Add captureLayers function to capture a layer and its children.

The captureLayers function gets a root layer as its argument.
It will capture the content for that layer and its descendants. The
capture will set the root layer's transform back to (0, 0).

Test: Transaction_test ScreenCaptureTest
Change-Id: I84fb66a65cd91434cddc99506b1924cf9f950935

19 files changed, 760 insertions, 386 deletions

diff --git a/libs/gui/ISurfaceComposer.cpp b/libs/gui/ISurfaceComposer.cpp
index 96771257c1..973302c226 100644
--- a/libs/gui/ISurfaceComposer.cpp
+++ b/libs/gui/ISurfaceComposer.cpp
@@ -122,6 +122,18 @@ public:
         return reply.readInt32();
     }
 
+    virtual status_t captureLayers(const sp<IBinder>& layerHandleBinder,
+                                   const sp<IGraphicBufferProducer>& producer,
+                                   ISurfaceComposer::Rotation rotation) {
+        Parcel data, reply;
+        data.writeInterfaceToken(ISurfaceComposer::getInterfaceDescriptor());
+        data.writeStrongBinder(layerHandleBinder);
+        data.writeStrongBinder(IInterface::asBinder(producer));
+        data.writeInt32(static_cast<int32_t>(rotation));
+        remote()->transact(BnSurfaceComposer::CAPTURE_LAYERS, data, &reply);
+        return reply.readInt32();
+    }
+
     virtual bool authenticateSurfaceTexture(
             const sp<IGraphicBufferProducer>& bufferProducer) const
     {
@@ -588,6 +600,18 @@ status_t BnSurfaceComposer::onTransact(
             reply->writeInt32(res);
             return NO_ERROR;
         }
+        case CAPTURE_LAYERS: {
+            CHECK_INTERFACE(ISurfaceComposer, data, reply);
+            sp<IBinder> layerHandleBinder = data.readStrongBinder();
+            sp<IGraphicBufferProducer> producer =
+                    interface_cast<IGraphicBufferProducer>(data.readStrongBinder());
+            int32_t rotation = data.readInt32();
+
+            status_t res = captureLayers(layerHandleBinder, producer,
+                                         static_cast<ISurfaceComposer::Rotation>(rotation));
+            reply->writeInt32(res);
+            return NO_ERROR;
+        }
         case AUTHENTICATE_SURFACE: {
             CHECK_INTERFACE(ISurfaceComposer, data, reply);
             sp<IGraphicBufferProducer> bufferProducer =
diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index 40e319e28a..15c4c9a880 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -731,6 +731,15 @@ status_t ScreenshotClient::captureToBuffer(const sp<IBinder>& display,
     return ret;
 }
 
+status_t ScreenshotClient::captureLayers(const sp<IBinder>& layerHandle,
+                                         const sp<IGraphicBufferProducer>& producer,
+                                         uint32_t rotation) {
+    sp<ISurfaceComposer> s(ComposerService::getComposerService());
+    if (s == NULL) return NO_INIT;
+    return s->captureLayers(layerHandle, producer,
+                            static_cast<ISurfaceComposer::Rotation>(rotation));
+}
+
 ScreenshotClient::ScreenshotClient()
     : mHaveBuffer(false) {
     memset(&mBuffer, 0, sizeof(mBuffer));
diff --git a/libs/gui/include/gui/ISurfaceComposer.h b/libs/gui/include/gui/ISurfaceComposer.h
index b2267426a8..13e7473d54 100644
--- a/libs/gui/include/gui/ISurfaceComposer.h
+++ b/libs/gui/include/gui/ISurfaceComposer.h
@@ -174,6 +174,10 @@ public:
             bool useIdentityTransform,
             Rotation rotation = eRotateNone) = 0;
 
+    virtual status_t captureLayers(const sp<IBinder>& layerHandleBinder,
+                                   const sp<IGraphicBufferProducer>& producer,
+                                   Rotation rotation = eRotateNone) = 0;
+
     /* Clears the frame statistics for animations.
      *
      * Requires the ACCESS_SURFACE_FLINGER permission.
@@ -226,6 +230,7 @@ public:
         SET_ACTIVE_CONFIG,
         CONNECT_DISPLAY,
         CAPTURE_SCREEN,
+        CAPTURE_LAYERS,
         CLEAR_ANIMATION_FRAME_STATS,
         GET_ANIMATION_FRAME_STATS,
         SET_POWER_MODE,
diff --git a/libs/gui/include/gui/SurfaceComposerClient.h b/libs/gui/include/gui/SurfaceComposerClient.h
index 00d593638d..d63dafea41 100644
--- a/libs/gui/include/gui/SurfaceComposerClient.h
+++ b/libs/gui/include/gui/SurfaceComposerClient.h
@@ -297,6 +297,9 @@ public:
             bool useIdentityTransform,
             uint32_t rotation,
             sp<GraphicBuffer>* outbuffer);
+    static status_t captureLayers(const sp<IBinder>& layerHandle,
+                                  const sp<IGraphicBufferProducer>& producer, uint32_t rotation);
+
 private:
     mutable sp<CpuConsumer> mCpuConsumer;
     mutable sp<IGraphicBufferProducer> mProducer;
diff --git a/libs/gui/tests/Surface_test.cpp b/libs/gui/tests/Surface_test.cpp
index 572760e77d..660680bf9e 100644
--- a/libs/gui/tests/Surface_test.cpp
+++ b/libs/gui/tests/Surface_test.cpp
@@ -529,6 +529,11 @@ public:
             int32_t /*minLayerZ*/, int32_t /*maxLayerZ*/,
             bool /*useIdentityTransform*/,
             Rotation /*rotation*/) override { return NO_ERROR; }
+    virtual status_t captureLayers(const sp<IBinder>& /*parentHandle*/,
+                                   const sp<IGraphicBufferProducer>& /*producer*/,
+                                   ISurfaceComposer::Rotation /*rotation*/) override {
+        return NO_ERROR;
+    }
     status_t clearAnimationFrameStats() override { return NO_ERROR; }
     status_t getAnimationFrameStats(FrameStats* /*outStats*/) const override {
         return NO_ERROR;
diff --git a/services/surfaceflinger/Android.mk b/services/surfaceflinger/Android.mk
index d8152e08cc..d9bca04b0b 100644
--- a/services/surfaceflinger/Android.mk
+++ b/services/surfaceflinger/Android.mk
@@ -40,6 +40,7 @@ LOCAL_SRC_FILES := \
     RenderEngine/Texture.cpp \
     RenderEngine/GLES20RenderEngine.cpp \
     LayerProtoHelper.cpp \
+    RenderArea.cpp \
 
 LOCAL_MODULE := libsurfaceflinger
 LOCAL_C_INCLUDES := \
diff --git a/services/surfaceflinger/ColorLayer.cpp b/services/surfaceflinger/ColorLayer.cpp
index 6923782b27..32526dd29b 100644
--- a/services/surfaceflinger/ColorLayer.cpp
+++ b/services/surfaceflinger/ColorLayer.cpp
@@ -40,13 +40,12 @@ ColorLayer::ColorLayer(SurfaceFlinger* flinger, const sp<Client>& client,
     : Layer(flinger, client, name, w, h, flags) {
 }
 
-void ColorLayer::onDraw(const sp<const DisplayDevice>& hw,
-        const Region& /* clip */, bool useIdentityTransform) const
-{
+void ColorLayer::onDraw(const RenderArea& renderArea, const Region& /* clip */,
+                        bool useIdentityTransform) const {
     const State& s(getDrawingState());
     if (s.color.a>0) {
         Mesh mesh(Mesh::TRIANGLE_FAN, 4, 2);
-        computeGeometry(hw, mesh, useIdentityTransform);
+        computeGeometry(renderArea, mesh, useIdentityTransform);
         RenderEngine& engine(mFlinger->getRenderEngine());
         engine.setupLayerBlending(getPremultipledAlpha(), false /* opaque */,
               true /* disableTexture */, s.color);
diff --git a/services/surfaceflinger/ColorLayer.h b/services/surfaceflinger/ColorLayer.h
index ac3e2a95dc..cdf3eca60a 100644
--- a/services/surfaceflinger/ColorLayer.h
+++ b/services/surfaceflinger/ColorLayer.h
@@ -34,7 +34,7 @@ public:
     virtual ~ColorLayer() = default;
 
     virtual const char* getTypeId() const { return "ColorLayer"; }
-    virtual void onDraw(const sp<const DisplayDevice>& hw, const Region& clip,
+    virtual void onDraw(const RenderArea& renderArea, const Region& clip,
             bool useIdentityTransform) const;
     virtual bool isOpaque(const Layer::State&) const { return false; }
     virtual bool isSecure() const         { return false; }
diff --git a/services/surfaceflinger/DisplayDevice.h b/services/surfaceflinger/DisplayDevice.h
index 8636e2af79..49fef5805f 100644
--- a/services/surfaceflinger/DisplayDevice.h
+++ b/services/surfaceflinger/DisplayDevice.h
@@ -37,7 +37,9 @@
 #include <utils/String8.h>
 #include <utils/Timers.h>
 
+#include <gui/ISurfaceComposer.h>
 #include <hardware/hwcomposer_defs.h>
+#include "RenderArea.h"
 
 #ifdef USE_HWC2
 #include <memory>
@@ -300,6 +302,35 @@ struct DisplayDeviceState {
     bool isSecure = false;
 };
 
+class DisplayRenderArea : public RenderArea {
+public:
+    DisplayRenderArea(const sp<const DisplayDevice> device,
+                      ISurfaceComposer::Rotation rotation = ISurfaceComposer::eRotateNone)
+          : DisplayRenderArea(device, device->getBounds(), device->getHeight(), device->getWidth(),
+                              rotation) {}
+    DisplayRenderArea(const sp<const DisplayDevice> device, Rect sourceCrop, uint32_t reqHeight,
+                      uint32_t reqWidth, ISurfaceComposer::Rotation rotation)
+          : RenderArea(reqHeight, reqWidth, rotation), mDevice(device), mSourceCrop(sourceCrop) {}
+
+    const Transform& getTransform() const override { return mDevice->getTransform(); }
+    Rect getBounds() const override { return mDevice->getBounds(); }
+    int getHeight() const override { return mDevice->getHeight(); }
+    int getWidth() const override { return mDevice->getWidth(); }
+    bool isSecure() const override { return mDevice->isSecure(); }
+    bool needsFiltering() const override { return mDevice->needsFiltering(); }
+    Rect getSourceCrop() const override { return mSourceCrop; }
+#ifdef USE_HWC2
+    bool getWideColorSupport() const override { return mDevice->getWideColorSupport(); }
+    android_color_mode_t getActiveColorMode() const override {
+        return mDevice->getActiveColorMode();
+    }
+#endif
+
+private:
+    const sp<const DisplayDevice> mDevice;
+    const Rect mSourceCrop;
+};
+
 }; // namespace android
 
