Move the C++ embedder code to a client wrapper

build/BUILDCONFIG.gn

@@ -12,17 +12,27 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+default_static_configs = [ "//build:defaults" ]
+
+default_dynamic_configs = [
+  "//build:defaults",
+  "//build:shared_library_defaults",
+]
+
 set_defaults("executable") {
-  configs = [ "//build:defaults" ]
+  configs = default_static_configs
 }
 set_defaults("static_library") {
-  configs = [ "//build:defaults" ]
+  configs = default_static_configs
+}
+set_defaults("source_set") {
+  configs = default_static_configs
 }
 set_defaults("shared_library") {
-  configs = [ "//build:defaults", "//build:shared_library_defaults" ]
+  configs = default_dynamic_configs
 }
 set_defaults("published_shared_library") {
-  configs = [ "//build:defaults", "//build:shared_library_defaults" ]
+  configs = default_dynamic_configs
 }
 
 if (host_os == "linux") {
@@ -40,3 +50,10 @@ if (host_os == "linux") {
   is_mac = false
   is_win = true
 }
+
+declare_args() {
+  # Whether to use the GLFW embedding implementation. Currently overriding this
+  # would not work since each platform only has one working implementation,
+  # but in the future GLFW may be one of multiple supported implementations.
+  use_glfw = is_linux || is_win
+}

example/linux_fde/Makefile

@@ -78,6 +78,17 @@ BIN_OUT=$(OUT_DIR)/flutter_embedder_example
 ICU_DATA_OUT=$(OUT_DATA_DIR)/$(ICU_DATA_NAME)
 ALL_LIBS_OUT=$(foreach lib,$(ALL_LIBS),$(OUT_LIB_DIR)/$(notdir $(lib)))
 
+# Add relevant code from the wrapper library, which is intended to be statically
+# built into the client.
+WRAPPER_ROOT = $(GN_OUT_DIR)/fde_cpp_wrapper
+WRAPPER_SOURCES = \
+	$(WRAPPER_ROOT)/flutter_window_controller.cc \
+	$(WRAPPER_ROOT)/plugin_handler.cc \
+	$(WRAPPER_ROOT)/engine_method_result.cc
+SOURCES += $(WRAPPER_SOURCES)
+INCLUDE_DIRS += $(WRAPPER_ROOT)/include
+
+
 # Build settings
 CXX=g++ -std=c++14
 CXXFLAGS.release=-DNDEBUG
@@ -104,7 +115,7 @@ $(BIN_OUT): $(SOURCES) $(ALL_LIBS_OUT)
 	$(CXX) $(CXXFLAGS) $(CPPFLAGS) $(SOURCES) $(LDFLAGS) -o $@
 
 .PHONY: gnbuild
-gnbuild: $(GN_OUT_DIR)
+gnbuild $(WRAPPER_SOURCES): $(GN_OUT_DIR)
 	$(NINJA_BIN) -C $(GN_OUT_DIR) $(FLUTTER_EMBEDDER_LIB_NAME) $(PLUGIN_NAMES)
 
 $(GN_OUT_DIR):

