[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
diff --git a/libs/gui/ISurfaceComposerClient.cpp b/libs/gui/ISurfaceComposerClient.cpp
index 129558b..b98e48b 100644
--- a/libs/gui/ISurfaceComposerClient.cpp
+++ b/libs/gui/ISurfaceComposerClient.cpp
@@ -34,7 +34,8 @@
     CREATE_WITH_SURFACE_PARENT,
     CLEAR_LAYER_FRAME_STATS,
     GET_LAYER_FRAME_STATS,
-    LAST = GET_LAYER_FRAME_STATS,
+    MIRROR_SURFACE,
+    LAST = MIRROR_SURFACE,
 };
 
 } // Anonymous namespace
@@ -80,6 +81,12 @@
                 &ISurfaceComposerClient::getLayerFrameStats)>(Tag::GET_LAYER_FRAME_STATS, handle,
                                                               outStats);
     }
+
+    status_t mirrorSurface(const sp<IBinder>& mirrorFromHandle, sp<IBinder>* outHandle) override {
+        return callRemote<decltype(&ISurfaceComposerClient::mirrorSurface)>(Tag::MIRROR_SURFACE,
+                                                                            mirrorFromHandle,
+                                                                            outHandle);
+    }
 };
 
 // Out-of-line virtual method definition to trigger vtable emission in this
@@ -105,6 +112,8 @@
             return callLocal(data, reply, &ISurfaceComposerClient::clearLayerFrameStats);
         case Tag::GET_LAYER_FRAME_STATS:
             return callLocal(data, reply, &ISurfaceComposerClient::getLayerFrameStats);
+        case Tag::MIRROR_SURFACE:
+            return callLocal(data, reply, &ISurfaceComposerClient::mirrorSurface);
     }
 }
 
diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index 547e5f1..7b256f5 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -1505,6 +1505,20 @@
     return err;
 }
 
+sp<SurfaceControl> SurfaceComposerClient::mirrorSurface(SurfaceControl* mirrorFromSurface) {
+    if (mirrorFromSurface == nullptr) {
+        return nullptr;
+    }
+
+    sp<IBinder> handle;
+    sp<IBinder> mirrorFromHandle = mirrorFromSurface->getHandle();
+    status_t err = mClient->mirrorSurface(mirrorFromHandle, &handle);
+    if (err == NO_ERROR) {
+        return new SurfaceControl(this, handle, nullptr, true /* owned */);
+    }
+    return nullptr;
+}
+
 status_t SurfaceComposerClient::clearLayerFrameStats(const sp<IBinder>& token) const {
     if (mStatus != NO_ERROR) {
         return mStatus;
diff --git a/libs/gui/include/gui/ISurfaceComposerClient.h b/libs/gui/include/gui/ISurfaceComposerClient.h
index 32ac9e8..5fe7ca5 100644
--- a/libs/gui/include/gui/ISurfaceComposerClient.h
+++ b/libs/gui/include/gui/ISurfaceComposerClient.h
@@ -76,6 +76,8 @@
      * Requires ACCESS_SURFACE_FLINGER permission
      */
     virtual status_t getLayerFrameStats(const sp<IBinder>& handle, FrameStats* outStats) const = 0;
+
+    virtual status_t mirrorSurface(const sp<IBinder>& mirrorFromHandle, sp<IBinder>* outHandle) = 0;
 };
 
 class BnSurfaceComposerClient : public SafeBnInterface<ISurfaceComposerClient> {
diff --git a/libs/gui/include/gui/SurfaceComposerClient.h b/libs/gui/include/gui/SurfaceComposerClient.h
index 15287e2..6676be4 100644
--- a/libs/gui/include/gui/SurfaceComposerClient.h
+++ b/libs/gui/include/gui/SurfaceComposerClient.h
@@ -245,6 +245,17 @@
                                                LayerMetadata metadata = LayerMetadata() // metadata
     );
 
