Move event forwarding to frontend

Move the event forwarding to frontend so that the target object
destruction can be handled properly.

Change-Id: I6bdee731760cee69334aad7ca39f0dd16c44a471
Reviewed-by: Tomi Korpipää <tomi.korpipaa@qt.io>
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

8 files changed, 217 insertions, 25 deletions

diff --git a/src/render/picking/eventforward.cpp b/src/render/picking/eventforward.cpp
index 132e022ce..0216542bd 100644
--- a/src/render/picking/eventforward.cpp
+++ b/src/render/picking/eventforward.cpp
@@ -40,6 +40,7 @@
 
 #include <private/qeventforward_p.h>
 #include <private/eventforward_p.h>
+#include <private/posteventstofrontend_p.h>
 
 #include <QtGui/qevent.h>
 #include <QtCore/qcoreapplication.h>
@@ -51,7 +52,7 @@ namespace Qt3DRender {
 namespace Render {
 
 EventForward::EventForward()
-    : m_target(nullptr)
+    : BackendNode(QBackendNode::ReadWrite)
     , m_forwardMouseEvents(false)
     , m_forwardKeyboardEvents(false)
     , m_focus(false)
@@ -67,7 +68,6 @@ EventForward::~EventForward()
 void EventForward::cleanup()
 {
     setEnabled(false);
-    m_target = nullptr;
     m_coordinateAttribute = "";
     m_coordinateTransform.setToIdentity();
     m_forwardMouseEvents = false;
@@ -75,11 +75,6 @@ void EventForward::cleanup()
     m_focus = false;
 }
 
-QObject *EventForward::target() const
-{
-    return m_target;
-}
-
 QString EventForward::coordinateAttribute() const
 {
     return m_coordinateAttribute;
@@ -105,11 +100,6 @@ bool EventForward::focus() const
     return m_focus;
 }
 
-void EventForward::setTarget(QObject *target)
-{
-    m_target = target;
-}
-
 void EventForward::setCoordinateTransform(const QMatrix4x4 &transform)
 {
     m_coordinateTransform = transform;
@@ -139,7 +129,6 @@ void EventForward::initializeFromPeer(const Qt3DCore::QNodeCreatedChangeBasePtr
 {
     const auto typedChange = qSharedPointerCast<Qt3DCore::QNodeCreatedChange<QEventForwardData>>(change);
     const auto &data = typedChange->data;
-    setTarget(data.target);
     setCoordinateAttribute(data.coordinateAttribute);
     setCoordinateTransform(data.coordinateTransform);
     setForwardMouseEvents(data.forwardMouseEvents);
@@ -153,9 +142,7 @@ void EventForward::sceneChangeEvent(const Qt3DCore::QSceneChangePtr &e)
         const Qt3DCore::QPropertyUpdatedChangePtr propertyChange
                 = qSharedPointerCast<Qt3DCore::QPropertyUpdatedChange>(e);
 
-        if (propertyChange->propertyName() == QByteArrayLiteral("target"))
-            setTarget(propertyChange->value().value<QObject*>());
-        else if (propertyChange->propertyName() == QByteArrayLiteral("coordinateTransform"))
+        if (propertyChange->propertyName() == QByteArrayLiteral("coordinateTransform"))
             setCoordinateTransform(propertyChange->value().value<QMatrix4x4>());
         else if (propertyChange->propertyName() == QByteArrayLiteral("coordinateAttribute"))
             setCoordinateAttribute(propertyChange->value().toString());
@@ -177,16 +164,30 @@ void EventForward::forward(const QMouseEvent &event, const QVector4D &coordinate
     QMouseEvent *mouseEvent = new QMouseEvent(event.type(), local, local, local, event.button(),
                                       event.buttons(), event.modifiers(),
                                       Qt::MouseEventSynthesizedByApplication);
-    QCoreApplication::postEvent(m_target, mouseEvent);
+
+    PostEventsToFrontendPtr events = PostEventsToFrontendPtr::create(mouseEvent);
+
+    auto e = Qt3DCore::QPropertyUpdatedChangePtr::create(peerId());
+    e->setDeliveryFlags(Qt3DCore::QSceneChange::DeliverToAll);
+    e->setPropertyName("events");
+    e->setValue(QVariant::fromValue(events));
+    notifyObservers(e);
 }
 