example/windows_fde/GLFW Example.vcxproj

@@ -45,13 +45,13 @@
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug Dynamic Library|x64'">
     <OutDir>$(SolutionDir)bin\$(Platform)\$(Configuration)\$(ProjectName)\</OutDir>
     <IntDir>$(SolutionDir)bin\intermediates\$(Platform)\$(Configuration)\$(ProjectName)\</IntDir>
-    <IncludePath>$(ProjectDir)..\..\library\windows\dependencies\;$(ProjectDir)..\..\;$(IncludePath);$(ProjectDir)..\..\library\windows\;$(ProjectDir)..\..\library\include\</IncludePath>
+    <IncludePath>$(ProjectDir)..\..\library\windows\dependencies\;$(ProjectDir)..\..\;$(IncludePath);$(ProjectDir)..\..\library\windows\;$(ProjectDir)..\..\library\include\;$(ProjectDir)..\..\library\common\client_wrapper\include\</IncludePath>
     <LibraryPath>$(ProjectDir)..\..\library\windows\dependencies\GLFW\;$(SolutionDir)bin\$(Platform)\$(Configuration)\GLFW Library\;$(LibraryPath)</LibraryPath>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release Dynamic Library|x64'">
     <OutDir>$(SolutionDir)bin\$(Platform)\$(Configuration)\$(ProjectName)\</OutDir>
     <IntDir>$(SolutionDir)bin\intermediates\$(Platform)\$(Configuration)\$(ProjectName)\</IntDir>
-	<IncludePath>$(ProjectDir)..\..\library\windows\dependencies\;$(ProjectDir)..\..\library\include\;$(IncludePath)</IncludePath> 
+    <IncludePath>$(ProjectDir)..\..\library\windows\dependencies\;$(ProjectDir)..\..\;$(IncludePath);$(ProjectDir)..\..\library\windows\;$(ProjectDir)..\..\library\include\;$(ProjectDir)..\..\library\common\client_wrapper\include\</IncludePath>
     <LibraryPath>$(ProjectDir)..\..\library\windows\dependencies\GLFW\;$(SolutionDir)bin\$(Platform)\$(Configuration)\GLFW Library\;$(LibraryPath)</LibraryPath>
   </PropertyGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug Dynamic Library|x64'">
@@ -62,6 +62,7 @@
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>
       </AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>_MBCS;%(PreprocessorDefinitions);USE_FDE_TREE_PATHS</PreprocessorDefinitions>
     </ClCompile>
     <Link>
       <AdditionalDependencies>flutter_embedder.lib;glfw3.lib;opengl32.lib;%(AdditionalDependencies)</AdditionalDependencies>
@@ -91,6 +92,7 @@
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>
       </AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>_MBCS;%(PreprocessorDefinitions);USE_FDE_TREE_PATHS</PreprocessorDefinitions>
     </ClCompile>
     <Link>
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
@@ -113,6 +115,9 @@
     </PostBuildEvent>
   </ItemDefinitionGroup>
   <ItemGroup>
+    <ClCompile Include="..\..\library\common\client_wrapper\src\engine_method_result.cc" />
+    <ClCompile Include="..\..\library\common\client_wrapper\src\glfw\flutter_window_controller.cc" />
+    <ClCompile Include="..\..\library\common\client_wrapper\src\plugin_handler.cc" />
     <ClCompile Include="flutter_embedder_example.cpp" />
   </ItemGroup>
   <ItemGroup>
@@ -126,4 +131,4 @@
   <PropertyGroup>
     <LocalDebuggerWorkingDirectory>$(SolutionDir)</LocalDebuggerWorkingDirectory>
   </PropertyGroup>
-</Project>
+</Project>

example/windows_fde/GLFW Example.vcxproj.filters

@@ -1,22 +1,40 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <ItemGroup>
-    <Filter Include="Source Files">
-      <UniqueIdentifier>{4FC737F1-C7A5-4376-A066-2A32D752A2FF}</UniqueIdentifier>
-      <Extensions>cpp;c;cc;cxx;def;odl;idl;hpj;bat;asm;asmx</Extensions>
-    </Filter>
-    <Filter Include="Header Files">
-      <UniqueIdentifier>{93995380-89BD-4b04-88EB-625FBE52EBFB}</UniqueIdentifier>
-      <Extensions>h;hh;hpp;hxx;hm;inl;inc;ipp;xsd</Extensions>
-    </Filter>
-    <Filter Include="Resource Files">
-      <UniqueIdentifier>{67DA6AB6-F800-4c08-8B7A-83BB121AAD01}</UniqueIdentifier>
-      <Extensions>rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe;resx;tiff;tif;png;wav;mfcribbon-ms</Extensions>
-    </Filter>
-  </ItemGroup>
-  <ItemGroup>
-    <ClCompile Include="flutter_embedder_example.cpp">
-      <Filter>Source Files</Filter>
-    </ClCompile>
-  </ItemGroup>
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <Filter Include="Source Files">
+      <UniqueIdentifier>{4FC737F1-C7A5-4376-A066-2A32D752A2FF}</UniqueIdentifier>
+      <Extensions>cpp;c;cc;cxx;def;odl;idl;hpj;bat;asm;asmx</Extensions>
+    </Filter>
+    <Filter Include="Header Files">
+      <UniqueIdentifier>{93995380-89BD-4b04-88EB-625FBE52EBFB}</UniqueIdentifier>
+      <Extensions>h;hh;hpp;hxx;hm;inl;inc;ipp;xsd</Extensions>
+    </Filter>
+    <Filter Include="Resource Files">
+      <UniqueIdentifier>{67DA6AB6-F800-4c08-8B7A-83BB121AAD01}</UniqueIdentifier>
+      <Extensions>rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe;resx;tiff;tif;png;wav;mfcribbon-ms</Extensions>
+    </Filter>
+    <Filter Include="Source Files\Client Wrapper">
+      <UniqueIdentifier>{2761a4b5-57b2-4d50-a677-d20ddc17a7f1}</UniqueIdentifier>
+    </Filter>
+  </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="flutter_embedder_example.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\library\common\client_wrapper\src\engine_method_result.cc">
+      <Filter>Source Files\Client Wrapper</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\library\common\client_wrapper\src\glfw\flutter_window_controller.cc">
+      <Filter>Source Files\Client Wrapper</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\library\common\client_wrapper\src\json_message_codec.cc">
+      <Filter>Source Files\Client Wrapper</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\library\common\client_wrapper\src\json_method_codec.cc">
+      <Filter>Source Files\Client Wrapper</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\library\common\client_wrapper\src\plugin_handler.cc">
+      <Filter>Source Files\Client Wrapper</Filter>
+    </ClCompile>
+  </ItemGroup>
 </Project>

