3 files changed, 29 insertions, 0 deletions
diff --git a/src/compositor/compositor_api/qwaylandview.cpp b/src/compositor/compositor_api/qwaylandview.cpp
index 636937abb..8707b22d3 100644
--- a/src/compositor/compositor_api/qwaylandview.cpp
+++ b/src/compositor/compositor_api/qwaylandview.cpp
@@ -162,6 +162,13 @@ bool QWaylandView::advance()
     if (d->bufferLock)
         return false;
 
+    if (d->surface && d->surface->throttlingView() == this) {
+        Q_FOREACH (QWaylandView *view, d->surface->views()) {
+            if (view != this && view->discardFrontBuffers() && view->d_func()->currentBuffer == d->currentBuffer)
+                view->discardCurrentBuffer();
+        }
+    }
+
     QMutexLocker locker(&d->bufferMutex);
     d->forceAdvanceSucceed = false;
     d->currentBuffer = d->nextBuffer;
@@ -203,6 +210,21 @@ void QWaylandView::setBufferLock(bool locked)
     d->bufferLock = locked;
 }
 
+bool QWaylandView::discardFrontBuffers() const
+{
+    Q_D(const QWaylandView);
+    return d->discardFrontBuffers;
+}
+
+void QWaylandView::setDiscardFrontBuffers(bool discard)
+{
+    Q_D(QWaylandView);
+    if (d->discardFrontBuffers == discard)
+        return;
+    d->discardFrontBuffers = discard;
+    emit discardFrontBuffersChanged();
+}
+
 struct wl_resource *QWaylandView::surfaceResource() const
 {
     Q_D(const QWaylandView);
diff --git a/src/compositor/compositor_api/qwaylandview.h b/src/compositor/compositor_api/qwaylandview.h
index 7eba0c809..5a820fb50 100644
--- a/src/compositor/compositor_api/qwaylandview.h
+++ b/src/compositor/compositor_api/qwaylandview.h
@@ -57,6 +57,7 @@ class Q_COMPOSITOR_EXPORT QWaylandView : public QObject
     Q_PROPERTY(QWaylandSurface *surface READ surface WRITE setSurface NOTIFY surfaceChanged)
     Q_PROPERTY(QWaylandOutput *output READ output WRITE setOutput NOTIFY outputChanged)
     Q_PROPERTY(bool bufferLock READ isBufferLocked WRITE setBufferLock NOTIFY bufferLockChanged)
+    Q_PROPERTY(bool discardFrontBuffers READ discardFrontBuffers WRITE setDiscardFrontBuffers NOTIFY discardFrontBuffersChanged)
 public:
     QWaylandView(QObject *renderObject = 0, QObject *parent = 0);
     virtual ~QWaylandView();
@@ -78,6 +79,9 @@ public:
     bool isBufferLocked() const;
     void setBufferLock(bool locked);
 
+    bool discardFrontBuffers() const;
+    void setDiscardFrontBuffers(bool discard);
+
     struct wl_resource *surfaceResource() const;
 
 Q_SIGNALS:
@@ -85,6 +89,7 @@ Q_SIGNALS:
     void surfaceDestroyed();
     void outputChanged();
     void bufferLockChanged();
+    void discardFrontBuffersChanged();
 };
 
 QT_END_NAMESPACE
diff --git a/src/compositor/compositor_api/qwaylandview_p.h b/src/compositor/compositor_api/qwaylandview_p.h
index a4a75a6cb..1b5fc53e8 100644
--- a/src/compositor/compositor_api/qwaylandview_p.h
+++ b/src/compositor/compositor_api/qwaylandview_p.h
@@ -61,6 +61,7 @@ public:
         , bufferLock(false)
         , broadcastRequestedPositionChanged(false)
         , forceAdvanceSucceed(false)
+        , discardFrontBuffers(false)
     { }
 
     void markSurfaceAsDestroyed(QWaylandSurface *surface);
@@ -77,6 +78,7 @@ public:
     bool bufferLock;
     bool broadcastRequestedPositionChanged;
     bool forceAdvanceSucceed;
+    bool discardFrontBuffers;
 };
 
 QT_END_NAMESPACE