Skel code in place

lib/renderer/webview/memory.go

@@ -0,0 +1,27 @@
+package webview
+
+/*
+#include <stdlib.h>
+*/
+import "C"
+
+import "unsafe"
+
+// This is our allocated C Memory
+var memory []unsafe.Pointer
+
+func saveMemoryReference(mem unsafe.Pointer) {
+	memory = append(memory, mem)
+}
+
+func freeMemory() {
+	for _, mem := range memory {
+		C.free(mem)
+	}
+}
+
+func string2CString(str string) *C.char {
+	result := C.CString(str)
+	saveMemoryReference(unsafe.Pointer(result))
+	return result
+}

lib/renderer/webview/webview.go

@@ -1,166 +1,20 @@
-// Package webview implements Go bindings to https://github.com/zserge/webview C library.
-// It is a modified version of webview.go from that repository
-// Bindings closely repeat the C APIs and include both, a simplified
-// single-function API to just open a full-screen webview window, and a more
-// advanced and featureful set of APIs, including Go-to-JavaScript bindings.
-//
-// The library uses gtk-webkit, Cocoa/Webkit and MSHTML (IE8..11) as a browser
-// engine and supports Linux, MacOS and Windows 7..10 respectively.
-//
 package webview
 
-/*
-#cgo linux openbsd freebsd CFLAGS: -DWEBVIEW_GTK=1 -Wno-deprecated-declarations
-#cgo linux openbsd freebsd pkg-config: gtk+-3.0 webkit2gtk-4.0
-
-#cgo windows CFLAGS: -DWEBVIEW_WINAPI=1 -std=c99
-#cgo windows LDFLAGS: -lole32 -lcomctl32 -loleaut32 -luuid -lgdi32
-
-#cgo darwin CFLAGS: -DWEBVIEW_COCOA=1 -x objective-c
-#cgo darwin LDFLAGS: -framework Cocoa -framework WebKit
-
-#include <stdlib.h>
-#include <stdint.h>
-#define WEBVIEW_STATIC
-#define WEBVIEW_IMPLEMENTATION
-#include "webview.h"
-
-extern void _webviewExternalInvokeCallback(void *, void *);
-
-static inline void CgoWebViewFree(void *w) {
-	free((void *)((struct webview *)w)->title);
-	free((void *)((struct webview *)w)->url);
-	free(w);
-}
-
-static inline void *CgoWebViewCreate(int width, int height, char *title, char *url, int resizable, int debug) {
-	struct webview *w = (struct webview *) calloc(1, sizeof(*w));
-	w->width = width;
-	w->height = height;
-	w->title = title;
-	w->url = url;
-	w->resizable = resizable;
-	w->debug = debug;
-	w->external_invoke_cb = (webview_external_invoke_cb_t) _webviewExternalInvokeCallback;
-	if (webview_init(w) != 0) {
-		CgoWebViewFree(w);
-		return NULL;
-	}
-	return (void *)w;
-}
-
-static inline int CgoWebViewLoop(void *w, int blocking) {
-	return webview_loop((struct webview *)w, blocking);
-}
-
-static inline void CgoWebViewTerminate(void *w) {
-	webview_terminate((struct webview *)w);
-}
-
-static inline void CgoWebViewExit(void *w) {
-	webview_exit((struct webview *)w);
-}
-
-static inline void CgoWebViewSetTitle(void *w, char *title) {
-	webview_set_title((struct webview *)w, title);
-}
-
-static inline void CgoWebViewSetFullscreen(void *w, int fullscreen) {
-	webview_set_fullscreen((struct webview *)w, fullscreen);
-}
-
-static inline void CgoWebViewSetColor(void *w, uint8_t r, uint8_t g, uint8_t b, uint8_t a) {
-	webview_set_color((struct webview *)w, r, g, b, a);
-}
-
-static inline void CgoDialog(void *w, int dlgtype, int flags,
-char *title, char *arg, char *res, size_t ressz, char *filter) {
-	webview_dialog(w, dlgtype, flags,
-	(const char*)title, (const char*) arg, res, ressz, filter);
-}
-
-static inline int CgoWebViewEval(void *w, char *js) {
-	return webview_eval((struct webview *)w, js);
-}
-
-static inline void CgoWebViewInjectCSS(void *w, char *css) {
-	webview_inject_css((struct webview *)w, css);
-}
-
-extern void _webviewDispatchGoCallback(void *);
-static inline void _webview_dispatch_cb(struct webview *w, void *arg) {
-	_webviewDispatchGoCallback(arg);
-}
-static inline void CgoWebViewDispatch(void *w, uintptr_t arg) {
-	webview_dispatch((struct webview *)w, _webview_dispatch_cb, (void *)arg);
-}
-*/
 import "C"
-import (
-	"errors"
-	"runtime"
-	"sync"
-	"unsafe"
+
+// DialogType is an enumeration of all supported system dialog types
+type DialogType int
+
+const (
+	// DialogTypeOpen is a system file open dialog
+	DialogTypeOpen DialogType = iota
+	// DialogTypeSave is a system file save dialog
+	DialogTypeSave
+	// DialogTypeAlert is a system alert dialog (message box)
+	DialogTypeAlert
 )
 
-func init() {
-	// Ensure that main.main is called from the main thread
-	runtime.LockOSThread()
-}
-
-// Open is a simplified API to open a single native window with a full-size webview in
-// it. It can be helpful if you want to communicate with the core app using XHR
-// or WebSockets (as opposed to using JavaScript bindings).
-//
-// Window appearance can be customized using title, width, height and resizable parameters.
-// URL must be provided and can user either a http or https protocol, or be a
-// local file:// URL. On some platforms "data:" URLs are also supported
-// (Linux/MacOS).
-func Open(title, url string, w, h int, resizable bool) error {
-	titleStr := C.CString(title)
-	defer C.free(unsafe.Pointer(titleStr))
-	urlStr := C.CString(url)
-	defer C.free(unsafe.Pointer(urlStr))
-	resize := C.int(0)
-	if resizable {
-		resize = C.int(1)
-	}
-
-	r := C.webview(titleStr, urlStr, C.int(w), C.int(h), resize)
-	if r != 0 {
-		return errors.New("failed to create webview")
-	}
-	return nil
-}
-
-// ExternalInvokeCallbackFunc is a function type that is called every time
-// "window.external.invoke()" is called from JavaScript. Data is the only
-// obligatory string parameter passed into the "invoke(data)" function from
-// JavaScript. To pass more complex data serialized JSON or base64 encoded
-// string can be used.
-type ExternalInvokeCallbackFunc func(w WebView, data string)
-
-// Settings is a set of parameters to customize the initial WebView appearance
-// and behavior. It is passed into the webview.New() constructor.
-type Settings struct {
-	// WebView main window title
-	Title string
-	// URL to open in a webview
-	URL string
-	// Window width in pixels
-	Width int
-	// Window height in pixels
-	Height int
-	// Allows/disallows window resizing
-	Resizable bool
-	// Enable debugging tools (Linux/BSD/MacOS, on Windows use Firebug)
-	Debug bool
-	// A callback that is executed when JavaScript calls "window.external.invoke()"
-	ExternalInvokeCallback ExternalInvokeCallbackFunc
-}
-
-// WebView is an interface that wraps the basic methods for controlling the UI
-// loop, handling multithreading and providing JavaScript bindings.
+// WebView is our webview interface
 type WebView interface {
 	// Run() starts the main UI loop until the user closes the webview window or
 	// Terminate() is called.
@@ -199,175 +53,21 @@ type WebView interface {
 	Exit()
 }
 
-// DialogType is an enumeration of all supported system dialog types
-type DialogType int
+type ExternalInvokeCallbackFunc func(w WebView, data string)
 
-const (
-	// DialogTypeOpen is a system file open dialog
-	DialogTypeOpen DialogType = iota
-	// DialogTypeSave is a system file save dialog
-	DialogTypeSave
-	// DialogTypeAlert is a system alert dialog (message box)
-	DialogTypeAlert
-)
-
-const (
-	// DialogFlagFile is a normal file picker dialog
-	DialogFlagFile = C.WEBVIEW_DIALOG_FLAG_FILE
-	// DialogFlagDirectory is an open directory dialog
-	DialogFlagDirectory = C.WEBVIEW_DIALOG_FLAG_DIRECTORY
-	// DialogFlagInfo is an info alert dialog
-	DialogFlagInfo = C.WEBVIEW_DIALOG_FLAG_INFO
-	// DialogFlagWarning is a warning alert dialog
-	DialogFlagWarning = C.WEBVIEW_DIALOG_FLAG_WARNING
-	// DialogFlagError is an error dialog
-	DialogFlagError = C.WEBVIEW_DIALOG_FLAG_ERROR
-)
-
-var (
-	m     sync.Mutex
-	index uintptr
-	fns   = map[uintptr]func(){}
-	cbs   = map[WebView]ExternalInvokeCallbackFunc{}
-)
-
-type webview struct {
-	w unsafe.Pointer
-}
-
-var _ WebView = &webview{}
-
-func boolToInt(b bool) int {
-	if b {
-		return 1
-	}
-	return 0
-}
-
-// NewWebview creates and opens a new webview window using the given settings. The
-// returned object implements the WebView interface. This function returns nil
-// if a window can not be created.
-func NewWebview(settings Settings) WebView {
-	if settings.Width == 0 {
-		settings.Width = 640
-	}
-	if settings.Height == 0 {
-		settings.Height = 480
-	}
-	if settings.Title == "" {
-		settings.Title = "WebView"
-	}
-	w := &webview{}
-	w.w = C.CgoWebViewCreate(C.int(settings.Width), C.int(settings.Height),
-		C.CString(settings.Title), C.CString(settings.URL),
-		C.int(boolToInt(settings.Resizable)), C.int(boolToInt(settings.Debug)))
-	m.Lock()
-	if settings.ExternalInvokeCallback != nil {
-		cbs[w] = settings.ExternalInvokeCallback
-	} else {
-		cbs[w] = func(w WebView, data string) {}
-	}
-	m.Unlock()
-	return w
-}
-
-func (w *webview) Loop(blocking bool) bool {
-	block := C.int(0)
-	if blocking {
-		block = 1
-	}
-	return C.CgoWebViewLoop(w.w, block) == 0
-}
-
-func (w *webview) Run() {
-	for w.Loop(true) {
-	}
-}
-
-func (w *webview) Exit() {
-	C.CgoWebViewExit(w.w)
-}
-
-func (w *webview) Dispatch(f func()) {
-	m.Lock()
-	for ; fns[index] != nil; index++ {
-	}
-	fns[index] = f
-	m.Unlock()
-	C.CgoWebViewDispatch(w.w, C.uintptr_t(index))
-}
-
-func (w *webview) SetTitle(title string) {
-	p := C.CString(title)
-	defer C.free(unsafe.Pointer(p))
-	C.CgoWebViewSetTitle(w.w, p)
-}
-
-func (w *webview) SetColor(r, g, b, a uint8) {
-	C.CgoWebViewSetColor(w.w, C.uint8_t(r), C.uint8_t(g), C.uint8_t(b), C.uint8_t(a))
-}
-
-func (w *webview) SetFullscreen(fullscreen bool) {
-	C.CgoWebViewSetFullscreen(w.w, C.int(boolToInt(fullscreen)))
-}
-
-func (w *webview) Dialog(dlgType DialogType, flags int, title string, arg string, filter string) string {
-	const maxPath = 4096
-	titlePtr := C.CString(title)
-	defer C.free(unsafe.Pointer(titlePtr))
-	argPtr := C.CString(arg)
-	defer C.free(unsafe.Pointer(argPtr))
-	resultPtr := (*C.char)(C.calloc((C.size_t)(unsafe.Sizeof((*C.char)(nil))), (C.size_t)(maxPath)))
-	defer C.free(unsafe.Pointer(resultPtr))
-	filterPtr := C.CString(filter)
-	defer C.free(unsafe.Pointer(filterPtr))
-	C.CgoDialog(w.w, C.int(dlgType), C.int(flags), titlePtr,
-		argPtr, resultPtr, C.size_t(maxPath), filterPtr)
-	return C.GoString(resultPtr)
-}
-
-func (w *webview) Eval(js string) error {
-	p := C.CString(js)
-	defer C.free(unsafe.Pointer(p))
-	switch C.CgoWebViewEval(w.w, p) {
-	case -1:
-		return errors.New("evaluation failed")
-	}
-	return nil
-}
-
-func (w *webview) InjectCSS(css string) {
-	p := C.CString(css)
-	defer C.free(unsafe.Pointer(p))
-	C.CgoWebViewInjectCSS(w.w, p)
-}
-
-func (w *webview) Terminate() {
-	C.CgoWebViewTerminate(w.w)
-}
-
-//export _webviewDispatchGoCallback
-func _webviewDispatchGoCallback(index unsafe.Pointer) {
-	var f func()
-	m.Lock()
-	f = fns[uintptr(index)]
-	delete(fns, uintptr(index))
-	m.Unlock()
-	f()
-}
-
-//export _webviewExternalInvokeCallback
-func _webviewExternalInvokeCallback(w unsafe.Pointer, data unsafe.Pointer) {
-	m.Lock()
-	var (
-		cb ExternalInvokeCallbackFunc
-		wv WebView
-	)
-	for wv, cb = range cbs {
-		if wv.(*webview).w == w {
-			break
-		}
-	}
-	m.Unlock()
-	cb(wv, C.GoString((*C.char)(data)))
+type Settings struct {
+	// WebView main window title
+	Title string
+	// URL to open in a webview
+	URL string
+	// Window width in pixels
+	Width int
+	// Window height in pixels
+	Height int
+	// Allows/disallows window resizing
+	Resizable bool
+	// Enable debugging tools (Linux/BSD/MacOS, on Windows use Firebug)
+	Debug bool
+	// A callback that is executed when JavaScript calls "window.external.invoke()"
+	ExternalInvokeCallback ExternalInvokeCallbackFunc
 }

