Merge branch 'v3-alpha_linux' into v3-alpha

# Conflicts:
#	v3/STATUS.md
#	v3/examples/menu/main.go
#	v3/go.mod
#	v3/pkg/application/application.go
#	v3/pkg/application/webview_window.go

v2/pkg/assetserver/webview/request_linux_purego.go

@@ -0,0 +1,96 @@
+//go:build linux && purego
+// +build linux,purego
+
+package webview
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/ebitengine/purego"
+)
+
+// NewRequest creates as new WebViewRequest based on a pointer to an `WebKitURISchemeRequest`
+//
+// Please make sure to call Release() when finished using the request.
+func NewRequest(webKitURISchemeRequest uintptr) Request {
+	webkitReq := webKitURISchemeRequest
+	req := &request{req: webkitReq}
+	req.AddRef()
+	return req
+}
+
+var _ Request = &request{}
+
+type request struct {
+	req uintptr
+
+	header http.Header
+	body   io.ReadCloser
+	rw     *responseWriter
+}
+
+func (r *request) AddRef() error {
+	var objectRef func(uintptr)
+	purego.RegisterLibFunc(&objectRef, gtk, "g_object_ref")
+	objectRef(r.req)
+	return nil
+}
+
+func (r *request) Release() error {
+	var objectUnref func(uintptr)
+	purego.RegisterLibFunc(&objectUnref, gtk, "g_object_unref")
+	objectUnref(r.req)
+	return nil
+}
+
+func (r *request) URL() (string, error) {
+	var getUri func(uintptr) string
+	purego.RegisterLibFunc(&getUri, webkit, "webkit_uri_scheme_request_get_uri")
+	return getUri(r.req), nil
+}
+
+func (r *request) Method() (string, error) {
+	return webkit_uri_scheme_request_get_http_method(r.req), nil
+}
+
+func (r *request) Header() (http.Header, error) {
+	if r.header != nil {
+		return r.header, nil
+	}
+
+	r.header = webkit_uri_scheme_request_get_http_headers(r.req)
+	return r.header, nil
+}
+
+func (r *request) Body() (io.ReadCloser, error) {
+	if r.body != nil {
+		return r.body, nil
+	}
+
+	// WebKit2GTK has currently no support for request bodies.
+	r.body = http.NoBody
+
+	return r.body, nil
+}
+
+func (r *request) Response() ResponseWriter {
+	fmt.Println("r.Response()")
+	if r.rw != nil {
+		return r.rw
+	}
+
+	r.rw = &responseWriter{req: r.req}
+	return r.rw
+}
+
+func (r *request) Close() error {
+	var err error
+	if r.body != nil {
+		err = r.body.Close()
+	}
+	r.Response().Finish()
+	r.Release()
+	return err
+}