+    // Creates a mirrored hierarchy for the mirrorFromSurface. This returns a SurfaceControl
+    // which is a parent of the root of the mirrored hierarchy.
+    //
+    //  Real Hierarchy    Mirror
+    //                      SC (value that's returned)
+    //                      |
+    //      A               A'
+    //      |               |
+    //      B               B'
+    sp<SurfaceControl> mirrorSurface(SurfaceControl* mirrorFromSurface);
+
     //! Create a virtual display
     static sp<IBinder> createDisplay(const String8& displayName, bool secure);
 
diff --git a/services/surfaceflinger/Client.cpp b/services/surfaceflinger/Client.cpp
index 6bfd302..c7ed9b0 100644
--- a/services/surfaceflinger/Client.cpp
+++ b/services/surfaceflinger/Client.cpp
@@ -106,6 +106,10 @@
                                  nullptr, layer);
 }
 
+status_t Client::mirrorSurface(const sp<IBinder>& mirrorFromHandle, sp<IBinder>* outHandle) {
+    return mFlinger->mirrorLayer(this, mirrorFromHandle, outHandle);
+}
+
 status_t Client::clearLayerFrameStats(const sp<IBinder>& handle) const {
     sp<Layer> layer = getLayerUser(handle);
     if (layer == nullptr) {
diff --git a/services/surfaceflinger/Client.h b/services/surfaceflinger/Client.h
index 74e4818..7d7cef8 100644
--- a/services/surfaceflinger/Client.h
+++ b/services/surfaceflinger/Client.h
@@ -62,6 +62,8 @@
                                              LayerMetadata metadata, sp<IBinder>* handle,
                                              sp<IGraphicBufferProducer>* gbp);
 
+    status_t mirrorSurface(const sp<IBinder>& mirrorFromHandle, sp<IBinder>* handle);
+
     virtual status_t clearLayerFrameStats(const sp<IBinder>& handle) const;
 
     virtual status_t getLayerFrameStats(const sp<IBinder>& handle, FrameStats* outStats) const;
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 86e73c2..a9fad1e 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -3388,6 +3388,35 @@
     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,
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 2ea8f78..a9a4276 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -623,6 +623,9 @@
                                   uint32_t h, uint32_t flags, LayerMetadata metadata,
                                   sp<IBinder>* outHandle, sp<Layer>* outLayer);
 
+    status_t mirrorLayer(const sp<Client>& client, const sp<IBinder>& mirrorFromHandle,
+                         sp<IBinder>* outHandle);
+
     String8 getUniqueLayerName(const String8& name);
 