library/BUILD.gn

@@ -16,23 +16,14 @@ import("//build/flutter.gni")
 import("//build/packaging.gni")
 import("//library/engine.gni")
 
-declare_args() {
-  # Whether to use the GLFW embedding implementation. Currently overriding this
-  # would not work since each platform only has one working implementation,
-  # but in the future GLFW may be one of multiple supported implementations.
-  use_glfw = is_linux || is_win
-}
-
 published_shared_library("flutter_embedder") {
   # GLFW embedding implementation.
   if (use_glfw) {
     public = [
-      "include/flutter_desktop_embedding/glfw/embedder.h",
-      "include/flutter_desktop_embedding/glfw/flutter_window_controller.h",
+      "include/flutter_desktop_embedding_core/glfw/embedder.h",
     ]
     sources = [
       "common/glfw/embedder.cc",
-      "common/glfw/flutter_window_controller.cc",
       "common/glfw/key_event_handler.cc",
       "common/glfw/key_event_handler.h",
       "common/glfw/keyboard_hook_handler.h",
@@ -41,42 +32,32 @@ published_shared_library("flutter_embedder") {
     ]
   }
 
+  deps = [
+    ":flutter_engine",
+  ]
+
   # Embedding-agnostic shared C++.
   if (is_linux || is_win) {
     sources += [
-      "common/engine_method_result.cc",
       "common/internal/incoming_message_dispatcher.cc",
       "common/internal/incoming_message_dispatcher.h",
-      "common/internal/plugin_handler.cc",
-      "common/internal/plugin_handler.h",
       "common/internal/text_input_model.cc",
       "common/internal/text_input_model.h",
-      "common/json_message_codec.cc",
-      "common/json_method_codec.cc",
     ]
-    public += [
-      "include/flutter_desktop_embedding/basic_message_channel.h",
-      "include/flutter_desktop_embedding/binary_messenger.h",
-      "include/flutter_desktop_embedding/engine_method_result.h",
-      "include/flutter_desktop_embedding/fde_export.h",
-      "include/flutter_desktop_embedding/json_message_codec.h",
-      "include/flutter_desktop_embedding/json_method_codec.h",
-      "include/flutter_desktop_embedding/message_codec.h",
-      "include/flutter_desktop_embedding/method_call.h",
-      "include/flutter_desktop_embedding/method_channel.h",
-      "include/flutter_desktop_embedding/method_codec.h",
-      "include/flutter_desktop_embedding/method_result.h",
-      "include/flutter_desktop_embedding/plugin_registrar.h",
+    public += [ "include/flutter_desktop_embedding_core/fde_export.h" ]
+
+    deps += [
+      "//library/common/client_wrapper:client_wrapper_internal",
+      "//library/common/client_wrapper:publish_wrapper",
     ]
   }
 
-  deps = [
-    ":flutter_engine",
+  defines = [
+    "FLUTTER_DESKTOP_EMBEDDING_IMPL",
+    "USE_FDE_TREE_PATHS",
   ]
 