v2/pkg/assetserver/webview/responsewriter_linux_purego.go

@@ -0,0 +1,175 @@
+//go:build linux && purego
+// +build linux,purego
+
+package webview
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"strconv"
+	"syscall"
+
+	"github.com/ebitengine/purego"
+)
+
+const (
+	gtk3 = "libgtk-3.so"
+	gtk4 = "libgtk-4.so"
+)
+
+var (
+	gtk     uintptr
+	webkit  uintptr
+	version int
+)
+
+func init() {
+	var err error
+	// gtk, err = purego.Dlopen(gtk4, purego.RTLD_NOW|purego.RTLD_GLOBAL)
+	// if err == nil {
+	// 	version = 4
+	// 	return
+	// }
+	//	log.Println("Failed to open GTK4: Falling back to GTK3")
+	gtk, err = purego.Dlopen(gtk3, purego.RTLD_NOW|purego.RTLD_GLOBAL)
+	if err != nil {
+		panic(err)
+	}
+	version = 3
+
+	var webkit4 string = "libwebkit2gtk-4.1.so"
+	webkit, err = purego.Dlopen(webkit4, purego.RTLD_NOW|purego.RTLD_GLOBAL)
+	if err != nil {
+		panic(err)
+	}
+}
+
+type responseWriter struct {
+	req uintptr
+
+	header      http.Header
+	wroteHeader bool
+	finished    bool
+
+	w    io.WriteCloser
+	wErr error
+}
+
+func (rw *responseWriter) Header() http.Header {
+	if rw.header == nil {
+		rw.header = http.Header{}
+	}
+	return rw.header
+}
+
+func (rw *responseWriter) Write(buf []byte) (int, error) {
+	if rw.finished {
+		return 0, errResponseFinished
+	}
+
+	rw.WriteHeader(http.StatusOK)
+	if rw.wErr != nil {
+		return 0, rw.wErr
+	}
+	return rw.w.Write(buf)
+}
+
+func (rw *responseWriter) WriteHeader(code int) {
+	// TODO? Is this ever called? I don't think so!
+	if rw.wroteHeader || rw.finished {
+		return
+	}
+	rw.wroteHeader = true
+
+	contentLength := int64(-1)
+	if sLen := rw.Header().Get(HeaderContentLength); sLen != "" {
+		if pLen, _ := strconv.ParseInt(sLen, 10, 64); pLen > 0 {
+			contentLength = pLen
+		}
+	}
+	fmt.Println("content_length", contentLength)
+	// We can't use os.Pipe here, because that returns files with a finalizer for closing the FD. But the control over the
+	// read FD is given to the InputStream and will be closed there.
+	// Furthermore we especially don't want to have the FD_CLOEXEC
+	rFD, w, err := pipe()
+	if err != nil {
+		rw.finishWithError(http.StatusInternalServerError, fmt.Errorf("unable to open pipe: %s", err))
+		return
+	}
+	rw.w = w
+
+	var newStream func(int, bool) uintptr
+	purego.RegisterLibFunc(&newStream, gtk, "g_unix_input_stream_new")
+	var unRef func(uintptr)
+	purego.RegisterLibFunc(&unRef, gtk, "g_object_unref")
+	stream := newStream(rFD, true)
+
+	/*	var reqFinish func(uintptr, uintptr, uintptr, uintptr, int64) int
+		purego.RegisterLibFunc(&reqFinish, webkit, "webkit_uri_scheme_request_finish")
+
+		header := rw.Header()
+			defer unRef(stream)
+		if err := reqFinish(rw.req, code, header, stream, contentLength); err != nil {
+			rw.finishWithError(http.StatusInternalServerError, fmt.Errorf("unable to finish request: %s", err))
+		}
+	*/
+	if err := webkit_uri_scheme_request_finish(rw.req, code, rw.Header(), stream, contentLength); err != nil {
+		rw.finishWithError(http.StatusInternalServerError, fmt.Errorf("unable to finish request: %s", err))
+		return
+	}
+}
+
+func (rw *responseWriter) Finish() {
+	if !rw.wroteHeader {
+		rw.WriteHeader(http.StatusNotImplemented)
+	}
+
+	if rw.finished {
+		return
+	}
+	rw.finished = true
+	if rw.w != nil {
+		rw.w.Close()
+	}
+}
+
+func (rw *responseWriter) finishWithError(code int, err error) {
+	if rw.w != nil {
+		rw.w.Close()
+		rw.w = &nopCloser{io.Discard}
+	}
+	rw.wErr = err
+
+	var newLiteral func(uint32, string, int, string) uintptr // is this correct?
+	purego.RegisterLibFunc(&newLiteral, gtk, "g_error_new_literal")
+	var newQuark func(string) uintptr
+	purego.RegisterLibFunc(&newQuark, gtk, "g_quark_from_string")
+	var freeError func(uintptr)
+	purego.RegisterLibFunc(&freeError, gtk, "g_error_free")
+	var finishError func(uintptr, uintptr)
+	purego.RegisterLibFunc(&finishError, webkit, "webkit_uri_scheme_request_finish_error")
+
+	msg := string(err.Error())
+	//gquark := newQuark(msg)
+	gerr := newLiteral(1, msg, code, msg)
+	finishError(rw.req, gerr)
+	freeError(gerr)
+}
+
+type nopCloser struct {
+	io.Writer
+}
+
+func (nopCloser) Close() error { return nil }
+
+func pipe() (r int, w *os.File, err error) {
+	var p [2]int
+	e := syscall.Pipe2(p[0:], 0)
+	if e != nil {
+		return 0, nil, fmt.Errorf("pipe2: %s", e)
+	}
+
+	return p[0], os.NewFile(uintptr(p[1]), "|1"), nil
+}

