Move PointerDataPacketConverter from PlatformView to RuntimeController (#51952)

This is a refactor that moves the `PointerDataPacketConverter` from `PlatformView` to `RuntimeController`. 

This change is made for the following reasons:
- Currently, the pointer data conversion contains no platform specific logic (because the current converter's only responsibility is to make the event sequence conform Flutter's protocol). Therefore these logics should reside in a platform-independent place.
- The converter typically converts one event to many. It's better to have this conversion later than earlier.
- It removes a member from `PlatformView`, making it closer to a pure virtual class.

The reason to choose `RuntimeController` as the destination is because `RuntimeController` manages a map for views, which is required for the converter to implement a later patch #51925.

[C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style

Author: dkwingsmt

lib/ui/window/pointer_data_packet_converter.cc

@@ -16,12 +16,12 @@ PointerDataPacketConverter::PointerDataPacketConverter() {}
 PointerDataPacketConverter::~PointerDataPacketConverter() = default;
 
 std::unique_ptr<PointerDataPacket> PointerDataPacketConverter::Convert(
-    std::unique_ptr<PointerDataPacket> packet) {
+    const PointerDataPacket& packet) {
   std::vector<PointerData> converted_pointers;
   // Converts each pointer data in the buffer and stores it in the
   // converted_pointers.
-  for (size_t i = 0; i < packet->GetLength(); i++) {
-    PointerData pointer_data = packet->GetPointerData(i);
+  for (size_t i = 0; i < packet.GetLength(); i++) {
+    PointerData pointer_data = packet.GetPointerData(i);
     ConvertPointerData(pointer_data, converted_pointers);
   }
 

lib/ui/window/pointer_data_packet_converter.h

@@ -89,12 +89,10 @@ class PointerDataPacketConverter {
   ///                                      embedding.
   ///
   /// @return     A full converted packet with all the required information
-  /// filled.
-  ///             It may contain synthetic pointer data as the result of
+  ///             filled. It may contain synthetic pointer data as the result of
   ///             converter's attempt to correct illegal pointer transitions.
   ///
-  std::unique_ptr<PointerDataPacket> Convert(
-      std::unique_ptr<PointerDataPacket> packet);
+  std::unique_ptr<PointerDataPacket> Convert(const PointerDataPacket& packet);
 
  private:
   std::map<int64_t, PointerState> states_;

lib/ui/window/pointer_data_packet_converter_unittests.cc

@@ -160,7 +160,7 @@ TEST(PointerDataPacketConverterTest, CanConvertPointerDataPacket) {
   CreateSimulatedPointerData(data, PointerData::Change::kRemove, 0, 3.0, 4.0,
                              0);
   packet->SetPointerData(5, data);
-  auto converted_packet = converter.Convert(std::move(packet));
+  auto converted_packet = converter.Convert(*packet);
 
   std::vector<PointerData> result;
   UnpackPointerPacket(result, std::move(converted_packet));
@@ -205,7 +205,7 @@ TEST(PointerDataPacketConverterTest, CanSynthesizeDownAndUp) {
   CreateSimulatedPointerData(data, PointerData::Change::kRemove, 0, 3.0, 4.0,
                              0);
   packet->SetPointerData(3, data);
-  auto converted_packet = converter.Convert(std::move(packet));
+  auto converted_packet = converter.Convert(*packet);
 
   std::vector<PointerData> result;
   UnpackPointerPacket(result, std::move(converted_packet));
@@ -262,7 +262,7 @@ TEST(PointerDataPacketConverterTest, CanUpdatePointerIdentifier) {
   CreateSimulatedPointerData(data, PointerData::Change::kRemove, 0, 3.0, 0.0,
                              0);
   packet->SetPointerData(6, data);
-  auto converted_packet = converter.Convert(std::move(packet));
+  auto converted_packet = converter.Convert(*packet);
 
   std::vector<PointerData> result;
   UnpackPointerPacket(result, std::move(converted_packet));
@@ -312,7 +312,7 @@ TEST(PointerDataPacketConverterTest, AlwaysForwardMoveEvent) {
   CreateSimulatedPointerData(data, PointerData::Change::kUp, 0, 0.0, 0.0, 0);
   packet->SetPointerData(3, data);
 
