Return events from mappers and InputDevice

We are changing the way android input events are reported from the
InputReader. Previously, the process was opaque - anywhere in the code
you were allowed to grab the listener and send events to it. Now, the
flow changes - you will have to explicitly return the events back to the
caller.

With the new approach, InputReader will ultimately be the one
dispatching the events to the listener.

Bug: 211379801
Test: atest inputflinger_tests
Change-Id: I2318ad1220fa66b197ca2a49b8625afcfb45103f

1 files changed, 23 insertions, 0 deletions

diff --git a/services/inputflinger/NotifyArgs.cpp b/services/inputflinger/NotifyArgs.cpp
index 1f37774218..b192ad73c3 100644
--- a/services/inputflinger/NotifyArgs.cpp
+++ b/services/inputflinger/NotifyArgs.cpp
@@ -225,4 +225,27 @@ NotifyPointerCaptureChangedArgs::NotifyPointerCaptureChangedArgs(
         int32_t id, nsecs_t eventTime, const PointerCaptureRequest& request)
       : id(id), eventTime(eventTime), request(request) {}
 
+// Helper to std::visit with lambdas.
+template <typename... V>
+struct Visitor : V... {};
+// explicit deduction guide (not needed as of C++20)
+template <typename... V>
+Visitor(V...) -> Visitor<V...>;
+
+const char* toString(const NotifyArgs& args) {
+    Visitor toStringVisitor{
+            [&](const NotifyConfigurationChangedArgs&) { return "NotifyConfigurationChangedArgs"; },
+            [&](const NotifyKeyArgs&) { return "NotifyKeyArgs"; },
+            [&](const NotifyMotionArgs&) { return "NotifyMotionArgs"; },
+            [&](const NotifySensorArgs&) { return "NotifySensorArgs"; },
+            [&](const NotifySwitchArgs&) { return "NotifySwitchArgs"; },
+            [&](const NotifyDeviceResetArgs&) { return "NotifyDeviceResetArgs"; },
+            [&](const NotifyPointerCaptureChangedArgs&) {
+                return "NotifyPointerCaptureChangedArgs";
+            },
+            [&](const NotifyVibratorStateArgs&) { return "NotifyVibratorStateArgs"; },
+    };
+    return std::visit(toStringVisitor, args);
+}
+
 } // namespace android