Begin engine impl

Author: GaryQian

shell/common/engine.cc

@@ -144,6 +144,12 @@ bool Engine::Restart(RunConfiguration configuration) {
   return Run(std::move(configuration)) == Engine::RunStatus::Success;
 }
 
+Dart_Handle DartDeferredLoadHandler(intptr_t loading_unit_id) {
+  FML_LOG(ERROR) << "LOAD REQUEST CALLED FOR ID: " << loading_unit_id;
+  // return delegate_.OnDartLoadLibrary(loading_unit_id);
+  return Dart_Null();
+}
+
 Engine::RunStatus Engine::Run(RunConfiguration configuration) {
   if (!configuration.IsValid()) {
     FML_LOG(ERROR) << "Engine run configuration was invalid.";
@@ -188,6 +194,8 @@ Engine::RunStatus Engine::Run(RunConfiguration configuration) {
             std::vector<uint8_t>(service_id.begin(), service_id.end()),
             nullptr);
     HandlePlatformMessage(service_id_message);
+
+    Dart_SetDeferredLoadHandler(&DartDeferredLoadHandler);
   }
 
   return isolate_running ? Engine::RunStatus::Success

shell/common/engine.h

@@ -29,6 +29,7 @@
 #include "flutter/shell/common/rasterizer.h"
 #include "flutter/shell/common/run_configuration.h"
 #include "flutter/shell/common/shell_io_manager.h"
+#include "third_party/dart/runtime/include/dart_api.h"
 #include "third_party/skia/include/core/SkPicture.h"
 
 namespace flutter {
@@ -249,6 +250,8 @@ class Engine final : public RuntimeDelegate,
     virtual std::unique_ptr<std::vector<std::string>>
     ComputePlatformResolvedLocale(
         const std::vector<std::string>& supported_locale_data) = 0;
+
+    virtual Dart_Handle OnDartLoadLibrary(intptr_t loading_unit_id) = 0;
   };
 
   //----------------------------------------------------------------------------
@@ -847,6 +850,8 @@ class Engine final : public RuntimeDelegate,
 
   RunStatus PrepareAndLaunchIsolate(RunConfiguration configuration);
 
+  // Dart_Handle DartDeferredLoadHandler(intptr_t loading_unit_id);
+
   friend class testing::ShellTest;
 
   FML_DISALLOW_COPY_AND_ASSIGN(Engine);

shell/common/shell.cc

@@ -1158,6 +1158,11 @@ Shell::ComputePlatformViewResolvedLocale(
   return platform_view_->ComputePlatformResolvedLocales(supported_locale_data);
 }
 
+// |Engine::Delegate|
+Dart_Handle Shell::OnDartLoadLibrary(intptr_t loading_unit_id) {
+  return Dart_Null();
+}
+
 void Shell::ReportTimings() {
   FML_DCHECK(is_setup_);
   FML_DCHECK(task_runners_.GetRasterTaskRunner()->RunsTasksOnCurrentThread());

shell/common/shell.h

@@ -34,6 +34,7 @@
 #include "flutter/shell/common/platform_view.h"
 #include "flutter/shell/common/rasterizer.h"
 #include "flutter/shell/common/shell_io_manager.h"
+#include "third_party/dart/runtime/include/dart_api.h"
 
 namespace flutter {
 
@@ -531,6 +532,9 @@ class Shell final : public PlatformView::Delegate,
   std::unique_ptr<std::vector<std::string>> ComputePlatformResolvedLocale(
       const std::vector<std::string>& supported_locale_data) override;
 
+  // |Engine::Delegate|
+  Dart_Handle OnDartLoadLibrary(intptr_t loading_unit_id) override;
+
   // |Rasterizer::Delegate|
   void OnFrameRasterized(const FrameTiming&) override;
 

shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java

@@ -958,6 +958,7 @@ public void downloadDynamicFeature(@NonNull String moduleName) {
     dynamicFeatureManager.downloadModule(moduleName);
   }
 
+  // This should be called for every loading unit to be loaded into the dart isolate.
   @UiThread
   public void loadDartLibrary(
       @NonNull String bundlePath,
@@ -969,7 +970,6 @@ public void loadDartLibrary(
         bundlePath,
         assetManager);
   }
-
   private native void nativeLoadDartLibrary(
       long nativePlatformViewId,
       @NonNull String bundlePath,

shell/platform/android/platform_view_android_jni_impl.cc

@@ -514,7 +514,7 @@ static jboolean FlutterTextUtilsIsRegionalIndicator(JNIEnv* env,
 static void LoadDartLibrary(JNIEnv* env,
                             jobject obj,
                             jlong shell_holder,
-                            jobject jLibPath,
+                            jstring jLibPath,
                             jobject jAssetManager) {
   // see RunBundleAndSnapshotFromLibrary above for dart loading code
   auto asset_manager = std::make_shared<flutter::AssetManager>();