v2/pkg/assetserver/webview/webkit2_36+_purego.go

@@ -0,0 +1,94 @@
+//go:build linux && (webkit2_36 || webkit2_40) && purego
+
+package webview
+
+import (
+	"net/http"
+	"strings"
+
+	"github.com/ebitengine/purego"
+)
+
+func webkit_uri_scheme_request_get_http_method(req uintptr) string {
+	var getMethod func(uintptr) string
+	purego.RegisterLibFunc(&getMethod, gtk, "webkit_uri_scheme_request_get_http_method")
+	return strings.ToUpper(getMethod(req))
+}
+
+func webkit_uri_scheme_request_get_http_headers(req uintptr) http.Header {
+	var getHeaders func(uintptr) uintptr
+	purego.RegisterLibFunc(&getUri, webkit, "webkit_uri_scheme_request_get_http_headers")
+
+	hdrs := getHeaders(req)
+
+	var headersIterInit func(uintptr, uintptr) uintptr
+	purego.RegisterLibFunc(&headersIterInit, gtk, "soup_message_headers_iter_init")
+
+	// TODO: How do we get a struct?
+	/*
+	   typedef struct {
+	   	SoupMessageHeaders *hdrs;
+	           int index_common;
+	   	int index_uncommon;
+	   } SoupMessageHeadersIterReal;
+	*/
+	iter := make([]byte, 12)
+	headersIterInit(&iter, hdrs)
+
+	var iterNext func(uintptr, *string, *string) int
+	purego.RegisterLibFunc(&iterNext, gtk, "soup_message_headers_iter_next")
+
+	var name string
+	var value string
+	h := http.Header{}
+
+	for iterNext(&iter, &name, &value) != 0 {
+		h.Add(name, value)
+	}
+
+	return h
+}
+
+func webkit_uri_scheme_request_finish(req uintptr, code int, header http.Header, stream uintptr, streamLength int64) error {
+
+	var newResponse func(uintptr, int64) string
+	purego.RegisterLibFunc(&newResponse, webkit, "webkit_uri_scheme_response_new")
+	var unRef func(uintptr)
+	purego.RegisterLibFunc(&unRef, gtk, "g_object_unref")
+
+	resp := newResponse(stream, streamLength)
+	defer unRef(resp)
+
+	var setStatus func(uintptr, int, string)
+	purego.RegisterLibFunc(&unRef, webkit, "webkit_uri_scheme_response_set_status")
+
+	setStatus(resp, code, cReason)
+
+	var setContentType func(uintptr, string)
+	purego.RegisterLibFunc(&unRef, webkit, "webkit_uri_scheme_response_set_content_type")
+
+	setContentType(resp, header.Get(HeaderContentType))
+
+	soup := gtk
+	var soupHeadersNew func(int) uintptr
+	purego.RegisterLibFunc(&unRef, soup, "soup_message_headers_new")
+	var soupHeadersAppend func(uintptr, string, string)
+	purego.RegisterLibFunc(&unRef, soup, "soup_message_headers_append")
+
+	hdrs := soupHeadersNew(SOUP_MESSAGE_HEADERS_RESPONSE)
+	for name, values := range header {
+		for _, value := range values {
+			soupHeadersAppend(hdrs, name, value)
+		}
+	}
+
+	var setHttpHeaders func(uintptr, uintptr)
+	purego.RegisterLibFunc(&unRef, webkit, "webkit_uri_scheme_response_set_http_headers")
+
+	setHttpHeaders(resp, hdrs)
+	var finishWithResponse func(uintptr, uintptr)
+	purego.RegisterLibFunc(&unRef, webkit, "webkit_uri_scheme_request_finish_with_response")
+	finishWithResponse(req, resp)
+
+	return nil
+}