lib/renderer/webview/webview_darwin.go

@@ -0,0 +1,57 @@
+package webview
+
+/*
+#include "webview_darwin.h"
+*/
+import "C"
+
+import "unsafe"
+
+const (
+	// DialogFlagFile is a normal file picker dialog
+	DialogFlagFile = C.WEBVIEW_DIALOG_FLAG_FILE
+	// DialogFlagDirectory is an open directory dialog
+	DialogFlagDirectory = C.WEBVIEW_DIALOG_FLAG_DIRECTORY
+	// DialogFlagInfo is an info alert dialog
+	DialogFlagInfo = C.WEBVIEW_DIALOG_FLAG_INFO
+	// DialogFlagWarning is a warning alert dialog
+	DialogFlagWarning = C.WEBVIEW_DIALOG_FLAG_WARNING
+	// DialogFlagError is an error dialog
+	DialogFlagError = C.WEBVIEW_DIALOG_FLAG_ERROR
+)
+
+type MacWebView struct {
+	app unsafe.Pointer
+}
+
+func NewWebview(settings Settings) WebView {
+	return &MacWebView{}
+}
+
+func (w *MacWebView) Dialog(dlgType DialogType, flags int, title string, arg string, filter string) string {
+	// TBD
+	return ""
+}
+
+func (w *MacWebView) Dispatch(func()) {
+	// TBD
+}
+
+func (w *MacWebView) Eval(js string) error {
+	// TBD
+	return nil
+}
+
+func (w *MacWebView) Exit() {
+	// TBD
+}
+
+func (w *MacWebView) Run() {}
+func (w *MacWebView) Loop(blocking bool) bool {
+	return true
+}
+func (w *MacWebView) SetTitle(title string)         {}
+func (w *MacWebView) SetFullscreen(fullscreen bool) {}
+func (w *MacWebView) SetColor(r, g, b, a uint8)     {}
+func (w *MacWebView) InjectCSS(css string)          {}
+func (w *MacWebView) Terminate()                    {}

lib/renderer/webview/webview_darwin.h

@@ -0,0 +1,13 @@
+
+#ifndef WEBVIEW_DARWIN
+#define WEBVIEW_DARWIN
+
+#define WEBVIEW_DIALOG_FLAG_FILE (0 << 0)
+#define WEBVIEW_DIALOG_FLAG_DIRECTORY (1 << 0)
+
+#define WEBVIEW_DIALOG_FLAG_INFO (1 << 1)
+#define WEBVIEW_DIALOG_FLAG_WARNING (2 << 1)
+#define WEBVIEW_DIALOG_FLAG_ERROR (3 << 1)
+#define WEBVIEW_DIALOG_FLAG_ALERT_MASK (3 << 1)
+
+#endif

lib/renderer/webview/webview_linux.go

@@ -0,0 +1,386 @@
+// Package webview implements Go bindings to https://github.com/zserge/webview C library.
+// It is a modified version of webview.go from that repository
+// Bindings closely repeat the C APIs and include both, a simplified
+// single-function API to just open a full-screen webview window, and a more
+// advanced and featureful set of APIs, including Go-to-JavaScript bindings.
+//
+// The library uses gtk-webkit, Cocoa/Webkit and MSHTML (IE8..11) as a browser
+// engine and supports Linux, MacOS and Windows 7..10 respectively.
+//
+package webview
+
+/*
+#cgo linux openbsd freebsd CFLAGS: -DWEBVIEW_GTK=1 -Wno-deprecated-declarations
+#cgo linux openbsd freebsd pkg-config: gtk+-3.0 webkit2gtk-4.0
+
+#cgo windows CFLAGS: -DWEBVIEW_WINAPI=1 -std=c99
+#cgo windows LDFLAGS: -lole32 -lcomctl32 -loleaut32 -luuid -lgdi32
+
+#cgo darwin CFLAGS: -DWEBVIEW_COCOA=1 -x objective-c
+#cgo darwin LDFLAGS: -framework Cocoa -framework WebKit
+
+#include <stdlib.h>
+#include <stdint.h>
+#define WEBVIEW_STATIC
+#define WEBVIEW_IMPLEMENTATION
+
+#ifdef WEBVIEW_GTK
+#include "webview_linux.h"
+#endif
+
+#ifdef WEBVIEW_COCOA
+#include "webview_darwin.h"
+#endif
+
+#ifdef WEBVIEW_COCOA
+#include "webview_darwin.h"
+#endif
+
+
+
+extern void _webviewExternalInvokeCallback(void *, void *);
+
+static inline void CgoWebViewFree(void *w) {
+	free((void *)((struct webview *)w)->title);
+	free((void *)((struct webview *)w)->url);
+	free(w);
+}
+
+static inline void *CgoWebViewCreate(int width, int height, char *title, char *url, int resizable, int debug) {
+	struct webview *w = (struct webview *) calloc(1, sizeof(*w));
+	w->width = width;
+	w->height = height;
+	w->title = title;
+	w->url = url;
+	w->resizable = resizable;
+	w->debug = debug;
+	w->external_invoke_cb = (webview_external_invoke_cb_t) _webviewExternalInvokeCallback;
+	if (webview_init(w) != 0) {
+		CgoWebViewFree(w);
+		return NULL;
+	}
+	return (void *)w;
+}
+
+static inline int CgoWebViewLoop(void *w, int blocking) {
+	return webview_loop((struct webview *)w, blocking);
+}
+
+static inline void CgoWebViewTerminate(void *w) {
+	webview_terminate((struct webview *)w);
+}
+
+static inline void CgoWebViewExit(void *w) {
+	webview_exit((struct webview *)w);
+}
+
+static inline void CgoWebViewSetTitle(void *w, char *title) {
+	webview_set_title((struct webview *)w, title);
+}
+
+static inline void CgoWebViewSetFullscreen(void *w, int fullscreen) {
+	webview_set_fullscreen((struct webview *)w, fullscreen);
+}
+
+static inline void CgoWebViewSetColor(void *w, uint8_t r, uint8_t g, uint8_t b, uint8_t a) {
+	webview_set_color((struct webview *)w, r, g, b, a);
+}
+
+static inline void CgoDialog(void *w, int dlgtype, int flags,
+char *title, char *arg, char *res, size_t ressz, char *filter) {
+	webview_dialog(w, dlgtype, flags,
+	(const char*)title, (const char*) arg, res, ressz, filter);
+}
+
+static inline int CgoWebViewEval(void *w, char *js) {
+	return webview_eval((struct webview *)w, js);
+}
+
+static inline void CgoWebViewInjectCSS(void *w, char *css) {
+	webview_inject_css((struct webview *)w, css);
+}
+
+extern void _webviewDispatchGoCallback(void *);
+static inline void _webview_dispatch_cb(struct webview *w, void *arg) {
+	_webviewDispatchGoCallback(arg);
+}
+static inline void CgoWebViewDispatch(void *w, uintptr_t arg) {
+	webview_dispatch((struct webview *)w, _webview_dispatch_cb, (void *)arg);
+}
+*/
+import "C"
+import (
+	"errors"
+	"runtime"
+	"sync"
+	"unsafe"
+)
+
+func init() {
+	// Ensure that main.main is called from the main thread
+	runtime.LockOSThread()
+}
+
+// Open is a simplified API to open a single native window with a full-size webview in
+// it. It can be helpful if you want to communicate with the core app using XHR
+// or WebSockets (as opposed to using JavaScript bindings).
+//
+// Window appearance can be customized using title, width, height and resizable parameters.
+// URL must be provided and can user either a http or https protocol, or be a
+// local file:// URL. On some platforms "data:" URLs are also supported
+// (Linux/MacOS).
+func Open(title, url string, w, h int, resizable bool) error {
+	titleStr := C.CString(title)
+	defer C.free(unsafe.Pointer(titleStr))
+	urlStr := C.CString(url)
+	defer C.free(unsafe.Pointer(urlStr))
+	resize := C.int(0)
+	if resizable {
+		resize = C.int(1)
+	}
+
+	r := C.webview(titleStr, urlStr, C.int(w), C.int(h), resize)
+	if r != 0 {
+		return errors.New("failed to create webview")
+	}
+	return nil
+}
+
+// ExternalInvokeCallbackFunc is a function type that is called every time
+// "window.external.invoke()" is called from JavaScript. Data is the only
+// obligatory string parameter passed into the "invoke(data)" function from
+// JavaScript. To pass more complex data serialized JSON or base64 encoded
+// string can be used.
+type ExternalInvokeCallbackFunc func(w WebView, data string)
+
+// Settings is a set of parameters to customize the initial WebView appearance
+// and behavior. It is passed into the webview.New() constructor.
+type Settings struct {
+	// WebView main window title
+	Title string
+	// URL to open in a webview
+	URL string
+	// Window width in pixels
+	Width int
+	// Window height in pixels
+	Height int
+	// Allows/disallows window resizing
+	Resizable bool
+	// Enable debugging tools (Linux/BSD/MacOS, on Windows use Firebug)
+	Debug bool
+	// A callback that is executed when JavaScript calls "window.external.invoke()"
+	ExternalInvokeCallback ExternalInvokeCallbackFunc
+}
+
+// WebView is an interface that wraps the basic methods for controlling the UI
+// loop, handling multithreading and providing JavaScript bindings.
+type WebView interface {
+	// Run() starts the main UI loop until the user closes the webview window or
+	// Terminate() is called.
+	Run()
+	// Loop() runs a single iteration of the main UI.
+	Loop(blocking bool) bool
+	// SetTitle() changes window title. This method must be called from the main
+	// thread only. See Dispatch() for more details.
+	SetTitle(title string)
+	// SetFullscreen() controls window full-screen mode. This method must be
+	// called from the main thread only. See Dispatch() for more details.
+	SetFullscreen(fullscreen bool)
+	// SetColor() changes window background color. This method must be called from
+	// the main thread only. See Dispatch() for more details.
+	SetColor(r, g, b, a uint8)
+	// Eval() evaluates an arbitrary JS code inside the webview. This method must
+	// be called from the main thread only. See Dispatch() for more details.
+	Eval(js string) error
+	// InjectJS() injects an arbitrary block of CSS code using the JS API. This
+	// method must be called from the main thread only. See Dispatch() for more
+	// details.
+	InjectCSS(css string)
+	// Dialog() opens a system dialog of the given type and title. String
+	// argument can be provided for certain dialogs, such as alert boxes. For
+	// alert boxes argument is a message inside the dialog box.
+	Dialog(dlgType DialogType, flags int, title string, arg string, filter string) string
+	// Terminate() breaks the main UI loop. This method must be called from the main thread
+	// only. See Dispatch() for more details.
+	Terminate()
+	// Dispatch() schedules some arbitrary function to be executed on the main UI
+	// thread. This may be helpful if you want to run some JavaScript from
+	// background threads/goroutines, or to terminate the app.
+	Dispatch(func())
+	// Exit() closes the window and cleans up the resources. Use Terminate() to
+	// forcefully break out of the main UI loop.
+	Exit()
+}
+
+// DialogType is an enumeration of all supported system dialog types
+type DialogType int
+
+const (
+	// DialogTypeOpen is a system file open dialog
+	DialogTypeOpen DialogType = iota
+	// DialogTypeSave is a system file save dialog
+	DialogTypeSave
+	// DialogTypeAlert is a system alert dialog (message box)
+	DialogTypeAlert
+)
+
+const (
+	// DialogFlagFile is a normal file picker dialog
+	DialogFlagFile = C.WEBVIEW_DIALOG_FLAG_FILE
+	// DialogFlagDirectory is an open directory dialog
+	DialogFlagDirectory = C.WEBVIEW_DIALOG_FLAG_DIRECTORY
+	// DialogFlagInfo is an info alert dialog
+	DialogFlagInfo = C.WEBVIEW_DIALOG_FLAG_INFO
+	// DialogFlagWarning is a warning alert dialog
+	DialogFlagWarning = C.WEBVIEW_DIALOG_FLAG_WARNING
+	// DialogFlagError is an error dialog
+	DialogFlagError = C.WEBVIEW_DIALOG_FLAG_ERROR
+)
+
+var (
+	m     sync.Mutex
+	index uintptr
+	fns   = map[uintptr]func(){}
+	cbs   = map[WebView]ExternalInvokeCallbackFunc{}
+)
+
+type webview struct {
+	w unsafe.Pointer
+}
+
+var _ WebView = &webview{}
+
+func boolToInt(b bool) int {
+	if b {
+		return 1
+	}
+	return 0
+}
+
+// NewWebview creates and opens a new webview window using the given settings. The
+// returned object implements the WebView interface. This function returns nil
+// if a window can not be created.
+func NewWebview(settings Settings) WebView {
+	if settings.Width == 0 {
+		settings.Width = 640
+	}
+	if settings.Height == 0 {
+		settings.Height = 480
+	}
+	if settings.Title == "" {
+		settings.Title = "WebView"
+	}
+	w := &webview{}
+	w.w = C.CgoWebViewCreate(C.int(settings.Width), C.int(settings.Height),
+		C.CString(settings.Title), C.CString(settings.URL),
+		C.int(boolToInt(settings.Resizable)), C.int(boolToInt(settings.Debug)))
+	m.Lock()
+	if settings.ExternalInvokeCallback != nil {
+		cbs[w] = settings.ExternalInvokeCallback
+	} else {
+		cbs[w] = func(w WebView, data string) {}
+	}
+	m.Unlock()
+	return w
+}
+
+func (w *webview) Loop(blocking bool) bool {
+	block := C.int(0)
+	if blocking {
+		block = 1
+	}
+	return C.CgoWebViewLoop(w.w, block) == 0
+}
+
+func (w *webview) Run() {
+	for w.Loop(true) {
+	}
+}
+
+func (w *webview) Exit() {
+	C.CgoWebViewExit(w.w)
+}
+
+func (w *webview) Dispatch(f func()) {
+	m.Lock()
+	for ; fns[index] != nil; index++ {
+	}
+	fns[index] = f
+	m.Unlock()
+	C.CgoWebViewDispatch(w.w, C.uintptr_t(index))
+}
+
+func (w *webview) SetTitle(title string) {
+	p := C.CString(title)
+	defer C.free(unsafe.Pointer(p))
+	C.CgoWebViewSetTitle(w.w, p)
+}
+
+func (w *webview) SetColor(r, g, b, a uint8) {
+	C.CgoWebViewSetColor(w.w, C.uint8_t(r), C.uint8_t(g), C.uint8_t(b), C.uint8_t(a))
+}
+
+func (w *webview) SetFullscreen(fullscreen bool) {
+	C.CgoWebViewSetFullscreen(w.w, C.int(boolToInt(fullscreen)))
+}
+
+func (w *webview) Dialog(dlgType DialogType, flags int, title string, arg string, filter string) string {
+	const maxPath = 4096
+	titlePtr := C.CString(title)
+	defer C.free(unsafe.Pointer(titlePtr))
+	argPtr := C.CString(arg)
+	defer C.free(unsafe.Pointer(argPtr))
+	resultPtr := (*C.char)(C.calloc((C.size_t)(unsafe.Sizeof((*C.char)(nil))), (C.size_t)(maxPath)))
+	defer C.free(unsafe.Pointer(resultPtr))
+	filterPtr := C.CString(filter)
+	defer C.free(unsafe.Pointer(filterPtr))
+	C.CgoDialog(w.w, C.int(dlgType), C.int(flags), titlePtr,
+		argPtr, resultPtr, C.size_t(maxPath), filterPtr)
+	return C.GoString(resultPtr)
+}
+
+func (w *webview) Eval(js string) error {
+	p := C.CString(js)
+	defer C.free(unsafe.Pointer(p))
+	switch C.CgoWebViewEval(w.w, p) {
+	case -1:
+		return errors.New("evaluation failed")
+	}
+	return nil
+}
+
+func (w *webview) InjectCSS(css string) {
+	p := C.CString(css)
+	defer C.free(unsafe.Pointer(p))
+	C.CgoWebViewInjectCSS(w.w, p)
+}
+
+func (w *webview) Terminate() {
+	C.CgoWebViewTerminate(w.w)
+}
+
+//export _webviewDispatchGoCallback
+func _webviewDispatchGoCallback(index unsafe.Pointer) {
+	var f func()
+	m.Lock()
+	f = fns[uintptr(index)]
+	delete(fns, uintptr(index))
+	m.Unlock()
+	f()
+}
+
+//export _webviewExternalInvokeCallback
+func _webviewExternalInvokeCallback(w unsafe.Pointer, data unsafe.Pointer) {
+	m.Lock()
+	var (
+		cb ExternalInvokeCallbackFunc
+		wv WebView
+	)
+	for wv, cb = range cbs {
+		if wv.(*webview).w == w {
+			break
+		}
+	}
+	m.Unlock()
+	cb(wv, C.GoString((*C.char)(data)))
+}