 #endif // ANDROID_DISPLAY_DEVICE_H
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 27739ce074..56328c9b3d 100755
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -1063,17 +1063,16 @@ Rect Layer::getPosition(
 // drawing...
 // ---------------------------------------------------------------------------
 
-void Layer::draw(const sp<const DisplayDevice>& hw, const Region& clip) const {
-    onDraw(hw, clip, false);
+void Layer::draw(const RenderArea& renderArea, const Region& clip) const {
+    onDraw(renderArea, clip, false);
 }
 
-void Layer::draw(const sp<const DisplayDevice>& hw,
-        bool useIdentityTransform) const {
-    onDraw(hw, Region(hw->bounds()), useIdentityTransform);
+void Layer::draw(const RenderArea& renderArea, bool useIdentityTransform) const {
+    onDraw(renderArea, Region(renderArea.getBounds()), useIdentityTransform);
 }
 
-void Layer::draw(const sp<const DisplayDevice>& hw) const {
-    onDraw(hw, Region(hw->bounds()), false);
+void Layer::draw(const RenderArea& renderArea) const {
+    onDraw(renderArea, Region(renderArea.getBounds()), false);
 }
 
 static constexpr mat4 inverseOrientation(uint32_t transform) {
@@ -1097,7 +1096,7 @@ static constexpr mat4 inverseOrientation(uint32_t transform) {
 /*
  * onDraw will draw the current layer onto the presentable buffer
  */
-void Layer::onDraw(const sp<const DisplayDevice>& hw, const Region& clip,
+void Layer::onDraw(const RenderArea& renderArea, const Region& clip,
         bool useIdentityTransform) const
 {
     ATRACE_CALL();
@@ -1119,12 +1118,12 @@ void Layer::onDraw(const sp<const DisplayDevice>& hw, const Region& clip,
                 finished = true;
                 return;
             }
-            under.orSelf( hw->getTransform().transform(layer->visibleRegion) );
+            under.orSelf(renderArea.getTransform().transform(layer->visibleRegion));
         });
         // if not everything below us is covered, we plug the holes!
         Region holes(clip.subtract(under));
         if (!holes.isEmpty()) {
-            clearWithOpenGL(hw, 0, 0, 0, 1);
+            clearWithOpenGL(renderArea, 0, 0, 0, 1);
         }
         return;
     }
@@ -1138,13 +1137,13 @@ void Layer::onDraw(const sp<const DisplayDevice>& hw, const Region& clip,
         // is probably going to have something visibly wrong.
     }
 
-    bool blackOutLayer = isProtected() || (isSecure() && !hw->isSecure());
+    bool blackOutLayer = isProtected() || (isSecure() && !renderArea.isSecure());
 
     RenderEngine& engine(mFlinger->getRenderEngine());
 
     if (!blackOutLayer) {
         // TODO: we could be more subtle with isFixedSize()
-        const bool useFiltering = getFiltering() || needsFiltering(hw) || isFixedSize();
+        const bool useFiltering = getFiltering() || needsFiltering(renderArea) || isFixedSize();
 
         // Query the texture matrix given our current filtering mode.
         float textureMatrix[16];
@@ -1190,31 +1189,29 @@ void Layer::onDraw(const sp<const DisplayDevice>& hw, const Region& clip,
     } else {
         engine.setupLayerBlackedOut();
     }
-    drawWithOpenGL(hw, useIdentityTransform);
+    drawWithOpenGL(renderArea, useIdentityTransform);
     engine.disableTexturing();
 }
 
 
-void Layer::clearWithOpenGL(const sp<const DisplayDevice>& hw,
+void Layer::clearWithOpenGL(const RenderArea& renderArea,
         float red, float green, float blue,
         float alpha) const
 {
     RenderEngine& engine(mFlinger->getRenderEngine());
-    computeGeometry(hw, mMesh, false);
+    computeGeometry(renderArea, mMesh, false);
     engine.setupFillWithColor(red, green, blue, alpha);
     engine.drawMesh(mMesh);
 }
 
-void Layer::clearWithOpenGL(
-        const sp<const DisplayDevice>& hw) const {
-    clearWithOpenGL(hw, 0,0,0,0);
+void Layer::clearWithOpenGL(const RenderArea& renderArea) const {
+    clearWithOpenGL(renderArea, 0,0,0,0);
 }
 
-void Layer::drawWithOpenGL(const sp<const DisplayDevice>& hw,
-        bool useIdentityTransform) const {
+void Layer::drawWithOpenGL(const RenderArea& renderArea, bool useIdentityTransform) const {
     const State& s(getDrawingState());
 
-    computeGeometry(hw, mMesh, useIdentityTransform);
+    computeGeometry(renderArea, mMesh, useIdentityTransform);
 
     /*
      * NOTE: the way we compute the texture coordinates here produces
@@ -1440,12 +1437,11 @@ static void boundPoint(vec2* point, const Rect& crop) {
     }
 }
 
-void Layer::computeGeometry(const sp<const DisplayDevice>& hw, Mesh& mesh,
-        bool useIdentityTransform) const
-{
+void Layer::computeGeometry(const RenderArea& renderArea, Mesh& mesh,
+                            bool useIdentityTransform) const {
     const Layer::State& s(getDrawingState());
-    const Transform hwTransform(hw->getTransform());
-    const uint32_t hw_h = hw->getHeight();
+    const Transform renderAreaTransform(renderArea.getTransform());
+    const uint32_t height = renderArea.getHeight();
     Rect win = computeBounds();
 
     vec2 lt = vec2(win.left, win.top);
@@ -1469,12 +1465,12 @@ void Layer::computeGeometry(const sp<const DisplayDevice>& hw, Mesh& mesh,
     }
 
     Mesh::VertexArray<vec2> position(mesh.getPositionArray<vec2>());
-    position[0] = hwTransform.transform(lt);
-    position[1] = hwTransform.transform(lb);
-    position[2] = hwTransform.transform(rb);
-    position[3] = hwTransform.transform(rt);
+    position[0] = renderAreaTransform.transform(lt);
+    position[1] = renderAreaTransform.transform(lb);
+    position[2] = renderAreaTransform.transform(rb);
+    position[3] = renderAreaTransform.transform(rt);
     for (size_t i=0 ; i<4 ; i++) {
-        position[i].y = hw_h - position[i].y;
+        position[i].y = height - position[i].y;
     }
 }
 
@@ -1512,8 +1508,8 @@ bool Layer::isCropped() const {
     return !mCurrentCrop.isEmpty();
 }
 
-bool Layer::needsFiltering(const sp<const DisplayDevice>& hw) const {
-    return mNeedsFiltering || hw->needsFiltering();
+bool Layer::needsFiltering(const RenderArea& renderArea) const {
+    return mNeedsFiltering || renderArea.needsFiltering();
 }
 
 void Layer::setVisibleRegion(const Region& visibleRegion) {
@@ -2773,6 +2769,29 @@ void Layer::traverseInReverseZOrder(LayerVector::StateSet stateSet,
     }
 }
 
+/**
+ * Traverse only children in z order, ignoring relative layers.
+ */
+void Layer::traverseChildrenInZOrder(LayerVector::StateSet stateSet,
+                                     const LayerVector::Visitor& visitor) {
+    const bool useDrawing = stateSet == LayerVector::StateSet::Drawing;
+    const LayerVector& children = useDrawing ? mDrawingChildren : mCurrentChildren;
+
+    size_t i = 0;
+    for (; i < children.size(); i++) {
+        const auto& relative = children[i];
+        if (relative->getZ() >= 0) {
+            break;
+        }
+        relative->traverseChildrenInZOrder(stateSet, visitor);
+    }
+    visitor(this);
+    for (; i < children.size(); i++) {
+        const auto& relative = children[i];
+        relative->traverseChildrenInZOrder(stateSet, visitor);
+    }
+}
+
 Transform Layer::getTransform() const {
     Transform t;
     const auto& p = mDrawingParent.promote();
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index 06c4863ce2..d75e175f5a 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -50,6 +50,7 @@
 #include "RenderEngine/Mesh.h"
 #include "RenderEngine/Texture.h"
 #include <layerproto/LayerProtoHeader.h>
+#include "RenderArea.h"
 
 #include <math/vec4.h>
 
@@ -255,8 +256,7 @@ public:
         return getLayerStack() == layerStack && (!mPrimaryDisplayOnly || isPrimaryDisplay);
     }
 
-    void computeGeometry(const sp<const DisplayDevice>& hw, Mesh& mesh,
-            bool useIdentityTransform) const;
+    void computeGeometry(const RenderArea& renderArea, Mesh& mesh, bool useIdentityTransform) const;
     Rect computeBounds(const Region& activeTransparentRegion) const;
     Rect computeBounds() const;
 
@@ -312,7 +312,7 @@ protected:
     /*
      * onDraw - draws the surface.
      */
-    virtual void onDraw(const sp<const DisplayDevice>& hw, const Region& clip,
+    virtual void onDraw(const RenderArea& renderArea, const Region& clip,
             bool useIdentityTransform) const;
 
 public:
@@ -379,9 +379,9 @@ public:
      * draw - performs some global clipping optimizations
      * and calls onDraw().
      */
-    void draw(const sp<const DisplayDevice>& hw, const Region& clip) const;
-    void draw(const sp<const DisplayDevice>& hw, bool useIdentityTransform) const;
-    void draw(const sp<const DisplayDevice>& hw) const;
+    void draw(const RenderArea& renderArea, const Region& clip) const;
+    void draw(const RenderArea& renderArea, bool useIdentityTransform) const;
+    void draw(const RenderArea& renderArea) const;
 
     /*
      * doTransaction - process the transaction. This is a good place to figure
@@ -472,7 +472,7 @@ public:
 #endif
     // -----------------------------------------------------------------------
 
-    void clearWithOpenGL(const sp<const DisplayDevice>& hw) const;
+    void clearWithOpenGL(const RenderArea& renderArea) const;
     void setFiltering(bool filtering);
     bool getFiltering() const;
 