v2/pkg/assetserver/webview/webkit2_40+_purego.go

@@ -0,0 +1,74 @@
+//go:build linux && webkit2_40 && purego
+
+package webview
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"unsafe"
+)
+
+func webkit_uri_scheme_request_get_http_body(req *C.WebKitURISchemeRequest) io.ReadCloser {
+	stream := C.webkit_uri_scheme_request_get_http_body(req)
+	if stream == nil {
+		return http.NoBody
+	}
+	return &webkitRequestBody{stream: stream}
+}
+
+type webkitRequestBody struct {
+	stream *C.GInputStream
+	closed bool
+}
+
+// Read implements io.Reader
+func (r *webkitRequestBody) Read(p []byte) (int, error) {
+	if r.closed {
+		return 0, io.ErrClosedPipe
+	}
+
+	var content unsafe.Pointer
+	var contentLen int
+	if p != nil {
+		content = unsafe.Pointer(&p[0])
+		contentLen = len(p)
+	}
+
+	var n C.gsize
+	var gErr *C.GError
+	res := C.g_input_stream_read_all(r.stream, content, C.gsize(contentLen), &n, nil, &gErr)
+	if res == 0 {
+		return 0, formatGError("stream read failed", gErr)
+	} else if n == 0 {
+		return 0, io.EOF
+	}
+	return int(n), nil
+}
+
+func (r *webkitRequestBody) Close() error {
+	if r.closed {
+		return nil
+	}
+	r.closed = true
+
+	// https://docs.gtk.org/gio/method.InputStream.close.html
+	// Streams will be automatically closed when the last reference is dropped, but you might want to call this function
+	// to make sure resources are released as early as possible.
+	var err error
+	var gErr *C.GError
+	if C.g_input_stream_close(r.stream, nil, &gErr) == 0 {
+		err = formatGError("stream close failed", gErr)
+	}
+	C.g_object_unref(C.gpointer(r.stream))
+	r.stream = nil
+	return err
+}
+
+func formatGError(msg string, gErr *C.GError, args ...any) error {
+	if gErr != nil && gErr.message != nil {
+		msg += ": " + C.GoString(gErr.message)
+		C.g_error_free(gErr)
+	}
+	return fmt.Errorf(msg, args...)
+}

v2/pkg/assetserver/webview/webkit2_legacy_purego.go

@@ -0,0 +1,36 @@
+//go:build linux && !(webkit2_36 || webkit2_40) && purego
+
+package webview
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/ebitengine/purego"
+)
+
+const Webkit2MinMinorVersion = 0
+
+func webkit_uri_scheme_request_get_http_method(_ uintptr) string {
+	return http.MethodGet
+}
+
+func webkit_uri_scheme_request_get_http_headers(_ uintptr) http.Header {
+	return http.Header{}
+}
+
+func webkit_uri_scheme_request_get_http_body(_ uintptr) io.ReadCloser {
+	return http.NoBody
+}
+
+func webkit_uri_scheme_request_finish(req uintptr, code int, header http.Header, stream uintptr, streamLength int64) error {
+	if code != http.StatusOK {
+		return fmt.Errorf("StatusCodes not supported: %d - %s", code, http.StatusText(code))
+	}
+
+	var requestFinish func(uintptr, uintptr, int64, string)
+	purego.RegisterLibFunc(&requestFinish, webkit, "webkit_uri_scheme_request_finish")
+	requestFinish(req, stream, streamLength, header.Get(HeaderContentType))
+	return nil
+}

v3/STATUS.md

@@ -14,21 +14,21 @@ Status of features in v3. Incomplete - please add as you see fit.
 
