🍎 MacOS Support, HighDPI Support.

More Option for window/engine

Author: pchampio

README.md

@@ -12,7 +12,7 @@ for desktop
 This project doesn't compete with
 [this](https://github.com/google/flutter-desktop-embedding) awesome one.
 The purpose of this project is to support the 
-[Flutter](https://github.com/flutter/flutter) framework on Windows, macOS, and
+[Flutter](https://github.com/flutter/flutter) framework on Windows, MacOS, and
 Linux using a **SINGLE** code base.  
 
 [**GLFW**](https://github.com/go-gl/glfw) fits the job because it
@@ -58,11 +58,11 @@ cd ../..
 # Download the share library (CORRESPONDING to the Flutter's version shown above)
 wget https://storage.googleapis.com/flutter_infra/flutter/af42b6dc95bd9f719e43c4e9f29a00640f0f0bba/linux-x64/linux-x64-embedder -O .build/temp.zip
 
-# Move the share library
-unzip .build/temp.zip -x flutter_embedder.h && mv libflutter_engine.so flutter/library/linux/
+# Extract the share library
+unzip .build/temp.zip -x flutter_embedder.h
 
 # REQUIRED: When using `go build` or `go run main.go`, the go library need to know where to look for the share library
-export CGO_LDFLAGS="-L${PWD}/flutter/library/linux"
+export CGO_LDFLAGS="-L${PWD}"
 
 # If you `go build`, the share library must stay in the same path, relative to the go binary
 
@@ -118,6 +118,48 @@ go run main.go
 
 </details>
 
+<details>
+<summary> :package: :checkered_flag: MacOS</summary>
+<h4>From binaries</h4>
+Check out the <a href="https://github.com/Drakirus/go-flutter-desktop-embedder/releases">Release</a> page for prebuilt versions.
+
+<h4>From source</h4>
+
+Go read first: [go-gl/glfw](https://github.com/go-gl/glfw/)  
+
+
+```bash
+# Clone
+git clone https://github.com/Drakirus/go-flutter-desktop-embedder.git
+cd go-flutter-desktop-embedder
+
+# Build the flutter simpleDemo project
+cd example/simpleDemo/
+cd flutter_project/demo/
+flutter build bundle
+cd ../..
+
+# Download the share library (CORRESPONDING to the Flutter's version shown above)
+wget https://storage.googleapis.com/flutter_infra/flutter/af42b6dc95bd9f719e43c4e9f29a00640f0f0bba/darwin-x64/FlutterEmbedder.framework.zip -O .build/temp.zip
+
+# Move the share library
+unzip .build/temp.zip -d .build && unzip .build/FlutterEmbedder.framework.zip -d .build/FlutterEmbedder.framework
+mv .build/FlutterEmbedder.framework .
+
+# REQUIRED: When using `go build` or `go run main.go`, the go library need to know where to look for the share library
+export CGO_LDFLAGS="-F${PWD} -Wl,-rpath,@executable_path"
+
+# If you `go build`, the share library must stay in the same path, relative to the go binary
+
+# Get the libraries
+go get -u -v github.com/Drakirus/go-flutter-desktop-embedder
+
+# Make sure the path in "main.go" to the `icudtl.dat` is correct.
+# Build the example project
+go build
+```
+
+</details>
 
 
 ## Flutter Demos Projects
@@ -128,7 +170,7 @@ The examples are available [here](./example/)
 
 - [x] Linux :penguin:
 - [x] Windows :checkered_flag:
-- [ ] MacOS :apple:
+- [x] MacOS :apple:
 - [x] Text input
 - [ ] Plugins
 - [x] Importable go library

example/stocks/flutter/library/linux/.gitignore

@@ -18,8 +18,12 @@ func main() {
 
 	options := []gutter.Option{
 		gutter.OptionAssetPath("flutter_project/stocks/build/flutter_assets"),
-		gutter.OptionICUDataPath("/opt/flutter/bin/cache/artifacts/engine/linux-x64/icudtl.dat"),
+		// gutter.OptionICUDataPath("/opt/flutter/bin/cache/artifacts/engine/linux-x64/icudtl.dat"), // Linux (arch)
+		gutter.OptionICUDataPath("./FlutterEmbedder.framework/Resources/icudtl.dat"), // OSX
+		gutter.OptionWindowDimension(800, 600),
 		gutter.OptionWindowInitializer(setIcon),
+		gutter.OptionPixelRatio(1.9),
+		gutter.OptionVmArguments([]string{"--dart-non-checked-mode", "--observatory-port=50300"}),
 	}
 
 	if err = gutter.Run(options...); err != nil {

example/stocks/main.go

@@ -4,13 +4,18 @@ package flutter
 // Linux Build Tags
 // ----------------
 #cgo linux CFLAGS: -I${SRCDIR}/library
-#cgo linux LDFLAGS: -lflutter_engine -Wl,-rpath,$ORIGIN/flutter/library/linux
+#cgo linux LDFLAGS: -lflutter_engine -Wl,-rpath,$ORIGIN
 