@@ -516,6 +516,9 @@ public:
                                  const LayerVector::Visitor& visitor);
     void traverseInZOrder(LayerVector::StateSet stateSet, const LayerVector::Visitor& visitor);
 
+    void traverseChildrenInZOrder(LayerVector::StateSet stateSet,
+                                  const LayerVector::Visitor& visitor);
+
     size_t getChildrenCount() const;
     void addChild(const sp<Layer>& layer);
     // Returns index if removed, or negative value otherwise
@@ -569,7 +572,7 @@ private:
     void commitTransaction(const State& stateToCommit);
 
     // needsLinearFiltering - true if this surface's state requires filtering
-    bool needsFiltering(const sp<const DisplayDevice>& hw) const;
+    bool needsFiltering(const RenderArea& renderArea) const;
 
     uint32_t getEffectiveUsage(uint32_t usage) const;
 
@@ -582,9 +585,9 @@ private:
     static bool getOpacityForFormat(uint32_t format);
 
     // drawing
-    void clearWithOpenGL(const sp<const DisplayDevice>& hw,
+    void clearWithOpenGL(const RenderArea& renderArea,
             float r, float g, float b, float alpha) const;
-    void drawWithOpenGL(const sp<const DisplayDevice>& hw,
+    void drawWithOpenGL(const RenderArea& renderArea,
             bool useIdentityTransform) const;
 
     // Temporary - Used only for LEGACY camera mode.
diff --git a/services/surfaceflinger/RenderArea.cpp b/services/surfaceflinger/RenderArea.cpp
new file mode 100644
index 0000000000..6225df134d
--- /dev/null
+++ b/services/surfaceflinger/RenderArea.cpp
@@ -0,0 +1,34 @@
+#include "RenderArea.h"
+
+namespace android {
+
+/*
+ * Checks that the requested width and height are valid and updates them to the render area
+ * dimensions if they are set to 0
+ */
+status_t RenderArea::updateDimensions() {
+    // get screen geometry
+
+    uint32_t width = getWidth();
+    uint32_t height = getHeight();
+
+    if (mRotationFlags & Transform::ROT_90) {
+        std::swap(width, height);
+    }
+
+    if ((mReqWidth > width) || (mReqHeight > height)) {
+        ALOGE("size mismatch (%d, %d) > (%d, %d)", mReqWidth, mReqHeight, width, height);
+        return BAD_VALUE;
+    }
+
+    if (mReqWidth == 0) {
+        mReqWidth = width;
+    }
+    if (mReqHeight == 0) {
+        mReqHeight = height;
+    }
+
+    return NO_ERROR;
+}
+
+} // namespace android
\ No newline at end of file
diff --git a/services/surfaceflinger/RenderArea.h b/services/surfaceflinger/RenderArea.h
new file mode 100644
index 0000000000..faf1ec64f8
--- /dev/null
+++ b/services/surfaceflinger/RenderArea.h
@@ -0,0 +1,40 @@
+#pragma once
+
+#include "Transform.h"
+
+namespace android {
+
+class RenderArea {
+public:
+    RenderArea(uint32_t reqHeight, uint32_t reqWidth, ISurfaceComposer::Rotation rotation)
+          : mReqHeight(reqHeight), mReqWidth(reqWidth) {
+        mRotationFlags = Transform::fromRotation(rotation);
+    }
+
+    virtual ~RenderArea() = default;
+
+    virtual const Transform& getTransform() const = 0;
+    virtual Rect getBounds() const = 0;
+    virtual int getHeight() const = 0;
+    virtual int getWidth() const = 0;
+    virtual bool isSecure() const = 0;
+    virtual bool needsFiltering() const = 0;
+    virtual Rect getSourceCrop() const = 0;
+
+    int getReqHeight() const { return mReqHeight; };
+    int getReqWidth() const { return mReqWidth; };
+    Transform::orientation_flags getRotationFlags() const { return mRotationFlags; };
+#ifdef USE_HWC2
+    virtual bool getWideColorSupport() const = 0;
+    virtual android_color_mode_t getActiveColorMode() const = 0;
+#endif
+
+    status_t updateDimensions();
+
+private:
+    uint32_t mReqHeight;
+    uint32_t mReqWidth;
+    Transform::orientation_flags mRotationFlags;
+};
+
+} // namespace android
\ No newline at end of file
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 05c76fce46..fe9409b35e 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -2650,6 +2650,7 @@ bool SurfaceFlinger::doComposeSurfaces(
 {
     ALOGV("doComposeSurfaces");
 
+    const DisplayRenderArea renderArea(displayDevice);
     const auto hwcId = displayDevice->getHwcDisplayId();
 
     mat4 oldColorMatrix;
@@ -2759,12 +2760,12 @@ bool SurfaceFlinger::doComposeSurfaces(
                                 && hasClientComposition) {
                             // never clear the very first layer since we're
                             // guaranteed the FB is already cleared
-                            layer->clearWithOpenGL(displayDevice);
+                            layer->clearWithOpenGL(renderArea);
                         }
                         break;
                     }
                     case HWC2::Composition::Client: {
-                        layer->draw(displayDevice, clip);
+                        layer->draw(renderArea, clip);
                         break;
                     }
                     default:
@@ -2781,7 +2782,7 @@ bool SurfaceFlinger::doComposeSurfaces(
             const Region clip(dirty.intersect(
                     displayTransform.transform(layer->visibleRegion)));
             if (!clip.isEmpty()) {
-                layer->draw(displayDevice, clip);
+                layer->draw(renderArea, clip);
             }
         }
     }
@@ -4029,6 +4030,17 @@ status_t SurfaceFlinger::CheckTransactCodeCredentials(uint32_t code) {
             }
             break;
         }
+        case CAPTURE_LAYERS: {
+            IPCThreadState* ipc = IPCThreadState::self();
+            const int pid = ipc->getCallingPid();
+            const int uid = ipc->getCallingUid();
+            if ((uid != AID_GRAPHICS) &&
+                !PermissionCache::checkPermission(sReadFramebuffer, pid, uid)) {
+                ALOGE("Permission Denial: can't read framebuffer pid=%d, uid=%d", pid, uid);
+                return PERMISSION_DENIED;
+            }
+            break;
+        }
     }
     return OK;
 }
@@ -4228,35 +4240,6 @@ void SurfaceFlinger::repaintEverything() {
     repaintEverythingLocked();
 }
 
-// Checks that the requested width and height are valid and updates them to the display dimensions
-// if they are set to 0
-static status_t updateDimensionsLocked(const sp<const DisplayDevice>& displayDevice,
-                                       Transform::orientation_flags rotation,
-                                       uint32_t* requestedWidth, uint32_t* requestedHeight) {
-    // get screen geometry
-    uint32_t displayWidth = displayDevice->getWidth();
-    uint32_t displayHeight = displayDevice->getHeight();
-
-    if (rotation & Transform::ROT_90) {
-        std::swap(displayWidth, displayHeight);
-    }
-
-    if ((*requestedWidth > displayWidth) || (*requestedHeight > displayHeight)) {
-        ALOGE("size mismatch (%d, %d) > (%d, %d)",
-                *requestedWidth, *requestedHeight, displayWidth, displayHeight);
-        return BAD_VALUE;
-    }
-
-    if (*requestedWidth == 0) {
-        *requestedWidth = displayWidth;
-    }
-    if (*requestedHeight == 0) {
-        *requestedHeight = displayHeight;
-    }
-
-    return NO_ERROR;
-}
-
 // A simple RAII class to disconnect from an ANativeWindow* when it goes out of scope
 class WindowDisconnector {
 public:
@@ -4305,50 +4288,86 @@ static status_t getWindowBuffer(ANativeWindow* window, uint32_t requestedWidth,
 }
 
 status_t SurfaceFlinger::captureScreen(const sp<IBinder>& display,
-        const sp<IGraphicBufferProducer>& producer,
-        Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
-        int32_t minLayerZ, int32_t maxLayerZ,
-        bool useIdentityTransform, ISurfaceComposer::Rotation rotation) {
+                                       const sp<IGraphicBufferProducer>& producer, Rect sourceCrop,
+                                       uint32_t reqWidth, uint32_t reqHeight, int32_t minLayerZ,
+                                       int32_t maxLayerZ, bool useIdentityTransform,
+                                       ISurfaceComposer::Rotation rotation) {
     ATRACE_CALL();
 
-    if (CC_UNLIKELY(display == 0))
-        return BAD_VALUE;
+    if (CC_UNLIKELY(display == 0)) return BAD_VALUE;
+
+    const sp<const DisplayDevice> device(getDisplayDeviceLocked(display));
+    DisplayRenderArea renderArea(device, sourceCrop, reqHeight, reqWidth, rotation);
+
+    auto traverseLayers = std::bind(std::mem_fn(&SurfaceFlinger::traverseLayersInDisplay), this,
+                                    device, minLayerZ, maxLayerZ, std::placeholders::_1);
+    return captureScreenCommon(renderArea, traverseLayers, producer, useIdentityTransform);
+}
+
+status_t SurfaceFlinger::captureLayers(const sp<IBinder>& layerHandleBinder,
+                                       const sp<IGraphicBufferProducer>& producer,
+                                       ISurfaceComposer::Rotation rotation) {
+    ATRACE_CALL();
+
+    class LayerRenderArea : public RenderArea {
+    public:
+        LayerRenderArea(const sp<Layer>& layer, ISurfaceComposer::Rotation rotation)
+              : RenderArea(layer->getCurrentState().active.h, layer->getCurrentState().active.w,
+                           rotation),
+                mLayer(layer) {}
+        const Transform& getTransform() const override {
+            // Make the top level transform the inverse the transform and it's parent so it sets
+            // the whole capture back to 0,0
+            return *new Transform(mLayer->getTransform().inverse());
+        }
+        Rect getBounds() const override {
+            const Layer::State& layerState(mLayer->getDrawingState());
+            return Rect(layerState.active.w, layerState.active.h);
+        }
+        int getHeight() const override { return mLayer->getDrawingState().active.h; }
+        int getWidth() const override { return mLayer->getDrawingState().active.w; }
+        bool isSecure() const override { return false; }
+        bool needsFiltering() const override { return false; }
+
+        Rect getSourceCrop() const override { return getBounds(); }
+        bool getWideColorSupport() const override { return false; }
+        android_color_mode_t getActiveColorMode() const override { return HAL_COLOR_MODE_NATIVE; }
+
+    private:
+        const sp<Layer>& mLayer;
+    };
+
+    auto layerHandle = reinterpret_cast<Layer::Handle*>(layerHandleBinder.get());
+    auto parent = layerHandle->owner.promote();
+
+    LayerRenderArea renderArea(parent, rotation);
+    auto traverseLayers = [parent](const LayerVector::Visitor& visitor) {
+        parent->traverseChildrenInZOrder(LayerVector::StateSet::Drawing, [&](Layer* layer) {
+            if (!layer->isVisible()) {
+                return;
+            }
+            visitor(layer);
+        });
+    };
+    return captureScreenCommon(renderArea, traverseLayers, producer, false);
+}
+
+status_t SurfaceFlinger::captureScreenCommon(RenderArea& renderArea,
+                                             TraverseLayersFunction traverseLayers,
+                                             const sp<IGraphicBufferProducer>& producer,
+                                             bool useIdentityTransform) {
+    ATRACE_CALL();
 
     if (CC_UNLIKELY(producer == 0))
         return BAD_VALUE;
 
