Add callbacks and policy to listen to sticky modifier state

DD: go/pk_accessibility
Test: None
Bug: 294546335
Change-Id: I7596fb61d8b8c1b29f51550f94bc0e6302feae67

7 files changed, 74 insertions, 9 deletions

diff --git a/services/inputflinger/InputFilter.cpp b/services/inputflinger/InputFilter.cpp
index 43ebc69c46..72c6f1a73b 100644
--- a/services/inputflinger/InputFilter.cpp
+++ b/services/inputflinger/InputFilter.cpp
@@ -44,9 +44,11 @@ AidlKeyEvent notifyKeyArgsToKeyEvent(const NotifyKeyArgs& args) {
     return event;
 }
 
-InputFilter::InputFilter(InputListenerInterface& listener, IInputFlingerRust& rust)
+InputFilter::InputFilter(InputListenerInterface& listener, IInputFlingerRust& rust,
+                         InputFilterPolicyInterface& policy)
       : mNextListener(listener),
-        mCallbacks(ndk::SharedRefBase::make<InputFilterCallbacks>(listener)) {
+        mCallbacks(ndk::SharedRefBase::make<InputFilterCallbacks>(listener, policy)),
+        mPolicy(policy) {
     LOG_ALWAYS_FATAL_IF(!rust.createInputFilter(mCallbacks, &mInputFilterRust).isOk());
     LOG_ALWAYS_FATAL_IF(!mInputFilterRust);
 }
@@ -122,6 +124,10 @@ void InputFilter::setAccessibilityStickyKeysEnabled(bool enabled) {
     if (mConfig.stickyKeysEnabled != enabled) {
         mConfig.stickyKeysEnabled = enabled;
         notifyConfigurationChangedLocked();
+        if (!enabled) {
+            // When Sticky keys is disabled, send callback to clear any saved sticky state.
+            mPolicy.notifyStickyModifierStateChanged(0, 0);
+        }
     }
 }
 
diff --git a/services/inputflinger/InputFilter.h b/services/inputflinger/InputFilter.h
index a38fbf6f61..153d29dd53 100644
--- a/services/inputflinger/InputFilter.h
+++ b/services/inputflinger/InputFilter.h
@@ -19,6 +19,7 @@
 #include <aidl/com/android/server/inputflinger/IInputFlingerRust.h>
 #include <utils/Mutex.h>
 #include "InputFilterCallbacks.h"
+#include "InputFilterPolicyInterface.h"
 #include "InputListener.h"
 #include "NotifyArgs.h"
 
@@ -47,7 +48,8 @@ public:
             aidl::com::android::server::inputflinger::InputFilterConfiguration;
     using AidlDeviceInfo = aidl::com::android::server::inputflinger::DeviceInfo;
 
-    explicit InputFilter(InputListenerInterface& listener, IInputFlingerRust&);
+    explicit InputFilter(InputListenerInterface& listener, IInputFlingerRust& rust,
+                         InputFilterPolicyInterface& policy);
     ~InputFilter() override = default;
     void notifyInputDevicesChanged(const NotifyInputDevicesChangedArgs& args) override;
     void notifyConfigurationChanged(const NotifyConfigurationChangedArgs& args) override;
@@ -65,6 +67,7 @@ public:
 private:
     InputListenerInterface& mNextListener;
     std::shared_ptr<InputFilterCallbacks> mCallbacks;
+    InputFilterPolicyInterface& mPolicy;
     std::shared_ptr<IInputFilter> mInputFilterRust;
     // Keep track of connected peripherals, so that if filters are enabled later, we can pass that
     // info to the filters
diff --git a/services/inputflinger/InputFilterCallbacks.cpp b/services/inputflinger/InputFilterCallbacks.cpp
index 8c8f5e8f71..a8759b7cbd 100644
--- a/services/inputflinger/InputFilterCallbacks.cpp
+++ b/services/inputflinger/InputFilterCallbacks.cpp
@@ -29,8 +29,9 @@ NotifyKeyArgs keyEventToNotifyKeyArgs(const AidlKeyEvent& event) {
                          event.scanCode, event.metaState, event.downTime);
 }
 
-InputFilterCallbacks::InputFilterCallbacks(InputListenerInterface& listener)
-      : mNextListener(listener) {}
+InputFilterCallbacks::InputFilterCallbacks(InputListenerInterface& listener,
+                                           InputFilterPolicyInterface& policy)
+      : mNextListener(listener), mPolicy(policy) {}
 
 ndk::ScopedAStatus InputFilterCallbacks::sendKeyEvent(const AidlKeyEvent& event) {
     mNextListener.notifyKey(keyEventToNotifyKeyArgs(event));
@@ -42,6 +43,7 @@ ndk::ScopedAStatus InputFilterCallbacks::onModifierStateChanged(int32_t modifier
     std::scoped_lock _l(mLock);
     mStickyModifierState.modifierState = modifierState;
     mStickyModifierState.lockedModifierState = lockedModifierState;
+    mPolicy.notifyStickyModifierStateChanged(modifierState, lockedModifierState);
     ALOGI("Sticky keys modifier state changed: modifierState=%d, lockedModifierState=%d",
           modifierState, lockedModifierState);
     return ndk::ScopedAStatus::ok();
diff --git a/services/inputflinger/InputFilterCallbacks.h b/services/inputflinger/InputFilterCallbacks.h
index c0a80fb6dc..31c160aeb9 100644
--- a/services/inputflinger/InputFilterCallbacks.h
+++ b/services/inputflinger/InputFilterCallbacks.h
@@ -20,6 +20,7 @@
 #include <android/binder_auto_utils.h>
 #include <utils/Mutex.h>
 #include <mutex>
+#include "InputFilterPolicyInterface.h"
 #include "InputListener.h"
 #include "NotifyArgs.h"
 
