Virtual rotary encoder native support

 - detect rotary encoder input devices if they have a single scroll
   axis and nothing else

 - make the rotary mapper display-aware as the virtual rotary is
   constrained to a single virtual display, just like the other
   virtual input devices

Fix: 320328752
Test: atest inputflinger_tests
Test: see CTS in topic
Flag: android.companion.virtualdevice.flags.virtual_rotary

Change-Id: I5581013d06708cbcc2c3ac8a622cd259aea8a9b4
diff --git a/services/inputflinger/tests/RotaryEncoderInputMapper_test.cpp b/services/inputflinger/tests/RotaryEncoderInputMapper_test.cpp
new file mode 100644
index 0000000..94cfc32
--- /dev/null
+++ b/services/inputflinger/tests/RotaryEncoderInputMapper_test.cpp
@@ -0,0 +1,169 @@
+/*
+ * Copyright 2024 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 "RotaryEncoderInputMapper.h"
+
+#include <list>
+#include <string>
+#include <tuple>
+#include <variant>
+
+#include <android-base/logging.h>
+#include <gtest/gtest.h>
+#include <input/DisplayViewport.h>
+#include <linux/input-event-codes.h>
+#include <linux/input.h>
+#include <utils/Timers.h>
+
+#include "InputMapperTest.h"
+#include "InputReaderBase.h"
+#include "InterfaceMocks.h"
+#include "NotifyArgs.h"
+#include "TestEventMatchers.h"
+#include "ui/Rotation.h"
+
+#define TAG "RotaryEncoderInputMapper_test"
+
+namespace android {
+
+using testing::AllOf;
+using testing::Return;
+using testing::VariantWith;
+constexpr ui::LogicalDisplayId DISPLAY_ID = ui::LogicalDisplayId::DEFAULT;
+constexpr ui::LogicalDisplayId SECONDARY_DISPLAY_ID = ui::LogicalDisplayId{DISPLAY_ID.val() + 1};
+constexpr int32_t DISPLAY_WIDTH = 480;
+constexpr int32_t DISPLAY_HEIGHT = 800;
+
+namespace {
+
+DisplayViewport createViewport() {
+    DisplayViewport v;
+    v.orientation = ui::Rotation::Rotation0;
+    v.logicalRight = DISPLAY_HEIGHT;
+    v.logicalBottom = DISPLAY_WIDTH;
+    v.physicalRight = DISPLAY_HEIGHT;
+    v.physicalBottom = DISPLAY_WIDTH;
+    v.deviceWidth = DISPLAY_HEIGHT;
+    v.deviceHeight = DISPLAY_WIDTH;
+    v.isActive = true;
+    return v;
+}
+
+DisplayViewport createPrimaryViewport() {
+    DisplayViewport v = createViewport();
+    v.displayId = DISPLAY_ID;
+    v.uniqueId = "local:1";
+    return v;
+}
+
+DisplayViewport createSecondaryViewport() {
+    DisplayViewport v = createViewport();
+    v.displayId = SECONDARY_DISPLAY_ID;
+    v.uniqueId = "local:2";
+    v.type = ViewportType::EXTERNAL;
+    return v;
+}
+
+/**
+ * A fake InputDeviceContext that allows the associated viewport to be specified for the mapper.
+ *
+ * This is currently necessary because InputMapperUnitTest doesn't register the mappers it creates
+ * with the InputDevice object, meaning that InputDevice::isIgnored becomes true, and the input
+ * device doesn't set its associated viewport when it's configured.
+ *
+ * TODO(b/319217713): work out a way to avoid this fake.
+ */
+class ViewportFakingInputDeviceContext : public InputDeviceContext {
+public:
+    ViewportFakingInputDeviceContext(InputDevice& device, int32_t eventHubId,
+                                     std::optional<DisplayViewport> viewport)
+          : InputDeviceContext(device, eventHubId), mAssociatedViewport(viewport) {}
+
+    ViewportFakingInputDeviceContext(InputDevice& device, int32_t eventHubId)
+          : ViewportFakingInputDeviceContext(device, eventHubId, createPrimaryViewport()) {}
+
+    std::optional<DisplayViewport> getAssociatedViewport() const override {
+        return mAssociatedViewport;
+    }
+
+    void setViewport(const std::optional<DisplayViewport>& viewport) {
+        mAssociatedViewport = viewport;
+    }
+
+private:
+    std::optional<DisplayViewport> mAssociatedViewport;
+};
+
+} // namespace
+
+/**
+ * Unit tests for RotaryEncoderInputMapper.
+ */
+class RotaryEncoderInputMapperTest : public InputMapperUnitTest {
+protected:
+    void SetUp() override { SetUpWithBus(BUS_USB); }
+    void SetUpWithBus(int bus) override {
+        InputMapperUnitTest::SetUpWithBus(bus);
+
+        EXPECT_CALL(mMockEventHub, hasRelativeAxis(EVENTHUB_ID, REL_WHEEL))
+                .WillRepeatedly(Return(true));
+        EXPECT_CALL(mMockEventHub, hasRelativeAxis(EVENTHUB_ID, REL_HWHEEL))
+                .WillRepeatedly(Return(false));
+    }
+};
+
+TEST_F(RotaryEncoderInputMapperTest, ConfigureDisplayIdWithAssociatedViewport) {
+    DisplayViewport primaryViewport = createPrimaryViewport();
+    DisplayViewport secondaryViewport = createSecondaryViewport();
+    mReaderConfiguration.setDisplayViewports({primaryViewport, secondaryViewport});
+
+    // Set up the secondary display as the associated viewport of the mapper.
+    createDevice();
+    ViewportFakingInputDeviceContext deviceContext(*mDevice, EVENTHUB_ID, secondaryViewport);
+    mMapper = createInputMapper<RotaryEncoderInputMapper>(deviceContext, mReaderConfiguration);
+
+    std::list<NotifyArgs> args;
+    // Ensure input events are generated for the secondary display.
+    args += process(ARBITRARY_TIME, EV_REL, REL_WHEEL, 1);
+    args += process(ARBITRARY_TIME, EV_SYN, SYN_REPORT, 0);
+    EXPECT_THAT(args,
+                ElementsAre(VariantWith<NotifyMotionArgs>(
+                        AllOf(WithMotionAction(AMOTION_EVENT_ACTION_SCROLL),
+                              WithSource(AINPUT_SOURCE_ROTARY_ENCODER),
+                              WithDisplayId(SECONDARY_DISPLAY_ID)))));
+}
+
+TEST_F(RotaryEncoderInputMapperTest, ConfigureDisplayIdNoAssociatedViewport) {
+    // Set up the default display.
+    mFakePolicy->clearViewports();
+    mFakePolicy->addDisplayViewport(createPrimaryViewport());
+
+    // Set up the mapper with no associated viewport.
+    createDevice();
+    mMapper = createInputMapper<RotaryEncoderInputMapper>(*mDeviceContext, mReaderConfiguration);
+
+    // Ensure input events are generated without display ID
+    std::list<NotifyArgs> args;
+    args += process(ARBITRARY_TIME, EV_REL, REL_WHEEL, 1);
+    args += process(ARBITRARY_TIME, EV_SYN, SYN_REPORT, 0);
+    EXPECT_THAT(args,
+                ElementsAre(VariantWith<NotifyMotionArgs>(
+                        AllOf(WithMotionAction(AMOTION_EVENT_ACTION_SCROLL),
+                              WithSource(AINPUT_SOURCE_ROTARY_ENCODER),
+                              WithDisplayId(ui::LogicalDisplayId::INVALID)))));
+}
+
+} // namespace android
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