+    renderArea.updateDimensions();
+
     // if we have secure windows on this display, never allow the screen capture
     // unless the producer interface is local (i.e.: we can take a screenshot for
     // ourselves).
     bool isLocalScreenshot = IInterface::asBinder(producer)->localBinder();
 
-    // Convert to surfaceflinger's internal rotation type.
-    Transform::orientation_flags rotationFlags;
-    switch (rotation) {
-        case ISurfaceComposer::eRotateNone:
-            rotationFlags = Transform::ROT_0;
-            break;
-        case ISurfaceComposer::eRotate90:
-            rotationFlags = Transform::ROT_90;
-            break;
-        case ISurfaceComposer::eRotate180:
-            rotationFlags = Transform::ROT_180;
-            break;
-        case ISurfaceComposer::eRotate270:
-            rotationFlags = Transform::ROT_270;
-            break;
-        default:
-            rotationFlags = Transform::ROT_0;
-            ALOGE("Invalid rotation passed to captureScreen(): %d\n", rotation);
-            break;
-    }
-
-    { // Autolock scope
-        Mutex::Autolock lock(mStateLock);
-        sp<const DisplayDevice> displayDevice(getDisplayDeviceLocked(display));
-        updateDimensionsLocked(displayDevice, rotationFlags, &reqWidth, &reqHeight);
-    }
-
     // create a surface (because we're a producer, and we need to
     // dequeue/queue a buffer)
     sp<Surface> surface = new Surface(producer, false);
@@ -4369,9 +4388,9 @@ status_t SurfaceFlinger::captureScreen(const sp<IBinder>& display,
     WindowDisconnector disconnector(window, NATIVE_WINDOW_API_EGL);
 
     ANativeWindowBuffer* buffer = nullptr;
-    result = getWindowBuffer(window, reqWidth, reqHeight,
-            hasWideColorDisplay && !mForceNativeColorMode,
-            getRenderEngine().usesWideColor(), &buffer);
+    result = getWindowBuffer(window, renderArea.getReqWidth(), renderArea.getReqHeight(),
+                             hasWideColorDisplay && !mForceNativeColorMode,
+                             getRenderEngine().usesWideColor(), &buffer);
     if (result != NO_ERROR) {
         return result;
     }
@@ -4399,10 +4418,8 @@ status_t SurfaceFlinger::captureScreen(const sp<IBinder>& display,
         int fd = -1;
         {
             Mutex::Autolock _l(mStateLock);
-            sp<const DisplayDevice> device(getDisplayDeviceLocked(display));
-            result = captureScreenImplLocked(device, buffer, sourceCrop, reqWidth, reqHeight,
-                                             minLayerZ, maxLayerZ, useIdentityTransform,
-                                             rotationFlags, isLocalScreenshot, &fd);
+            result = captureScreenImplLocked(renderArea, traverseLayers, buffer,
+                                             useIdentityTransform, isLocalScreenshot, &fd);
         }
 
         {
@@ -4431,84 +4448,66 @@ status_t SurfaceFlinger::captureScreen(const sp<IBinder>& display,
         // queueBuffer takes ownership of syncFd
         result = window->queueBuffer(window, buffer, syncFd);
     }
-
     return result;
 }
 
-
-void SurfaceFlinger::renderScreenImplLocked(
-        const sp<const DisplayDevice>& hw,
-        Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
-        int32_t minLayerZ, int32_t maxLayerZ,
-        bool yswap, bool useIdentityTransform, Transform::orientation_flags rotation)
-{
+void SurfaceFlinger::renderScreenImplLocked(const RenderArea& renderArea,
+                                            TraverseLayersFunction traverseLayers, bool yswap,
+                                            bool useIdentityTransform) {
     ATRACE_CALL();
+
     RenderEngine& engine(getRenderEngine());
 
     // get screen geometry
-    const int32_t hw_w = hw->getWidth();
-    const int32_t hw_h = hw->getHeight();
-    const bool filtering = static_cast<int32_t>(reqWidth) != hw_w ||
-                           static_cast<int32_t>(reqHeight) != hw_h;
+    const auto raWidth = renderArea.getWidth();
+    const auto raHeight = renderArea.getHeight();
+
+    const auto reqWidth = renderArea.getReqWidth();
+    const auto reqHeight = renderArea.getReqHeight();
+    Rect sourceCrop = renderArea.getSourceCrop();
+
+    const bool filtering = static_cast<int32_t>(reqWidth) != raWidth ||
+            static_cast<int32_t>(reqHeight) != raHeight;
 
     // if a default or invalid sourceCrop is passed in, set reasonable values
-    if (sourceCrop.width() == 0 || sourceCrop.height() == 0 ||
-            !sourceCrop.isValid()) {
+    if (sourceCrop.width() == 0 || sourceCrop.height() == 0 || !sourceCrop.isValid()) {
         sourceCrop.setLeftTop(Point(0, 0));
-        sourceCrop.setRightBottom(Point(hw_w, hw_h));
+        sourceCrop.setRightBottom(Point(raWidth, raHeight));
     }
 
     // ensure that sourceCrop is inside screen
     if (sourceCrop.left < 0) {
         ALOGE("Invalid crop rect: l = %d (< 0)", sourceCrop.left);
     }
-    if (sourceCrop.right > hw_w) {
-        ALOGE("Invalid crop rect: r = %d (> %d)", sourceCrop.right, hw_w);
+    if (sourceCrop.right > raWidth) {
+        ALOGE("Invalid crop rect: r = %d (> %d)", sourceCrop.right, raWidth);
     }
     if (sourceCrop.top < 0) {
         ALOGE("Invalid crop rect: t = %d (< 0)", sourceCrop.top);
     }
-    if (sourceCrop.bottom > hw_h) {
-        ALOGE("Invalid crop rect: b = %d (> %d)", sourceCrop.bottom, hw_h);
+    if (sourceCrop.bottom > raHeight) {
+        ALOGE("Invalid crop rect: b = %d (> %d)", sourceCrop.bottom, raHeight);
     }
 
-#ifdef USE_HWC2
-     engine.setWideColor(hw->getWideColorSupport() && !mForceNativeColorMode);
-     engine.setColorMode(mForceNativeColorMode ? HAL_COLOR_MODE_NATIVE : hw->getActiveColorMode());
-#endif
+    engine.setWideColor(renderArea.getWideColorSupport() && !mForceNativeColorMode);
+    engine.setColorMode(mForceNativeColorMode ? HAL_COLOR_MODE_NATIVE : renderArea.getActiveColorMode());
 
     // make sure to clear all GL error flags
     engine.checkErrors();
 
     // set-up our viewport
-    engine.setViewportAndProjection(
-        reqWidth, reqHeight, sourceCrop, hw_h, yswap, rotation);
+    engine.setViewportAndProjection(reqWidth, reqHeight, sourceCrop, raHeight, yswap,
+                                    renderArea.getRotationFlags());
     engine.disableTexturing();
 
     // redraw the screen entirely...
     engine.clearWithColor(0, 0, 0, 1);
 
-    // We loop through the first level of layers without traversing,
-    // as we need to interpret min/max layer Z in the top level Z space.
-    for (const auto& layer : mDrawingState.layersSortedByZ) {
-        if (!layer->belongsToDisplay(hw->getLayerStack(), false)) {
-            continue;
-        }
-        const Layer::State& state(layer->getDrawingState());
-        if (state.z < minLayerZ || state.z > maxLayerZ) {
-            continue;
-        }
-        layer->traverseInZOrder(LayerVector::StateSet::Drawing, [&](Layer* layer) {
-            if (!layer->isVisible()) {
-                return;
-            }
-            if (filtering) layer->setFiltering(true);
-            layer->draw(hw, useIdentityTransform);
-            if (filtering) layer->setFiltering(false);
-        });
-    }
-
-    hw->setViewportAndProjection();
+    traverseLayers([&](Layer* layer) {
+        if (filtering) layer->setFiltering(true);
+        layer->draw(renderArea, useIdentityTransform);
+        if (filtering) layer->setFiltering(false);
+    });
 }
 
 // A simple RAII class that holds an EGLImage and destroys it either:
@@ -4531,27 +4530,18 @@ private:
     EGLImageKHR mImage;
 };
 
-status_t SurfaceFlinger::captureScreenImplLocked(const sp<const DisplayDevice>& hw,
-                                                 ANativeWindowBuffer* buffer, Rect sourceCrop,
-                                                 uint32_t reqWidth, uint32_t reqHeight,
-                                                 int32_t minLayerZ, int32_t maxLayerZ,
-                                                 bool useIdentityTransform,
-                                                 Transform::orientation_flags rotation,
-                                                 bool isLocalScreenshot, int* outSyncFd) {
+status_t SurfaceFlinger::captureScreenImplLocked(const RenderArea& renderArea,
+                                                 TraverseLayersFunction traverseLayers,
+                                                 ANativeWindowBuffer* buffer,
+                                                 bool useIdentityTransform, bool isLocalScreenshot,
+                                                 int* outSyncFd) {
     ATRACE_CALL();
 
     bool secureLayerIsVisible = false;
-    for (const auto& layer : mDrawingState.layersSortedByZ) {
-        const Layer::State& state(layer->getDrawingState());
-        if (!layer->belongsToDisplay(hw->getLayerStack(), false) ||
-                (state.z < minLayerZ || state.z > maxLayerZ)) {
-            continue;
-        }
-        layer->traverseInZOrder(LayerVector::StateSet::Drawing, [&](Layer *layer) {
-            secureLayerIsVisible = secureLayerIsVisible || (layer->isVisible() &&
-                    layer->isSecure());
-        });
-    }
+
+    traverseLayers([&](Layer* layer) {
+        secureLayerIsVisible = secureLayerIsVisible || (layer->isVisible() && layer->isSecure());
+    });
 
     if (!isLocalScreenshot && secureLayerIsVisible) {
         ALOGW("FB is protected: PERMISSION_DENIED");
@@ -4582,9 +4572,7 @@ status_t SurfaceFlinger::captureScreenImplLocked(const sp<const DisplayDevice>&
     // via an FBO, which means we didn't have to create
     // an EGLSurface and therefore we're not
     // dependent on the context's EGLConfig.
-    renderScreenImplLocked(
-        hw, sourceCrop, reqWidth, reqHeight, minLayerZ, maxLayerZ, true,
-        useIdentityTransform, rotation);
+    renderScreenImplLocked(renderArea, traverseLayers, true, useIdentityTransform);
 
     // Attempt to create a sync khr object that can produce a sync point. If that
     // isn't available, create a non-dupable sync object in the fallback path and
@@ -4625,46 +4613,40 @@ status_t SurfaceFlinger::captureScreenImplLocked(const sp<const DisplayDevice>&
     *outSyncFd = syncFd;
 
     if (DEBUG_SCREENSHOTS) {
+        const auto reqWidth = renderArea.getReqWidth();
+        const auto reqHeight = renderArea.getReqHeight();
+
         uint32_t* pixels = new uint32_t[reqWidth*reqHeight];
         getRenderEngine().readPixels(0, 0, reqWidth, reqHeight, pixels);
-        checkScreenshot(reqWidth, reqHeight, reqWidth, pixels,
-                hw, minLayerZ, maxLayerZ);
+        checkScreenshot(reqWidth, reqHeight, reqWidth, pixels, traverseLayers);
         delete [] pixels;
     }
 
     // destroy our image
     imageHolder.destroy();
-
     return NO_ERROR;
 }
 
 void SurfaceFlinger::checkScreenshot(size_t w, size_t s, size_t h, void const* vaddr,
-        const sp<const DisplayDevice>& hw, int32_t minLayerZ, int32_t maxLayerZ) {
+                                     TraverseLayersFunction traverseLayers) {
     if (DEBUG_SCREENSHOTS) {
-        for (size_t y=0 ; y<h ; y++) {
-            uint32_t const * p = (uint32_t const *)vaddr + y*s;
-            for (size_t x=0 ; x<w ; x++) {
+        for (size_t y = 0; y < h; y++) {
+            uint32_t const* p = (uint32_t const*)vaddr + y * s;
+            for (size_t x = 0; x < w; x++) {
                 if (p[x] != 0xFF000000) return;
             }
         }
-        ALOGE("*** we just took a black screenshot ***\n"
-                "requested minz=%d, maxz=%d, layerStack=%d",
-                minLayerZ, maxLayerZ, hw->getLayerStack());
+        ALOGE("*** we just took a black screenshot ***");
 
         size_t i = 0;
-        for (const auto& layer : mDrawingState.layersSortedByZ) {
+        traverseLayers([&](Layer* layer) {
             const Layer::State& state(layer->getDrawingState());
-            if (layer->belongsToDisplay(hw->getLayerStack(), false) && state.z >= minLayerZ &&
-                    state.z <= maxLayerZ) {
-                layer->traverseInZOrder(LayerVector::StateSet::Drawing, [&](Layer* layer) {
-                    ALOGE("%c index=%zu, name=%s, layerStack=%d, z=%d, visible=%d, flags=%x, alpha=%.3f",
-                            layer->isVisible() ? '+' : '-',
-                            i, layer->getName().string(), layer->getLayerStack(), state.z,
-                            layer->isVisible(), state.flags, static_cast<float>(state.color.a));
-                    i++;
-                });
-            }
-        }
+            ALOGE("%c index=%zu, name=%s, layerStack=%d, z=%d, visible=%d, flags=%x, alpha=%.3f",
+                  layer->isVisible() ? '+' : '-', i, layer->getName().string(),
+                  layer->getLayerStack(), state.z, layer->isVisible(), state.flags,
+                  static_cast<float>(state.color.a));
+            i++;
+        });
     }
 }
 
@@ -4678,6 +4660,28 @@ void SurfaceFlinger::State::traverseInReverseZOrder(const LayerVector::Visitor&
     layersSortedByZ.traverseInReverseZOrder(stateSet, visitor);
 }
 
+void SurfaceFlinger::traverseLayersInDisplay(const sp<const DisplayDevice>& hw, int32_t minLayerZ,
+                                             int32_t maxLayerZ,
+                                             const LayerVector::Visitor& visitor) {
+    // We loop through the first level of layers without traversing,
+    // as we need to interpret min/max layer Z in the top level Z space.
+    for (const auto& layer : mDrawingState.layersSortedByZ) {
+        if (!layer->belongsToDisplay(hw->getLayerStack(), false)) {
+            continue;
+        }
+        const Layer::State& state(layer->getDrawingState());
+        if (state.z < minLayerZ || state.z > maxLayerZ) {
+            continue;
+        }
+        layer->traverseInZOrder(LayerVector::StateSet::Drawing, [&](Layer* layer) {
+            if (!layer->isVisible()) {
+                return;
+            }
+            visitor(layer);
+        });
+    }
+}
+
 }; // namespace android
 
 
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index bd98c8f0e0..9975de9252 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -77,6 +77,7 @@
 #include <string>
 #include <thread>
 #include <utility>
+#include "RenderArea.h"
 
 #include <layerproto/LayerProtoHeader.h>
 
@@ -97,6 +98,8 @@ class EventControlThread;
 class VSyncSource;
 class InjectVSyncSource;
 
+typedef std::function<void(const LayerVector::Visitor&)> TraverseLayersFunction;
+
 namespace dvr {
 class VrFlinger;
 } // namespace dvr
@@ -303,6 +306,9 @@ private:
             Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
             int32_t minLayerZ, int32_t maxLayerZ,
             bool useIdentityTransform, ISurfaceComposer::Rotation rotation);
+    virtual status_t captureLayers(const sp<IBinder>& parentHandle,
+                                   const sp<IGraphicBufferProducer>& producer,
+                                   ISurfaceComposer::Rotation rotation);
     virtual status_t getDisplayStats(const sp<IBinder>& display,
             DisplayStatInfo* stats);
     virtual status_t getDisplayConfigs(const sp<IBinder>& display,
@@ -448,28 +454,26 @@ private:
 
     void startBootAnim();
 
-    void renderScreenImplLocked(
-            const sp<const DisplayDevice>& hw,
-            Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
-            int32_t minLayerZ, int32_t maxLayerZ,
-            bool yswap, bool useIdentityTransform, Transform::orientation_flags rotation);
+    void renderScreenImplLocked(const RenderArea& renderArea, TraverseLayersFunction traverseLayers,
+                                bool yswap, bool useIdentityTransform);
+
+    status_t captureScreenCommon(RenderArea& renderArea, TraverseLayersFunction traverseLayers,
+                                 const sp<IGraphicBufferProducer>& producer,
+                                 bool useIdentityTransform);
 
 #ifdef USE_HWC2
-    status_t captureScreenImplLocked(const sp<const DisplayDevice>& device,
-                                     ANativeWindowBuffer* buffer, Rect sourceCrop,
-                                     uint32_t reqWidth, uint32_t reqHeight, int32_t minLayerZ,
-                                     int32_t maxLayerZ, bool useIdentityTransform,
-                                     Transform::orientation_flags rotation, bool isLocalScreenshot,
-                                     int* outSyncFd);
+    status_t captureScreenImplLocked(const RenderArea& renderArea,
+                                     TraverseLayersFunction traverseLayers,
+                                     ANativeWindowBuffer* buffer, bool useIdentityTransform,
+                                     bool isLocalScreenshot, int* outSyncFd);
 #else
-    status_t captureScreenImplLocked(
-            const sp<const DisplayDevice>& hw,
-            const sp<IGraphicBufferProducer>& producer,
-            Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
-            int32_t minLayerZ, int32_t maxLayerZ,
-            bool useIdentityTransform, Transform::orientation_flags rotation,
-            bool isLocalScreenshot);
+    status_t captureScreenImplLocked(const RenderArea& renderArea,
+                                     TraverseLayersFunction traverseLayers,
+                                     const sp<IGraphicBufferProducer>& producer,
+                                     bool useIdentityTransform, bool isLocalScreenshot);
 #endif
+    void traverseLayersInDisplay(const sp<const DisplayDevice>& display, int32_t minLayerZ,
+                                 int32_t maxLayerZ, const LayerVector::Visitor& visitor);
 
     sp<StartPropertySetThread> mStartPropertySetThread = nullptr;
 
@@ -613,8 +617,7 @@ private:
     bool startDdmConnection();
     void appendSfConfigString(String8& result) const;
     void checkScreenshot(size_t w, size_t s, size_t h, void const* vaddr,
-            const sp<const DisplayDevice>& hw,
-            int32_t minLayerZ, int32_t maxLayerZ);
+                         TraverseLayersFunction traverseLayers);
 
     void logFrameStats();
 
diff --git a/services/surfaceflinger/SurfaceFlinger_hwc1.cpp b/services/surfaceflinger/SurfaceFlinger_hwc1.cpp
index ed7641fe99..8c530e0f61 100644
--- a/services/surfaceflinger/SurfaceFlinger_hwc1.cpp
+++ b/services/surfaceflinger/SurfaceFlinger_hwc1.cpp
@@ -2212,6 +2212,8 @@ void SurfaceFlinger::doDisplayComposition(const sp<const DisplayDevice>& hw,
 
 bool SurfaceFlinger::doComposeSurfaces(const sp<const DisplayDevice>& hw, const Region& dirty)
 {
+    DisplayRenderArea renderArea(hw);
+
     RenderEngine& engine(getRenderEngine());
     const int32_t id = hw->getHwcDisplayId();
     HWComposer& hwc(getHwComposer());
@@ -2303,12 +2305,12 @@ bool SurfaceFlinger::doComposeSurfaces(const sp<const DisplayDevice>& hw, const
                                 && hasGlesComposition) {
                             // never clear the very first layer since we're
                             // guaranteed the FB is already cleared
-                            layer->clearWithOpenGL(hw);
+                            layer->clearWithOpenGL(renderArea);
                         }
                         break;
                     }
                     case HWC_FRAMEBUFFER: {
-                        layer->draw(hw, clip);
+                        layer->draw(renderArea, clip);
                         break;
                     }
                     case HWC_FRAMEBUFFER_TARGET: {
@@ -2328,7 +2330,7 @@ bool SurfaceFlinger::doComposeSurfaces(const sp<const DisplayDevice>& hw, const
             const Region clip(dirty.intersect(
                     tr.transform(layer->visibleRegion)));
             if (!clip.isEmpty()) {
-                layer->draw(hw, clip);
+                layer->draw(renderArea, clip);
             }
         }
     }
@@ -3493,6 +3495,18 @@ status_t SurfaceFlinger::onTransact(
             }
             break;
         }
+        case CAPTURE_LAYERS:
+        {
+            IPCThreadState* ipc = IPCThreadState::self();
+            const int pid = ipc->getCallingPid();
+            const int uid = ipc->getCallingUid();
+            if ((uid != AID_GRAPHICS) &&
+                !PermissionCache::checkPermission(sReadFramebuffer, pid, uid)) {
+                ALOGE("Permission Denial: can't read framebuffer pid=%d, uid=%d", pid, uid);
+                return PERMISSION_DENIED;
+            }
+            break;
+        }
     }
 
     status_t err = BnSurfaceComposer::onTransact(code, data, reply, flags);
@@ -3766,16 +3780,72 @@ public:
     }
 };
 