     // called when all clients have released all their references to
diff --git a/services/surfaceflinger/tests/Android.bp b/services/surfaceflinger/tests/Android.bp
index f422939..d021fc2 100644
--- a/services/surfaceflinger/tests/Android.bp
+++ b/services/surfaceflinger/tests/Android.bp
@@ -28,6 +28,7 @@
         "LayerTypeAndRenderTypeTransaction_test.cpp",
         "LayerTypeTransaction_test.cpp",
         "LayerUpdate_test.cpp",
+        "MirrorLayer_test.cpp",
         "MultiDisplayLayerBounds_test.cpp",
         "RelativeZ_test.cpp",
         "SetGeometry_test.cpp",
diff --git a/services/surfaceflinger/tests/MirrorLayer_test.cpp b/services/surfaceflinger/tests/MirrorLayer_test.cpp
new file mode 100644
index 0000000..0bcac1a
--- /dev/null
+++ b/services/surfaceflinger/tests/MirrorLayer_test.cpp
@@ -0,0 +1,226 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "LayerTransactionTest.h"
+
+namespace android {
+
+class MirrorLayerTest : public LayerTransactionTest {
+protected:
+    virtual void SetUp() {
+        LayerTransactionTest::SetUp();
+        ASSERT_EQ(NO_ERROR, mClient->initCheck());
+
+        const auto display = SurfaceComposerClient::getInternalDisplayToken();
+        ASSERT_FALSE(display == nullptr);
+
+        mParentLayer = createColorLayer("Parent layer", Color::RED);
+        mChildLayer = createColorLayer("Child layer", Color::GREEN, mParentLayer.get());
+        asTransaction([&](Transaction& t) {
+            t.setDisplayLayerStack(display, 0);
+            t.setLayer(mParentLayer, INT32_MAX - 2).show(mParentLayer);
+            t.setCrop_legacy(mChildLayer, Rect(0, 0, 400, 400)).show(mChildLayer);
+            t.setPosition(mChildLayer, 50, 50);
+            t.setFlags(mParentLayer, layer_state_t::eLayerOpaque, layer_state_t::eLayerOpaque);
+            t.setFlags(mChildLayer, layer_state_t::eLayerOpaque, layer_state_t::eLayerOpaque);
+        });
+    }
+
+    virtual void TearDown() {
+        LayerTransactionTest::TearDown();
+        mParentLayer = 0;
+        mChildLayer = 0;
+    }
+
+    sp<SurfaceControl> mParentLayer;
+    sp<SurfaceControl> mChildLayer;
+};
+
+TEST_F(MirrorLayerTest, MirrorColorLayer) {
+    sp<SurfaceControl> grandchild =
+            createColorLayer("Grandchild layer", Color::BLUE, mChildLayer.get());
+    Transaction()
+            .setFlags(grandchild, layer_state_t::eLayerOpaque, layer_state_t::eLayerOpaque)
+            .setCrop_legacy(grandchild, Rect(0, 0, 200, 200))
+            .show(grandchild)
+            .apply();
+
+    // Mirror mChildLayer
+    sp<SurfaceControl> mirrorLayer = mClient->mirrorSurface(mChildLayer.get());
+    ASSERT_NE(mirrorLayer, nullptr);
+
+    // Add mirrorLayer as child of mParentLayer so it's shown on the display
+    Transaction()
+            .reparent(mirrorLayer, mParentLayer->getHandle())
+            .setPosition(mirrorLayer, 500, 500)
+            .show(mirrorLayer)
+            .apply();
+
+    {
+        SCOPED_TRACE("Initial Mirror");
+        auto shot = screenshot();
+        // Grandchild mirror
+        shot->expectColor(Rect(550, 550, 750, 750), Color::BLUE);
+        // Child mirror
+        shot->expectColor(Rect(750, 750, 950, 950), Color::GREEN);
+    }
+
+    // Set color to white on grandchild layer.
+    Transaction().setColor(grandchild, half3{1, 1, 1}).apply();
+    {
+        SCOPED_TRACE("Updated Grandchild Layer Color");
+        auto shot = screenshot();
+        // Grandchild mirror
+        shot->expectColor(Rect(550, 550, 750, 750), Color::WHITE);
+        // Child mirror
+        shot->expectColor(Rect(750, 750, 950, 950), Color::GREEN);
+    }
+
+    // Set color to black on child layer.
+    Transaction().setColor(mChildLayer, half3{0, 0, 0}).apply();
+    {
+        SCOPED_TRACE("Updated Child Layer Color");
+        auto shot = screenshot();
+        // Grandchild mirror
+        shot->expectColor(Rect(550, 550, 750, 750), Color::WHITE);
+        // Child mirror
+        shot->expectColor(Rect(750, 750, 950, 950), Color::BLACK);
+    }
+
+    // Remove grandchild layer
+    Transaction().reparent(grandchild, nullptr).apply();
+    {
+        SCOPED_TRACE("Removed Grandchild Layer");
+        auto shot = screenshot();
+        // Grandchild mirror