-  auto converted_packet = converter.Convert(std::move(packet));
+  auto converted_packet = converter.Convert(*packet);
 
   std::vector<PointerData> result;
   UnpackPointerPacket(result, std::move(converted_packet));
@@ -365,7 +365,7 @@ TEST(PointerDataPacketConverterTest, CanWorkWithDifferentDevices) {
   CreateSimulatedPointerData(data, PointerData::Change::kRemove, 1, 0.0, 4.0,
                              0);
   packet->SetPointerData(11, data);
-  auto converted_packet = converter.Convert(std::move(packet));
+  auto converted_packet = converter.Convert(*packet);
 
   std::vector<PointerData> result;
   UnpackPointerPacket(result, std::move(converted_packet));
@@ -441,7 +441,7 @@ TEST(PointerDataPacketConverterTest, CanSynthesizeAdd) {
   packet->SetPointerData(0, data);
   CreateSimulatedPointerData(data, PointerData::Change::kUp, 0, 0.0, 0.0, 0);
   packet->SetPointerData(1, data);
-  auto converted_packet = converter.Convert(std::move(packet));
+  auto converted_packet = converter.Convert(*packet);
 
   std::vector<PointerData> result;
   UnpackPointerPacket(result, std::move(converted_packet));
@@ -485,14 +485,14 @@ TEST(PointerDataPacketConverterTest, CanHandleThreeFingerGesture) {
   auto packet = std::make_unique<PointerDataPacket>(1);
   CreateSimulatedPointerData(data, PointerData::Change::kDown, 0, 0.0, 0.0, 1);
   packet->SetPointerData(0, data);
-  auto converted_packet = converter.Convert(std::move(packet));
+  auto converted_packet = converter.Convert(*packet);
   UnpackPointerPacket(result, std::move(converted_packet));
   // Second finger down.
   packet = std::make_unique<PointerDataPacket>(1);
   CreateSimulatedPointerData(data, PointerData::Change::kDown, 1, 33.0, 44.0,
                              1);
   packet->SetPointerData(0, data);
-  converted_packet = converter.Convert(std::move(packet));
+  converted_packet = converter.Convert(*packet);
   UnpackPointerPacket(result, std::move(converted_packet));
   // Triggers three cancels.
   packet = std::make_unique<PointerDataPacket>(3);
@@ -505,7 +505,7 @@ TEST(PointerDataPacketConverterTest, CanHandleThreeFingerGesture) {
   CreateSimulatedPointerData(data, PointerData::Change::kCancel, 2, 40.0, 50.0,
                              0);
   packet->SetPointerData(2, data);
-  converted_packet = converter.Convert(std::move(packet));
+  converted_packet = converter.Convert(*packet);
   UnpackPointerPacket(result, std::move(converted_packet));
 
   ASSERT_EQ(result.size(), (size_t)6);
@@ -582,7 +582,7 @@ TEST(PointerDataPacketConverterTest, CanConvertPointerSignals) {
     CreateSimulatedMousePointerData(data, PointerData::Change::kHover, kind, 2,
                                     10.0, 20.0, 30.0, 40.0, 0);
     packet->SetPointerData(5, data);
-    auto converted_packet = converter.Convert(std::move(packet));
+    auto converted_packet = converter.Convert(*packet);
 
     std::vector<PointerData> result;
     UnpackPointerPacket(result, std::move(converted_packet));
@@ -678,7 +678,7 @@ TEST(PointerDataPacketConverterTest, CanConvertTrackpadGesture) {
   CreateSimulatedTrackpadGestureData(data, PointerData::Change::kPanZoomEnd, 0,
                                      0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
   packet->SetPointerData(2, data);
-  auto converted_packet = converter.Convert(std::move(packet));
+  auto converted_packet = converter.Convert(*packet);
 