-
 status_t SurfaceFlinger::captureScreen(const sp<IBinder>& display,
-        const sp<IGraphicBufferProducer>& producer,
-        Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
-        int32_t minLayerZ, int32_t maxLayerZ,
-        bool useIdentityTransform, ISurfaceComposer::Rotation rotation) {
-
+    const sp<IGraphicBufferProducer>& producer,
+    Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
+    int32_t minLayerZ, int32_t maxLayerZ,
+    bool useIdentityTransform, ISurfaceComposer::Rotation rotation) {
+    ATRACE_CALL();
     if (CC_UNLIKELY(display == 0))
         return BAD_VALUE;
 
+    const sp<const DisplayDevice> device(getDisplayDeviceLocked(display));
+    DisplayRenderArea renderArea(device, sourceCrop, reqHeight, reqWidth, rotation);
+
+    auto traverseLayers = std::bind(std::mem_fn(&SurfaceFlinger::traverseLayersInDisplay), this,
+                                    device, minLayerZ, maxLayerZ, std::placeholders::_1);
+    return captureScreenCommon(renderArea, traverseLayers, producer, useIdentityTransform);
+}
+
+status_t SurfaceFlinger::captureLayers(const sp<IBinder>& layerHandleBinder,
+                                       const sp<IGraphicBufferProducer>& producer,
+                                       ISurfaceComposer::Rotation rotation) {
+    ATRACE_CALL();
+    class LayerRenderArea : public RenderArea {
+    public:
+        LayerRenderArea(const sp<Layer>& layer, ISurfaceComposer::Rotation rotation)
+              : RenderArea(layer->getCurrentState().active.h, layer->getCurrentState().active.w,
+                           rotation),
+                mLayer(layer) {}
+        const Transform& getTransform() const override {
+            // Make the top level transform the inverse the transform and it's parent so it sets
+            // the whole capture back to 0,0
+            return *new Transform(mLayer->getTransform().inverse());
+        }
+        Rect getBounds() const override {
+            const Layer::State& layerState(mLayer->getDrawingState());
+            return Rect(layerState.active.w, layerState.active.h);
+        }
+        int getHeight() const override { return mLayer->getDrawingState().active.h; }
+        int getWidth() const override { return mLayer->getDrawingState().active.w; }
+        bool isSecure() const override { return false; }
+        bool needsFiltering() const override { return false; }
+
+        Rect getSourceCrop() const override { return getBounds(); }
+
+    private:
+        const sp<Layer>& mLayer;
+    };
+
+    auto layerHandle = reinterpret_cast<Layer::Handle*>(layerHandleBinder.get());
+    auto parent = layerHandle->owner.promote();
+
+    LayerRenderArea renderArea(parent, rotation);
+    auto traverseLayers = [parent](const LayerVector::Visitor& visitor) {
+        parent->traverseChildrenInZOrder(LayerVector::StateSet::Drawing, [&](Layer* layer) {
+            if (!layer->isVisible()) {
+                return;
+            }
+            visitor(layer);
+        });
+    };
+    return captureScreenCommon(renderArea, traverseLayers, producer, false);
+}
+
+status_t SurfaceFlinger::captureScreenCommon(RenderArea& renderArea,
+                                             TraverseLayersFunction traverseLayers,
+                                             const sp<IGraphicBufferProducer>& producer,
+                                             bool useIdentityTransform) {
     if (CC_UNLIKELY(producer == 0))
         return BAD_VALUE;
 
@@ -3784,64 +3854,33 @@ status_t SurfaceFlinger::captureScreen(const sp<IBinder>& display,
     // ourselves).
     bool isLocalScreenshot = IInterface::asBinder(producer)->localBinder();
 
-    // Convert to surfaceflinger's internal rotation type.
-    Transform::orientation_flags rotationFlags;
-    switch (rotation) {
-        case ISurfaceComposer::eRotateNone:
-            rotationFlags = Transform::ROT_0;
-            break;
-        case ISurfaceComposer::eRotate90:
-            rotationFlags = Transform::ROT_90;
-            break;
-        case ISurfaceComposer::eRotate180:
-            rotationFlags = Transform::ROT_180;
-            break;
-        case ISurfaceComposer::eRotate270:
-            rotationFlags = Transform::ROT_270;
-            break;
-        default:
-            rotationFlags = Transform::ROT_0;
-            ALOGE("Invalid rotation passed to captureScreen(): %d\n", rotation);
-            break;
-    }
-
     class MessageCaptureScreen : public MessageBase {
         SurfaceFlinger* flinger;
-        sp<IBinder> display;
+        const RenderArea* renderArea;
+        TraverseLayersFunction traverseLayers;
         sp<IGraphicBufferProducer> producer;
-        Rect sourceCrop;
-        uint32_t reqWidth, reqHeight;
-        int32_t minLayerZ,maxLayerZ;
         bool useIdentityTransform;
-        Transform::orientation_flags rotation;
         status_t result;
         bool isLocalScreenshot;
     public:
-        MessageCaptureScreen(SurfaceFlinger* flinger,
-                const sp<IBinder>& display,
-                const sp<IGraphicBufferProducer>& producer,
-                Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
-                int32_t minLayerZ, int32_t maxLayerZ,
-                bool useIdentityTransform,
-                Transform::orientation_flags rotation,
-                bool isLocalScreenshot)
-            : flinger(flinger), display(display), producer(producer),
-              sourceCrop(sourceCrop), reqWidth(reqWidth), reqHeight(reqHeight),
-              minLayerZ(minLayerZ), maxLayerZ(maxLayerZ),
-              useIdentityTransform(useIdentityTransform),
-              rotation(rotation), result(PERMISSION_DENIED),
-              isLocalScreenshot(isLocalScreenshot)
-        {
-        }
+        MessageCaptureScreen(SurfaceFlinger* flinger, const RenderArea* renderArea,
+                             TraverseLayersFunction traverseLayers,
+                             const sp<IGraphicBufferProducer>& producer, bool useIdentityTransform,
+                             bool isLocalScreenshot)
+              : flinger(flinger),
+                renderArea(renderArea),
+                traverseLayers(traverseLayers),
+                producer(producer),
+                useIdentityTransform(useIdentityTransform),
+                result(PERMISSION_DENIED),
+                isLocalScreenshot(isLocalScreenshot) {}
         status_t getResult() const {
             return result;
         }
         virtual bool handler() {
             Mutex::Autolock _l(flinger->mStateLock);
-            sp<const DisplayDevice> hw(flinger->getDisplayDeviceLocked(display));
-            result = flinger->captureScreenImplLocked(hw, producer,
-                    sourceCrop, reqWidth, reqHeight, minLayerZ, maxLayerZ,
-                    useIdentityTransform, rotation, isLocalScreenshot);
+            result = flinger->captureScreenImplLocked(*renderArea, traverseLayers, producer,
+                                                      useIdentityTransform, isLocalScreenshot);
             static_cast<GraphicProducerWrapper*>(IInterface::asBinder(producer).get())->exit(result);
             return true;
         }
@@ -3855,9 +3894,8 @@ status_t SurfaceFlinger::captureScreen(const sp<IBinder>& display,
     // the asInterface() call below creates our "fake" BpGraphicBufferProducer
     // which does the marshaling work forwards to our "fake remote" above.
     sp<MessageBase> msg = new MessageCaptureScreen(this,
-            display, IGraphicBufferProducer::asInterface( wrapper ),
-            sourceCrop, reqWidth, reqHeight, minLayerZ, maxLayerZ,
-            useIdentityTransform, rotationFlags, isLocalScreenshot);
+            &renderArea, traverseLayers, IGraphicBufferProducer::asInterface( wrapper ),
+            useIdentityTransform, isLocalScreenshot);
 
     status_t res = postMessageAsync(msg);
     if (res == NO_ERROR) {
@@ -3866,41 +3904,42 @@ status_t SurfaceFlinger::captureScreen(const sp<IBinder>& display,
     return res;
 }
 
-
-void SurfaceFlinger::renderScreenImplLocked(
-        const sp<const DisplayDevice>& hw,
-        Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
-        int32_t minLayerZ, int32_t maxLayerZ,
-        bool yswap, bool useIdentityTransform, Transform::orientation_flags rotation)
+void SurfaceFlinger::renderScreenImplLocked(const RenderArea& renderArea, TraverseLayersFunction traverseLayers,
+        bool yswap, bool useIdentityTransform)
 {
     ATRACE_CALL();
     RenderEngine& engine(getRenderEngine());
 
     // get screen geometry
-    const int32_t hw_w = hw->getWidth();
-    const int32_t hw_h = hw->getHeight();
-    const bool filtering = static_cast<int32_t>(reqWidth) != hw_w ||
-                           static_cast<int32_t>(reqHeight) != hw_h;
+    const auto raWidth = renderArea.getWidth();
+    const auto raHeight = renderArea.getHeight();
+
+    const auto reqWidth = renderArea.getReqWidth();
+    const auto reqHeight = renderArea.getReqHeight();
+    Rect sourceCrop = renderArea.getSourceCrop();
+
+    const bool filtering = static_cast<int32_t>(reqWidth) != raWidth ||
+        static_cast<int32_t>(reqHeight) != raHeight;
 