lib/renderer/webview/webview_linux.h

@@ -0,0 +1,522 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 Serge Zaitsev
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef WEBVIEW_H
+#define WEBVIEW_H
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#ifdef WEBVIEW_STATIC
+#define WEBVIEW_API static
+#else
+#define WEBVIEW_API extern
+#endif
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <JavaScriptCore/JavaScript.h>
+#include <gtk/gtk.h>
+#include <webkit2/webkit2.h>
+
+struct webview_priv
+{
+  GtkWidget *window;
+  GtkWidget *scroller;
+  GtkWidget *webview;
+  GtkWidget *inspector_window;
+  GAsyncQueue *queue;
+  int ready;
+  int js_busy;
+  int should_exit;
+};
+
+struct webview;
+
+typedef void (*webview_external_invoke_cb_t)(struct webview *w,
+                                              const char *arg);
+
+struct webview
+{
+  const char *url;
+  const char *title;
+  int width;
+  int height;
+  int resizable;
+  int transparentTitlebar;
+  int debug;
+  webview_external_invoke_cb_t external_invoke_cb;
+  struct webview_priv priv;
+  void *userdata;
+};
+
+enum webview_dialog_type
+{
+  WEBVIEW_DIALOG_TYPE_OPEN = 0,
+  WEBVIEW_DIALOG_TYPE_SAVE = 1,
+  WEBVIEW_DIALOG_TYPE_ALERT = 2
+};
+
+#define WEBVIEW_DIALOG_FLAG_FILE (0 << 0)
+#define WEBVIEW_DIALOG_FLAG_DIRECTORY (1 << 0)
+
+#define WEBVIEW_DIALOG_FLAG_INFO (1 << 1)
+#define WEBVIEW_DIALOG_FLAG_WARNING (2 << 1)
+#define WEBVIEW_DIALOG_FLAG_ERROR (3 << 1)
+#define WEBVIEW_DIALOG_FLAG_ALERT_MASK (3 << 1)
+
+typedef void (*webview_dispatch_fn)(struct webview *w, void *arg);
+
+struct webview_dispatch_arg
+{
+  webview_dispatch_fn fn;
+  struct webview *w;
+  void *arg;
+};
+
+#define DEFAULT_URL                                                            \
+"data:text/"                                                                 \
+"html,%3C%21DOCTYPE%20html%3E%0A%3Chtml%20lang=%22en%22%3E%0A%3Chead%3E%"    \
+"3Cmeta%20charset=%22utf-8%22%3E%3Cmeta%20http-equiv=%22IE=edge%22%"         \
+"20content=%22IE=edge%22%3E%3C%2Fhead%3E%0A%3Cbody%3E%3Cdiv%20id=%22app%22%" \
+"3E%3C%2Fdiv%3E%3Cscript%20type=%22text%2Fjavascript%22%3E%3C%2Fscript%3E%"  \
+"3C%2Fbody%3E%0A%3C%2Fhtml%3E"
+
+#define CSS_INJECT_FUNCTION                                           \
+"(function(e){var "                                                 \
+"t=document.createElement('style'),d=document.head||document."      \
+"getElementsByTagName('head')[0];t.setAttribute('type','text/"      \
+"css'),t.styleSheet?t.styleSheet.cssText=e:t.appendChild(document." \
+"createTextNode(e)),d.appendChild(t)})"
+
+static const char *webview_check_url(const char *url)
+{
+  if (url == NULL || strlen(url) == 0)
+  {
+    return DEFAULT_URL;
+  }
+  return url;
+}
+
+WEBVIEW_API int webview(const char *title, const char *url, int width,
+                        int height, int resizable);
+
+WEBVIEW_API int webview_init(struct webview *w);
+WEBVIEW_API int webview_loop(struct webview *w, int blocking);
+WEBVIEW_API int webview_eval(struct webview *w, const char *js);
+WEBVIEW_API int webview_inject_css(struct webview *w, const char *css);
+WEBVIEW_API void webview_set_title(struct webview *w, const char *title);
+WEBVIEW_API void webview_set_fullscreen(struct webview *w, int fullscreen);
+WEBVIEW_API void webview_set_color(struct webview *w, uint8_t r, uint8_t g,
+                                    uint8_t b, uint8_t a);
+WEBVIEW_API void webview_dialog(struct webview *w,
+                                enum webview_dialog_type dlgtype, int flags,
+                                const char *title, const char *arg,
+                                char *result, size_t resultsz, char *filter);
+WEBVIEW_API void webview_dispatch(struct webview *w, webview_dispatch_fn fn,
+                                  void *arg);
+WEBVIEW_API void webview_terminate(struct webview *w);
+WEBVIEW_API void webview_exit(struct webview *w);
+WEBVIEW_API void webview_debug(const char *format, ...);
+WEBVIEW_API void webview_print_log(const char *s);
+
+WEBVIEW_API int webview(const char *title, const char *url, int width,
+                        int height, int resizable)
+{
+  struct webview webview;
+  memset(&webview, 0, sizeof(webview));
+  webview.title = title;
+  webview.url = url;
+  webview.width = width;
+  webview.height = height;
+  webview.resizable = resizable;
+  int r = webview_init(&webview);
+  if (r != 0)
+  {
+    return r;
+  }
+  while (webview_loop(&webview, 1) == 0)
+  {
+  }
+  webview_exit(&webview);
+  return 0;
+}
+
+WEBVIEW_API void webview_debug(const char *format, ...)
+{
+  char buf[4096];
+  va_list ap;
+  va_start(ap, format);
+  vsnprintf(buf, sizeof(buf), format, ap);
+  webview_print_log(buf);
+  va_end(ap);
+}
+
+static int webview_js_encode(const char *s, char *esc, size_t n)
+{
+  int r = 1; /* At least one byte for trailing zero */
+  for (; *s; s++)
+  {
+    const unsigned char c = *s;
+    if (c >= 0x20 && c < 0x80 && strchr("<>\\'\"", c) == NULL)
+    {
+      if (n > 0)
+      {
+        *esc++ = c;
+        n--;
+      }
+      r++;
+    }
+    else
+    {
+      if (n > 0)
+      {
+        snprintf(esc, n, "\\x%02x", (int)c);
+        esc += 4;
+        n -= 4;
+      }
+      r += 4;
+    }
+  }
+  return r;
+}
+
+WEBVIEW_API int webview_inject_css(struct webview *w, const char *css)
+{
+  int n = webview_js_encode(css, NULL, 0);
+  char *esc = (char *)calloc(1, sizeof(CSS_INJECT_FUNCTION) + n + 4);
+  if (esc == NULL)
+  {
+    return -1;
+  }
+  char *js = (char *)calloc(1, n);
+  webview_js_encode(css, js, n);
+  snprintf(esc, sizeof(CSS_INJECT_FUNCTION) + n + 4, "%s(\"%s\")",
+            CSS_INJECT_FUNCTION, js);
+  int r = webview_eval(w, esc);
+  free(js);
+  free(esc);
+  return r;
+}
+
+static void external_message_received_cb(WebKitUserContentManager *m,
+                                          WebKitJavascriptResult *r,
+                                          gpointer arg)
+{
+  (void)m;
+  struct webview *w = (struct webview *)arg;
+  if (w->external_invoke_cb == NULL)
+  {
+    return;
+  }
+  JSGlobalContextRef context = webkit_javascript_result_get_global_context(r);
+  JSValueRef value = webkit_javascript_result_get_value(r);
+  JSStringRef js = JSValueToStringCopy(context, value, NULL);
+  size_t n = JSStringGetMaximumUTF8CStringSize(js);
+  char *s = g_new(char, n);
+  JSStringGetUTF8CString(js, s, n);
+  w->external_invoke_cb(w, s);
+  JSStringRelease(js);
+  g_free(s);
+}
+
+static void webview_load_changed_cb(WebKitWebView *webview,
+                                    WebKitLoadEvent event, gpointer arg)
+{
+  (void)webview;
+  struct webview *w = (struct webview *)arg;
+  if (event == WEBKIT_LOAD_FINISHED)
+  {
+    w->priv.ready = 1;
+  }
+}
+
+static void webview_destroy_cb(GtkWidget *widget, gpointer arg)
+{
+  (void)widget;
+  struct webview *w = (struct webview *)arg;
+  webview_terminate(w);
+}
+
+static gboolean webview_context_menu_cb(WebKitWebView *webview,
+                                        GtkWidget *default_menu,
+                                        WebKitHitTestResult *hit_test_result,
+                                        gboolean triggered_with_keyboard,
+                                        gpointer userdata)
+{
+  (void)webview;
+  (void)default_menu;
+  (void)hit_test_result;
+  (void)triggered_with_keyboard;
+  (void)userdata;
+  return TRUE;
+}
+
+WEBVIEW_API int webview_init(struct webview *w)
+{
+  if (gtk_init_check(0, NULL) == FALSE)
+  {
+    return -1;
+  }
+
+  w->priv.ready = 0;
+  w->priv.should_exit = 0;
+  w->priv.queue = g_async_queue_new();
+  w->priv.window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
