading status of the QDeclarativeGraphicsWidget.
+
+    \value Null This QDeclarativeGraphicsWidget has no source set.
+    \value Ready This QDeclarativeGraphicsWidget has loaded and created the declarative component.
+    \value Loading This QDeclarativeGraphicsWidget is loading network data.
+    \value Error An error has occured.  Calling errorDescription() to retrieve a description.
+*/
+
+/*!
+    \property QDeclarativeGraphicsWidget::status
+    The component's current \l{QDeclarativeGraphicsWidget::Status} {status}.
+*/
+
+QDeclarativeGraphicsWidget::Status QDeclarativeGraphicsWidget::status() const
+{
+    if (!d->component)
+        return QDeclarativeGraphicsWidget::Null;
+
+    return QDeclarativeGraphicsWidget::Status(d->component->status());
+}
+
+/*!
+    Return the list of errors that occured during the last compile or create
+    operation.  An empty list is returned if isError() is not set.
+*/
+QList<QDeclarativeError> QDeclarativeGraphicsWidget::errors() const
+{
+    if (d->component)
+        return d->component->errors();
+    return QList<QDeclarativeError>();
+}
+
+
+/*!
+    \property QDeclarativeGraphicsWidget::resizeMode
+    \brief whether the view should resize the canvas contents
+
+    If this property is set to SizeViewToRootObject (the default), the view
+    resizes with the root item in the declarative file.
+
+    If this property is set to SizeRootObjectToView, the view will
+    automatically resize the root item.
+
+    Regardless of this property, the sizeHint of the view
+    is the initial size of the root item. Note though that
+    since declarative files may load dynamically, that size may change.
+
+    \sa initialSize()
+*/
+
+void QDeclarativeGraphicsWidget::setResizeMode(ResizeMode mode)
+{
+    if (d->resizeMode == mode)
+        return;
+
+    d->resizeMode = mode;
+    if (d->declarativeRoot) {
+        if (d->resizeMode == SizeRootObjectToView) {
+            d->declarativeRoot->setWidth(size().width());
+            d->declarativeRoot->setHeight(size().height());
+        } else {
+            d->declarativeRoot->setWidth(d->initialSize.width());
+            d->declarativeRoot->setHeight(d->initialSize.height());
+        }
+    }
+}
+
+QDeclarativeGraphicsWidget::ResizeMode QDeclarativeGraphicsWidget::resizeMode() const
+{
+    return d->resizeMode;
+}
+
+/*!
+  \internal
+ */
+void QDeclarativeGraphicsWidget::continueExecute()
+{
+
+    disconnect(d->component, SIGNAL(statusChanged(QDeclarativeComponent::Status)), this, SLOT(continueExecute()));
+
+    if (d->component->isError()) {
+        QList<QDeclarativeError> errorList = d->component->errors();
+        foreach (const QDeclarativeError &error, errorList) {
+            qWarning() << error;
+        }
+        emit statusChanged(status());
+        return;
+    }
+
+    QObject *obj = d->component->create();
+
+    if(d->component->isError()) {
+        QList<QDeclarativeError> errorList = d->component->errors();
+        foreach (const QDeclarativeError &error, errorList) {
+            qWarning() << error;
+        }
+        emit statusChanged(status());
+        return;
+    }
+
+    if (obj) {
+        if (QDeclarativeItem *item = qobject_cast<QDeclarativeItem *>(obj)) {
+
+            item->QGraphicsItem::setParentItem(this);
+            item->QObject::setParent(this);
+
+            d->root = item;
+            d->declarativeRoot = item;
+            connect(item, SIGNAL(widthChanged()), this, SLOT(sizeChanged()));
+            connect(item, SIGNAL(heightChanged()), this, SLOT(sizeChanged()));
+            if (d->initialSize.height() <= 0 && d->declarativeRoot->width() > 0)
+                d->initialSize.setWidth(d->declarativeRoot->width());
+            if (d->initialSize.height() <= 0 && d->declarativeRoot->height() > 0)
+                d->initialSize.setHeight(d->declarativeRoot->height());
+            resize(d->initialSize);
+
+            if (d->resizeMode == SizeRootObjectToView) {
+                d->declarativeRoot->setWidth(size().width());
+                d->declarativeRoot->setHeight(size().height());
+            } else {
+                QSizeF sz(d->declarativeRoot->width(),d->declarativeRoot->height());
+                emit sceneResized(sz);
+                resize(sz);
+            }
+            updateGeometry();
+        } else if (QGraphicsObject *item = qobject_cast<QGraphicsObject *>(obj)) {
+            item->setParent(this);
+            qWarning() << "QDeclarativeGraphicsWidget::resizeMode is not honored for components of type QGraphicsObject";
+        } else if (qobject_cast<QWidget *>(obj)) {
+            qWarning() << "QDeclarativeGraphicsWidget does not support loading QML files containing QWidgets";
+        }
+    }
+    emit statusChanged(status());
+}
+
+/*!
+  \internal
+ */
+void QDeclarativeGraphicsWidget::sizeChanged()
+{
+    // delay, so we catch both width and height changing.
+    d->resizetimer.start(0,this);
+}
+
+/*!
+  \internal
+  If the \l {QTimerEvent} {timer event} \a e is this
+  view's resize timer, sceneResized() is emitted.