     // if a default or invalid sourceCrop is passed in, set reasonable values
     if (sourceCrop.width() == 0 || sourceCrop.height() == 0 ||
             !sourceCrop.isValid()) {
         sourceCrop.setLeftTop(Point(0, 0));
-        sourceCrop.setRightBottom(Point(hw_w, hw_h));
+        sourceCrop.setRightBottom(Point(raWidth, raHeight));
     }
 
     // ensure that sourceCrop is inside screen
     if (sourceCrop.left < 0) {
         ALOGE("Invalid crop rect: l = %d (< 0)", sourceCrop.left);
     }
-    if (sourceCrop.right > hw_w) {
-        ALOGE("Invalid crop rect: r = %d (> %d)", sourceCrop.right, hw_w);
+    if (sourceCrop.right > raWidth) {
+        ALOGE("Invalid crop rect: r = %d (> %d)", sourceCrop.right, raWidth);
     }
     if (sourceCrop.top < 0) {
         ALOGE("Invalid crop rect: t = %d (< 0)", sourceCrop.top);
     }
-    if (sourceCrop.bottom > hw_h) {
-        ALOGE("Invalid crop rect: b = %d (> %d)", sourceCrop.bottom, hw_h);
+    if (sourceCrop.bottom > raHeight) {
+        ALOGE("Invalid crop rect: b = %d (> %d)", sourceCrop.bottom, raHeight);
     }
 
     // make sure to clear all GL error flags
@@ -3908,77 +3947,35 @@ void SurfaceFlinger::renderScreenImplLocked(
 
     // set-up our viewport
     engine.setViewportAndProjection(
-        reqWidth, reqHeight, sourceCrop, hw_h, yswap, rotation);
+        reqWidth, reqHeight, sourceCrop, raHeight, yswap, renderArea.getRotationFlags());
     engine.disableTexturing();
 
     // redraw the screen entirely...
     engine.clearWithColor(0, 0, 0, 1);
 
-    // We loop through the first level of layers without traversing,
-    // as we need to interpret min/max layer Z in the top level Z space.
-    for (const auto& layer : mDrawingState.layersSortedByZ) {
-        if (layer->getLayerStack() != hw->getLayerStack()) {
-            continue;
-        }
-        const Layer::State& state(layer->getDrawingState());
-        if (state.z < minLayerZ || state.z > maxLayerZ) {
-            continue;
-        }
-        layer->traverseInZOrder(LayerVector::StateSet::Drawing, [&](Layer* layer) {
-            if (!layer->isVisible()) {
-                return;
-            }
-            if (filtering) layer->setFiltering(true);
-            layer->draw(hw, useIdentityTransform);
-            if (filtering) layer->setFiltering(false);
-        });
-    }
+    traverseLayers([&](Layer* layer) {
+        if (filtering) layer->setFiltering(true);
+        layer->draw(renderArea, useIdentityTransform);
+        if (filtering) layer->setFiltering(false);
+    });
 
     // compositionComplete is needed for older driver
-    hw->compositionComplete();
-    hw->setViewportAndProjection();
+//    hw->compositionComplete();
+//    hw->setViewportAndProjection();
 }
 
-
-status_t SurfaceFlinger::captureScreenImplLocked(
-        const sp<const DisplayDevice>& hw,
-        const sp<IGraphicBufferProducer>& producer,
-        Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
-        int32_t minLayerZ, int32_t maxLayerZ,
-        bool useIdentityTransform, Transform::orientation_flags rotation,
-        bool isLocalScreenshot)
-{
+status_t SurfaceFlinger::captureScreenImplLocked(const RenderArea& renderArea,
+                                                 TraverseLayersFunction traverseLayers,
+                                                 const sp<IGraphicBufferProducer>& producer,
+                                                 bool useIdentityTransform,
+                                                 bool isLocalScreenshot) {
     ATRACE_CALL();
 
-    // get screen geometry
-    uint32_t hw_w = hw->getWidth();
-    uint32_t hw_h = hw->getHeight();
-
-    if (rotation & Transform::ROT_90) {
-        std::swap(hw_w, hw_h);
-    }
-
-    if ((reqWidth > hw_w) || (reqHeight > hw_h)) {
-        ALOGE("size mismatch (%d, %d) > (%d, %d)",
-                reqWidth, reqHeight, hw_w, hw_h);
-        return BAD_VALUE;
-    }
-
-    reqWidth  = (!reqWidth)  ? hw_w : reqWidth;
-    reqHeight = (!reqHeight) ? hw_h : reqHeight;
-
     bool secureLayerIsVisible = false;
-    for (const auto& layer : mDrawingState.layersSortedByZ) {
-        const Layer::State& state(layer->getDrawingState());
-        if ((layer->getLayerStack() != hw->getLayerStack()) ||
-                (state.z < minLayerZ || state.z > maxLayerZ)) {
-            continue;
-        }
-        layer->traverseInZOrder(LayerVector::StateSet::Drawing, [&](Layer *layer) {
-            secureLayerIsVisible = secureLayerIsVisible || (layer->isVisible() &&
-                    layer->isSecure());
-        });
-    }
+    traverseLayers([&](Layer *layer) {
+        secureLayerIsVisible = secureLayerIsVisible || (layer->isVisible() &&
+            layer->isSecure());
+    });
 
     if (!isLocalScreenshot && secureLayerIsVisible) {
         ALOGW("FB is protected: PERMISSION_DENIED");
@@ -3996,7 +3993,8 @@ status_t SurfaceFlinger::captureScreenImplLocked(
                         GRALLOC_USAGE_HW_RENDER | GRALLOC_USAGE_HW_TEXTURE;
 
         int err = 0;
-        err = native_window_set_buffers_dimensions(window, reqWidth, reqHeight);
+        err = native_window_set_buffers_dimensions(window, renderArea.getReqWidth(),
+                                                   renderArea.getReqHeight());
         err |= native_window_set_scaling_mode(window, NATIVE_WINDOW_SCALING_MODE_SCALE_TO_WINDOW);
         err |= native_window_set_buffers_format(window, HAL_PIXEL_FORMAT_RGBA_8888);
         err |= native_window_set_usage(window, usage);
@@ -4022,9 +4020,7 @@ status_t SurfaceFlinger::captureScreenImplLocked(
                         // via an FBO, which means we didn't have to create
                         // an EGLSurface and therefore we're not
                         // dependent on the context's EGLConfig.
-                        renderScreenImplLocked(
-                            hw, sourceCrop, reqWidth, reqHeight, minLayerZ, maxLayerZ, true,
-                            useIdentityTransform, rotation);
+                        renderScreenImplLocked(renderArea, traverseLayers, true, useIdentityTransform);
 
                         // Attempt to create a sync khr object that can produce a sync point. If that
                         // isn't available, create a non-dupable sync object in the fallback path and
@@ -4064,10 +4060,12 @@ status_t SurfaceFlinger::captureScreenImplLocked(
                             }
                         }
                         if (DEBUG_SCREENSHOTS) {
-                            uint32_t* pixels = new uint32_t[reqWidth*reqHeight];
-                            getRenderEngine().readPixels(0, 0, reqWidth, reqHeight, pixels);
-                            checkScreenshot(reqWidth, reqHeight, reqWidth, pixels,
-                                    hw, minLayerZ, maxLayerZ);
+                            uint32_t* pixels = new uint32_t[renderArea.getReqWidth() *
+                                                            renderArea.getReqHeight()];
+                            getRenderEngine().readPixels(0, 0, renderArea.getReqWidth(),
+                                                         renderArea.getReqHeight(), pixels);
+                            checkScreenshot(renderArea.getReqWidth(), renderArea.getReqHeight(),
+                                            renderArea.getReqWidth(), pixels, traverseLayers);
                             delete [] pixels;
                         }
 
@@ -4097,7 +4095,7 @@ status_t SurfaceFlinger::captureScreenImplLocked(
 }
 
 void SurfaceFlinger::checkScreenshot(size_t w, size_t s, size_t h, void const* vaddr,
-        const sp<const DisplayDevice>& hw, int32_t minLayerZ, int32_t maxLayerZ) {
+    TraverseLayersFunction traverseLayers) {
     if (DEBUG_SCREENSHOTS) {
         for (size_t y=0 ; y<h ; y++) {
             uint32_t const * p = (uint32_t const *)vaddr + y*s;
@@ -4105,23 +4103,17 @@ void SurfaceFlinger::checkScreenshot(size_t w, size_t s, size_t h, void const* v
                 if (p[x] != 0xFF000000) return;
             }
         }
-        ALOGE("*** we just took a black screenshot ***\n"
-                "requested minz=%d, maxz=%d, layerStack=%d",
-                minLayerZ, maxLayerZ, hw->getLayerStack());
+        ALOGE("*** we just took a black screenshot ***");
+
         size_t i = 0;
-        for (const auto& layer : mDrawingState.layersSortedByZ) {
+        traverseLayers([&](Layer* layer) {
             const Layer::State& state(layer->getDrawingState());
-            if (layer->getLayerStack() == hw->getLayerStack() && state.z >= minLayerZ &&
-                    state.z <= maxLayerZ) {
-                layer->traverseInZOrder(LayerVector::StateSet::Drawing, [&](Layer* layer) {
-                    ALOGE("%c index=%zu, name=%s, layerStack=%d, z=%d, visible=%d, flags=%x, alpha=%.3f",
-                            layer->isVisible() ? '+' : '-',
-                            i, layer->getName().string(), layer->getLayerStack(), state.z,
-                            layer->isVisible(), state.flags, static_cast<float>(state.color.a));
-                    i++;
-                });
-            }
-        }
+            ALOGE("%c index=%zu, name=%s, layerStack=%d, z=%d, visible=%d, flags=%x, alpha=%.3f",
+                layer->isVisible() ? '+' : '-',
+                i, layer->getName().string(), layer->getLayerStack(), state.z,
+                layer->isVisible(), state.flags, static_cast<float>(state.color.a));
+            i++;
+        });
     }
 }
 
@@ -4135,6 +4127,28 @@ void SurfaceFlinger::State::traverseInReverseZOrder(const LayerVector::Visitor&
     layersSortedByZ.traverseInReverseZOrder(stateSet, visitor);
 }
 