 // Windows Build Tags
 // ----------------
 #cgo windows CFLAGS: -I${SRCDIR}/library
 #cgo windows LDFLAGS: -lflutter_engine
 
+// Darwin Build Tags
+// ----------------
+#cgo darwin CFLAGS: -I${SRCDIR}/library
+#cgo darwin LDFLAGS: -framework FlutterEmbedder
+
 */
 import "C"
 

flutter/build.go

@@ -1,7 +1,10 @@
 package flutter
 
 // #include "flutter_embedder.h"
-// FlutterResult runFlutter(uintptr_t window, FlutterEngine *engine, FlutterProjectArgs * Args);
+// FlutterResult runFlutter(uintptr_t window, FlutterEngine *engine, FlutterProjectArgs * Args,
+//						 const char *const * vmArgs, int nVmAgrs);
+// char** makeCharArray(int size);
+// void setArrayString(char **a, char *s, int n);
 import "C"
 import (
 	"encoding/json"
@@ -41,12 +44,13 @@ type EngineOpenGL struct {
 	FPlatfromMessage func(message PlatformMessage, window unsafe.Pointer) bool
 
 	// Engine arguments
+	PixelRatio  float64
 	AssetsPath  *CharExportedType
 	IcuDataPath *CharExportedType
 }
 
 // Run launches the Flutter Engine in a background thread.
-func (flu *EngineOpenGL) Run(window uintptr) Result {
+func (flu *EngineOpenGL) Run(window uintptr, vmArgs []string) Result {
 
 	globalFlutterOpenGL = *flu
 
@@ -59,7 +63,12 @@ func (flu *EngineOpenGL) Run(window uintptr) Result {
 
 	args.struct_size = C.size_t(unsafe.Sizeof(args))
 
-	res := C.runFlutter(C.uintptr_t(window), &flu.Engine, &args)
+	cVmArgs := C.makeCharArray(C.int(len(vmArgs)))
+	for i, s := range vmArgs {
+		C.setArrayString(cVmArgs, C.CString(s), C.int(i))
+	}
+
+	res := C.runFlutter(C.uintptr_t(window), &flu.Engine, &args, cVmArgs, C.int(len(vmArgs)))
 	if flu.Engine == nil {
 		return KInvalidArguments
 	}

flutter/flutter.go

@@ -1,5 +1,7 @@
 
- #include "library/flutter_embedder.h"
+#include "library/flutter_embedder.h"
+#include <stdlib.h>
+
 
 // C proxies def
 bool proxy_make_current(void *v);
@@ -12,7 +14,8 @@ bool proxy_on_platform_message(FlutterPlatformMessage *message,
                              void *window);
 
 // C helper
-FlutterResult runFlutter(uintptr_t window, FlutterEngine *engine, FlutterProjectArgs * Args){
+FlutterResult runFlutter(uintptr_t window, FlutterEngine *engine, FlutterProjectArgs * Args,
+						 const char *const * vmArgs, int nVmAgrs) {
 
 	FlutterRendererConfig config = {};
 	config.type = kOpenGL;
@@ -25,16 +28,18 @@ FlutterResult runFlutter(uintptr_t window, FlutterEngine *engine, FlutterProject
 	config.open_gl.fbo_callback = proxy_fbo_callback;
 	config.open_gl.make_resource_current = proxy_make_resource_current;
 
-	const char *args_arr[] = {
-		"",
-		"--dart-non-checked-mode",
-		NULL,
-	};
-
-	Args->command_line_argc = 2;
-	Args->command_line_argv = args_arr;
+	Args->command_line_argc = nVmAgrs;
+	Args->command_line_argv = vmArgs;
 	Args->platform_message_callback = (FlutterPlatformMessageCallback)proxy_on_platform_message;
 
 	return FlutterEngineRun(FLUTTER_ENGINE_VERSION, &config, Args, (void*)window, engine);
 }
 
+char** makeCharArray(int size) {
+        return calloc(sizeof(char*), size);
+}
+
+void setArrayString(char **a, char *s, int n) {
+        a[n] = s;
+}
+

flutter/flutter_helper.c

@@ -29,17 +29,43 @@ func OptionICUDataPath(p string) Option {
 	}
 }
 
+// OptionVmArguments specify the arguments to the Dart VM.
+func OptionVmArguments(a []string) Option {
+	return func(c *config) {
+		// First should be argument is argv[0]
+		c.VmArguments = append([]string{""}, a...)
+	}
+}
+
+// OptionWindowDimension specify the startup's dimention of the window.
+func OptionWindowDimension(x int, y int) Option {
+	return func(c *config) {
+		c.WindowDimension.x = x
+		c.WindowDimension.y = y
+	}
+}
+
 // OptionWindowInitializer allow initializing the window.
 func OptionWindowInitializer(ini func(*glfw.Window) error) Option {
 	return func(c *config) {
 		c.WindowInitializer = ini
 	}
 }
 
