Fix crash with running animators on re-shown windows.

The non-threaded render loops would clean up the nodes for a window
when it was hidden, but the animators kept running and had a reference
to the deleted nodes. This was not a problem for the threaded render
loop as it would wipe the animator controller as well which would
clean the jobs.

Fix it by triggering a reset of all nodes in the animators when the
window is told to clean up. If an animator is ticked when it doesn't
have a node, it will simply do nothing. When the window is made visible
again, we call initialize on all animators to find the new node.

Task-number: QTBUG-37995
Change-Id: Ie5609d95db29f4b2b30ca5bf641dce901e528389
Reviewed-by: Michael Brasser <michael.brasser@live.com>

5 files changed, 68 insertions, 9 deletions

diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index d258b63484..6220ea2e1f 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -2449,6 +2449,7 @@ void QQuickWindowPrivate::cleanupNodesOnShutdown()
     QSet<QQuickItem *>::const_iterator it = parentlessItems.begin();
     for (; it != parentlessItems.end(); ++it)
         cleanupNodesOnShutdown(*it);
+    animationController->windowNodesDestroyed();
     q->cleanupSceneGraph();
 }
 
diff --git a/src/quick/util/qquickanimatorcontroller.cpp b/src/quick/util/qquickanimatorcontroller.cpp
index 7991dd8110..697c25b211 100644
--- a/src/quick/util/qquickanimatorcontroller.cpp
+++ b/src/quick/util/qquickanimatorcontroller.cpp
@@ -54,6 +54,7 @@ QT_BEGIN_NAMESPACE
 
 QQuickAnimatorController::QQuickAnimatorController()
     : m_window(0)
+    , m_nodesAreInvalid(false)
 {
 }
 
@@ -80,6 +81,26 @@ QQuickAnimatorController::~QQuickAnimatorController()
     }
 }
 
+static void qquickanimator_invalidate_node(QAbstractAnimationJob *job)
+{
+    if (job->isRenderThreadJob()) {
+        static_cast<QQuickAnimatorJob *>(job)->nodeWasDestroyed();
+    } else if (job->isGroup()) {
+        QAnimationGroupJob *g = static_cast<QAnimationGroupJob *>(job);
+        for (QAbstractAnimationJob *a = g->firstChild(); a; a = a->nextSibling())
+            qquickanimator_invalidate_node(a);
+    }
+}
+
+void QQuickAnimatorController::windowNodesDestroyed()
+{
+    m_nodesAreInvalid = true;
+    for (QHash<QAbstractAnimationJob *, QQuickAnimatorProxyJob *>::const_iterator it = m_animatorRoots.constBegin();
+         it != m_animatorRoots.constEnd(); ++it) {
+        qquickanimator_invalidate_node(it.key());
+    }
+}
+
 void QQuickAnimatorController::itemDestroyed(QObject *o)
 {
     m_deletedSinceLastFrame << (QQuickItem *) o;
@@ -112,7 +133,7 @@ void QQuickAnimatorController::advance()
         m_window->update();
 }
 
-static void qquick_initialize_helper(QAbstractAnimationJob *job, QQuickAnimatorController *c)
+static void qquick_initialize_helper(QAbstractAnimationJob *job, QQuickAnimatorController *c, bool attachListener)
 {
     if (job->isRenderThreadJob()) {
         QQuickAnimatorJob *j = static_cast<QQuickAnimatorJob *>(job);
@@ -121,13 +142,14 @@ static void qquick_initialize_helper(QAbstractAnimationJob *job, QQuickAnimatorC
         } else if (c->m_deletedSinceLastFrame.contains(j->target())) {
             j->targetWasDeleted();
         } else {
-            j->addAnimationChangeListener(c, QAbstractAnimationJob::StateChange);
+            if (attachListener)
+                j->addAnimationChangeListener(c, QAbstractAnimationJob::StateChange);
             j->initialize(c);
         }
     } else if (job->isGroup()) {
         QAnimationGroupJob *g = static_cast<QAnimationGroupJob *>(job);
         for (QAbstractAnimationJob *a = g->firstChild(); a; a = a->nextSibling())
-            qquick_initialize_helper(a, c);
+            qquick_initialize_helper(a, c, attachListener);
     }
 }
 
@@ -147,7 +169,7 @@ void QQuickAnimatorController::beforeNodeSync()
     foreach (QQuickAnimatorProxyJob *proxy, m_starting) {
         QAbstractAnimationJob *job = proxy->job();
         job->addAnimationChangeListener(this, QAbstractAnimationJob::Completion);
-        qquick_initialize_helper(job, this);
+        qquick_initialize_helper(job, this, true);
         m_animatorRoots[job] = proxy;
         job->start();
         proxy->startedByController();
@@ -160,6 +182,18 @@ void QQuickAnimatorController::beforeNodeSync()
     }
     m_stopping.clear();
 