 Application interface methods
 
-| Method                                                        | Windows | Linux | Mac | Notes |
-|---------------------------------------------------------------|---------|-------|-----|-------|
-| run() error                                                   | Y       |       | Y   |       |
-| destroy()                                                     |         |       | Y   |       |
-| setApplicationMenu(menu *Menu)                                | Y       |       | Y   |       |
-| name() string                                                 |         |       | Y   |       |
-| getCurrentWindowID() uint                                     | Y       |       | Y   |       |
-| showAboutDialog(name string, description string, icon []byte) |         |       | Y   |       |
-| setIcon(icon []byte)                                          | -       |       | Y   |       |
-| on(id uint)                                                   |         |       | Y   |       |
-| dispatchOnMainThread(fn func())                               | Y       |       | Y   |       |
-| hide()                                                        | Y       |       | Y   |       |
-| show()                                                        | Y       |       | Y   |       |
-| getPrimaryScreen() (*Screen, error)                           |         |       | Y   |       |
-| getScreens() ([]*Screen, error)                               |         |       | Y   |       |
+| Method                                                        | Windows | Linux | Mac | Notes                        |
+|---------------------------------------------------------------|---------|-------|-----|------------------------------|
+| run() error                                                   | Y       | Y     | Y   |                              |
+| destroy()                                                     |         | Y     | Y   |                              |
+| setApplicationMenu(menu *Menu)                                | Y       |       | Y   |                              |
+| name() string                                                 |         |       | Y   |                              |
+| getCurrentWindowID() uint                                     | Y       | Y     | Y   |                              |
+| showAboutDialog(name string, description string, icon []byte) |         | Y     | Y   | [linux] No icon possible yet |
+| setIcon(icon []byte)                                          | -       |       | Y   |                              |
+| on(id uint)                                                   |         |       | Y   |                              |
+| dispatchOnMainThread(fn func())                               | Y       | Y     | Y   |                              |
+| hide()                                                        | Y       |       | Y   |                              |
+| show()                                                        | Y       |       | Y   |                              |
+| getPrimaryScreen() (*Screen, error)                           |         | Y     | Y   |                              |
+| getScreens() ([]*Screen, error)                               |         | Y     | Y   |                              |
 