+ */
+void QDeclarativeGraphicsWidget::timerEvent(QTimerEvent* e)
+{
+    if (!e || e->timerId() == d->resizetimer.timerId()) {
+        if (d->declarativeRoot) {
+            QSize sz(d->declarativeRoot->width(),d->declarativeRoot->height());
+            emit sceneResized(sz);
+        }
+        d->resizetimer.stop();
+        updateGeometry();
+    }
+}
+
+/*!
+    \internal
+    The size hint is the size of the root item.
+*/
+QSizeF QDeclarativeGraphicsWidget::sizeHint() const
+{
+    if (d->declarativeRoot) {
+        if (d->initialSize.width() <= 0)
+            d->initialSize.setWidth(d->declarativeRoot->width());
+        if (d->initialSize.height() <= 0)
+            d->initialSize.setHeight(d->declarativeRoot->height());
+    }
+    return d->initialSize;
+}
+
+/*!
+  Returns the view's root \l {QGraphicsObject} {item}.
+ */
+QGraphicsObject *QDeclarativeGraphicsWidget::rootObject() const
+{
+    return d->root;
+}
+
+/*!
+  \internal
+  This function handles the \l {QGraphicsSceneResizeEvent} {resize event}
+  \a e.
+ */
+void QDeclarativeGraphicsWidget::resizeEvent(QGraphicsSceneResizeEvent *e)
+{
+    if (d->resizeMode == SizeRootObjectToView && d->declarativeRoot) {
+        d->declarativeRoot->setWidth(size().width());
+        d->declarativeRoot->setHeight(size().height());
+    }
+    QGraphicsWidget::resizeEvent(e);
+}
+
+QT_END_NAMESPACE
diff --git a/src/declarative/util/qdeclarativegraphicswidget.h b/src/declarative/util/qdeclarativegraphicswidget.h
new file mode 100644
index 0000000..33ebc7b
--- /dev/null
+++ b/src/declarative/util/qdeclarativegraphicswidget.h
@@ -0,0 +1,113 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtDeclarative 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 Technology Preview License Agreement accompanying
+** this package.
+**
+** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QDECLARATIVEGRAPHICSWIDGET_H
+#define QDECLARATIVEGRAPHICSWIDGET_H
+
+#include <QtCore/qdatetime.h>
+#include <QtCore/qurl.h>
+#include <QtGui/qgraphicssceneevent.h>
+#include <QtGui/qgraphicswidget.h>
+#include <QtGui/qwidget.h>
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+QT_MODULE(Declarative)
+
+class QGraphicsObject;
+class QDeclarativeEngine;
+class QDeclarativeContext;
+class QDeclarativeError;
+
+class QDeclarativeGraphicsWidgetPrivate;
+
+class Q_DECLARATIVE_EXPORT QDeclarativeGraphicsWidget : public QGraphicsWidget
+{
+    Q_OBJECT
+    Q_PROPERTY(ResizeMode resizeMode READ resizeMode WRITE setResizeMode)
+    Q_PROPERTY(Status status READ status NOTIFY statusChanged)
+    Q_PROPERTY(QUrl source READ source WRITE setSource)
+
+public:
+    explicit QDeclarativeGraphicsWidget(QGraphicsItem *parent = 0);
+    virtual ~QDeclarativeGraphicsWidget();
+
+    QUrl source() const;
+    void setSource(const QUrl&);
+
+    QDeclarativeEngine* engine();
+    QDeclarativeContext* rootContext();
+
+    QGraphicsObject *rootObject() const;
+
+    enum ResizeMode { SizeViewToRootObject, SizeRootObjectToView };
+    ResizeMode resizeMode() const;
+    void setResizeMode(ResizeMode);
+    QSizeF sizeHint() const;
+
+    enum Status { Null, Ready, Loading, Error };
+    Status status() const;
+
+    QList<QDeclarativeError> errors() const;
+
+Q_SIGNALS:
+    void sceneResized(QSizeF size);
+    void statusChanged(QDeclarativeGraphicsWidget::Status);
+
+private Q_SLOTS:
+    void continueExecute();
+    void sizeChanged();
+
+protected:
+    virtual void resizeEvent(QGraphicsSceneResizeEvent *);
+    void timerEvent(QTimerEvent*);
+
+private:
+    QDeclarativeGraphicsWidgetPrivate* d;
+};
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif // QDECLARATIVEGRAPHICSWIDGET_H
diff --git a/src/declarative/util/util.pri b/src/declarative/util/util.pri
index 610eb3f..46126e5 100644
--- a/src/declarative/util/util.pri
+++ b/src/declarative/util/util.pri
@@ -30,7 +30,8 @@ SOURCES += \
     $$PWD/qdeclarativedatetimeformatter.cpp \
     $$PWD/qdeclarativebehavior.cpp \
     $$PWD/qdeclarativefontloader.cpp \
-    $$PWD/qdeclarativestyledtext.cpp
+    $$PWD/qdeclarativestyledtext.cpp \
+    $$PWD/qdeclarativegraphicswidget.cpp
 
 HEADERS += \
     $$PWD/qdeclarativeutilmodule_p.h\
@@ -65,7 +66,8 @@ HEADERS += \
     $$PWD/qdeclarativedatetimeformatter_p.h \
     $$PWD/qdeclarativebehavior_p.h \
     $$PWD/qdeclarativefontloader_p.h \
-    $$PWD/qdeclarativestyledtext_p.h
+    $$PWD/qdeclarativestyledtext_p.h \
+    $$PWD/qdeclarativegraphicswidget.h
 
 contains(QT_CONFIG, xmlpatterns) {
     QT+=xmlpatterns