@@ -33,7 +34,8 @@ using AidlKeyEvent = aidl::com::android::server::inputflinger::KeyEvent;
 
 class InputFilterCallbacks : public IInputFilter::BnInputFilterCallbacks {
 public:
-    explicit InputFilterCallbacks(InputListenerInterface& listener);
+    explicit InputFilterCallbacks(InputListenerInterface& listener,
+                                  InputFilterPolicyInterface& policy);
     ~InputFilterCallbacks() override = default;
 
     uint32_t getModifierState();
@@ -41,6 +43,7 @@ public:
 
 private:
     InputListenerInterface& mNextListener;
+    InputFilterPolicyInterface& mPolicy;
     mutable std::mutex mLock;
     struct StickyModifierState {
         uint32_t modifierState;
diff --git a/services/inputflinger/InputManager.cpp b/services/inputflinger/InputManager.cpp
index 296f2449ea..4863513eb5 100644
--- a/services/inputflinger/InputManager.cpp
+++ b/services/inputflinger/InputManager.cpp
@@ -127,7 +127,8 @@ std::shared_ptr<IInputFlingerRust> createInputFlingerRust() {
  */
 InputManager::InputManager(const sp<InputReaderPolicyInterface>& readerPolicy,
                            InputDispatcherPolicyInterface& dispatcherPolicy,
-                           PointerChoreographerPolicyInterface& choreographerPolicy) {
+                           PointerChoreographerPolicyInterface& choreographerPolicy,
+                           InputFilterPolicyInterface& inputFilterPolicy) {
     mInputFlingerRust = createInputFlingerRust();
 
     mDispatcher = createInputDispatcher(dispatcherPolicy);
@@ -135,7 +136,8 @@ InputManager::InputManager(const sp<InputReaderPolicyInterface>& readerPolicy,
             std::make_unique<TracedInputListener>("InputDispatcher", *mDispatcher));
 
     if (ENABLE_INPUT_FILTER_RUST) {
-        mInputFilter = std::make_unique<InputFilter>(*mTracingStages.back(), *mInputFlingerRust);
+        mInputFilter = std::make_unique<InputFilter>(*mTracingStages.back(), *mInputFlingerRust,
+                                                     inputFilterPolicy);
         mTracingStages.emplace_back(
                 std::make_unique<TracedInputListener>("InputFilter", *mInputFilter));
     }
diff --git a/services/inputflinger/InputManager.h b/services/inputflinger/InputManager.h
index fa7db379e0..df944ef807 100644
--- a/services/inputflinger/InputManager.h
+++ b/services/inputflinger/InputManager.h
@@ -29,6 +29,7 @@
 
 #include <InputDispatcherInterface.h>
 #include <InputDispatcherPolicyInterface.h>
+#include <InputFilterPolicyInterface.h>
 #include <PointerChoreographerPolicyInterface.h>
 #include <input/Input.h>
 #include <input/InputTransport.h>
@@ -119,7 +120,8 @@ protected:
 public:
     InputManager(const sp<InputReaderPolicyInterface>& readerPolicy,
                  InputDispatcherPolicyInterface& dispatcherPolicy,
-                 PointerChoreographerPolicyInterface& choreographerPolicy);
+                 PointerChoreographerPolicyInterface& choreographerPolicy,
+                 InputFilterPolicyInterface& inputFilterPolicy);
 
     status_t start() override;
     status_t stop() override;
diff --git a/services/inputflinger/include/InputFilterPolicyInterface.h b/services/inputflinger/include/InputFilterPolicyInterface.h
new file mode 100644
index 0000000000..4d39b977d5
--- /dev/null
+++ b/services/inputflinger/include/InputFilterPolicyInterface.h
@@ -0,0 +1,47 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+namespace android {
+
+/**
+ * The InputFilter policy interface.
+ *
+ * This is the interface that InputFilter uses to talk to Input Manager and other system components.
+ */
+class InputFilterPolicyInterface {
+public:
+    virtual ~InputFilterPolicyInterface() = default;
+
+    /**
+     * A callback to notify about sticky modifier state changes when Sticky keys feature is enabled.
+     *
+     * modifierState: Current sticky modifier state which will be sent with all subsequent
+     * KeyEvents. This only includes modifiers that can be 'Sticky' which includes: Meta, Ctrl,
+     * Shift, Alt and AltGr.
+     *
+     * lockedModifierState: Current locked modifier state representing modifiers that don't get
+     * cleared after non-modifier key press. This only includes modifiers that can be 'Sticky' which
+     * includes: Meta, Ctrl, Shift, Alt and AltGr.
+     *
+     * For more information {@see sticky_keys_filter.rs}
+     */
+    virtual void notifyStickyModifierStateChanged(uint32_t modifierState,
+                                                  uint32_t lockedModifierState) = 0;
+};
+
+} // namespace android