 ## Webview Window
 
@@ -36,52 +36,52 @@ Webview Window Interface Methods
 
 | Method                                             | Windows | Linux | Mac | Notes                                    |
 |----------------------------------------------------|---------|-------|-----|------------------------------------------|
-| center()                                           | Y       |       | Y   |                                          |
-| close()                                            | Y       |       | Y   |                                          |
-| destroy()                                          |         |       | Y   |                                          |
-| execJS(js string)                                  | Y       |       | Y   |                                          |
-| focus()                                            | Y       |       | Y   |                                          |
-| forceReload()                                      |         |       | Y   |                                          |
-| fullscreen()                                       | Y       |       | Y   |                                          |
-| getScreen() (*Screen, error)                       | Y       |       | Y   |                                          |
-| getZoom() float64                                  |         |       | Y   |                                          |
-| height() int                                       | Y       |       | Y   |                                          |
-| hide()                                             | Y       |       | Y   |                                          |
-| isFullscreen() bool                                | Y       |       | Y   |                                          |
-| isMaximised() bool                                 | Y       |       | Y   |                                          |
-| isMinimised() bool                                 | Y       |       | Y   |                                          |
-| maximise()                                         | Y       |       | Y   |                                          |
-| minimise()                                         | Y       |       | Y   |                                          |
-| nativeWindowHandle() (uintptr, error)              | Y       |       | Y   |                                          |
-| on(eventID uint)                                   | Y       |       | Y   |                                          |
-| openContextMenu(menu *Menu, data *ContextMenuData) | Y       |       | Y   |                                          |
-| position() (int, int)                              | Y       |       | Y   |                                          |
-| reload()                                           | Y       |       | Y   |                                          |
-| run()                                              | Y       |       | Y   |                                          |
-| setAlwaysOnTop(alwaysOnTop bool)                   | Y       |       | Y   |                                          |
-| setBackgroundColour(color RGBA)                    | Y       |       | Y   |                                          |
-| setFrameless(bool)                                 |         |       | Y   |                                          |
-| setFullscreenButtonEnabled(enabled bool)           | -       |       | Y   | There is no fullscreen button in Windows |
-| setHTML(html string)                               | Y       |       | Y   |                                          |
-| setMaxSize(width, height int)                      | Y       |       | Y   |                                          |
-| setMinSize(width, height int)                      | Y       |       | Y   |                                          |
-| setPosition(x int, y int)                          | Y       |       | Y   |                                          |
-| setResizable(resizable bool)                       | Y       |       | Y   |                                          |
-| setSize(width, height int)                         | Y       |       | Y   |                                          |
-| setTitle(title string)                             | Y       |       | Y   |                                          |
-| setURL(url string)                                 | Y       |       | Y   |                                          |
-| setZoom(zoom float64)                              | Y       |       | Y   |                                          |
-| show()                                             | Y       |       | Y   |                                          |
-| size() (int, int)                                  | Y       |       | Y   |                                          |
-| toggleDevTools()                                   | Y       |       | Y   |                                          |
-| unfullscreen()                                     | Y       |       | Y   |                                          |
-| unmaximise()                                       | Y       |       | Y   |                                          |
-| unminimise()                                       | Y       |       | Y   |                                          |
-| width() int                                        | Y       |       | Y   |                                          |
-| zoom()                                             |         |       | Y   |                                          |
-| zoomIn()                                           | Y       |       | Y   |                                          |
-| zoomOut()                                          | Y       |       | Y   |                                          |
-| zoomReset()                                        | Y       |       | Y   |                                          |
+| center()                                           | Y       | Y     | Y   |                                          |
+| close()                                            | y       | Y     | Y   |                                          |
+| destroy()                                          |         | Y     | Y   |                                          |
+| execJS(js string)                                  | y       | Y     | Y   |                                          |
+| focus()                                            | Y       | Y     |     |                                          |
+| forceReload()                                      |         | Y     | Y   |                                          |
+| fullscreen()                                       | Y       | Y     | Y   |                                          |
+| getScreen() (*Screen, error)                       | y       | Y     | Y   |                                          |
+| getZoom() float64                                  |         | Y     | Y   |                                          |
+| height() int                                       | Y       | Y     | Y   |                                          |
+| hide()                                             | Y       | Y     | Y   |                                          |
+| isFullscreen() bool                                | Y       | Y     | Y   |                                          |
+| isMaximised() bool                                 | Y       | Y     | Y   |                                          |
+| isMinimised() bool                                 | Y       | Y     | Y   |                                          |
+| maximise()                                         | Y       | Y     | Y   |                                          |
+| minimise()                                         | Y       | Y     | Y   |                                          |
+| nativeWindowHandle() (uintptr, error)              | Y       | Y     |     |                                          |
+| on(eventID uint)                                   | y       |       | Y   |                                          |
+| openContextMenu(menu *Menu, data *ContextMenuData) | y       |       | Y   |                                          |
+| position() (int, int)                              | Y       | Y     | Y   |                                          |
+| reload()                                           | y       | Y     | Y   |                                          |
+| run()                                              | Y       | Y     | Y   |                                          |
+| setAlwaysOnTop(alwaysOnTop bool)                   | Y       | Y     | Y   |                                          |
+| setBackgroundColour(color RGBA)                    | Y       | Y     | Y   |                                          |
+| setFrameless(bool)                                 |         | Y     | Y   |                                          |
+| setFullscreenButtonEnabled(enabled bool)           | -       | Y     | Y   | There is no fullscreen button in Windows |
+| setHTML(html string)                               | Y       | Y     | Y   |                                          |
+| setMaxSize(width, height int)                      | Y       | Y     | Y   |                                          |
+| setMinSize(width, height int)                      | Y       | Y     | Y   |                                          |
+| setPosition(x int, y int)                          | Y       | Y     | Y   |                                          |
+| setResizable(resizable bool)                       | Y       | Y     | Y   |                                          |
+| setSize(width, height int)                         | Y       | Y     | Y   |                                          |
+| setTitle(title string)                             | Y       | Y     | Y   |                                          |
+| setURL(url string)                                 | Y       | Y     | Y   |                                          |
+| setZoom(zoom float64)                              | Y       | Y     | Y   |                                          |
+| show()                                             | Y       | Y     | Y   |                                          |
+| size() (int, int)                                  | Y       | Y     | Y   |                                          |
+| toggleDevTools()                                   | Y       | Y     | Y   |                                          |
+| unfullscreen()                                     | Y       | Y     | Y   |                                          |
+| unmaximise()                                       | Y       | Y     | Y   |                                          |
+| unminimise()                                       | Y       | Y     | Y   |                                          |
+| width() int                                        | Y       | Y     | Y   |                                          |
+| zoom()                                             |         | Y     | Y   |                                          |
+| zoomIn()                                           | Y       | Y     | Y   |                                          |
+| zoomOut()                                          | Y       | Y     | Y   |                                          |
+| zoomReset()                                        | Y       | Y     | Y   |                                          |
 
