[Mirror Layers] Added mirrorSurface API to enable mirroring (3/4)

Added a new SurfaceComposer API called mirrorSurface that allows a
client to request a mirror of a particular heirarchy starting from the
passed in layer. The API will return a SurfaceControl that's the parent
of the mirrored layer that can be updated by the client.

Test: MirrorLayerTest
Bug: 131622422
Change-Id: Ia6047f0334eabfc59d6222b2edfd4e9576ba31e5

1 files changed, 29 insertions, 0 deletions

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 86e73c2481..a9fad1e21b 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -3388,6 +3388,35 @@ uint32_t SurfaceFlinger::addInputWindowCommands(const InputWindowCommands& input
     return flags;
 }
 
+status_t SurfaceFlinger::mirrorLayer(const sp<Client>& client, const sp<IBinder>& mirrorFromHandle,
+                                     sp<IBinder>* outHandle) {
+    if (!mirrorFromHandle) {
+        return NAME_NOT_FOUND;
+    }
+
+    sp<Layer> mirrorLayer;
+    sp<Layer> mirrorFrom;
+    String8 uniqueName = getUniqueLayerName(String8("MirrorRoot"));
+
+    {
+        Mutex::Autolock _l(mStateLock);
+        mirrorFrom = fromHandle(mirrorFromHandle);
+        if (!mirrorFrom) {
+            return NAME_NOT_FOUND;
+        }
+
+        status_t result = createContainerLayer(client, uniqueName, -1, -1, 0, LayerMetadata(),
+                                               outHandle, &mirrorLayer);
+        if (result != NO_ERROR) {
+            return result;
+        }
+
+        mirrorLayer->mClonedChild = mirrorFrom->createClone();
+    }
+
+    return addClientLayer(client, *outHandle, nullptr, mirrorLayer, nullptr, nullptr, false);
+}
+
 status_t SurfaceFlinger::createLayer(const String8& name, const sp<Client>& client, uint32_t w,
                                      uint32_t h, PixelFormat format, uint32_t flags,
                                      LayerMetadata metadata, sp<IBinder>* handle,