[refactor] Migrate to View.focus.*. (flutter#27005)

shell/platform/fuchsia/flutter/focus_delegate.cc

@@ -16,33 +16,49 @@ void FocusDelegate::WatchLoop(std::function<void(bool)> callback) {
 
   watch_loop_ = [this, callback = std::move(callback)](auto focus_state) {
     callback(is_focused_ = focus_state.focused());
-    if (next_focus_request_) {
-      CompleteCurrentFocusState(std::exchange(next_focus_request_, nullptr));
-    }
+    Complete(std::exchange(next_focus_request_, nullptr),
+             is_focused_ ? "[true]" : "[false]");
     view_ref_focused_->Watch(watch_loop_);
   };
   view_ref_focused_->Watch(watch_loop_);
 }
 
-bool FocusDelegate::CompleteCurrentFocusState(
+bool FocusDelegate::HandlePlatformMessage(
+    rapidjson::Value request,
     fml::RefPtr<flutter::PlatformMessageResponse> response) {
-  std::string result(is_focused_ ? "[true]" : "[false]");
-  response->Complete(std::make_unique<fml::DataMapping>(
-      std::vector<uint8_t>(result.begin(), result.end())));
-  return true;
-}
+  auto method = request.FindMember("method");
+  if (method == request.MemberEnd() || !method->value.IsString()) {
+    return false;
+  }
 
-bool FocusDelegate::CompleteNextFocusState(
-    fml::RefPtr<flutter::PlatformMessageResponse> response) {
-  if (next_focus_request_) {
-    FML_LOG(ERROR) << "An outstanding PlatformMessageResponse already exists "
-                      "for the next focus state!";
+  if (method->value == "View.focus.getCurrent") {
+    Complete(std::move(response), is_focused_ ? "[true]" : "[false]");
+  } else if (method->value == "View.focus.getNext") {
+    if (next_focus_request_) {
+      FML_LOG(ERROR) << "An outstanding PlatformMessageResponse already exists "
+                        "for the next focus state!";
+      Complete(std::move(response), "[null]");
+    } else {
+      next_focus_request_ = std::move(response);
+    }
+  } else if (method->value == "View.focus.request") {
+    return RequestFocus(std::move(request), std::move(response));
+  } else {
     return false;
   }
-  next_focus_request_ = std::move(response);
+  // All of our methods complete the platform message response.
   return true;
 }
 
+void FocusDelegate::Complete(
+    fml::RefPtr<flutter::PlatformMessageResponse> response,
+    std::string value) {
+  if (response) {
+    response->Complete(std::make_unique<fml::DataMapping>(
+        std::vector<uint8_t>(value.begin(), value.end())));
+  }
+}
+
 bool FocusDelegate::RequestFocus(
     rapidjson::Value request,
     fml::RefPtr<flutter::PlatformMessageResponse> response) {
@@ -55,7 +71,7 @@ bool FocusDelegate::RequestFocus(
 
   auto view_ref = args.FindMember("viewRef");
   if (!view_ref->value.IsUint64()) {
-    FML_LOG(ERROR) << "Argument 'viewRef' is not a int64";
+    FML_LOG(ERROR) << "Argument 'viewRef' is not a uint64";
     return false;
   }
 
@@ -72,25 +88,36 @@ bool FocusDelegate::RequestFocus(
   });
   focuser_->RequestFocus(
       std::move(ref),
-      [view_ref = view_ref->value.GetUint64(), response = std::move(response)](
+      [this, response = std::move(response)](
           fuchsia::ui::views::Focuser_RequestFocus_Result result) {
-        if (!response) {
-          return;
-        }
         int result_code =
             result.is_err()
                 ? static_cast<
                       std::underlying_type_t<fuchsia::ui::views::Error>>(
                       result.err())
                 : 0;
-
-        std::ostringstream out;
-        out << "[" << result_code << "]";
-        std::string output = out.str();
-        response->Complete(std::make_unique<fml::DataMapping>(
-            std::vector<uint8_t>(output.begin(), output.end())));
+        Complete(std::move(response), "[" + std::to_string(result_code) + "]");
       });
   return true;
 }
 
+bool FocusDelegate::CompleteCurrentFocusState(
+    fml::RefPtr<flutter::PlatformMessageResponse> response) {
+  std::string result(is_focused_ ? "[true]" : "[false]");
+  response->Complete(std::make_unique<fml::DataMapping>(
+      std::vector<uint8_t>(result.begin(), result.end())));
+  return true;
+}
+
+bool FocusDelegate::CompleteNextFocusState(
+    fml::RefPtr<flutter::PlatformMessageResponse> response) {
+  if (next_focus_request_) {
+    FML_LOG(ERROR) << "An outstanding PlatformMessageResponse already exists "
+                      "for the next focus state!";
+    return false;
+  }
+  next_focus_request_ = std::move(response);
+  return true;
+}
+
 }  // namespace flutter_runner

shell/platform/fuchsia/flutter/focus_delegate.h

@@ -21,32 +21,50 @@ class FocusDelegate {
                 fidl::InterfaceHandle<fuchsia::ui::views::Focuser> focuser)
       : view_ref_focused_(view_ref_focused.Bind()), focuser_(focuser.Bind()) {}
 