-void EventForward::forward(const QList<QKeyEvent> &events)
+void EventForward::forward(const QList<QKeyEvent> &keyEvents)
 {
-    for (const QKeyEvent &e : events) {
+    QVector<QEvent *> eventsToSend;
+    for (const QKeyEvent &e : keyEvents) {
         QKeyEvent *keyEvent = new QKeyEvent(e.type(), e.key(), e.modifiers(), e.nativeScanCode(),
                                       e.nativeVirtualKey(), e.nativeModifiers());
-        QCoreApplication::postEvent(m_target, keyEvent);
+        eventsToSend.append(keyEvent);
     }
+    PostEventsToFrontendPtr events = PostEventsToFrontendPtr::create(eventsToSend);
+    auto e = Qt3DCore::QPropertyUpdatedChangePtr::create(peerId());
+    e->setDeliveryFlags(Qt3DCore::QSceneChange::DeliverToAll);
+    e->setPropertyName("events");
+    e->setValue(QVariant::fromValue(events));
+    notifyObservers(e);
 }
 
 } // Render
diff --git a/src/render/picking/eventforward_p.h b/src/render/picking/eventforward_p.h
index e090ba5e4..663298e40 100644
--- a/src/render/picking/eventforward_p.h
+++ b/src/render/picking/eventforward_p.h
@@ -69,7 +69,6 @@ public:
 
     void cleanup();
 
-    QObject *target() const;
     QString coordinateAttribute() const;
     QMatrix4x4 coordinateTransform() const;
     bool forwardMouseEvents() const;
@@ -86,12 +85,11 @@ public:
     void sceneChangeEvent(const Qt3DCore::QSceneChangePtr &e) Q_DECL_FINAL;
 
     void forward(const QMouseEvent &event, const QVector4D &coordinate);
-    void forward(const QList<QKeyEvent> &events);
+    void forward(const QList<QKeyEvent> &keyEvents);
 
 private:
     void initializeFromPeer(const Qt3DCore::QNodeCreatedChangeBasePtr &change) Q_DECL_FINAL;
 
-    QObject *m_target;
     QString m_coordinateAttribute;
     QMatrix4x4 m_coordinateTransform;
     bool m_forwardMouseEvents;
diff --git a/src/render/picking/picking.pri b/src/render/picking/picking.pri
index e581a8f8a..c2eb8f50b 100644
--- a/src/render/picking/picking.pri
+++ b/src/render/picking/picking.pri
@@ -10,7 +10,8 @@ HEADERS += \
     $$PWD/qobjectpicker_p.h \
     $$PWD/qeventforward.h \
     $$PWD/qeventforward_p.h \
-    $$PWD/eventforward_p.h
+    $$PWD/eventforward_p.h \
+    $$PWD/posteventstofrontend_p.h
 
 SOURCES += \
     $$PWD/qobjectpicker.cpp \
@@ -19,4 +20,5 @@ SOURCES += \
     $$PWD/objectpicker.cpp \
     $$PWD/pickeventfilter.cpp \
     $$PWD/qeventforward.cpp \
-    $$PWD/eventforward.cpp
+    $$PWD/eventforward.cpp \
+    $$PWD/posteventstofrontend.cpp
diff --git a/src/render/picking/posteventstofrontend.cpp b/src/render/picking/posteventstofrontend.cpp
new file mode 100644
index 000000000..51f986902
--- /dev/null
+++ b/src/render/picking/posteventstofrontend.cpp
@@ -0,0 +1,74 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later 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 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "posteventstofrontend_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace Qt3DRender {
+
+PostEventsToFrontend::PostEventsToFrontend()
+    : QObject()
+{
+
+}
+
+PostEventsToFrontend::PostEventsToFrontend(QEvent *event)
+    : QObject()
+{
+    m_events.append(event);
+}
+
+PostEventsToFrontend::PostEventsToFrontend(const QVector<QEvent *> &events)
+    : QObject()
+{
+    m_events = events;
+}
+
+PostEventsToFrontend::~PostEventsToFrontend()
+{
+    for (QEvent *e : m_events)
+        delete e;
+}
+
+QVector<QEvent *> &PostEventsToFrontend::events()
+{
+    return m_events;
+}
+
+}
+
+QT_END_NAMESPACE
diff --git a/src/render/picking/posteventstofrontend_p.h b/src/render/picking/posteventstofrontend_p.h
new file mode 100644
index 000000000..5dd29b047
--- /dev/null
+++ b/src/render/picking/posteventstofrontend_p.h
@@ -0,0 +1,81 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later 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 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QT3DRENDER_POSTEVENTSTOFRONTEND_P_H
+#define QT3DRENDER_POSTEVENTSTOFRONTEND_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists for the convenience
+// of other Qt classes.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtGui/qevent.h>
+#include <QtCore/qvector.h>
+#include <QtCore/qsharedpointer.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace Qt3DRender {
+
+class Q_AUTOTEST_EXPORT PostEventsToFrontend : public QObject
+{
+    Q_OBJECT
+public:
+    PostEventsToFrontend();
+    PostEventsToFrontend(QEvent *event);
+    PostEventsToFrontend(const QVector<QEvent *> &events);
+    ~PostEventsToFrontend();
+
+    QVector<QEvent *> &events();
+private:
+    QVector<QEvent *> m_events;
+};
+
+typedef QSharedPointer<PostEventsToFrontend> PostEventsToFrontendPtr;
+
+} // Qt3DRender
+
+QT_END_NAMESPACE
+
+Q_DECLARE_METATYPE(Qt3DRender::PostEventsToFrontend*)
+
+#endif // QT3DRENDER_POSTEVENTSTOFRONTEND_P_H
diff --git a/src/render/picking/qeventforward.cpp b/src/render/picking/qeventforward.cpp
index 8aa22e276..08546fabd 100644
--- a/src/render/picking/qeventforward.cpp
+++ b/src/render/picking/qeventforward.cpp
@@ -36,8 +36,12 @@
 
 #include "qeventforward.h"
 #include "qeventforward_p.h"
+#include "posteventstofrontend_p.h"
 
 #include <Qt3DCore/qpropertyupdatedchange.h>
+#include <QtCore/qcoreapplication.h>
+
+#include <QtGui/qevent.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -148,11 +152,24 @@ QObject *QEventForward::target() const
     return d->m_target;
 }
 
+void QEventForward::targetDestroyed(QObject *target)
+{
+    Q_D(QEventForward);
+    Q_ASSERT(target == d->m_target);
+    setTarget(nullptr);
+}
+
 void QEventForward::setTarget(QObject *target)
 {
     Q_D(QEventForward);
     if (target != d->m_target) {
+        if (d->m_target != nullptr)
+            QObject::disconnect(d->m_destructionConnection);
         d->m_target = target;
+        if (d->m_target) {
+            d->m_destructionConnection = QObject::connect(target, &QObject::destroyed,
+                                                          this, &QEventForward::targetDestroyed);
+        }
         emit targetChanged(target);
     }
 }
@@ -249,6 +266,20 @@ Qt3DCore::QNodeCreatedChangeBasePtr QEventForward::createNodeCreationChange() co
     return creationChange;
 }
 
+void QEventForward::sceneChangeEvent(const Qt3DCore::QSceneChangePtr &change)
+{
+    Q_D(QEventForward);
+    Qt3DCore::QPropertyUpdatedChangePtr e
+            = qSharedPointerCast<Qt3DCore::QPropertyUpdatedChange>(change);
+    if (e->type() == Qt3DCore::PropertyUpdated && d->m_target != nullptr) {
+        if (e->propertyName() == QByteArrayLiteral("events")) {
+            PostEventsToFrontendPtr postedEvents = e->value().value<PostEventsToFrontendPtr>();
+            for (QEvent *event : postedEvents->events())
+                QCoreApplication::sendEvent(d->m_target, event);
+        }
+    }
+}
+
 } // Qt3DRender
 
 QT_END_NAMESPACE
diff --git a/src/render/picking/qeventforward.h b/src/render/picking/qeventforward.h
index 28659606b..ee8100318 100644
--- a/src/render/picking/qeventforward.h
+++ b/src/render/picking/qeventforward.h
@@ -87,9 +87,13 @@ Q_SIGNALS:
     void forwardKeyboardEventsChanged(bool forward);
     void focusChanged(bool focus);
 
+protected:
+    void sceneChangeEvent(const Qt3DCore::QSceneChangePtr &change) Q_DECL_OVERRIDE;
+
 private:
     Q_DECLARE_PRIVATE(QEventForward)
     Qt3DCore::QNodeCreatedChangeBasePtr createNodeCreationChange() const Q_DECL_OVERRIDE;
+    void targetDestroyed(QObject *target);
 };
 
 } // Qt3DRender
diff --git a/src/render/picking/qeventforward_p.h b/src/render/picking/qeventforward_p.h
index 4aa6834df..c087bc8f5 100644
--- a/src/render/picking/qeventforward_p.h
+++ b/src/render/picking/qeventforward_p.h
@@ -81,6 +81,7 @@ public:
     bool m_forwardMouseEvents;
     bool m_forwardKeyboardEvents;
     bool m_focus;
+    QMetaObject::Connection m_destructionConnection;
 };
 
 struct QEventForwardData