3 files changed, 17 insertions, 1 deletions
diff --git a/services/surfaceflinger/LayerBase.cpp b/services/surfaceflinger/LayerBase.cpp
index f4eebb2..f654445 100644
--- a/services/surfaceflinger/LayerBase.cpp
+++ b/services/surfaceflinger/LayerBase.cpp
@@ -77,6 +77,7 @@ void LayerBase::initStates(uint32_t w, uint32_t h, uint32_t flags)
     mCurrentState.active.crop.makeInvalid();
     mCurrentState.z = 0;
     mCurrentState.alpha = 0xFF;
+    mCurrentState.layerStack = 0;
     mCurrentState.flags = layerFlags;
     mCurrentState.sequence = 0;
     mCurrentState.transform.set(0, 0);
@@ -169,6 +170,15 @@ bool LayerBase::setCrop(const Rect& crop) {
     return true;
 }
 
+bool LayerBase::setLayerStack(uint32_t layerStack) {
+    if (mCurrentState.layerStack == layerStack)
+        return false;
+    mCurrentState.sequence++;
+    mCurrentState.layerStack = layerStack;
+    requestTransaction();
+    return true;
+}
+
 void LayerBase::setVisibleRegion(const Region& visibleRegion) {
     // always called from main thread
     this->visibleRegion = visibleRegion;
diff --git a/services/surfaceflinger/LayerBase.h b/services/surfaceflinger/LayerBase.h
index 80bc4c3..aeafe4f 100644
--- a/services/surfaceflinger/LayerBase.h
+++ b/services/surfaceflinger/LayerBase.h
@@ -79,6 +79,7 @@ public:
                 Geometry        active;
                 Geometry        requested;
                 uint32_t        z;
+                uint32_t        layerStack;
                 uint8_t         alpha;
                 uint8_t         flags;
                 uint8_t         reserved[2];
@@ -113,7 +114,8 @@ public:
             bool setTransparentRegionHint(const Region& opaque);
             bool setFlags(uint8_t flags, uint8_t mask);
             bool setCrop(const Rect& crop);
-            
+            bool setLayerStack(uint32_t layerStack);
+
             void commitTransaction();
             bool requestTransaction();
             void forceVisibilityTransaction();
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 8da2543..b70c720 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -1572,6 +1572,10 @@ uint32_t SurfaceFlinger::setClientStateLocked(
             if (layer->setCrop(s.crop))
                 flags |= eTraversalNeeded;
         }
+        if (what & eLayerStackChanged) {
+            if (layer->setLayerStack(s.layerStack))
+                flags |= eTraversalNeeded;
+        }
     }
     return flags;
 }