-  virtual ~FocusDelegate() = default;
-
   /// Continuously watches the host viewRef for focus events, invoking a
   /// callback each time.
   ///
   /// This can only be called once.
-  virtual void WatchLoop(std::function<void(bool)> callback);
+  void WatchLoop(std::function<void(bool)> callback);
+
+  /// Handles the following focus-related platform message requests:
+  /// View.focus.getCurrent
+  ///  - Completes with the FocusDelegate's most recent focus state, either
+  ///    [true] or [false].
+  /// View.focus.getNext
+  ///  - Completes with the FocusDelegate's next focus state, either [true] or
+  ///    [false].
+  ///  - Only one outstanding request may exist at a time. Any others will be
+  ///    completed with [null].
+  /// View.focus.request
+  ///  - Attempts to give focus for a given viewRef. Completes with [0] on
+  ///    success, or [fuchsia::ui::views::Error] on failure.
+  ///
+  /// Returns false if a malformed/invalid request needs to be completed empty.
+  bool HandlePlatformMessage(
+      rapidjson::Value request,
+      fml::RefPtr<flutter::PlatformMessageResponse> response);
 
   /// Completes the platform message request with the FocusDelegate's most
   /// recent focus state.
-  virtual bool CompleteCurrentFocusState(
+  // TODO(fxbug.dev/79740): Delete after soft transition.
+  bool CompleteCurrentFocusState(
       fml::RefPtr<flutter::PlatformMessageResponse> response);
 
   /// Completes the platform message request with the FocusDelegate's next focus
   /// state.
   ///
   /// Only one outstanding request may exist at a time. Any others will be
   /// completed empty.
-  virtual bool CompleteNextFocusState(
+  // TODO(fxbug.dev/79740): Delete after soft transition.
+  bool CompleteNextFocusState(
       fml::RefPtr<flutter::PlatformMessageResponse> response);
 
   /// Completes a platform message request by attempting to give focus for a
   /// given viewRef.
-  virtual bool RequestFocus(
-      rapidjson::Value request,
-      fml::RefPtr<flutter::PlatformMessageResponse> response);
+  // TODO(fxbug.dev/79740): Make private after soft transition.
+  bool RequestFocus(rapidjson::Value request,
+                    fml::RefPtr<flutter::PlatformMessageResponse> response);
 
  private:
   fuchsia::ui::views::ViewRefFocusedPtr view_ref_focused_;
@@ -57,7 +75,7 @@ class FocusDelegate {
   fml::RefPtr<flutter::PlatformMessageResponse> next_focus_request_;
 
   void Complete(fml::RefPtr<flutter::PlatformMessageResponse> response,
-                bool value);
+                std::string value);
 
   FML_DISALLOW_COPY_AND_ASSIGN(FocusDelegate);
 };

