Add a signal for syncing external animation systems

[ChangeLog] QQuickWindow will now emit the afterAnimating() signal
from the gui thread before each scenegraph sync request.

Change-Id: I4897c82f75066238e781455d4fce4fb6bbe2558e
Reviewed-by: Pasi Keränen <pasi.keranen@digia.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

5 files changed, 17 insertions, 0 deletions

diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index f035e87d99..bc8558e1d8 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -3044,6 +3044,16 @@ QQmlIncubationController *QQuickWindow::incubationController() const
     do so can result in the scene not rendering properly.
  */
 
+/*!
+    \fn void QQuickWindow::afterAnimating()
+
+    This signal is emitted on the gui thread before requesting the render thread to
+    perform the synchronization of the scene graph.
+
+    Unlike the other similar signals, this one is emitted on the gui thread instead
+    of the render thread. It can be used to synchronize external animation systems
+    with the QML content.
+ */
 
 
 /*!
diff --git a/src/quick/items/qquickwindow.h b/src/quick/items/qquickwindow.h
index 233340d6fa..ced232467b 100644
--- a/src/quick/items/qquickwindow.h
+++ b/src/quick/items/qquickwindow.h
@@ -138,6 +138,7 @@ Q_SIGNALS:
     void beforeSynchronizing();
     void beforeRendering();
     void afterRendering();
+    void afterAnimating();
     Q_REVISION(1) void closing(QQuickCloseEvent *close);
     void colorChanged(const QColor &);
     Q_REVISION(1) void activeFocusItemChanged();
diff --git a/src/quick/scenegraph/qsgrenderloop.cpp b/src/quick/scenegraph/qsgrenderloop.cpp
index 4e8fa67869..50c5b141c3 100644
--- a/src/quick/scenegraph/qsgrenderloop.cpp
+++ b/src/quick/scenegraph/qsgrenderloop.cpp
@@ -302,6 +302,8 @@ void QSGGuiThreadRenderLoop::renderWindow(QQuickWindow *window)
     QQuickWindowPrivate *cd = QQuickWindowPrivate::get(window);
     cd->polishItems();
 
+    emit window->afterAnimating();
+
     qint64 renderTime = 0, syncTime = 0;
     QElapsedTimer renderTimer;
     bool profileFrames = qsg_render_timing()  || QQuickProfiler::enabled;
diff --git a/src/quick/scenegraph/qsgthreadedrenderloop.cpp b/src/quick/scenegraph/qsgthreadedrenderloop.cpp
index ffc6d31aa7..ddf724b89f 100644
--- a/src/quick/scenegraph/qsgthreadedrenderloop.cpp
+++ b/src/quick/scenegraph/qsgthreadedrenderloop.cpp
@@ -1096,6 +1096,8 @@ void QSGThreadedRenderLoop::polishAndSync(Window *w)
 
     w->updateDuringSync = false;
 
+    emit w->window->afterAnimating();
+
     QSG_GUI_DEBUG(w->window, " - lock for sync...");
     w->thread->mutex.lock();
     m_locked = true;
diff --git a/src/quick/scenegraph/qsgwindowsrenderloop.cpp b/src/quick/scenegraph/qsgwindowsrenderloop.cpp
index 995d80bb82..204a303d2c 100644
--- a/src/quick/scenegraph/qsgwindowsrenderloop.cpp
+++ b/src/quick/scenegraph/qsgwindowsrenderloop.cpp
@@ -442,6 +442,8 @@ void QSGWindowsRenderLoop::renderWindow(QQuickWindow *window)
     d->polishItems();
     QSG_RENDER_TIMING_SAMPLE(time_polished);
 
+    emit window->afterAnimating();
+
     RLDEBUG(" - syncing");
     d->syncSceneGraph();
     QSG_RENDER_TIMING_SAMPLE(time_synced);