Refactor interceptKeyBeforeDispatching to use variant

Use <variant> as interceptKeyBeforeDispatching can have either
a KeyEntry::InterceptKeyResult or nsecs_t to indicate state or
amount of delay on a key interception attempt.

Bug: 384113980
Test: compile + local

Flag: EXEMPT refactor

Change-Id: I90a67a7ba2efc0ff7e03ddb0d11193902021f4be

Author: Jimmy

services/inputflinger/dispatcher/InputDispatcher.cpp

@@ -46,6 +46,7 @@
 #include <ctime>
 #include <queue>
 #include <sstream>
+#include <variant>
 
 #include "../InputDeviceMetricsSource.h"
 
@@ -6608,24 +6609,27 @@ void InputDispatcher::updateLastAnrStateLocked(const std::string& windowLabel,
 void InputDispatcher::doInterceptKeyBeforeDispatchingCommand(const sp<IBinder>& focusedWindowToken,
                                                              const KeyEntry& entry) {
     const KeyEvent event = createKeyEvent(entry);
+    std::variant<nsecs_t, KeyEntry::InterceptKeyResult> interceptResult;
     nsecs_t delay = 0;
     { // release lock
         scoped_unlock unlock(mLock);
         android::base::Timer t;
-        delay = mPolicy.interceptKeyBeforeDispatching(focusedWindowToken, event, entry.policyFlags);
+        interceptResult =
+                mPolicy.interceptKeyBeforeDispatching(focusedWindowToken, event, entry.policyFlags);
         if (t.duration() > SLOW_INTERCEPTION_THRESHOLD) {
             ALOGW("Excessive delay in interceptKeyBeforeDispatching; took %s ms",
                   std::to_string(t.duration().count()).c_str());
         }
     } // acquire lock
 
-    if (delay < 0) {
-        entry.interceptKeyResult = KeyEntry::InterceptKeyResult::SKIP;
-    } else if (delay == 0) {
-        entry.interceptKeyResult = KeyEntry::InterceptKeyResult::CONTINUE;
-    } else {
+    if (std::holds_alternative<KeyEntry::InterceptKeyResult>(interceptResult)) {
+        entry.interceptKeyResult = std::get<KeyEntry::InterceptKeyResult>(interceptResult);
+        return;
+    }
+
+    if (std::holds_alternative<nsecs_t>(interceptResult)) {
         entry.interceptKeyResult = KeyEntry::InterceptKeyResult::TRY_AGAIN_LATER;
-        entry.interceptKeyWakeupTime = now() + delay;
+        entry.interceptKeyWakeupTime = now() + std::get<nsecs_t>(interceptResult);
     }
 }
 

services/inputflinger/dispatcher/include/InputDispatcherPolicyInterface.h

@@ -20,12 +20,14 @@
 
 #include <android-base/properties.h>
 #include <binder/IBinder.h>
+#include <dispatcher/Entry.h>
 #include <gui/InputApplication.h>
 #include <gui/PidUid.h>
 #include <input/Input.h>
 #include <input/InputDevice.h>
 #include <utils/RefBase.h>
 #include <set>
+#include <variant>
 
 namespace android {
 
@@ -106,9 +108,9 @@ class InputDispatcherPolicyInterface {
                                                uint32_t& policyFlags) = 0;
 
     /* Allows the policy a chance to intercept a key before dispatching. */
-    virtual nsecs_t interceptKeyBeforeDispatching(const sp<IBinder>& token,
-                                                  const KeyEvent& keyEvent,
-                                                  uint32_t policyFlags) = 0;
+    virtual std::variant<nsecs_t, inputdispatcher::KeyEntry::InterceptKeyResult>
+    interceptKeyBeforeDispatching(const sp<IBinder>& token, const KeyEvent& keyEvent,
+                                  uint32_t policyFlags) = 0;
 
     /* Allows the policy a chance to perform default processing for an unhandled key.
      * Returns an alternate key event to redispatch as a fallback, if needed. */

services/inputflinger/tests/FakeInputDispatcherPolicy.cpp

@@ -16,6 +16,8 @@
 
 #include "FakeInputDispatcherPolicy.h"
 
+#include <variant>
+
 #include <gtest/gtest.h>
 
 namespace android {
@@ -409,12 +411,18 @@ void FakeInputDispatcherPolicy::interceptKeyBeforeQueueing(const KeyEvent& input
 void FakeInputDispatcherPolicy::interceptMotionBeforeQueueing(ui::LogicalDisplayId, uint32_t,
                                                               int32_t, nsecs_t, uint32_t&) {}
 
-nsecs_t FakeInputDispatcherPolicy::interceptKeyBeforeDispatching(const sp<IBinder>&,
-                                                                 const KeyEvent&, uint32_t) {
+std::variant<nsecs_t, inputdispatcher::KeyEntry::InterceptKeyResult>
+FakeInputDispatcherPolicy::interceptKeyBeforeDispatching(const sp<IBinder>&, const KeyEvent&,
+                                                         uint32_t) {
     if (mConsumeKeyBeforeDispatching) {
-        return -1;
+        return inputdispatcher::KeyEntry::InterceptKeyResult::SKIP;
     }
+
     nsecs_t delay = std::chrono::nanoseconds(mInterceptKeyTimeout).count();
+    if (delay == 0) {
+        return inputdispatcher::KeyEntry::InterceptKeyResult::CONTINUE;
+    }
+
     // Clear intercept state so we could dispatch the event in next wake.
     mInterceptKeyTimeout = 0ms;
     return delay;

services/inputflinger/tests/FakeInputDispatcherPolicy.h

@@ -28,11 +28,13 @@
 #include <optional>
 #include <queue>
 #include <string>
+#include <variant>
 #include <vector>
 
 #include <android-base/logging.h>
 #include <android-base/thread_annotations.h>
 #include <binder/IBinder.h>
+#include <dispatcher/Entry.h>
 #include <gui/PidUid.h>
 #include <gui/WindowInfo.h>
 #include <input/BlockingQueue.h>
@@ -189,7 +191,8 @@ class FakeInputDispatcherPolicy : public InputDispatcherPolicyInterface {
     void interceptKeyBeforeQueueing(const KeyEvent& inputEvent, uint32_t&) override;
     void interceptMotionBeforeQueueing(ui::LogicalDisplayId, uint32_t, int32_t, nsecs_t,
                                        uint32_t&) override;
-    nsecs_t interceptKeyBeforeDispatching(const sp<IBinder>&, const KeyEvent&, uint32_t) override;
+    std::variant<nsecs_t, inputdispatcher::KeyEntry::InterceptKeyResult>
+    interceptKeyBeforeDispatching(const sp<IBinder>&, const KeyEvent&, uint32_t) override;
     std::optional<KeyEvent> dispatchUnhandledKey(const sp<IBinder>&, const KeyEvent& event,
                                                  uint32_t) override;
     void notifySwitch(nsecs_t when, uint32_t switchValues, uint32_t switchMask,