+// OptionPixelRatio specify the scale factor for the physical screen.
+func OptionPixelRatio(ratio float64) Option {
+	return func(c *config) {
+		c.PixelRatio = ratio
+	}
+}
+
 type config struct {
+	WindowDimension   struct {x int; y int}
 	AssetPath         string
 	ICUDataPath       string
 	WindowInitializer func(*glfw.Window) error
+	PixelRatio        float64
+	VmArguments       []string
 }
 
 func (t config) merge(options ...Option) config {
@@ -64,7 +90,8 @@ func Run(options ...Option) (err error) {
 	}
 	defer glfw.Terminate()
 
-	if window, err = glfw.CreateWindow(800, 600, "Loading..", nil, nil); err != nil {
+	window, err = glfw.CreateWindow(c.WindowDimension.x, c.WindowDimension.y, "Loading..", nil, nil)
+	if err != nil {
 		return err
 	}
 	defer window.Destroy()
@@ -73,7 +100,7 @@ func Run(options ...Option) (err error) {
 		return err
 	}
 
-	engine := runFlutter(window, c.AssetPath, c.ICUDataPath)
+	engine := runFlutter(window, c)
 
 	defer engine.Shutdown()
 
@@ -91,11 +118,13 @@ func glfwCursorPositionCallbackAtPhase(
 	window *glfw.Window, phase flutter.PointerPhase,
 	x float64, y float64,
 ) {
-
+	winWidth, _ := window.GetSize()
+	frameBuffWidth, _ := window.GetFramebufferSize()
+	contentScale := float64(frameBuffWidth / winWidth)
 	event := flutter.PointerEvent{
 		Phase:     phase,
-		X:         x,
-		Y:         y,
+		X:         x * contentScale,
+		Y:         y * contentScale,
 		Timestamp: time.Now().UnixNano() / int64(time.Millisecond),
 	}
 
@@ -185,13 +214,12 @@ func glfwKeyCallback(w *glfw.Window, key glfw.Key, scancode int, action glfw.Act
 }
 
 func glfwWindowSizeCallback(window *glfw.Window, width int, height int) {
+	flutterOGL := *(*flutter.EngineOpenGL)(window.GetUserPointer())
 	event := flutter.WindowMetricsEvent{
 		Width:      width,
 		Height:     height,
-		PixelRatio: 1.2,
+		PixelRatio: flutterOGL.PixelRatio,
 	}
-
-	flutterOGL := *(*flutter.EngineOpenGL)(window.GetUserPointer())
 	flutterOGL.EngineSendWindowMetricsEvent(event)
 }
 
@@ -202,12 +230,12 @@ func glfwCharCallback(w *glfw.Window, char rune) {
 }
 
 // Flutter Engine
-func runFlutter(window *glfw.Window, assetsPath string, icuDataPath string) *flutter.EngineOpenGL {
+func runFlutter(window *glfw.Window, c config) *flutter.EngineOpenGL {
 
 	flutterOGL := flutter.EngineOpenGL{
 		// Engine arguments
-		AssetsPath:  (*flutter.CharExportedType)(C.CString(assetsPath)),
-		IcuDataPath: (*flutter.CharExportedType)(C.CString(icuDataPath)),
+		AssetsPath:  (*flutter.CharExportedType)(C.CString(c.AssetPath)),
+		IcuDataPath: (*flutter.CharExportedType)(C.CString(c.ICUDataPath)),
 		// Render callbacks
 		FMakeCurrent: func(v unsafe.Pointer) bool {
 			w := glfw.GoWindow(v)
@@ -231,14 +259,15 @@ func runFlutter(window *glfw.Window, assetsPath string, icuDataPath string) *flu
 		},
 		// Messaging (TextInput)
 		FPlatfromMessage: onPlatformMessage,
+		PixelRatio: c.PixelRatio,
 	}
 
 	state.notifyState = func() {
 		// log.Printf("Text: Sending to the flutter engine %v", state)
 		updateEditingState(window)
 	}
 
-	result := flutterOGL.Run(window.GLFWWindow())
+	result := flutterOGL.Run(window.GLFWWindow(), c.VmArguments)
 
 	if result != flutter.KSuccess {
 		window.Destroy()
@@ -247,11 +276,11 @@ func runFlutter(window *glfw.Window, assetsPath string, icuDataPath string) *flu
 
 	window.SetUserPointer(unsafe.Pointer(&flutterOGL))
 
-	width, height := window.GetSize()
+	width, height := window.GetFramebufferSize()
 	glfwWindowSizeCallback(window, width, height)
 
 	window.SetKeyCallback(glfwKeyCallback)
-	window.SetSizeCallback(glfwWindowSizeCallback)
+	window.SetFramebufferSizeCallback(glfwWindowSizeCallback)
 	window.SetMouseButtonCallback(glfwMouseButtonCallback)
 	window.SetCharCallback(glfwCharCallback)
 	return &flutterOGL