shell/platform/fuchsia/flutter/focus_delegate_unittests.cc

@@ -64,6 +64,129 @@ class FocusDelegateTest : public ::testing::Test {
 // Tests that WatchLoop() should callback and complete PlatformMessageResponses
 // correctly, given a series of vrf invocations.
 TEST_F(FocusDelegateTest, WatchCallbackSeries) {
+  std::vector<bool> vrf_states{false, true,  true, false,
+                               true,  false, true, true};
+  std::size_t vrf_index = 0;
+  std::size_t callback_index = 0;
+  focus_delegate->WatchLoop([&](bool focus_state) {
+    // Make sure the focus state that FocusDelegate gives us is consistent with
+    // what was fired from the vrf.
+    EXPECT_EQ(vrf_states[callback_index], focus_state);
+
+    // View.focus.getCurrent should complete with the current (up to date) focus
+    // state.
+    auto response = FakePlatformMessageResponse::Create();
+    EXPECT_TRUE(focus_delegate->HandlePlatformMessage(
+        ParsePlatformMessage("{\"method\":\"View.focus.getCurrent\"}"),
+        response));
+    response->ExpectCompleted(focus_state ? "[true]" : "[false]");
+
+    // Ensure this callback always happens in lockstep with
+    // vrf->ScheduleCallback.
+    EXPECT_EQ(vrf_index, callback_index++);
+  });
+
+  // Subsequent WatchLoop calls should not be respected.
+  focus_delegate->WatchLoop([](bool _) {
+    ADD_FAILURE() << "Subsequent WatchLoops should not be respected!";
+  });
+
+  do {
+    // Ensure the next focus state is handled correctly.
+    auto response1 = FakePlatformMessageResponse::Create();
+    EXPECT_TRUE(focus_delegate->HandlePlatformMessage(
+        ParsePlatformMessage("{\"method\":\"View.focus.getNext\"}"),
+        response1));
+
+    // Since there's already an outstanding PlatformMessageResponse, this one
+    // should be completed null.
+    auto response2 = FakePlatformMessageResponse::Create();
+    EXPECT_TRUE(focus_delegate->HandlePlatformMessage(
+        ParsePlatformMessage("{\"method\":\"View.focus.getNext\"}"),
+        response2));
+    response2->ExpectCompleted("[null]");
+
+    // Post watch events and trigger the next vrf event.
+    RunLoopUntilIdle();
+    vrf->ScheduleCallback(vrf_states[vrf_index]);
+    RunLoopUntilIdle();
+
+    // Next focus state should be completed by now.
+    response1->ExpectCompleted(vrf_states[vrf_index] ? "[true]" : "[false]");
+
+    // Check View.focus.getCurrent again, and increment vrf_index since we move
+    // on to the next focus state.
+    auto response3 = FakePlatformMessageResponse::Create();
+    EXPECT_TRUE(focus_delegate->HandlePlatformMessage(
+        ParsePlatformMessage("{\"method\":\"View.focus.getCurrent\"}"),
+        response3));
+    response3->ExpectCompleted(vrf_states[vrf_index++] ? "[true]" : "[false]");
+
+    // vrf->times_watched should always be 1 more than the amount of vrf events
+    // emitted.
+    EXPECT_EQ(vrf_index + 1, vrf->times_watched);
+  } while (vrf_index < vrf_states.size());
+}
+
+// Tests that HandlePlatformMessage() completes a "View.focus.request" response
+// with a non-error status code.
+TEST_F(FocusDelegateTest, RequestFocusTest) {
+  // This "Mock" ViewRef serves as the target for the RequestFocus operation.
+  auto mock_view_ref_pair = scenic::ViewRefPair::New();
+  // Create the platform message request.
+  std::ostringstream message;
+  message << "{"
+          << "    \"method\":\"View.focus.request\","
+          << "    \"args\": {"
+          << "       \"viewRef\":"
+          << mock_view_ref_pair.view_ref.reference.get() << "    }"
+          << "}";
+
+  // Dispatch the plaform message request with an expected completion response.
+  auto response = FakePlatformMessageResponse::Create();
+  EXPECT_TRUE(focus_delegate->HandlePlatformMessage(
+      ParsePlatformMessage(message.str()), response));
+  RunLoopUntilIdle();
+
+  response->ExpectCompleted("[0]");
+  EXPECT_TRUE(focuser->request_focus_called());
+}
+
+// Tests that HandlePlatformMessage() completes a "View.focus.request" response
+// with a Error::DENIED status code.
+TEST_F(FocusDelegateTest, RequestFocusFailTest) {
+  // This "Mock" ViewRef serves as the target for the RequestFocus operation.
+  auto mock_view_ref_pair = scenic::ViewRefPair::New();
+  // We're testing the focus failure case.
+  focuser->fail_request_focus();
+  // Create the platform message request.
+  std::ostringstream message;
+  message << "{"
+          << "    \"method\":\"View.focus.request\","
+          << "    \"args\": {"
+          << "       \"viewRef\":"
+          << mock_view_ref_pair.view_ref.reference.get() << "    }"
+          << "}";
+
+  // Dispatch the plaform message request with an expected completion response.
+  auto response = FakePlatformMessageResponse::Create();
+  EXPECT_TRUE(focus_delegate->HandlePlatformMessage(
+      ParsePlatformMessage(message.str()), response));
+  RunLoopUntilIdle();
+
+  response->ExpectCompleted(
+      "[" +
+      std::to_string(
+          static_cast<std::underlying_type_t<fuchsia::ui::views::Error>>(
+              fuchsia::ui::views::Error::DENIED)) +
+      "]");
+  EXPECT_TRUE(focuser->request_focus_called());
+}
+
+// Tests that WatchLoop() should callback and complete PlatformMessageResponses
+// correctly, given a series of vrf invocations.
+// TODO(fxbug.dev/79740): Delete after soft transition.
+TEST_F(FocusDelegateTest, DeprecatedWatchCallbackSeries) {
   std::vector<bool> vrf_states{false, true,  true, false,
                                true,  false, true, true};
   std::size_t vrf_index = 0;
@@ -121,7 +244,8 @@ TEST_F(FocusDelegateTest, WatchCallbackSeries) {
 
 // Tests that RequestFocus() completes the platform message's response with a
 // non-error status code.
-TEST_F(FocusDelegateTest, RequestFocusTest) {
+// TODO(fxbug.dev/79740): Delete after soft transition.
+TEST_F(FocusDelegateTest, DeprecatedRequestFocusTest) {
   // This "Mock" ViewRef serves as the target for the RequestFocus operation.
   auto mock_view_ref_pair = scenic::ViewRefPair::New();
   // Create the platform message request.
@@ -144,7 +268,8 @@ TEST_F(FocusDelegateTest, RequestFocusTest) {
 
 // Tests that RequestFocus() completes the platform message's response with a
 // Error::DENIED status code.
-TEST_F(FocusDelegateTest, RequestFocusFailTest) {
+// TODO(fxbug.dev/79740): Delete after soft transition.
+TEST_F(FocusDelegateTest, DeprecatedRequestFocusFailTest) {
   // This "Mock" ViewRef serves as the target for the RequestFocus operation.
   auto mock_view_ref_pair = scenic::ViewRefPair::New();
   // We're testing the focus failure case.