+  gtk_window_set_title(GTK_WINDOW(w->priv.window), w->title);
+
+  if (w->resizable)
+  {
+    gtk_window_set_default_size(GTK_WINDOW(w->priv.window), w->width,
+                                w->height);
+  }
+  else
+  {
+    gtk_widget_set_size_request(w->priv.window, w->width, w->height);
+  }
+  gtk_window_set_resizable(GTK_WINDOW(w->priv.window), !!w->resizable);
+  gtk_window_set_position(GTK_WINDOW(w->priv.window), GTK_WIN_POS_CENTER);
+
+  w->priv.scroller = gtk_scrolled_window_new(NULL, NULL);
+  gtk_container_add(GTK_CONTAINER(w->priv.window), w->priv.scroller);
+
+  WebKitUserContentManager *m = webkit_user_content_manager_new();
+  webkit_user_content_manager_register_script_message_handler(m, "external");
+  g_signal_connect(m, "script-message-received::external",
+                    G_CALLBACK(external_message_received_cb), w);
+
+  w->priv.webview = webkit_web_view_new_with_user_content_manager(m);
+  webkit_web_view_load_uri(WEBKIT_WEB_VIEW(w->priv.webview),
+                            webview_check_url(w->url));
+  g_signal_connect(G_OBJECT(w->priv.webview), "load-changed",
+                    G_CALLBACK(webview_load_changed_cb), w);
+  gtk_container_add(GTK_CONTAINER(w->priv.scroller), w->priv.webview);
+
+  if (w->debug)
+  {
+    WebKitSettings *settings =
+        webkit_web_view_get_settings(WEBKIT_WEB_VIEW(w->priv.webview));
+    webkit_settings_set_enable_write_console_messages_to_stdout(settings, true);
+    webkit_settings_set_enable_developer_extras(settings, true);
+  }
+  else
+  {
+    g_signal_connect(G_OBJECT(w->priv.webview), "context-menu",
+                      G_CALLBACK(webview_context_menu_cb), w);
+  }
+
+  gtk_widget_show_all(w->priv.window);
+
+  webkit_web_view_run_javascript(
+      WEBKIT_WEB_VIEW(w->priv.webview),
+      "window.external={invoke:function(x){"
+      "window.webkit.messageHandlers.external.postMessage(x);}}",
+      NULL, NULL, NULL);
+
+  g_signal_connect(G_OBJECT(w->priv.window), "destroy",
+                    G_CALLBACK(webview_destroy_cb), w);
+  return 0;
+}
+
+WEBVIEW_API int webview_loop(struct webview *w, int blocking)
+{
+  gtk_main_iteration_do(blocking);
+  return w->priv.should_exit;
+}
+
+WEBVIEW_API void webview_set_title(struct webview *w, const char *title)
+{
+  gtk_window_set_title(GTK_WINDOW(w->priv.window), title);
+}
+
+WEBVIEW_API void webview_set_fullscreen(struct webview *w, int fullscreen)
+{
+  if (fullscreen)
+  {
+    gtk_window_fullscreen(GTK_WINDOW(w->priv.window));
+  }
+  else
+  {
+    gtk_window_unfullscreen(GTK_WINDOW(w->priv.window));
+  }
+}
+
+WEBVIEW_API void webview_set_color(struct webview *w, uint8_t r, uint8_t g,
+                                    uint8_t b, uint8_t a)
+{
+  GdkRGBA color = {r / 255.0, g / 255.0, b / 255.0, a / 255.0};
+  webkit_web_view_set_background_color(WEBKIT_WEB_VIEW(w->priv.webview),
+                                        &color);
+}
+
+WEBVIEW_API void webview_dialog(struct webview *w,
+                                enum webview_dialog_type dlgtype, int flags,
+                                const char *title, const char *arg,
+                                char *result, size_t resultsz, char *filter)
+{
+  GtkWidget *dlg;
+  if (result != NULL)
+  {
+    result[0] = '\0';
+  }
+  if (dlgtype == WEBVIEW_DIALOG_TYPE_OPEN ||
+      dlgtype == WEBVIEW_DIALOG_TYPE_SAVE)
+  {
+    dlg = gtk_file_chooser_dialog_new(
+        title, GTK_WINDOW(w->priv.window),
+        (dlgtype == WEBVIEW_DIALOG_TYPE_OPEN
+              ? (flags & WEBVIEW_DIALOG_FLAG_DIRECTORY
+                    ? GTK_FILE_CHOOSER_ACTION_SELECT_FOLDER
+                    : GTK_FILE_CHOOSER_ACTION_OPEN)
+              : GTK_FILE_CHOOSER_ACTION_SAVE),
+        "_Cancel", GTK_RESPONSE_CANCEL,
+        (dlgtype == WEBVIEW_DIALOG_TYPE_OPEN ? "_Open" : "_Save"),
+        GTK_RESPONSE_ACCEPT, NULL);
+    if (filter[0] != '\0') {
+        GtkFileFilter *file_filter = gtk_file_filter_new();
+        gchar **filters  = g_strsplit(filter, ",", -1);
+        gint i;
+        for(i = 0; filters && filters[i]; i++) {
+            gtk_file_filter_add_pattern(file_filter, filters[i]);
+        }
+        gtk_file_filter_set_name(file_filter, filter);
+        gtk_file_chooser_add_filter(GTK_FILE_CHOOSER(dlg), file_filter);
+        g_strfreev(filters);
+    }
+    gtk_file_chooser_set_local_only(GTK_FILE_CHOOSER(dlg), FALSE);
+    gtk_file_chooser_set_select_multiple(GTK_FILE_CHOOSER(dlg), FALSE);
+    gtk_file_chooser_set_show_hidden(GTK_FILE_CHOOSER(dlg), TRUE);
+    gtk_file_chooser_set_do_overwrite_confirmation(GTK_FILE_CHOOSER(dlg), TRUE);
+    gtk_file_chooser_set_create_folders(GTK_FILE_CHOOSER(dlg), TRUE);
+    gint response = gtk_dialog_run(GTK_DIALOG(dlg));
+    if (response == GTK_RESPONSE_ACCEPT)
+    {
+      gchar *filename = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(dlg));
+      g_strlcpy(result, filename, resultsz);
+      g_free(filename);
+    }
+    gtk_widget_destroy(dlg);
+  }
+  else if (dlgtype == WEBVIEW_DIALOG_TYPE_ALERT)
+  {
+    GtkMessageType type = GTK_MESSAGE_OTHER;
+    switch (flags & WEBVIEW_DIALOG_FLAG_ALERT_MASK)
+    {
+    case WEBVIEW_DIALOG_FLAG_INFO:
+      type = GTK_MESSAGE_INFO;
+      break;
+    case WEBVIEW_DIALOG_FLAG_WARNING:
+      type = GTK_MESSAGE_WARNING;
+      break;
+    case WEBVIEW_DIALOG_FLAG_ERROR:
+      type = GTK_MESSAGE_ERROR;
+      break;
+    }
+    dlg = gtk_message_dialog_new(GTK_WINDOW(w->priv.window), GTK_DIALOG_MODAL,
+                                  type, GTK_BUTTONS_OK, "%s", title);
+    gtk_message_dialog_format_secondary_text(GTK_MESSAGE_DIALOG(dlg), "%s",
+                                              arg);
+    gtk_dialog_run(GTK_DIALOG(dlg));
+    gtk_widget_destroy(dlg);
+  }
+}
+
+static void webview_eval_finished(GObject *object, GAsyncResult *result,
+                                  gpointer userdata)
+{
+  (void)object;
+  (void)result;
+  struct webview *w = (struct webview *)userdata;
+  w->priv.js_busy = 0;
+}
+
+WEBVIEW_API int webview_eval(struct webview *w, const char *js)
+{
+  while (w->priv.ready == 0)
+  {
+    g_main_context_iteration(NULL, TRUE);
+  }
+  w->priv.js_busy = 1;
+  webkit_web_view_run_javascript(WEBKIT_WEB_VIEW(w->priv.webview), js, NULL,
+                                  webview_eval_finished, w);
+  while (w->priv.js_busy)
+  {
+    g_main_context_iteration(NULL, TRUE);
+  }
+  return 0;
+}
+
+static gboolean webview_dispatch_wrapper(gpointer userdata)
+{
+  struct webview *w = (struct webview *)userdata;
+  for (;;)
+  {
+    struct webview_dispatch_arg *arg =
+        (struct webview_dispatch_arg *)g_async_queue_try_pop(w->priv.queue);
+    if (arg == NULL)
+    {
+      break;
+    }
+    (arg->fn)(w, arg->arg);
+    g_free(arg);
+  }
+  return FALSE;
+}
+
+WEBVIEW_API void webview_dispatch(struct webview *w, webview_dispatch_fn fn,
+                                  void *arg)
+{
+  struct webview_dispatch_arg *context =
+      (struct webview_dispatch_arg *)g_new(struct webview_dispatch_arg *, 1);
+  context->w = w;
+  context->arg = arg;
+  context->fn = fn;
+  g_async_queue_lock(w->priv.queue);
+  g_async_queue_push_unlocked(w->priv.queue, context);
+  if (g_async_queue_length_unlocked(w->priv.queue) == 1)
+  {
+    gdk_threads_add_idle(webview_dispatch_wrapper, w);
+  }
+  g_async_queue_unlock(w->priv.queue);
+}
+
+WEBVIEW_API void webview_terminate(struct webview *w)
+{
+  w->priv.should_exit = 1;
+}
+
+WEBVIEW_API void webview_exit(struct webview *w) { (void)w; }
+WEBVIEW_API void webview_print_log(const char *s)
+{
+  fprintf(stderr, "%s\n", s);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* WEBVIEW_H */

