commit fb2ebce32db6506c04ef86a6f262383da2d07af9
author Arthur Hung <arthurhung@google.com> Mon Oct 04 14:08:48 2021 +0000
committer Arthur Hung <arthurhung@google.com> Tue Oct 12 00:58:36 2021 +0000
tree 9f5a8e60d5b9fb315110a9256f557269da2283e7
parent ca9bc644567443ae1973e368a66e1dd15d019d94

Check BufferLayer's alpha value when canReceiveInput

For BufferLayer, the alpha value will affect the final present result.
However, in previous behavior, it only checked the policy flag, that
could cause the transparent surface can still recevie the touch if WM
side didn't hide the surface properly and the alpha value becomes to 0.

To fix this, we have to check the alpha value if the buffer is exist.

Bug: 201647070
Bug: 200837970
Test: atest InputSurfacesTest
Test: adb shell monkey 10000; make sure monkey does not get stuck
Change-Id: I54090811286654062d613cf1e0a637214d1e8c5d

libs/gui/tests/EndToEndNativeInputTest.cpp

diff --git a/libs/gui/tests/EndToEndNativeInputTest.cpp b/libs/gui/tests/EndToEndNativeInputTest.cpp
index 16208a7..d9beb23 100644
--- a/libs/gui/tests/EndToEndNativeInputTest.cpp
+++ b/libs/gui/tests/EndToEndNativeInputTest.cpp
@@ -569,7 +569,7 @@
     bufferSurface->expectTap(1, 1);
 }
 
-TEST_F(InputSurfacesTest, input_ignores_buffer_layer_alpha) {
+TEST_F(InputSurfacesTest, input_respects_buffer_layer_alpha) {
     std::unique_ptr<InputSurface> bgSurface = makeSurface(100, 100);
     std::unique_ptr<BlastInputSurface> bufferSurface =
             BlastInputSurface::makeBlastInputSurface(mComposerClient, 100, 100);
@@ -584,7 +584,7 @@
     bufferSurface->doTransaction([](auto &t, auto &sc) { t.setAlpha(sc, 0.0); });
 
     injectTap(11, 11);
-    bufferSurface->expectTap(1, 1);
+    bgSurface->expectTap(1, 1);
 }
 
 TEST_F(InputSurfacesTest, input_ignores_color_layer_alpha) {

services/surfaceflinger/BufferLayer.cpp

diff --git a/services/surfaceflinger/BufferLayer.cpp b/services/surfaceflinger/BufferLayer.cpp
index 82c91e7..155987d 100644
--- a/services/surfaceflinger/BufferLayer.cpp
+++ b/services/surfaceflinger/BufferLayer.cpp
@@ -111,6 +111,10 @@
     return ((s.flags & layer_state_t::eLayerOpaque) != 0) || getOpacityForFormat(getPixelFormat());
 }
 
+bool BufferLayer::canReceiveInput() const {
+    return !isHiddenByPolicy() && (mBufferInfo.mBuffer == nullptr || getAlpha() > 0.0f);
+}
+
 bool BufferLayer::isVisible() const {
     return !isHiddenByPolicy() && getAlpha() > 0.0f &&
             (mBufferInfo.mBuffer != nullptr || mSidebandStream != nullptr);

services/surfaceflinger/BufferLayer.h

diff --git a/services/surfaceflinger/BufferLayer.h b/services/surfaceflinger/BufferLayer.h
index 61e7ac5..8c4c8b7 100644
--- a/services/surfaceflinger/BufferLayer.h
+++ b/services/surfaceflinger/BufferLayer.h
@@ -62,6 +62,7 @@
     void useEmptyDamage() override;
 
     bool isOpaque(const Layer::State& s) const override;
+    bool canReceiveInput() const override;
 
     // isVisible - true if this layer is visible, false otherwise
     bool isVisible() const override;