-  defines = [ "FLUTTER_DESKTOP_EMBEDDING_IMPL" ]
-
-  public_header_subdir = "flutter_desktop_embedding"
+  public_header_subdir = "flutter_desktop_embedding_core"
 
   public_configs = [ ":relative_public_headers" ]
 

library/common/client_wrapper/BUILD.gn

@@ -0,0 +1,128 @@
+# Copyright 2019 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+_wrapper_includes = [
+  "include/flutter_desktop_embedding/basic_message_channel.h",
+  "include/flutter_desktop_embedding/binary_messenger.h",
+  "include/flutter_desktop_embedding/engine_method_result.h",
+  "include/flutter_desktop_embedding/json_message_codec.h",
+  "include/flutter_desktop_embedding/json_method_codec.h",
+  "include/flutter_desktop_embedding/message_codec.h",
+  "include/flutter_desktop_embedding/method_call.h",
+  "include/flutter_desktop_embedding/method_channel.h",
+  "include/flutter_desktop_embedding/method_codec.h",
+  "include/flutter_desktop_embedding/method_result.h",
+  "include/flutter_desktop_embedding/plugin_registrar.h",
+]
+
+# TODO: Re-evaluate this once more codecs are supported, since most libraries
+# won't need all the codecs.
+_wrapper_sources = [
+  "src/engine_method_result.cc",
+  "src/json_message_codec.cc",
+  "src/json_method_codec.cc",
+  "src/plugin_handler.cc",
+  "src/plugin_handler.h",
+]
+
+_wrapper_publish_dir = "$root_out_dir/fde_cpp_wrapper"
+
+# Template for building the wrapper code in two different modes.
+# This is needed because the implementation of the embedding library
+# uses this code internally, in addition to it being published for
+# client use, but the internal version needs to set the flag that
+# controls the export macro.
+template("client_wrapper") {
+  template_target_name = target_name
+
+  source_set(template_target_name) {
+    forward_variables_from(invoker, "*")
+  }
+
+  source_set("${template_target_name}_internal") {
+    forward_variables_from(invoker, "*")
+
+    defines += [ "FLUTTER_DESKTOP_EMBEDDING_IMPL" ]
+  }
+}
+
+# A static library version of the client wrapper, for use both within the
+# framework implementation itself, as well as with the plugin builds.
+client_wrapper("client_wrapper") {
+  sources = _wrapper_sources
+  public = _wrapper_includes
+
+  # Use shared library settings since this target will be folded into shared
+  # libraries.
+  configs = default_dynamic_configs
+
+  if (is_linux) {
+    configs += [ "//build/linux/config:jsoncpp" ]
+  }
+  if (is_win) {
+    deps = [
+      "//third_party/jsoncpp:jsoncpp",
+    ]
+  }
+
+  public_configs = [ ":_relative_headers" ]
+
+  # Since these sources are for client use, they are written assuming they will
+  # consume the embedder as a framework.
+  include_dirs = [ "//library/include/" ]
+
+  # Explicitly disable flattened headers, since this is being built in-tree.
+  # TODO: Simplify down to one define once Windows is using GN.
+  defines = [
+    "USE_FLATTENED_INCLUDES=0",
+    "USE_FDE_TREE_PATHS",
+  ]
+}
+
+# Since this code is intended to be used by clients in a source bundle, the
+# include paths use library-relative header paths rather than project-relative.
+config("_relative_headers") {
+  include_dirs = [ "include" ]
+}
+
+copy("_publish_includes") {
+  sources = _wrapper_includes
+  if (use_glfw) {
+    sources +=
+        [ "include/flutter_desktop_embedding/glfw/flutter_window_controller.h" ]
+  }
+  output_dir = "$_wrapper_publish_dir/include/flutter_desktop_embedding"
+  outputs = [
+    "$output_dir/{{source_file_part}}",
+  ]
+}
+
+copy("_publish_sources") {
+  sources = _wrapper_sources + [ "README" ]
+
+  if (use_glfw) {
+    sources += [ "src/glfw/flutter_window_controller.cc" ]
+  }
+  output_dir = "$_wrapper_publish_dir"
+  outputs = [
+    "$output_dir/{{source_file_part}}",
+  ]
+}
+
+group("publish_wrapper") {
+  deps = [
+    ":_publish_includes",
+    ":_publish_sources",
+  ]
+}