PlatformSurfaceFilter/Renderer: render only when surface is exposed

Change-Id: Idec2f0ee5f3ace590421698293742932e8843aae
Reviewed-by: Andy Nichols <andy.nichols@theqtcompany.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/render/backend/platformsurfacefilter.cpp b/src/render/backend/platformsurfacefilter.cpp
index 6e7e1a21c..248e54d93 100644
--- a/src/render/backend/platformsurfacefilter.cpp
+++ b/src/render/backend/platformsurfacefilter.cpp
@@ -95,6 +95,11 @@ bool PlatformSurfaceFilter::eventFilter(QObject *obj, QEvent *e)
             Q_UNREACHABLE();
         }
     }
+
+    if (obj == m_obj && e->type() == QEvent::Expose) {
+        QExposeEvent *ev = static_cast<QExposeEvent *>(e);
+        m_renderer->setSurfaceExposed(!ev->region().isEmpty());
+    }
     return false;
 }