lib/renderer/webview/webview_windows.go

@@ -0,0 +1,368 @@
+// Package webview implements Go bindings to https://github.com/zserge/webview C library.
+// It is a modified version of webview.go from that repository
+// Bindings closely repeat the C APIs and include both, a simplified
+// single-function API to just open a full-screen webview window, and a more
+// advanced and featureful set of APIs, including Go-to-JavaScript bindings.
+//
+// The library uses gtk-webkit, Cocoa/Webkit and MSHTML (IE8..11) as a browser
+// engine and supports Linux, MacOS and Windows 7..10 respectively.
+//
+package webview
+
+/*
+#cgo windows CFLAGS: -DWEBVIEW_WINAPI=1 -std=c99
+#cgo windows LDFLAGS: -lole32 -lcomctl32 -loleaut32 -luuid -lgdi32
+
+#include <stdlib.h>
+#include <stdint.h>
+#define WEBVIEW_STATIC
+#define WEBVIEW_IMPLEMENTATION
+
+#include "webview_windows.h"
+
+extern void _webviewExternalInvokeCallback(void *, void *);
+
+static inline void CgoWebViewFree(void *w) {
+	free((void *)((struct webview *)w)->title);
+	free((void *)((struct webview *)w)->url);
+	free(w);
+}
+
+static inline void *CgoWebViewCreate(int width, int height, char *title, char *url, int resizable, int debug) {
+	struct webview *w = (struct webview *) calloc(1, sizeof(*w));
+	w->width = width;
+	w->height = height;
+	w->title = title;
+	w->url = url;
+	w->resizable = resizable;
+	w->debug = debug;
+	w->external_invoke_cb = (webview_external_invoke_cb_t) _webviewExternalInvokeCallback;
+	if (webview_init(w) != 0) {
+		CgoWebViewFree(w);
+		return NULL;
+	}
+	return (void *)w;
+}
+
+static inline int CgoWebViewLoop(void *w, int blocking) {
+	return webview_loop((struct webview *)w, blocking);
+}
+
+static inline void CgoWebViewTerminate(void *w) {
+	webview_terminate((struct webview *)w);
+}
+
+static inline void CgoWebViewExit(void *w) {
+	webview_exit((struct webview *)w);
+}
+
+static inline void CgoWebViewSetTitle(void *w, char *title) {
+	webview_set_title((struct webview *)w, title);
+}
+
+static inline void CgoWebViewSetFullscreen(void *w, int fullscreen) {
+	webview_set_fullscreen((struct webview *)w, fullscreen);
+}
+
+static inline void CgoWebViewSetColor(void *w, uint8_t r, uint8_t g, uint8_t b, uint8_t a) {
+	webview_set_color((struct webview *)w, r, g, b, a);
+}
+
+static inline void CgoDialog(void *w, int dlgtype, int flags,
+char *title, char *arg, char *res, size_t ressz, char *filter) {
+	webview_dialog(w, dlgtype, flags,
+	(const char*)title, (const char*) arg, res, ressz, filter);
+}
+
+static inline int CgoWebViewEval(void *w, char *js) {
+	return webview_eval((struct webview *)w, js);
+}
+
+static inline void CgoWebViewInjectCSS(void *w, char *css) {
+	webview_inject_css((struct webview *)w, css);
+}
+
+extern void _webviewDispatchGoCallback(void *);
+static inline void _webview_dispatch_cb(struct webview *w, void *arg) {
+	_webviewDispatchGoCallback(arg);
+}
+static inline void CgoWebViewDispatch(void *w, uintptr_t arg) {
+	webview_dispatch((struct webview *)w, _webview_dispatch_cb, (void *)arg);
+}
+*/
+import "C"
+import (
+	"errors"
+	"runtime"
+	"sync"
+	"unsafe"
+)
+
+func init() {
+	// Ensure that main.main is called from the main thread
+	runtime.LockOSThread()
+}
+
+// Open is a simplified API to open a single native window with a full-size webview in
+// it. It can be helpful if you want to communicate with the core app using XHR
+// or WebSockets (as opposed to using JavaScript bindings).
+//
+// Window appearance can be customized using title, width, height and resizable parameters.
+// URL must be provided and can user either a http or https protocol, or be a
+// local file:// URL. On some platforms "data:" URLs are also supported
+// (Linux/MacOS).
+func Open(title, url string, w, h int, resizable bool) error {
+	titleStr := C.CString(title)
+	defer C.free(unsafe.Pointer(titleStr))
+	urlStr := C.CString(url)
+	defer C.free(unsafe.Pointer(urlStr))
+	resize := C.int(0)
+	if resizable {
+		resize = C.int(1)
+	}
+
+	r := C.webview(titleStr, urlStr, C.int(w), C.int(h), resize)
+	if r != 0 {
+		return errors.New("failed to create webview")
+	}
+	return nil
+}
+
+// ExternalInvokeCallbackFunc is a function type that is called every time
+// "window.external.invoke()" is called from JavaScript. Data is the only
+// obligatory string parameter passed into the "invoke(data)" function from
+// JavaScript. To pass more complex data serialized JSON or base64 encoded
+// string can be used.
+type ExternalInvokeCallbackFunc func(w WebView, data string)
+
+// Settings is a set of parameters to customize the initial WebView appearance
+// and behavior. It is passed into the webview.New() constructor.
+type Settings struct {
+	// WebView main window title
+	Title string
+	// URL to open in a webview
+	URL string
+	// Window width in pixels
+	Width int
+	// Window height in pixels
+	Height int
+	// Allows/disallows window resizing
+	Resizable bool
+	// Enable debugging tools (Linux/BSD/MacOS, on Windows use Firebug)
+	Debug bool
+	// A callback that is executed when JavaScript calls "window.external.invoke()"
+	ExternalInvokeCallback ExternalInvokeCallbackFunc
+}
+
+// WebView is an interface that wraps the basic methods for controlling the UI
+// loop, handling multithreading and providing JavaScript bindings.
+type WebView interface {
+	// Run() starts the main UI loop until the user closes the webview window or
+	// Terminate() is called.
+	Run()
+	// Loop() runs a single iteration of the main UI.
+	Loop(blocking bool) bool
+	// SetTitle() changes window title. This method must be called from the main
+	// thread only. See Dispatch() for more details.
+	SetTitle(title string)
+	// SetFullscreen() controls window full-screen mode. This method must be
+	// called from the main thread only. See Dispatch() for more details.
+	SetFullscreen(fullscreen bool)
+	// SetColor() changes window background color. This method must be called from
+	// the main thread only. See Dispatch() for more details.
+	SetColor(r, g, b, a uint8)
+	// Eval() evaluates an arbitrary JS code inside the webview. This method must
+	// be called from the main thread only. See Dispatch() for more details.
+	Eval(js string) error
+	// InjectJS() injects an arbitrary block of CSS code using the JS API. This
+	// method must be called from the main thread only. See Dispatch() for more
+	// details.
+	InjectCSS(css string)
+	// Dialog() opens a system dialog of the given type and title. String
+	// argument can be provided for certain dialogs, such as alert boxes. For
+	// alert boxes argument is a message inside the dialog box.
+	Dialog(dlgType DialogType, flags int, title string, arg string, filter string) string
+	// Terminate() breaks the main UI loop. This method must be called from the main thread
+	// only. See Dispatch() for more details.
+	Terminate()
+	// Dispatch() schedules some arbitrary function to be executed on the main UI
+	// thread. This may be helpful if you want to run some JavaScript from
+	// background threads/goroutines, or to terminate the app.
+	Dispatch(func())
+	// Exit() closes the window and cleans up the resources. Use Terminate() to
+	// forcefully break out of the main UI loop.
+	Exit()
+}
+
+// DialogType is an enumeration of all supported system dialog types
+type DialogType int
+
+const (
+	// DialogTypeOpen is a system file open dialog
+	DialogTypeOpen DialogType = iota
+	// DialogTypeSave is a system file save dialog
+	DialogTypeSave
+	// DialogTypeAlert is a system alert dialog (message box)
+	DialogTypeAlert
+)
+
+const (
+	// DialogFlagFile is a normal file picker dialog
+	DialogFlagFile = C.WEBVIEW_DIALOG_FLAG_FILE
+	// DialogFlagDirectory is an open directory dialog
+	DialogFlagDirectory = C.WEBVIEW_DIALOG_FLAG_DIRECTORY
+	// DialogFlagInfo is an info alert dialog
+	DialogFlagInfo = C.WEBVIEW_DIALOG_FLAG_INFO
+	// DialogFlagWarning is a warning alert dialog
+	DialogFlagWarning = C.WEBVIEW_DIALOG_FLAG_WARNING
+	// DialogFlagError is an error dialog
+	DialogFlagError = C.WEBVIEW_DIALOG_FLAG_ERROR
+)
+
+var (
+	m     sync.Mutex
+	index uintptr
+	fns   = map[uintptr]func(){}
+	cbs   = map[WebView]ExternalInvokeCallbackFunc{}
+)
+
+type webview struct {
+	w unsafe.Pointer
+}
+
+var _ WebView = &webview{}
+
+func boolToInt(b bool) int {
+	if b {
+		return 1
+	}
+	return 0
+}
+
+// NewWebview creates and opens a new webview window using the given settings. The
+// returned object implements the WebView interface. This function returns nil
+// if a window can not be created.
+func NewWebview(settings Settings) WebView {
+	if settings.Width == 0 {
+		settings.Width = 640
+	}
+	if settings.Height == 0 {
+		settings.Height = 480
+	}
+	if settings.Title == "" {
+		settings.Title = "WebView"
+	}
+	w := &webview{}
+	w.w = C.CgoWebViewCreate(C.int(settings.Width), C.int(settings.Height),
+		C.CString(settings.Title), C.CString(settings.URL),
+		C.int(boolToInt(settings.Resizable)), C.int(boolToInt(settings.Debug)))
+	m.Lock()
+	if settings.ExternalInvokeCallback != nil {
+		cbs[w] = settings.ExternalInvokeCallback
+	} else {
+		cbs[w] = func(w WebView, data string) {}
+	}
+	m.Unlock()
+	return w
+}
+
+func (w *webview) Loop(blocking bool) bool {
+	block := C.int(0)
+	if blocking {
+		block = 1
+	}
+	return C.CgoWebViewLoop(w.w, block) == 0
+}
+
+func (w *webview) Run() {
+	for w.Loop(true) {
+	}
+}
+
+func (w *webview) Exit() {
+	C.CgoWebViewExit(w.w)
+}
+
+func (w *webview) Dispatch(f func()) {
+	m.Lock()
+	for ; fns[index] != nil; index++ {
+	}
+	fns[index] = f
+	m.Unlock()
+	C.CgoWebViewDispatch(w.w, C.uintptr_t(index))
+}
+
+func (w *webview) SetTitle(title string) {
+	p := C.CString(title)
+	defer C.free(unsafe.Pointer(p))
+	C.CgoWebViewSetTitle(w.w, p)
+}
+
+func (w *webview) SetColor(r, g, b, a uint8) {
+	C.CgoWebViewSetColor(w.w, C.uint8_t(r), C.uint8_t(g), C.uint8_t(b), C.uint8_t(a))
+}
+
+func (w *webview) SetFullscreen(fullscreen bool) {
+	C.CgoWebViewSetFullscreen(w.w, C.int(boolToInt(fullscreen)))
+}
+
+func (w *webview) Dialog(dlgType DialogType, flags int, title string, arg string, filter string) string {
+	const maxPath = 4096
+	titlePtr := C.CString(title)
+	defer C.free(unsafe.Pointer(titlePtr))
+	argPtr := C.CString(arg)
+	defer C.free(unsafe.Pointer(argPtr))
+	resultPtr := (*C.char)(C.calloc((C.size_t)(unsafe.Sizeof((*C.char)(nil))), (C.size_t)(maxPath)))
+	defer C.free(unsafe.Pointer(resultPtr))
+	filterPtr := C.CString(filter)
+	defer C.free(unsafe.Pointer(filterPtr))
+	C.CgoDialog(w.w, C.int(dlgType), C.int(flags), titlePtr,
+		argPtr, resultPtr, C.size_t(maxPath), filterPtr)
+	return C.GoString(resultPtr)
+}
+
+func (w *webview) Eval(js string) error {
+	p := C.CString(js)
+	defer C.free(unsafe.Pointer(p))
+	switch C.CgoWebViewEval(w.w, p) {
+	case -1:
+		return errors.New("evaluation failed")
+	}
+	return nil
+}
+
+func (w *webview) InjectCSS(css string) {
+	p := C.CString(css)
+	defer C.free(unsafe.Pointer(p))
+	C.CgoWebViewInjectCSS(w.w, p)
+}
+
+func (w *webview) Terminate() {
+	C.CgoWebViewTerminate(w.w)
+}
+
+//export _webviewDispatchGoCallback
+func _webviewDispatchGoCallback(index unsafe.Pointer) {
+	var f func()
+	m.Lock()
+	f = fns[uintptr(index)]
+	delete(fns, uintptr(index))
+	m.Unlock()
+	f()
+}
+
+//export _webviewExternalInvokeCallback
+func _webviewExternalInvokeCallback(w unsafe.Pointer, data unsafe.Pointer) {
+	m.Lock()
+	var (
+		cb ExternalInvokeCallbackFunc
+		wv WebView
+	)
+	for wv, cb = range cbs {
+		if wv.(*webview).w == w {
+			break
+		}
+	}
+	m.Unlock()
+	cb(wv, C.GoString((*C.char)(data)))
+}

