Make it possible to discard currentBuffer of a view

This will be convenient if there is a view which copies the
currentBuffer to a cache and then wants to release the ref to the buffer

Change-Id: I0b7bbb4bc22c420fdf0d1af4bb1bbf0a4f888bc8

1 files changed, 10 insertions, 1 deletions

diff --git a/src/compositor/compositor_api/qwaylandview.cpp b/src/compositor/compositor_api/qwaylandview.cpp
index 90f182c5d..fa1371925 100644
--- a/src/compositor/compositor_api/qwaylandview.cpp
+++ b/src/compositor/compositor_api/qwaylandview.cpp
@@ -200,18 +200,27 @@ void QWaylandView::attach(const QWaylandBufferRef &ref, const QRegion &damage)
 bool QWaylandView::advance()
 {
     Q_D(QWaylandView);
-    if (d->currentBuffer == d->nextBuffer)
+    if (d->currentBuffer == d->nextBuffer && !d->forceAdvanceSucceed)
         return false;
 
     if (d->bufferLock)
         return false;
 
     QMutexLocker locker(&d->bufferMutex);
+    d->forceAdvanceSucceed = false;
     d->currentBuffer = d->nextBuffer;
     d->currentDamage = d->nextDamage;
     return true;
 }
 
+void QWaylandView::discardCurrentBuffer()
+{
+    Q_D(QWaylandView);
+    QMutexLocker locker(&d->bufferMutex);
+    d->currentBuffer = QWaylandBufferRef();
+    d->forceAdvanceSucceed = true;
+}
+
 QWaylandBufferRef QWaylandView::currentBuffer()
 {
     Q_D(QWaylandView);