Added ScreenCaptureListener to allow for screenshot request callbacks

Added boiler plate code to send a listener to the screenshot requests to
allow screenshots to be async.

Test: LayerStateTest
Bug: 162367424
Change-Id: I747e7316364a145bed6a920d72a592e493ca0029
diff --git a/libs/gui/Android.bp b/libs/gui/Android.bp
index 686e274..9285b23 100644
--- a/libs/gui/Android.bp
+++ b/libs/gui/Android.bp
@@ -62,6 +62,7 @@
         "IGraphicBufferProducer.cpp",
         "IProducerListener.cpp",
         "IRegionSamplingListener.cpp",
+        "IScreenCaptureListener.cpp",
         "ISurfaceComposer.cpp",
         "ISurfaceComposerClient.cpp",
         "ITransactionCompletedListener.cpp",
diff --git a/libs/gui/IScreenCaptureListener.cpp b/libs/gui/IScreenCaptureListener.cpp
new file mode 100644
index 0000000..0635e9c
--- /dev/null
+++ b/libs/gui/IScreenCaptureListener.cpp
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2020 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 <gui/IScreenCaptureListener.h>
+#include <gui/LayerState.h>
+
+namespace android {
+
+namespace { // Anonymous
+
+enum class Tag : uint32_t {
+    ON_SCREEN_CAPTURE_COMPLETE = IBinder::FIRST_CALL_TRANSACTION,
+    LAST = ON_SCREEN_CAPTURE_COMPLETE,
+};
+
+} // Anonymous namespace
+
+class BpScreenCaptureListener : public SafeBpInterface<IScreenCaptureListener> {
+public:
+    explicit BpScreenCaptureListener(const sp<IBinder>& impl)
+          : SafeBpInterface<IScreenCaptureListener>(impl, "BpScreenCaptureListener") {}
+
+    ~BpScreenCaptureListener() override;
+
+    status_t onScreenCaptureComplete(const ScreenCaptureResults& captureResults) override {
+        Parcel data, reply;
+        data.writeInterfaceToken(IScreenCaptureListener::getInterfaceDescriptor());
+
+        SAFE_PARCEL(captureResults.write, data);
+        return remote()->transact(static_cast<uint32_t>(Tag::ON_SCREEN_CAPTURE_COMPLETE), data,
+                                  &reply, IBinder::FLAG_ONEWAY);
+    }
+};
+
+// Out-of-line virtual method definitions to trigger vtable emission in this translation unit (see
+// clang warning -Wweak-vtables)
+BpScreenCaptureListener::~BpScreenCaptureListener() = default;
+
+IMPLEMENT_META_INTERFACE(ScreenCaptureListener, "android.gui.IScreenCaptureListener");
+
+status_t BnScreenCaptureListener::onTransact(uint32_t code, const Parcel& data, Parcel* reply,
+                                             uint32_t flags) {
+    auto tag = static_cast<Tag>(code);
+    switch (tag) {
+        case Tag::ON_SCREEN_CAPTURE_COMPLETE: {
+            CHECK_INTERFACE(IScreenCaptureListener, data, reply);
+            ScreenCaptureResults captureResults;
+            SAFE_PARCEL(captureResults.read, data);
+            return onScreenCaptureComplete(captureResults);
+        }
+        default: {
+            return BBinder::onTransact(code, data, reply, flags);
+        }
+    }
+}
+
+} // namespace android
\ No newline at end of file
diff --git a/libs/gui/LayerState.cpp b/libs/gui/LayerState.cpp
index 62f7c23..3b0b392 100644
--- a/libs/gui/LayerState.cpp
+++ b/libs/gui/LayerState.cpp
@@ -607,19 +607,31 @@
 }
 
 status_t ScreenCaptureResults::write(Parcel& output) const {
-    SAFE_PARCEL(output.write, *buffer);
+    if (buffer != nullptr) {
+        SAFE_PARCEL(output.writeBool, true);
+        SAFE_PARCEL(output.write, *buffer);
+    } else {
+        SAFE_PARCEL(output.writeBool, false);
+    }
     SAFE_PARCEL(output.writeBool, capturedSecureLayers);
     SAFE_PARCEL(output.writeUint32, static_cast<uint32_t>(capturedDataspace));
+    SAFE_PARCEL(output.writeInt32, result);
     return NO_ERROR;
 }
 
 status_t ScreenCaptureResults::read(const Parcel& input) {
-    buffer = new GraphicBuffer();
-    SAFE_PARCEL(input.read, *buffer);
+    bool hasGraphicBuffer;
+    SAFE_PARCEL(input.readBool, &hasGraphicBuffer);
+    if (hasGraphicBuffer) {
+        buffer = new GraphicBuffer();
+        SAFE_PARCEL(input.read, *buffer);
+    }
+
     SAFE_PARCEL(input.readBool, &capturedSecureLayers);
     uint32_t dataspace = 0;
     SAFE_PARCEL(input.readUint32, &dataspace);
     capturedDataspace = static_cast<ui::Dataspace>(dataspace);
+    SAFE_PARCEL(input.readInt32, &result);
     return NO_ERROR;
 }
 
diff --git a/libs/gui/include/gui/IScreenCaptureListener.h b/libs/gui/include/gui/IScreenCaptureListener.h
new file mode 100644
index 0000000..a2ddc9f
--- /dev/null
+++ b/libs/gui/include/gui/IScreenCaptureListener.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright 2020 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.
+ */
+
+#pragma once
+
+#include <binder/Binder.h>
+#include <binder/IInterface.h>
+#include <binder/Parcel.h>
+#include <binder/SafeInterface.h>
+
+namespace android {
+
+struct ScreenCaptureResults;
+
+// TODO(b/166271443): Convert to AIDL
+class IScreenCaptureListener : public IInterface {
+public:
+    DECLARE_META_INTERFACE(ScreenCaptureListener)
+
+    virtual status_t onScreenCaptureComplete(const ScreenCaptureResults& captureResults) = 0;
+};
+
+class BnScreenCaptureListener : public SafeBnInterface<IScreenCaptureListener> {
+public:
+    BnScreenCaptureListener()
+          : SafeBnInterface<IScreenCaptureListener>("BnScreenCaptureListener") {}
+
+    status_t onTransact(uint32_t code, const Parcel& data, Parcel* reply,
+                        uint32_t flags = 0) override;
+};
+
+} // namespace android
diff --git a/libs/gui/include/gui/LayerState.h b/libs/gui/include/gui/LayerState.h
index 653d849..47d62fe 100644
--- a/libs/gui/include/gui/LayerState.h
+++ b/libs/gui/include/gui/LayerState.h
@@ -369,6 +369,7 @@
     sp<GraphicBuffer> buffer;
     bool capturedSecureLayers{false};
     ui::Dataspace capturedDataspace{ui::Dataspace::V0_SRGB};
+    status_t result = NO_ERROR;
 
     status_t write(Parcel& output) const;
     status_t read(const Parcel& input);