lib/renderer/webview/webview_windows.h

@@ -39,23 +39,6 @@ extern "C"
 #include <stdlib.h>
 #include <string.h>
 
-#if defined(WEBVIEW_GTK)
-#include <JavaScriptCore/JavaScript.h>
-#include <gtk/gtk.h>
-#include <webkit2/webkit2.h>
-
-  struct webview_priv
-  {
-    GtkWidget *window;
-    GtkWidget *scroller;
-    GtkWidget *webview;
-    GtkWidget *inspector_window;
-    GAsyncQueue *queue;
-    int ready;
-    int js_busy;
-    int should_exit;
-  };
-#elif defined(WEBVIEW_WINAPI)
 #define CINTERFACE
 #include <windows.h>
 
@@ -76,22 +59,6 @@ struct webview_priv
   DWORD saved_ex_style;
   RECT saved_rect;
 };
-#elif defined(WEBVIEW_COCOA)
-#import <Cocoa/Cocoa.h>
-#import <WebKit/WebKit.h>
-#import <objc/runtime.h>
-
-struct webview_priv
-{
-  NSAutoreleasePool *pool;
-  NSWindow *window;
-  WebView *webview;
-  id delegate;
-  int should_exit;
-};
-#else
-#error "Define one of: WEBVIEW_GTK, WEBVIEW_COCOA or WEBVIEW_WINAPI"
-#endif
 
   struct webview;
 
@@ -182,9 +149,6 @@ struct webview_priv
   WEBVIEW_API void webview_debug(const char *format, ...);
   WEBVIEW_API void webview_print_log(const char *s);
 
-#ifdef WEBVIEW_IMPLEMENTATION
-#undef WEBVIEW_IMPLEMENTATION
-
   WEBVIEW_API int webview(const char *title, const char *url, int width,
                           int height, int resizable)
   {
@@ -264,301 +228,6 @@ struct webview_priv
     return r;
   }
 
-#if defined(WEBVIEW_GTK)
-  static void external_message_received_cb(WebKitUserContentManager *m,
-                                           WebKitJavascriptResult *r,
-                                           gpointer arg)
-  {
-    (void)m;
-    struct webview *w = (struct webview *)arg;
-    if (w->external_invoke_cb == NULL)
-    {
-      return;
-    }
-    JSGlobalContextRef context = webkit_javascript_result_get_global_context(r);
-    JSValueRef value = webkit_javascript_result_get_value(r);
-    JSStringRef js = JSValueToStringCopy(context, value, NULL);
-    size_t n = JSStringGetMaximumUTF8CStringSize(js);
-    char *s = g_new(char, n);
-    JSStringGetUTF8CString(js, s, n);
-    w->external_invoke_cb(w, s);
-    JSStringRelease(js);
-    g_free(s);
-  }
-
-  static void webview_load_changed_cb(WebKitWebView *webview,
-                                      WebKitLoadEvent event, gpointer arg)
-  {
-    (void)webview;
-    struct webview *w = (struct webview *)arg;
-    if (event == WEBKIT_LOAD_FINISHED)
-    {
-      w->priv.ready = 1;
-    }
-  }
-
-  static void webview_destroy_cb(GtkWidget *widget, gpointer arg)
-  {
-    (void)widget;
-    struct webview *w = (struct webview *)arg;
-    webview_terminate(w);
-  }
-
-  static gboolean webview_context_menu_cb(WebKitWebView *webview,
-                                          GtkWidget *default_menu,
-                                          WebKitHitTestResult *hit_test_result,
-                                          gboolean triggered_with_keyboard,
-                                          gpointer userdata)
-  {
-    (void)webview;
-    (void)default_menu;
-    (void)hit_test_result;
-    (void)triggered_with_keyboard;
-    (void)userdata;
-    return TRUE;
-  }
-
-  WEBVIEW_API int webview_init(struct webview *w)
-  {
-    if (gtk_init_check(0, NULL) == FALSE)
-    {
-      return -1;
-    }
-
-    w->priv.ready = 0;
-    w->priv.should_exit = 0;
-    w->priv.queue = g_async_queue_new();
-    w->priv.window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
-    gtk_window_set_title(GTK_WINDOW(w->priv.window), w->title);
-
-    if (w->resizable)
-    {
-      gtk_window_set_default_size(GTK_WINDOW(w->priv.window), w->width,
-                                  w->height);
-    }
-    else
-    {
-      gtk_widget_set_size_request(w->priv.window, w->width, w->height);
-    }
-    gtk_window_set_resizable(GTK_WINDOW(w->priv.window), !!w->resizable);
-    gtk_window_set_position(GTK_WINDOW(w->priv.window), GTK_WIN_POS_CENTER);
-
-    w->priv.scroller = gtk_scrolled_window_new(NULL, NULL);
-    gtk_container_add(GTK_CONTAINER(w->priv.window), w->priv.scroller);
-
-    WebKitUserContentManager *m = webkit_user_content_manager_new();
-    webkit_user_content_manager_register_script_message_handler(m, "external");
-    g_signal_connect(m, "script-message-received::external",
-                     G_CALLBACK(external_message_received_cb), w);
-
-    w->priv.webview = webkit_web_view_new_with_user_content_manager(m);
-    webkit_web_view_load_uri(WEBKIT_WEB_VIEW(w->priv.webview),
-                             webview_check_url(w->url));
-    g_signal_connect(G_OBJECT(w->priv.webview), "load-changed",
-                     G_CALLBACK(webview_load_changed_cb), w);
-    gtk_container_add(GTK_CONTAINER(w->priv.scroller), w->priv.webview);
-
-    if (w->debug)
-    {
-      WebKitSettings *settings =
-          webkit_web_view_get_settings(WEBKIT_WEB_VIEW(w->priv.webview));
-      webkit_settings_set_enable_write_console_messages_to_stdout(settings, true);
-      webkit_settings_set_enable_developer_extras(settings, true);
-    }
-    else
-    {
-      g_signal_connect(G_OBJECT(w->priv.webview), "context-menu",
-                       G_CALLBACK(webview_context_menu_cb), w);
-    }
-
-    gtk_widget_show_all(w->priv.window);
-
-    webkit_web_view_run_javascript(
-        WEBKIT_WEB_VIEW(w->priv.webview),
-        "window.external={invoke:function(x){"
-        "window.webkit.messageHandlers.external.postMessage(x);}}",
-        NULL, NULL, NULL);
-
-    g_signal_connect(G_OBJECT(w->priv.window), "destroy",
-                     G_CALLBACK(webview_destroy_cb), w);
-    return 0;
-  }
-
-  WEBVIEW_API int webview_loop(struct webview *w, int blocking)
-  {
-    gtk_main_iteration_do(blocking);
-    return w->priv.should_exit;
-  }
-
-  WEBVIEW_API void webview_set_title(struct webview *w, const char *title)
-  {
-    gtk_window_set_title(GTK_WINDOW(w->priv.window), title);
-  }
-
-  WEBVIEW_API void webview_set_fullscreen(struct webview *w, int fullscreen)
-  {
-    if (fullscreen)
-    {
-      gtk_window_fullscreen(GTK_WINDOW(w->priv.window));
-    }
-    else
-    {
-      gtk_window_unfullscreen(GTK_WINDOW(w->priv.window));
-    }
-  }
-
-  WEBVIEW_API void webview_set_color(struct webview *w, uint8_t r, uint8_t g,
-                                     uint8_t b, uint8_t a)
-  {
-    GdkRGBA color = {r / 255.0, g / 255.0, b / 255.0, a / 255.0};
-    webkit_web_view_set_background_color(WEBKIT_WEB_VIEW(w->priv.webview),
-                                         &color);
-  }
-
-  WEBVIEW_API void webview_dialog(struct webview *w,
-                                  enum webview_dialog_type dlgtype, int flags,
-                                  const char *title, const char *arg,
-                                  char *result, size_t resultsz, char *filter)
-  {
-    GtkWidget *dlg;
-    if (result != NULL)
-    {
-      result[0] = '\0';
-    }
-    if (dlgtype == WEBVIEW_DIALOG_TYPE_OPEN ||
-        dlgtype == WEBVIEW_DIALOG_TYPE_SAVE)
-    {
-      dlg = gtk_file_chooser_dialog_new(
-          title, GTK_WINDOW(w->priv.window),
-          (dlgtype == WEBVIEW_DIALOG_TYPE_OPEN
-               ? (flags & WEBVIEW_DIALOG_FLAG_DIRECTORY
-                      ? GTK_FILE_CHOOSER_ACTION_SELECT_FOLDER
-                      : GTK_FILE_CHOOSER_ACTION_OPEN)
-               : GTK_FILE_CHOOSER_ACTION_SAVE),
-          "_Cancel", GTK_RESPONSE_CANCEL,
-          (dlgtype == WEBVIEW_DIALOG_TYPE_OPEN ? "_Open" : "_Save"),
-          GTK_RESPONSE_ACCEPT, NULL);
-      if (filter[0] != '\0') {
-          GtkFileFilter *file_filter = gtk_file_filter_new();
-          gchar **filters  = g_strsplit(filter, ",", -1);
-          gint i;
-          for(i = 0; filters && filters[i]; i++) {
-              gtk_file_filter_add_pattern(file_filter, filters[i]);
-          }
-          gtk_file_filter_set_name(file_filter, filter);
-          gtk_file_chooser_add_filter(GTK_FILE_CHOOSER(dlg), file_filter);
-          g_strfreev(filters);
-      }
-      gtk_file_chooser_set_local_only(GTK_FILE_CHOOSER(dlg), FALSE);
-      gtk_file_chooser_set_select_multiple(GTK_FILE_CHOOSER(dlg), FALSE);
-      gtk_file_chooser_set_show_hidden(GTK_FILE_CHOOSER(dlg), TRUE);
-      gtk_file_chooser_set_do_overwrite_confirmation(GTK_FILE_CHOOSER(dlg), TRUE);
-      gtk_file_chooser_set_create_folders(GTK_FILE_CHOOSER(dlg), TRUE);
-      gint response = gtk_dialog_run(GTK_DIALOG(dlg));
-      if (response == GTK_RESPONSE_ACCEPT)
-      {
-        gchar *filename = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(dlg));
-        g_strlcpy(result, filename, resultsz);
-        g_free(filename);
-      }
-      gtk_widget_destroy(dlg);
-    }
-    else if (dlgtype == WEBVIEW_DIALOG_TYPE_ALERT)
-    {
-      GtkMessageType type = GTK_MESSAGE_OTHER;
-      switch (flags & WEBVIEW_DIALOG_FLAG_ALERT_MASK)
-      {
-      case WEBVIEW_DIALOG_FLAG_INFO:
-        type = GTK_MESSAGE_INFO;
-        break;
-      case WEBVIEW_DIALOG_FLAG_WARNING:
-        type = GTK_MESSAGE_WARNING;
-        break;
-      case WEBVIEW_DIALOG_FLAG_ERROR:
-        type = GTK_MESSAGE_ERROR;
-        break;
-      }
-      dlg = gtk_message_dialog_new(GTK_WINDOW(w->priv.window), GTK_DIALOG_MODAL,
-                                   type, GTK_BUTTONS_OK, "%s", title);
-      gtk_message_dialog_format_secondary_text(GTK_MESSAGE_DIALOG(dlg), "%s",
-                                               arg);
-      gtk_dialog_run(GTK_DIALOG(dlg));
-      gtk_widget_destroy(dlg);
-    }
-  }
-
-  static void webview_eval_finished(GObject *object, GAsyncResult *result,
-                                    gpointer userdata)
-  {
-    (void)object;
-    (void)result;
-    struct webview *w = (struct webview *)userdata;
-    w->priv.js_busy = 0;
-  }
-
-  WEBVIEW_API int webview_eval(struct webview *w, const char *js)
-  {
-    while (w->priv.ready == 0)
-    {
-      g_main_context_iteration(NULL, TRUE);
-    }
-    w->priv.js_busy = 1;
-    webkit_web_view_run_javascript(WEBKIT_WEB_VIEW(w->priv.webview), js, NULL,
-                                   webview_eval_finished, w);
-    while (w->priv.js_busy)
-    {
-      g_main_context_iteration(NULL, TRUE);
-    }
-    return 0;
-  }
-
-  static gboolean webview_dispatch_wrapper(gpointer userdata)
-  {
-    struct webview *w = (struct webview *)userdata;
-    for (;;)
-    {
-      struct webview_dispatch_arg *arg =
-          (struct webview_dispatch_arg *)g_async_queue_try_pop(w->priv.queue);
-      if (arg == NULL)
-      {
-        break;
-      }
-      (arg->fn)(w, arg->arg);
-      g_free(arg);
-    }
-    return FALSE;
-  }
-
-  WEBVIEW_API void webview_dispatch(struct webview *w, webview_dispatch_fn fn,
-                                    void *arg)
-  {
-    struct webview_dispatch_arg *context =
-        (struct webview_dispatch_arg *)g_new(struct webview_dispatch_arg *, 1);
-    context->w = w;
-    context->arg = arg;
-    context->fn = fn;
-    g_async_queue_lock(w->priv.queue);
-    g_async_queue_push_unlocked(w->priv.queue, context);
-    if (g_async_queue_length_unlocked(w->priv.queue) == 1)
-    {
-      gdk_threads_add_idle(webview_dispatch_wrapper, w);
-    }
-    g_async_queue_unlock(w->priv.queue);
-  }
-
-  WEBVIEW_API void webview_terminate(struct webview *w)
-  {
-    w->priv.should_exit = 1;
-  }
-
-  WEBVIEW_API void webview_exit(struct webview *w) { (void)w; }
-  WEBVIEW_API void webview_print_log(const char *s)
-  {
-    fprintf(stderr, "%s\n", s);
-  }
-
-#endif /* WEBVIEW_GTK */
-
 #if defined(WEBVIEW_WINAPI)
 
 #pragma comment(lib, "user32.lib")
@@ -1930,433 +1599,6 @@ struct webview_priv
   WEBVIEW_API void webview_exit(struct webview *w) { OleUninitialize(); }
   WEBVIEW_API void webview_print_log(const char *s) { OutputDebugString(s); }
 
-#endif /* WEBVIEW_WINAPI */
-
-#if defined(WEBVIEW_COCOA)
-#if (!defined MAC_OS_X_VERSION_10_12) || \
-    MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_12
-#define NSAlertStyleWarning NSWarningAlertStyle
-#define NSAlertStyleCritical NSCriticalAlertStyle
-#define NSWindowStyleMaskResizable NSResizableWindowMask
-#define NSWindowStyleMaskMiniaturizable NSMiniaturizableWindowMask
-#define NSWindowStyleMaskTitled NSTitledWindowMask
-#define NSWindowStyleMaskClosable NSClosableWindowMask
-#define NSWindowStyleMaskFullScreen NSFullScreenWindowMask
-#define NSEventMaskAny NSAnyEventMask
-#define NSEventModifierFlagCommand NSCommandKeyMask
-#define NSEventModifierFlagOption NSAlternateKeyMask
-#define NSAlertStyleInformational NSInformationalAlertStyle
-#endif /* MAC_OS_X_VERSION_10_12 */
-#if (!defined MAC_OS_X_VERSION_10_13) || \
-    MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_13
-#define NSModalResponseOK NSFileHandlingPanelOKButton
-#endif /* MAC_OS_X_VERSION_10_12, MAC_OS_X_VERSION_10_13 */
-  static void webview_window_will_close(id self, SEL cmd, id notification)
-  {
-    struct webview *w =
-        (struct webview *)objc_getAssociatedObject(self, "webview");
-    webview_terminate(w);
-  }
-
-  static BOOL webview_is_selector_excluded_from_web_script(id self, SEL cmd,
-                                                           SEL selector)
-  {
-    return selector != @selector(invoke:);
-  }
-
-  static NSString *webview_webscript_name_for_selector(id self, SEL cmd,
-                                                       SEL selector)
-  {
-    return selector == @selector(invoke:) ? @"invoke" : nil;
-  }
-
-  static void webview_did_clear_window_object(id self, SEL cmd, id webview,
-                                              id script, id frame)
-  {
-    [script setValue:self forKey:@"external"];
-  }
-
-  static void webview_run_input_open_panel(id self, SEL cmd, id webview,
-                                           id listener, BOOL allowMultiple)
-  {
-    char filename[256] = "";
-    struct webview *w =
-        (struct webview *)objc_getAssociatedObject(self, "webview");
-
-    webview_dialog(w, WEBVIEW_DIALOG_TYPE_OPEN, WEBVIEW_DIALOG_FLAG_FILE, "", "",
-                   filename, 255, "");
-    filename[255] = '\0';
-    if (strlen(filename) > 0)
-    {
-      [listener chooseFilename:[NSString stringWithUTF8String:filename]];
-    }
-    else
-    {
-      [listener cancel];
-    }
-  }
-
-  static void webview_external_invoke(id self, SEL cmd, id arg)
-  {
-    struct webview *w =
-        (struct webview *)objc_getAssociatedObject(self, "webview");
-    if (w == NULL || w->external_invoke_cb == NULL)
-    {
-      return;
-    }
-    if ([arg isKindOfClass:[NSString class]] == NO)
-    {
-      return;
-    }
-    w->external_invoke_cb(w, [(NSString *)(arg) UTF8String]);
-  }
-
-  WEBVIEW_API int webview_init(struct webview *w)
-  {
-    w->priv.pool = [[NSAutoreleasePool alloc] init];
-    [NSApplication sharedApplication];
-
-    Class webViewDelegateClass =
-        objc_allocateClassPair([NSObject class], "WebViewDelegate", 0);
-    class_addMethod(webViewDelegateClass, sel_registerName("windowWillClose:"),
-                    (IMP)webview_window_will_close, "v@:@");
-    class_addMethod(object_getClass(webViewDelegateClass),
-                    sel_registerName("isSelectorExcludedFromWebScript:"),
-                    (IMP)webview_is_selector_excluded_from_web_script, "c@::");
-    class_addMethod(object_getClass(webViewDelegateClass),
-                    sel_registerName("webScriptNameForSelector:"),
-                    (IMP)webview_webscript_name_for_selector, "c@::");
-    class_addMethod(webViewDelegateClass,
-                    sel_registerName("webView:didClearWindowObject:forFrame:"),
-                    (IMP)webview_did_clear_window_object, "v@:@@@");
-    class_addMethod(
-        webViewDelegateClass,
-        sel_registerName("webView:runOpenPanelForFileButtonWithResultListener:"
-                         "allowMultipleFiles:"),
-        (IMP)webview_run_input_open_panel, "v@:@@c");
-    class_addMethod(webViewDelegateClass, sel_registerName("invoke:"),
-                    (IMP)webview_external_invoke, "v@:@");
-    objc_registerClassPair(webViewDelegateClass);
-
-    w->priv.delegate = [[webViewDelegateClass alloc] init];
-    objc_setAssociatedObject(w->priv.delegate, "webview", (id)(w),
-                             OBJC_ASSOCIATION_ASSIGN);
-
-    NSRect r = NSMakeRect(0, 0, w->width, w->height);
-    NSUInteger style = NSWindowStyleMaskTitled | NSWindowStyleMaskClosable |
-                       NSWindowStyleMaskMiniaturizable;
-    if (w->resizable)
-    {
-      style = style | NSWindowStyleMaskResizable;
-      // style = style | NSTexturedBackgroundWindowMask;
-      // style = style | NSUnifiedTitleAndToolbarWindowMask;
-    }
-
-    // Transparent title bar
-    // if (w->transparentTitlebar) {
-    //   style = style | NSFullSizeContentViewWindowMask | NSUnifiedTitleAndToolbarWindowMask | NSTexturedBackgroundWindowMask;
-    // }
-
-    w->priv.window = [[NSWindow alloc] initWithContentRect:r
-                                                 styleMask:style
-                                                   backing:NSBackingStoreBuffered
-                                                     defer:NO];
-    [w->priv.window autorelease];
-
-    // Title
-    NSString *nsTitle = [NSString stringWithUTF8String:w->title];
-    [w->priv.window setTitle:nsTitle];
-
-    [w->priv.window setDelegate:w->priv.delegate];
-    [w->priv.window center];
-
-    //  NSToolbar *toolbar = [[NSToolbar alloc] initWithIdentifier:@"wat"];
-    //   toolbar.showsBaselineSeparator = NO;
-    //   [w->priv.window setToolbar:toolbar];
-
-    // if (w->transparentTitlebar) {
-
-    //   // Configure window look with hidden toolbar
-    //   [w->priv.window setTitlebarAppearsTransparent:YES];
-    //   [w->priv.window setTitleVisibility:NSWindowTitleHidden];
-    //   // w->priv.window.isMovableByWindowBackground = true;
-    // }
-
-    [[NSUserDefaults standardUserDefaults] setBool:!!w->debug
-                                            forKey:@"WebKitDeveloperExtras"];
-    [[NSUserDefaults standardUserDefaults] synchronize];
-    w->priv.webview =
-        [[WebView alloc] initWithFrame:r
-                             frameName:@"WebView"
-                             groupName:nil];
-    NSURL *nsURL = [NSURL
-        URLWithString:[NSString stringWithUTF8String:webview_check_url(w->url)]];
-    [[w->priv.webview mainFrame] loadRequest:[NSURLRequest requestWithURL:nsURL]];
-
-    [w->priv.webview setAutoresizesSubviews:YES];
-    [w->priv.webview
-        setAutoresizingMask:NSViewWidthSizable | NSViewHeightSizable];
-    w->priv.webview.frameLoadDelegate = w->priv.delegate;
-    w->priv.webview.UIDelegate = w->priv.delegate;
-    [[w->priv.window contentView] addSubview:w->priv.webview];
-    [w->priv.window orderFrontRegardless];
-
-    // Disable scrolling - make this configurable
-    // [[[w->priv.webview mainFrame] frameView] setAllowsScrolling:NO];
-
-    // ----> Enables WebGL but won't pass the app store guidelines
-    //
-    // WebPreferences *p = [w->priv.webview preferences];
-    // if ([p respondsToSelector:@selector(setWebGLEnabled:)]) {
-    //     [p setWebGLEnabled:YES];
-    // }
-
-    [NSApp setActivationPolicy:NSApplicationActivationPolicyRegular];
-    [NSApp finishLaunching];
-    [NSApp activateIgnoringOtherApps:YES];
-
-    NSMenu *menubar = [[[NSMenu alloc] initWithTitle:@""] autorelease];
-
-    NSMenuItem *appMenuItem =
-        [[[NSMenuItem alloc] initWithTitle:@"wails app" action:NULL keyEquivalent:@""]
-            autorelease];
-    NSMenu *appMenu = [[[NSMenu alloc] initWithTitle:@"wails app"] autorelease];
-    [appMenuItem setSubmenu:appMenu];
-    [menubar addItem:appMenuItem];
-
-    NSMenuItem *item = [[[NSMenuItem alloc] initWithTitle:@"Hide"
-                                                   action:@selector(hide:)
-                                            keyEquivalent:@"h"] autorelease];
-    [appMenu addItem:item];
-    item = [[[NSMenuItem alloc] initWithTitle:@"Hide Others"
-                                       action:@selector(hideOtherApplications:)
-                                keyEquivalent:@"h"] autorelease];
-    [item setKeyEquivalentModifierMask:(NSEventModifierFlagOption |
-                                        NSEventModifierFlagCommand)];
-    [appMenu addItem:item];
-    item = [[[NSMenuItem alloc] initWithTitle:@"Show All"
-                                       action:@selector(unhideAllApplications:)
-                                keyEquivalent:@""] autorelease];
-    [appMenu addItem:item];
-    [appMenu addItem:[NSMenuItem separatorItem]];
-
-    NSMenuItem *editMenuItem =
-        [[[NSMenuItem alloc] initWithTitle:@"Edit" action:NULL keyEquivalent:@""]
-            autorelease];
-    NSMenu *editMenu = [[[NSMenu alloc] initWithTitle:@"Edit"] autorelease];
-    [editMenuItem setSubmenu:editMenu];
-    [menubar addItem:editMenuItem];
-
-    item = [[[NSMenuItem alloc] initWithTitle:@"Cut"
-                                       action:@selector(cut:)
-                                keyEquivalent:@"x"] autorelease];
-    [editMenu addItem:item];
-
-    item = [[[NSMenuItem alloc] initWithTitle:@"Copy"
-                                       action:@selector(copy:)
-                                keyEquivalent:@"c"] autorelease];
-    [editMenu addItem:item];
-
-    item = [[[NSMenuItem alloc] initWithTitle:@"Paste"
-                                       action:@selector(paste:)
-                                keyEquivalent:@"v"] autorelease];
-    [editMenu addItem:item];
-
-    item = [[[NSMenuItem alloc] initWithTitle:@"Select All"
-                                       action:@selector(selectAll:)
-                                keyEquivalent:@"a"] autorelease];
-    [editMenu addItem:item];
-
-    [appMenu addItem:[NSMenuItem separatorItem]];
-
-    item = [[[NSMenuItem alloc] initWithTitle:@"Quit"
-                                       action:@selector(terminate:)
-                                keyEquivalent:@"q"] autorelease];
-    [appMenu addItem:item];
-
-    [NSApp setMainMenu:menubar];
-
-    w->priv.should_exit = 0;
-    return 0;
-  }
-
-  WEBVIEW_API int webview_loop(struct webview *w, int blocking)
-  {
-    NSDate *until = (blocking ? [NSDate distantFuture] : [NSDate distantPast]);
-    NSEvent *event = [NSApp nextEventMatchingMask:NSEventMaskAny
-                                        untilDate:until
-                                           inMode:NSDefaultRunLoopMode
-                                          dequeue:YES];
-    if (event)
-    {
-      [NSApp sendEvent:event];
-    }
-    return w->priv.should_exit;
-  }
-
-  WEBVIEW_API int webview_eval(struct webview *w, const char *js)
-  {
-    NSString *nsJS = [NSString stringWithUTF8String:js];
-    [[w->priv.webview windowScriptObject] evaluateWebScript:nsJS];
-    return 0;
-  }
-
-  WEBVIEW_API void webview_set_title(struct webview *w, const char *title)
-  {
-    NSString *nsTitle = [NSString stringWithUTF8String:title];
-    [w->priv.window setTitle:nsTitle];
-  }
-
-  WEBVIEW_API void webview_set_fullscreen(struct webview *w, int fullscreen)
-  {
-    int b = ((([w->priv.window styleMask] & NSWindowStyleMaskFullScreen) ==
-              NSWindowStyleMaskFullScreen)
-                 ? 1
-                 : 0);
-    if (b != fullscreen)
-    {
-      [w->priv.window toggleFullScreen:nil];
-    }
-  }
-
-  WEBVIEW_API void webview_set_color(struct webview *w, uint8_t r, uint8_t g,
-                                     uint8_t b, uint8_t a)
-  {
-    [w->priv.window setBackgroundColor:[NSColor colorWithRed:(CGFloat)r / 255.0
-                                                       green:(CGFloat)g / 255.0
-                                                        blue:(CGFloat)b / 255.0
-                                                       alpha:(CGFloat)a / 255.0]];
-    if (0.5 >= ((r / 255.0 * 299.0) + (g / 255.0 * 587.0) + (b / 255.0 * 114.0)) /
-                   1000.0)
-    {
-      [w->priv.window
-          setAppearance:[NSAppearance
-                            appearanceNamed:NSAppearanceNameVibrantDark]];
-    }
-    else
-    {
-      [w->priv.window
-          setAppearance:[NSAppearance
-                            appearanceNamed:NSAppearanceNameVibrantLight]];
-    }
-    [w->priv.window setOpaque:NO];
-    [w->priv.window setTitlebarAppearsTransparent:YES];
-    [w->priv.webview setDrawsBackground:NO];
-  }
-
-  WEBVIEW_API void webview_dialog(struct webview *w,
-                                  enum webview_dialog_type dlgtype, int flags,
-                                  const char *title, const char *arg,
-                                  char *result, size_t resultsz, char *filter)
-  {
-    if (dlgtype == WEBVIEW_DIALOG_TYPE_OPEN ||
-        dlgtype == WEBVIEW_DIALOG_TYPE_SAVE)
-    {
-      NSSavePanel *panel;
-      NSString *filter_str = [NSString stringWithUTF8String:filter];
-      filter_str = [filter_str stringByReplacingOccurrencesOfString:@"*."
-                                     withString:@""];
-      NSArray *fileTypes = [filter_str componentsSeparatedByString:@","];
-      if (dlgtype == WEBVIEW_DIALOG_TYPE_OPEN)
-      {
-        NSOpenPanel *openPanel = [NSOpenPanel openPanel];
-        if (flags & WEBVIEW_DIALOG_FLAG_DIRECTORY)
-        {
-          [openPanel setCanChooseFiles:NO];
-          [openPanel setCanChooseDirectories:YES];
-        }
-        else
-        {
-          [openPanel setCanChooseFiles:YES];
-          [openPanel setCanChooseDirectories:NO];
-          if(filter[0] != NULL)
-          {
-            [openPanel setAllowedFileTypes:fileTypes];
-          }
-        }
-        [openPanel setResolvesAliases:NO];
-        [openPanel setAllowsMultipleSelection:NO];
-        panel = openPanel;
-      }
-      else
-      {
-        panel = [NSSavePanel savePanel];
-      }
-      [panel setCanCreateDirectories:YES];
-      [panel setShowsHiddenFiles:YES];
-      [panel setExtensionHidden:NO];
-      [panel setCanSelectHiddenExtension:NO];
-      if(filter[0] != NULL)
-      {
-        [panel setAllowedFileTypes:fileTypes];
-      }
-      [panel setTreatsFilePackagesAsDirectories:YES];
-      [panel beginSheetModalForWindow:w->priv.window
-                    completionHandler:^(NSInteger result) {
-                      [NSApp stopModalWithCode:result];
-                    }];
-      if ([NSApp runModalForWindow:panel] == NSModalResponseOK)
-      {
-        const char *filename = [[[panel URL] path] UTF8String];
-        strlcpy(result, filename, resultsz);
-      }
-    }
-    else if (dlgtype == WEBVIEW_DIALOG_TYPE_ALERT)
-    {
-      NSAlert *a = [NSAlert new];
-      switch (flags & WEBVIEW_DIALOG_FLAG_ALERT_MASK)
-      {
-      case WEBVIEW_DIALOG_FLAG_INFO:
-        [a setAlertStyle:NSAlertStyleInformational];
-        break;
-      case WEBVIEW_DIALOG_FLAG_WARNING:
-        NSLog(@"warning");
-        [a setAlertStyle:NSAlertStyleWarning];
-        break;
-      case WEBVIEW_DIALOG_FLAG_ERROR:
-        NSLog(@"error");
-        [a setAlertStyle:NSAlertStyleCritical];
-        break;
-      }
-      [a setShowsHelp:NO];
-      [a setShowsSuppressionButton:NO];
-      [a setMessageText:[NSString stringWithUTF8String:title]];
-      [a setInformativeText:[NSString stringWithUTF8String:arg]];
-      [a addButtonWithTitle:@"OK"];
-      [a runModal];
-      [a release];
-    }
-  }
-
-  static void webview_dispatch_cb(void *arg)
-  {
-    struct webview_dispatch_arg *context = (struct webview_dispatch_arg *)arg;
-    (context->fn)(context->w, context->arg);
-    free(context);
-  }
-
-  WEBVIEW_API void webview_dispatch(struct webview *w, webview_dispatch_fn fn,
-                                    void *arg)
-  {
-    struct webview_dispatch_arg *context = (struct webview_dispatch_arg *)malloc(
-        sizeof(struct webview_dispatch_arg));
-    context->w = w;
-    context->arg = arg;
-    context->fn = fn;
-    dispatch_async_f(dispatch_get_main_queue(), context, webview_dispatch_cb);
-  }
-
-  WEBVIEW_API void webview_terminate(struct webview *w)
-  {
-    w->priv.should_exit = 1;
-  }
-  WEBVIEW_API void webview_exit(struct webview *w) { [NSApp terminate:NSApp]; }
-  WEBVIEW_API void webview_print_log(const char *s) { NSLog(@"%s", s); }
-
-#endif /* WEBVIEW_COCOA */
-
-#endif /* WEBVIEW_IMPLEMENTATION */
-
 #ifdef __cplusplus
 }
 #endif