Use futures to images used for comparison with fixtures in embedder u…

…nit-tests. (flutter#14465) This earlier pattern was to use callbacks with latching.
engine-flutter-autoroll · Dec 12, 2019 · 181ad4e · 181ad4e
1 parent 18c89f1
commit 181ad4e
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Showing 3 changed files with 47 additions and 141 deletions.
diff --git a/shell/platform/embedder/tests/embedder_test_context.cc b/shell/platform/embedder/tests/embedder_test_context.cc
@@ -4,6 +4,7 @@
 
 #include "flutter/shell/platform/embedder/tests/embedder_test_context.h"
 
+#include "flutter/fml/make_copyable.h"
 #include "flutter/runtime/dart_vm.h"
 #include "flutter/shell/platform/embedder/tests/embedder_assertions.h"
 #include "third_party/dart/runtime/bin/elf_loader.h"
@@ -225,6 +226,16 @@ void EmbedderTestContext::SetNextSceneCallback(
   next_scene_callback_ = next_scene_callback;
 }
 
+std::future<sk_sp<SkImage>> EmbedderTestContext::GetNextSceneImage() {
+  std::promise<sk_sp<SkImage>> promise;
+  auto future = promise.get_future();
+  SetNextSceneCallback(
+      fml::MakeCopyable([promise = std::move(promise)](auto image) mutable {
+        promise.set_value(image);
+      }));
+  return future;
+}
+
 bool EmbedderTestContext::SofwarePresent(sk_sp<SkImage> image) {
   software_surface_present_count_++;
 

diff --git a/shell/platform/embedder/tests/embedder_test_context.h b/shell/platform/embedder/tests/embedder_test_context.h
@@ -5,6 +5,7 @@
 #ifndef FLUTTER_SHELL_PLATFORM_EMBEDDER_TESTS_EMBEDDER_CONTEXT_H_
 #define FLUTTER_SHELL_PLATFORM_EMBEDDER_TESTS_EMBEDDER_CONTEXT_H_
 
+#include <future>
 #include <map>
 #include <memory>
 #include <string>
@@ -60,8 +61,7 @@ class EmbedderTestContext {
 
   EmbedderTestCompositor& GetCompositor();
 
-  using NextSceneCallback = std::function<void(sk_sp<SkImage> image)>;
-  void SetNextSceneCallback(const NextSceneCallback& next_scene_callback);
+  std::future<sk_sp<SkImage>> GetNextSceneImage();
 
   size_t GetGLSurfacePresentCount() const;
 
@@ -71,6 +71,8 @@ class EmbedderTestContext {
   // This allows the builder to access the hooks.
   friend class EmbedderConfigBuilder;
 
+  using NextSceneCallback = std::function<void(sk_sp<SkImage> image)>;
+
   std::string assets_path_;
 
   // Pieces of the Dart snapshot in ELF form, loaded by Dart's ELF library.
@@ -129,6 +131,8 @@ class EmbedderTestContext {
   void FireRootSurfacePresentCallbackIfPresent(
       const std::function<sk_sp<SkImage>(void)>& image_callback);
 
+  void SetNextSceneCallback(const NextSceneCallback& next_scene_callback);
+
   FML_DISALLOW_COPY_AND_ASSIGN(EmbedderTestContext);
 };