+void SurfaceFlinger::traverseLayersInDisplay(const sp<const DisplayDevice>& hw,
+    int32_t minLayerZ, int32_t maxLayerZ, const LayerVector::Visitor& visitor) {
+
+    // We loop through the first level of layers without traversing,
+    // as we need to interpret min/max layer Z in the top level Z space.
+    for (const auto& layer : mDrawingState.layersSortedByZ) {
+        if (!layer->belongsToDisplay(hw->getLayerStack(), false)) {
+            continue;
+        }
+        const Layer::State& state(layer->getDrawingState());
+        if (state.z < minLayerZ || state.z > maxLayerZ) {
+            continue;
+        }
+        layer->traverseInZOrder(LayerVector::StateSet::Drawing, [&](Layer* layer) {
+            if (!layer->isVisible()) {
+                return;
+            }
+            visitor(layer);
+        });
+    }
+}
+
 }; // namespace android
 
 
diff --git a/services/surfaceflinger/Transform.cpp b/services/surfaceflinger/Transform.cpp
index 6be9ae2c5f..37925a1641 100644
--- a/services/surfaceflinger/Transform.cpp
+++ b/services/surfaceflinger/Transform.cpp
@@ -20,8 +20,8 @@
 #include <utils/String8.h>
 #include <ui/Region.h>
 
-#include "clz.h"
 #include "Transform.h"
+#include "clz.h"
 
 // ---------------------------------------------------------------------------
 
@@ -388,6 +388,23 @@ void Transform::dump(const char* name) const
     ALOGD("%.4f  %.4f  %.4f", m[0][2], m[1][2], m[2][2]);
 }
 
+Transform::orientation_flags Transform::fromRotation(ISurfaceComposer::Rotation rotation) {
+    // Convert to surfaceflinger's internal rotation type.
+    switch (rotation) {
+        case ISurfaceComposer::eRotateNone:
+            return Transform::ROT_0;
+        case ISurfaceComposer::eRotate90:
+            return Transform::ROT_90;
+        case ISurfaceComposer::eRotate180:
+            return Transform::ROT_180;
+        case ISurfaceComposer::eRotate270:
+            return Transform::ROT_270;
+        default:
+            ALOGE("Invalid rotation passed to captureScreen(): %d\n", rotation);
+            return Transform::ROT_0;
+    }
+}
+
 // ---------------------------------------------------------------------------
 
 }; // namespace android
diff --git a/services/surfaceflinger/Transform.h b/services/surfaceflinger/Transform.h
index 6640a13839..bfc66eccb9 100644
--- a/services/surfaceflinger/Transform.h
+++ b/services/surfaceflinger/Transform.h
@@ -25,6 +25,8 @@
 #include <math/vec2.h>
 #include <math/vec3.h>
 
+#include <gui/ISurfaceComposer.h>
+
 #include <hardware/hardware.h>
 
 namespace android {
@@ -51,6 +53,8 @@ public:
                 ROT_INVALID = 0x80
             };
 
+            static orientation_flags fromRotation(ISurfaceComposer::Rotation rotation);
+
             enum type_mask {
                 IDENTITY            = 0,
                 TRANSLATE           = 0x1,
diff --git a/services/surfaceflinger/tests/Transaction_test.cpp b/services/surfaceflinger/tests/Transaction_test.cpp
index f61a978487..ec87eeec77 100644
--- a/services/surfaceflinger/tests/Transaction_test.cpp
+++ b/services/surfaceflinger/tests/Transaction_test.cpp
@@ -116,6 +116,60 @@ private:
     CpuConsumer::LockedBuffer mBuf;
 };
 
+class CaptureLayer {
+public:
+    static void captureScreen(std::unique_ptr<CaptureLayer>* sc, sp<IBinder>& parentHandle) {
+        sp<IGraphicBufferProducer> producer;
+        sp<IGraphicBufferConsumer> consumer;
+        BufferQueue::createBufferQueue(&producer, &consumer);
+        sp<CpuConsumer> cpuConsumer = new CpuConsumer(consumer, 1);
+        sp<ISurfaceComposer> sf(ComposerService::getComposerService());
+        sp<IBinder> display(sf->getBuiltInDisplay(
+            ISurfaceComposer::eDisplayIdMain));
+        SurfaceComposerClient::Transaction().apply(true);
+        ASSERT_EQ(NO_ERROR, sf->captureLayers(parentHandle, producer));
+        *sc = std::make_unique<CaptureLayer>(cpuConsumer);
+    }
+
+    void checkPixel(uint32_t x, uint32_t y, uint8_t r, uint8_t g, uint8_t b) {
+        ASSERT_EQ(HAL_PIXEL_FORMAT_RGBA_8888, mBuffer.format);
+        const uint8_t* img = static_cast<const uint8_t*>(mBuffer.data);
+        const uint8_t* pixel = img + (4 * (y * mBuffer.stride + x));
+        if (r != pixel[0] || g != pixel[1] || b != pixel[2]) {
+            String8 err(String8::format("pixel @ (%3d, %3d): "
+                                            "expected [%3d, %3d, %3d], got [%3d, %3d, %3d]",
+                                        x, y, r, g, b, pixel[0], pixel[1], pixel[2]));
+            EXPECT_EQ(String8(), err) << err.string();
+        }
+    }
+
+    void expectFGColor(uint32_t x, uint32_t y) {
+        checkPixel(x, y, 195, 63, 63);
+    }
+
+    void expectBGColor(uint32_t x, uint32_t y) {
+        checkPixel(x, y, 63, 63, 195);
+    }
+
+    void expectChildColor(uint32_t x, uint32_t y) {
+        checkPixel(x, y, 200, 200, 200);
+    }
+
+    CaptureLayer(const sp<CpuConsumer>& cc) :
+        mCC(cc) {
+        EXPECT_EQ(NO_ERROR, mCC->lockNextBuffer(&mBuffer));
+    }
+
+    ~CaptureLayer() {
+        mCC->unlockBuffer(mBuffer);
+    }
+
+private:
+    sp<CpuConsumer> mCC;
+    CpuConsumer::LockedBuffer mBuffer;
+};
+
+
 class LayerUpdateTest : public ::testing::Test {
 protected:
     virtual void SetUp() {
@@ -1431,4 +1485,109 @@ TEST_F(LayerColorTest, ColorLayerWithNoColor) {
     }
 }
 
+class ScreenCaptureTest : public LayerUpdateTest {
+protected:
+    std::unique_ptr<CaptureLayer> mCapture;
+};
+
+TEST_F(ScreenCaptureTest, CaptureSingleLayer) {
+    auto bgHandle = mBGSurfaceControl->getHandle();
+    CaptureLayer::captureScreen(&mCapture, bgHandle);
+    mCapture->expectBGColor(0, 0);
+    // Doesn't capture FG layer which is at 64, 64
+    mCapture->expectBGColor(64, 64);
+}
+
+TEST_F(ScreenCaptureTest, CaptureLayerWithChild) {
+    auto fgHandle = mFGSurfaceControl->getHandle();
+
+    sp<SurfaceControl> child = mComposerClient->createSurface(
+        String8("Child surface"),
+        10, 10, PIXEL_FORMAT_RGBA_8888,
+        0, mFGSurfaceControl.get());
+    fillSurfaceRGBA8(child, 200, 200, 200);
+
+    SurfaceComposerClient::Transaction()
+        .show(child)
+        .apply(true);
+
+    // Captures mFGSurfaceControl layer and its child.
+    CaptureLayer::captureScreen(&mCapture, fgHandle);
+    mCapture->expectFGColor(10, 10);
+    mCapture->expectChildColor(0, 0);
+}
+
+TEST_F(ScreenCaptureTest, CaptureLayerWithGrandchild) {
+    auto fgHandle = mFGSurfaceControl->getHandle();
+
+    sp<SurfaceControl> child = mComposerClient->createSurface(
+        String8("Child surface"),
+        10, 10, PIXEL_FORMAT_RGBA_8888,
+        0, mFGSurfaceControl.get());
+    fillSurfaceRGBA8(child, 200, 200, 200);
+
+    sp<SurfaceControl> grandchild = mComposerClient->createSurface(
+        String8("Grandchild surface"), 5, 5,
+        PIXEL_FORMAT_RGBA_8888, 0, child.get());
+
+    fillSurfaceRGBA8(grandchild, 50, 50, 50);
+    SurfaceComposerClient::Transaction()
+        .show(child)
+        .setPosition(grandchild, 5, 5)
+        .show(grandchild)
+        .apply(true);
+
+    // Captures mFGSurfaceControl, its child, and the grandchild.
+    CaptureLayer::captureScreen(&mCapture, fgHandle);
+    mCapture->expectFGColor(10, 10);
+    mCapture->expectChildColor(0, 0);
+    mCapture->checkPixel(5, 5, 50, 50, 50);
+}
+
+TEST_F(ScreenCaptureTest, CaptureChildOnly) {
+    sp<SurfaceControl> child = mComposerClient->createSurface(
+        String8("Child surface"),
+        10, 10, PIXEL_FORMAT_RGBA_8888,
+        0, mFGSurfaceControl.get());
+    fillSurfaceRGBA8(child, 200, 200, 200);
+    auto childHandle = child->getHandle();
+
+    SurfaceComposerClient::Transaction()
+        .setPosition(child, 5, 5)
+        .show(child)
+        .apply(true);
+
+    // Captures only the child layer, and not the parent.
+    CaptureLayer::captureScreen(&mCapture, childHandle);
+    mCapture->expectChildColor(0, 0);
+    mCapture->expectChildColor(9, 9);
+}
+
+TEST_F(ScreenCaptureTest, CaptureGrandchildOnly) {
+    sp<SurfaceControl> child = mComposerClient->createSurface(
+        String8("Child surface"),
+        10, 10, PIXEL_FORMAT_RGBA_8888,
+        0, mFGSurfaceControl.get());
+    fillSurfaceRGBA8(child, 200, 200, 200);
+    auto childHandle = child->getHandle();
+
+    sp<SurfaceControl> grandchild = mComposerClient->createSurface(
+        String8("Grandchild surface"), 5, 5,
+        PIXEL_FORMAT_RGBA_8888, 0, child.get());
+    fillSurfaceRGBA8(grandchild, 50, 50, 50);
+
+    SurfaceComposerClient::Transaction()
+        .show(child)
+        .setPosition(grandchild, 5, 5)
+        .show(grandchild)
+        .apply(true);
+
+    auto grandchildHandle = grandchild->getHandle();
+
+    // Captures only the grandchild.
+    CaptureLayer::captureScreen(&mCapture, grandchildHandle);
+    mCapture->checkPixel(0, 0, 50, 50, 50);
+    mCapture->checkPixel(4, 4, 50, 50, 50);
+}
+
 }