+        shot->expectColor(Rect(550, 550, 750, 750), Color::BLACK);
+        // Child mirror
+        shot->expectColor(Rect(750, 750, 950, 950), Color::BLACK);
+    }
+
+    // Remove child layer
+    Transaction().reparent(mChildLayer, nullptr).apply();
+    {
+        SCOPED_TRACE("Removed Child Layer");
+        auto shot = screenshot();
+        // Grandchild mirror
+        shot->expectColor(Rect(550, 550, 750, 750), Color::RED);
+        // Child mirror
+        shot->expectColor(Rect(750, 750, 950, 950), Color::RED);
+    }
+
+    // Add grandchild layer to offscreen layer
+    Transaction().reparent(grandchild, mChildLayer->getHandle()).apply();
+    {
+        SCOPED_TRACE("Added Grandchild Layer");
+        auto shot = screenshot();
+        // Grandchild mirror
+        shot->expectColor(Rect(550, 550, 750, 750), Color::RED);
+        // Child mirror
+        shot->expectColor(Rect(750, 750, 950, 950), Color::RED);
+    }
+
+    // Add child layer
+    Transaction().reparent(mChildLayer, mParentLayer->getHandle()).apply();
+    {
+        SCOPED_TRACE("Added Child Layer");
+        auto shot = screenshot();
+        // Grandchild mirror
+        shot->expectColor(Rect(550, 550, 750, 750), Color::WHITE);
+        // Child mirror
+        shot->expectColor(Rect(750, 750, 950, 950), Color::BLACK);
+    }
+}
+
+TEST_F(MirrorLayerTest, MirrorBufferLayer) {
+    sp<SurfaceControl> bufferQueueLayer =
+            createLayer("BufferQueueLayer", 200, 200, 0, mChildLayer.get());
+    fillBufferQueueLayerColor(bufferQueueLayer, Color::BLUE, 200, 200);
+    Transaction().show(bufferQueueLayer).apply();
+
+    sp<SurfaceControl> mirrorLayer = mClient->mirrorSurface(mChildLayer.get());
+    Transaction()
+            .reparent(mirrorLayer, mParentLayer->getHandle())
+            .setPosition(mirrorLayer, 500, 500)
+            .show(mirrorLayer)
+            .apply();
+
+    {
+        SCOPED_TRACE("Initial Mirror BufferQueueLayer");
+        auto shot = screenshot();
+        // Buffer mirror
+        shot->expectColor(Rect(550, 550, 750, 750), Color::BLUE);
+        // Child mirror
+        shot->expectColor(Rect(750, 750, 950, 950), Color::GREEN);
+    }
+
+    fillBufferQueueLayerColor(bufferQueueLayer, Color::WHITE, 200, 200);
+    {
+        SCOPED_TRACE("Update BufferQueueLayer");
+        auto shot = screenshot();
+        // Buffer mirror
+        shot->expectColor(Rect(550, 550, 750, 750), Color::WHITE);
+        // Child mirror
+        shot->expectColor(Rect(750, 750, 950, 950), Color::GREEN);
+    }
+
+    Transaction().reparent(bufferQueueLayer, nullptr).apply();
+    {
+        SCOPED_TRACE("Removed BufferQueueLayer");
+        auto shot = screenshot();
+        // Buffer mirror
+        shot->expectColor(Rect(550, 550, 750, 750), Color::GREEN);
+        // Child mirror
+        shot->expectColor(Rect(750, 750, 950, 950), Color::GREEN);
+    }
+
+    sp<SurfaceControl> bufferStateLayer =
+            createLayer("BufferStateLayer", 200, 200, ISurfaceComposerClient::eFXSurfaceBufferState,
+                        mChildLayer.get());
+    fillBufferStateLayerColor(bufferStateLayer, Color::BLUE, 200, 200);
+    Transaction().setFrame(bufferStateLayer, Rect(0, 0, 200, 200)).show(bufferStateLayer).apply();
+
+    {
+        SCOPED_TRACE("Initial Mirror BufferStateLayer");
+        auto shot = screenshot();
+        // Buffer mirror
+        shot->expectColor(Rect(550, 550, 750, 750), Color::BLUE);
+        // Child mirror
+        shot->expectColor(Rect(750, 750, 950, 950), Color::GREEN);
+    }
+
+    fillBufferStateLayerColor(bufferStateLayer, Color::WHITE, 200, 200);
+    {
+        SCOPED_TRACE("Update BufferStateLayer");
+        auto shot = screenshot();
+        // Buffer mirror
+        shot->expectColor(Rect(550, 550, 750, 750), Color::WHITE);
+        // Child mirror
+        shot->expectColor(Rect(750, 750, 950, 950), Color::GREEN);
+    }
+
+    Transaction().reparent(bufferStateLayer, nullptr).apply();
+    {
+        SCOPED_TRACE("Removed BufferStateLayer");
+        auto shot = screenshot();
+        // Buffer mirror
+        shot->expectColor(Rect(550, 550, 750, 750), Color::GREEN);
+        // Child mirror
+        shot->expectColor(Rect(750, 750, 950, 950), Color::GREEN);
+    }
+}
+
+} // namespace android