 ## Runtime
 
@@ -89,7 +89,7 @@ Webview Window Interface Methods
 
 | Feature | Windows | Linux | Mac | Notes |
 |---------|---------|-------|-----|-------|
-| Quit    | Y       |       | Y   |       |
+| Quit    | Y       | Y     | Y   |       |
 | Hide    | Y       |       | Y   |       |
 | Show    | Y       |       | Y   |       |
 
@@ -129,81 +129,79 @@ Anything nested under a tag with `--default-contextmenu: hide` style will not sh
 
 | Feature    | Windows | Linux | Mac | Notes |
 |------------|---------|-------|-----|-------|
-| GetAll     | Y       |       | Y   |       |
-| GetPrimary | Y       |       | Y   |       |
-| GetCurrent | Y       |       | Y   |       |
+| GetAll     | Y       | Y     | Y   |       |
+| GetPrimary | Y       | Y     | Y   |       |
+| GetCurrent | Y       | Y     | Y   |       |
 
 ### Window
 
 | Feature             | Windows | Linux | Mac | Notes                                                                                |
 |---------------------|---------|-------|-----|--------------------------------------------------------------------------------------|
-| SetTitle            | Y       |       | Y   |                                                                                      |
-| SetSize             | Y       |       | Y   |                                                                                      |
-| Size                | Y       |       | Y   |                                                                                      |
-| SetPosition         | Y       |       | Y   |                                                                                      |
-| Position            | Y       |       | Y   |                                                                                      |
-| Focus               | Y       |       | Y   |                                                                                      |
-| FullScreen          | Y       |       | Y   |                                                                                      |
-| UnFullscreen        | Y       |       | Y   |                                                                                      |
-| Minimise            | Y       |       | Y   |                                                                                      |
-| UnMinimise          | Y       |       | Y   |                                                                                      |
-| Maximise            | Y       |       | Y   |                                                                                      |
-| UnMaximise          | Y       |       | Y   |                                                                                      |
-| Show                | Y       |       | Y   |                                                                                      |
-| Hide                | Y       |       | Y   |                                                                                      |
-| Center              | Y       |       | Y   |                                                                                      |
-| SetBackgroundColour | Y       |       | Y   | https://github.com/MicrosoftEdge/WebView2Feedback/issues/1621#issuecomment-938234294 |
-| SetAlwaysOnTop      | Y       |       | Y   |                                                                                      |
-| SetResizable        | Y       |       | Y   |                                                                                      |
-| SetMinSize          | Y       |       | Y   |                                                                                      |
-| SetMaxSize          | Y       |       | Y   |                                                                                      |
-| Width               | Y       |       | Y   |                                                                                      |
-| Height              | Y       |       | Y   |                                                                                      |
-| ZoomIn              | Y       |       | Y   | Increase view scale                                                                  |
-| ZoomOut             | Y       |       | Y   | Decrease view scale                                                                  |
-| ZoomReset           | Y       |       | Y   | Reset view scale                                                                     |
-| GetZoom             | Y       |       | Y   | Get current view scale                                                               |
-| SetZoom             | Y       |       | Y   | Set view scale                                                                       |
-| Screen              | Y       |       | Y   | Get screen for window                                                                |
+| SetTitle            | Y       | Y     | Y   |                                                                                      |
+| SetSize             | Y       | Y     | Y   |                                                                                      |
+| Size                | Y       | Y     | Y   |                                                                                      |
+| SetPosition         | Y       | Y     | Y   |                                                                                      |
+| Position            | Y       | Y     | Y   |                                                                                      |
+| Focus               | Y       | Y     |     |                                                                                      |
+| FullScreen          | Y       | Y     | Y   |                                                                                      |
+| UnFullscreen        | Y       | Y     | Y   |                                                                                      |
+| Minimise            | Y       | Y     | Y   |                                                                                      |
+| UnMinimise          | Y       | Y     | Y   |                                                                                      |
+| Maximise            | Y       | Y     | Y   |                                                                                      |
+| UnMaximise          | Y       | Y     | Y   |                                                                                      |
+| Show                | Y       | Y     | Y   |                                                                                      |
+| Hide                | Y       | Y     | Y   |                                                                                      |
+| Center              | Y       | Y     | Y   |                                                                                      |
+| SetBackgroundColour | Y       | Y     | Y   | https://github.com/MicrosoftEdge/WebView2Feedback/issues/1621#issuecomment-938234294 |
+| SetAlwaysOnTop      | Y       | Y     | Y   |                                                                                      |
+| SetResizable        | Y       | Y     | Y   |                                                                                      |
+| SetMinSize          | Y       | Y     | Y   |                                                                                      |
+| SetMaxSize          | Y       | Y     | Y   |                                                                                      |
+| Width               | Y       | Y     | Y   |                                                                                      |
+| Height              | Y       | Y     | Y   |                                                                                      |
+| ZoomIn              | Y       | Y     | Y   | Increase view scale                                                                  |
+| ZoomOut             | Y       | Y     | Y   | Decrease view scale                                                                  |
+| ZoomReset           | Y       | Y     | Y   | Reset view scale                                                                     |
+| GetZoom             | Y       | Y     | Y   | Get current view scale                                                               |
+| SetZoom             | Y       | Y     | Y   | Set view scale                                                                       |
+| Screen              | Y       | Y     | Y   | Get screen for window                                                                |
 