   std::vector<PointerData> result;
   UnpackPointerPacket(result, std::move(converted_packet));
@@ -726,7 +726,7 @@ TEST(PointerDataPacketConverterTest, CanConvertViewId) {
   CreateSimulatedPointerData(data, PointerData::Change::kHover, 0, 1.0, 0.0, 0);
   data.view_id = 200;
   packet->SetPointerData(1, data);
-  auto converted_packet = converter.Convert(std::move(packet));
+  auto converted_packet = converter.Convert(*packet);
 
   std::vector<PointerData> result;
   UnpackPointerPacket(result, std::move(converted_packet));

runtime/runtime_controller.cc

@@ -358,7 +358,9 @@ bool RuntimeController::DispatchPointerDataPacket(
     const PointerDataPacket& packet) {
   if (auto* platform_configuration = GetPlatformConfigurationIfAvailable()) {
     TRACE_EVENT0("flutter", "RuntimeController::DispatchPointerDataPacket");
-    platform_configuration->DispatchPointerDataPacket(packet);
+    std::unique_ptr<PointerDataPacket> converted_packet =
+        pointer_data_packet_converter_.Convert(packet);
+    platform_configuration->DispatchPointerDataPacket(*converted_packet);
     return true;
   }
 

runtime/runtime_controller.h

@@ -20,6 +20,7 @@
 #include "flutter/lib/ui/volatile_path_tracker.h"
 #include "flutter/lib/ui/window/platform_configuration.h"
 #include "flutter/lib/ui/window/pointer_data_packet.h"
+#include "flutter/lib/ui/window/pointer_data_packet_converter.h"
 #include "flutter/runtime/dart_vm.h"
 #include "flutter/runtime/platform_data.h"
 #include "flutter/runtime/platform_isolate_manager.h"
@@ -687,6 +688,7 @@ class RuntimeController : public PlatformConfigurationClient {
   const fml::closure isolate_shutdown_callback_;
   std::shared_ptr<const fml::Mapping> persistent_isolate_data_;
   UIDartState::Context context_;
+  PointerDataPacketConverter pointer_data_packet_converter_;
   std::shared_ptr<PlatformIsolateManager> platform_isolate_manager_ =
       std::shared_ptr<PlatformIsolateManager>(new PlatformIsolateManager());
   bool has_flushed_runtime_state_ = false;

shell/common/input_events_unittests.cc

@@ -146,6 +146,7 @@ static void TestSimulatedInputEvents(
 
   // Make sure that all events have been consumed so
   // https://github.com/flutter/flutter/issues/40863 won't happen again.
+  ASSERT_GT(events_consumed_at_frame.size(), 0u);
   ASSERT_EQ(events_consumed_at_frame.back(), num_events);
 }
 

shell/common/platform_view.cc

@@ -32,8 +32,7 @@ void PlatformView::DispatchPlatformMessage(
 
 void PlatformView::DispatchPointerDataPacket(
     std::unique_ptr<PointerDataPacket> packet) {
-  delegate_.OnPlatformViewDispatchPointerDataPacket(
-      pointer_data_packet_converter_.Convert(std::move(packet)));
+  delegate_.OnPlatformViewDispatchPointerDataPacket(std::move(packet));
 }
 
 void PlatformView::DispatchSemanticsAction(int32_t node_id,

shell/common/platform_view.h

@@ -20,7 +20,6 @@
 #include "flutter/lib/ui/window/key_data_packet.h"
 #include "flutter/lib/ui/window/platform_message.h"
 #include "flutter/lib/ui/window/pointer_data_packet.h"
-#include "flutter/lib/ui/window/pointer_data_packet_converter.h"
 #include "flutter/lib/ui/window/viewport_metrics.h"
 #include "flutter/shell/common/platform_message_handler.h"
 #include "flutter/shell/common/pointer_data_dispatcher.h"
@@ -961,7 +960,6 @@ class PlatformView {
 
   PlatformView::Delegate& delegate_;
   const TaskRunners task_runners_;
-  PointerDataPacketConverter pointer_data_packet_converter_;
   fml::WeakPtrFactory<PlatformView> weak_factory_;  // Must be the last member.
 
  private: