Use delegate

Author: liyuqian

shell/common/engine.cc

@@ -47,7 +47,6 @@ Engine::Engine(Delegate& delegate,
     : delegate_(delegate),
       settings_(std::move(settings)),
       animator_(std::move(animator)),
-      dispatcher_maker_(std::move(dispatcher_maker)),
       activity_running_(true),
       have_surface_(false),
       image_decoder_(task_runners,
@@ -73,8 +72,7 @@ Engine::Engine(Delegate& delegate,
       settings_.isolate_shutdown_callback    // isolate shutdown callback
   );
 
-  pointer_data_dispatcher_ =
-      dispatcher_maker_(*animator_, *runtime_controller_, task_runners_);
+  pointer_data_dispatcher_ = dispatcher_maker(*this);
 }
 
 Engine::~Engine() = default;
@@ -117,8 +115,6 @@ bool Engine::Restart(RunConfiguration configuration) {
   }
   delegate_.OnPreEngineRestart();
   runtime_controller_ = runtime_controller_->Clone();
-  pointer_data_dispatcher_ =
-      dispatcher_maker_(*animator_, *runtime_controller_, task_runners_);
   UpdateAssetManager(nullptr);
   return Run(std::move(configuration)) == Engine::RunStatus::Success;
 }
@@ -472,6 +468,12 @@ FontCollection& Engine::GetFontCollection() {
   return font_collection_;
 }
 
+void Engine::DoDispatchPacket(std::unique_ptr<PointerDataPacket> packet,
+                              uint64_t trace_flow_id) {
+  animator_->EnqueueTraceFlowId(trace_flow_id);
+  runtime_controller_->DispatchPointerDataPacket(*packet);
+}
+
 void Engine::HandleAssetPlatformMessage(fml::RefPtr<PlatformMessage> message) {
   fml::RefPtr<PlatformMessageResponse> response = message->response();
   if (!response) {

shell/common/engine.h

@@ -67,7 +67,7 @@ namespace flutter {
 ///           name and it does happen to be one of the older classes in the
 ///           repository.
 ///
-class Engine final : public RuntimeDelegate {
+class Engine final : public RuntimeDelegate, PointerDataDispatcher::Delegate {
  public:
   //----------------------------------------------------------------------------
   /// @brief      Indicates the result of the call to `Engine::Run`.
@@ -709,13 +709,23 @@ class Engine final : public RuntimeDelegate {
   // |RuntimeDelegate|
   FontCollection& GetFontCollection() override;
 
+  // |PointerDataDispatcher::Delegate|
+  void DoDispatchPacket(std::unique_ptr<PointerDataPacket> packet,
+                        uint64_t trace_flow_id) override;
+
+  TaskRunners& task_runners() override { return task_runners_; }
+
  private:
   Engine::Delegate& delegate_;
   const Settings settings_;
   std::unique_ptr<Animator> animator_;
   std::unique_ptr<RuntimeController> runtime_controller_;
+
+  // The pointer_data_dispatcher_ depends on animator_ and runtime_controller_.
+  // So it should be defined after them to ensure that pointer_data_dispatcher_
+  // is destructed first.
   std::unique_ptr<PointerDataDispatcher> pointer_data_dispatcher_;
-  PointerDataDispatcherMaker dispatcher_maker_;  // stored for restart
+
   std::string initial_route_;
   ViewportMetrics viewport_metrics_;
   std::shared_ptr<AssetManager> asset_manager_;

shell/common/platform_view.cc

@@ -89,9 +89,8 @@ sk_sp<GrContext> PlatformView::CreateResourceContext() const {
 void PlatformView::ReleaseResourceContext() const {}
 
 PointerDataDispatcherMaker PlatformView::GetDispatcherMaker() {
-  return [](Animator& animator, RuntimeController& controller,
-            TaskRunners task_runners) {
-    return std::make_unique<DefaultPointerDataDispatcher>(animator, controller);
+  return [](DefaultPointerDataDispatcher::Delegate& delegate) {
+    return std::make_unique<DefaultPointerDataDispatcher>(delegate);
   };
 }
 

shell/common/pointer_data_dispatcher.cc

@@ -13,8 +13,7 @@ SmoothPointerDataDispatcher::~SmoothPointerDataDispatcher() = default;
 void DefaultPointerDataDispatcher::DispatchPacket(
     std::unique_ptr<PointerDataPacket> packet,
     uint64_t trace_flow_id) {
-  animator_.EnqueueTraceFlowId(trace_flow_id);
-  runtime_controller_.DispatchPointerDataPacket(*packet);
+  delegate_.DoDispatchPacket(std::move(packet), trace_flow_id);
 }
 
 // Intentional no-op.
@@ -49,7 +48,7 @@ void SmoothPointerDataDispatcher::OnFrameLayerTreeReceived() {
       // we'll post a new UI thread task to fire the packet after `VSYNC` task
       // is done. When a non-VSYNC UI thread task (like the following one) is
       // run, the Flutter framework is always in `SchedulerPhase.idle` phase).
-      task_runners_.GetUITaskRunner()->PostTask(
+      delegate_.task_runners().GetUITaskRunner()->PostTask(
           // Use and validate a `fml::WeakPtr` because this dispatcher might
           // have been destructed with engine when the task is run.
           [dispatcher = weak_factory_.GetWeakPtr()]() {

shell/common/pointer_data_dispatcher.h

@@ -12,19 +12,6 @@ namespace flutter {
 
 class PointerDataDispatcher;
 
-//--------------------------------------------------------------------------
-/// @brief      Signature for constructing PointerDataDispatcher.
-///
-/// @param[in]  animator      the animator of `Flutter::Engine`
-/// @param[in]  controller    the runtime controller of `Flutter::Engine`
-/// @param[in]  task_runners  the task runners of `Flutter::Engine`
-///
-using PointerDataDispatcherMaker =
-    std::function<std::unique_ptr<PointerDataDispatcher>(
-        Animator& animator,
-        RuntimeController& runtime_controller,
-        TaskRunners task_runners)>;
-
 //------------------------------------------------------------------------------
 /// The `Engine` pointer data dispatcher that forwards the packet received from
 /// `PlatformView::DispatchPointerDataPacket` on the platform thread, to
@@ -52,6 +39,18 @@ using PointerDataDispatcherMaker =
 ///       construction of the `PointerDataDispatcher`.
 class PointerDataDispatcher {
  public:
+  /// The interface for Engine to implement.
+  class Delegate {
+   public:
+    /// Actually dispatch the packet using Engine's `animator_` and
+    /// `runtime_controller_`.
+    virtual void DoDispatchPacket(std::unique_ptr<PointerDataPacket> packet,
+                                  uint64_t trace_flow_id) = 0;
+
+    /// Get the task runners to schedule tasks on specific threads.
+    virtual TaskRunners& task_runners() = 0;
+  };
+
   //----------------------------------------------------------------------------
   /// @brief      Signal that `PlatformView` has a packet to be dispatched.
   ///
@@ -77,9 +76,7 @@ class PointerDataDispatcher {
 ///
 class DefaultPointerDataDispatcher : public PointerDataDispatcher {
  public:
-  DefaultPointerDataDispatcher(Animator& animator,
-                               RuntimeController& runtime_controller)
-      : runtime_controller_(runtime_controller), animator_(animator) {}
+  DefaultPointerDataDispatcher(Delegate& delegate) : delegate_(delegate) {}
 
   // |PointerDataDispatcer|
   void DispatchPacket(std::unique_ptr<PointerDataPacket> packet,
@@ -91,8 +88,7 @@ class DefaultPointerDataDispatcher : public PointerDataDispatcher {
   virtual ~DefaultPointerDataDispatcher();
 
  protected:
-  RuntimeController& runtime_controller_;
-  Animator& animator_;
+  Delegate& delegate_;
 
   FML_DISALLOW_COPY_AND_ASSIGN(DefaultPointerDataDispatcher);
 };
@@ -136,12 +132,8 @@ class DefaultPointerDataDispatcher : public PointerDataDispatcher {
 /// See also input_events_unittests.cc where we test all our claims above.
 class SmoothPointerDataDispatcher : public DefaultPointerDataDispatcher {
  public:
-  SmoothPointerDataDispatcher(Animator& animator,
-                              RuntimeController& runtime_controller,
-                              TaskRunners task_runners)
-      : DefaultPointerDataDispatcher(animator, runtime_controller),
-        task_runners_(task_runners),
-        weak_factory_(this) {}
+  SmoothPointerDataDispatcher(Delegate& delegate)
+      : DefaultPointerDataDispatcher(delegate), weak_factory_(this) {}
 
   // |PointerDataDispatcer|
   void DispatchPacket(std::unique_ptr<PointerDataPacket> packet,
@@ -153,8 +145,6 @@ class SmoothPointerDataDispatcher : public DefaultPointerDataDispatcher {
   virtual ~SmoothPointerDataDispatcher();
 
  private:
-  TaskRunners task_runners_;
-
   // If non-null, this will be a pending pointer data packet for the next frame
   // to consume. This is used to smooth out the irregular drag events delivery.
   // See also `DispatchPointerDataPacket` and input_events_unittests.cc.
@@ -170,6 +160,15 @@ class SmoothPointerDataDispatcher : public DefaultPointerDataDispatcher {
   FML_DISALLOW_COPY_AND_ASSIGN(SmoothPointerDataDispatcher);
 };
 
+//--------------------------------------------------------------------------
+/// @brief      Signature for constructing PointerDataDispatcher.
+///
+/// @param[in]  delegate      the `Flutter::Engine`
+///
+using PointerDataDispatcherMaker =
+    std::function<std::unique_ptr<PointerDataDispatcher>(
+        PointerDataDispatcher::Delegate&)>;
+
 }  // namespace flutter
 
 #endif  // POINTER_DATA_DISPATCHER_H_

shell/common/shell_test.cc

@@ -245,10 +245,8 @@ std::unique_ptr<Surface> ShellTestPlatformView::CreateRenderingSurface() {
 
 // |PlatformView|
 PointerDataDispatcherMaker ShellTestPlatformView::GetDispatcherMaker() {
-  return [](Animator& animator, RuntimeController& controller,
-            TaskRunners task_runners) {
-    return std::make_unique<SmoothPointerDataDispatcher>(animator, controller,
-                                                         task_runners);
+  return [](DefaultPointerDataDispatcher::Delegate& delegate) {
+    return std::make_unique<SmoothPointerDataDispatcher>(delegate);
   };
 }
 

shell/platform/darwin/ios/platform_view_ios.mm

@@ -67,8 +67,8 @@ new AccessibilityBridge(static_cast<FlutterView*>(owner_controller_.get().view),
 }
 
 PointerDataDispatcherMaker PlatformViewIOS::GetDispatcherMaker() {
-  return [](Animator& animator, RuntimeController& controller, TaskRunners task_runners) {
-    return std::make_unique<SmoothPointerDataDispatcher>(animator, controller, task_runners);
+  return [](DefaultPointerDataDispatcher::Delegate& delegate) {
+    return std::make_unique<SmoothPointerDataDispatcher>(delegate);
   };
 }