+    // First sync after a window was hidden or otherwise invalidated.
+    // call initialize again to pick up new nodes..
+    if (m_nodesAreInvalid) {
+        for (QHash<QAbstractAnimationJob *, QQuickAnimatorProxyJob *>::const_iterator it = m_animatorRoots.constBegin();
+             it != m_animatorRoots.constEnd(); ++it) {
+            qquick_initialize_helper(it.key(), this, false);
+        }
+        m_nodesAreInvalid = false;
+    }
+
+
+
     foreach (QQuickAnimatorJob *job, m_activeLeafAnimations) {
         if (!job->target())
             continue;
diff --git a/src/quick/util/qquickanimatorcontroller_p.h b/src/quick/util/qquickanimatorcontroller_p.h
index 6223a9938f..745a494eec 100644
--- a/src/quick/util/qquickanimatorcontroller_p.h
+++ b/src/quick/util/qquickanimatorcontroller_p.h
@@ -76,6 +76,8 @@ public:
     void lock() { m_mutex.lock(); }
     void unlock() { m_mutex.unlock(); }
 
+    void windowNodesDestroyed();
+
 public Q_SLOTS:
     void itemDestroyed(QObject *);
 
@@ -92,6 +94,8 @@ public:
     QSet<QQuickItem *> m_deletedSinceLastFrame;
     QQuickWindow *m_window;
     QMutex m_mutex;
+
+    bool m_nodesAreInvalid;
 };
 
 QT_END_NAMESPACE
diff --git a/src/quick/util/qquickanimatorjob.cpp b/src/quick/util/qquickanimatorjob.cpp
index 3bc4cef5b9..0bf95a49b4 100644
--- a/src/quick/util/qquickanimatorjob.cpp
+++ b/src/quick/util/qquickanimatorjob.cpp
@@ -281,6 +281,12 @@ void QQuickTransformAnimatorJob::initialize(QQuickAnimatorController *controller
     }
 }
 
+void QQuickTransformAnimatorJob::nodeWasDestroyed()
+{
+    if (m_helper)
+        m_helper->node = 0;
+}
+
 void QQuickTransformAnimatorJob::Helper::sync()
 {
     const quint32 mask = QQuickItemPrivate::Position
@@ -326,7 +332,7 @@ void QQuickTransformAnimatorJob::Helper::sync()
 
 void QQuickTransformAnimatorJob::Helper::apply()
 {
-    if (!wasChanged)
+    if (!wasChanged || !node)
         return;
 
     QMatrix4x4 m;
@@ -412,6 +418,11 @@ void QQuickOpacityAnimatorJob::initialize(QQuickAnimatorController *controller)
     }
 }
 
+void QQuickOpacityAnimatorJob::nodeWasDestroyed()
+{
+    m_opacityNode = 0;
+}
+
 void QQuickOpacityAnimatorJob::writeBack()
 {
     if (m_target)
@@ -420,7 +431,7 @@ void QQuickOpacityAnimatorJob::writeBack()
 
 void QQuickOpacityAnimatorJob::updateCurrentTime(int time)
 {
-    if (!m_controller)
+    if (!m_controller || !m_opacityNode)
         return;
     Q_ASSERT(m_controller->m_window->openglContext()->thread() == QThread::currentThread());
 
@@ -504,13 +515,18 @@ void QQuickUniformAnimatorJob::setTarget(QQuickItem *target)
         m_target = target;
 }
 
+void QQuickUniformAnimatorJob::nodeWasDestroyed()
+{
+    m_node = 0;
+    m_uniformIndex = -1;
+    m_uniformType = -1;
+}
+
 void QQuickUniformAnimatorJob::afterNodeSync()
 {
     m_node = static_cast<QQuickShaderEffectNode *>(QQuickItemPrivate::get(m_target)->paintNode);
 
-    if (m_node) {
-        m_uniformIndex = -1;
-        m_uniformType = -1;
+    if (m_node && m_uniformIndex == -1 && m_uniformType == -1) {
         QQuickShaderEffectMaterial *material =
                 static_cast<QQuickShaderEffectMaterial *>(m_node->material());
         bool found = false;
diff --git a/src/quick/util/qquickanimatorjob_p.h b/src/quick/util/qquickanimatorjob_p.h
index 8aae121106..03b13bcd30 100644
--- a/src/quick/util/qquickanimatorjob_p.h
+++ b/src/quick/util/qquickanimatorjob_p.h
@@ -131,6 +131,7 @@ public:
     void targetWasDeleted();
     virtual void initialize(QQuickAnimatorController *controller);
     virtual void writeBack() = 0;
+    virtual void nodeWasDestroyed() = 0;
 
     bool isTransform() const { return m_isTransform; }
     bool isUniform() const { return m_isUniform; }
@@ -208,6 +209,7 @@ public:
 protected:
     QQuickTransformAnimatorJob();
     void initialize(QQuickAnimatorController *controller);
+    void nodeWasDestroyed();
 
     Helper *m_helper;
 };
@@ -256,6 +258,7 @@ public:
     void initialize(QQuickAnimatorController *controller);
     void updateCurrentTime(int time);
     void writeBack();
+    void nodeWasDestroyed();
 
 private:
     QSGOpacityNode *m_opacityNode;
@@ -275,6 +278,7 @@ public:
 
     void updateCurrentTime(int time);
     void writeBack();
+    void nodeWasDestroyed();
 
 private:
     QByteArray m_uniform;