 ### Window Options
 
 A 'Y' in the table below indicates that the option has been tested and is applied when the window is created.
 An 'X' indicates that the option is not supported by the platform.
 
-| Feature                         | Windows | Linux | Mac | Notes                                      |
-|---------------------------------|---------|-------|-----|--------------------------------------------|
-| AlwaysOnTop                     | Y       |       |     |                                            |
-| BackgroundColour                | Y       |       |     |                                            |
-| BackgroundType                  |         |       |     | Acrylic seems to work but the others don't |
-| CSS                             | Y       |       |     |                                            |
-| DevToolsEnabled                 | Y       |       | Y   |                                            |
-| DisableResize                   | Y       |       |     |                                            |
-| EnableDragAndDrop               |         |       |     |                                            |
-| EnableFraudulentWebsiteWarnings |         |       |     |                                            |
-| Focused                         | Y       |       |     |                                            |
-| Frameless                       | Y       |       |     |                                            |
-| FullscreenButtonEnabled         | Y       |       |     |                                            |
-| Height                          | Y       |       |     |                                            |
-| Hidden                          | Y       |       |     |                                            |
-| HTML                            | Y       |       |     |                                            |
-| JS                              | Y       |       |     |                                            |
-| Mac                             | -       | -     |     |                                            |
-| MaxHeight                       | Y       |       |     |                                            |
-| MaxWidth                        | Y       |       |     |                                            |
-| MinHeight                       | Y       |       |     |                                            |
-| MinWidth                        | Y       |       |     |                                            |
-| Name                            | Y       |       |     |                                            |
-| OpenInspectorOnStartup          |         |       |     |                                            |
-| StartState                      | Y       |       |     |                                            |
-| Title                           | Y       |       |     |                                            |
-| URL                             | Y       |       |     |                                            |
-| Width                           | Y       |       |     |                                            |
-| Windows                         | Y       | -     | -   |                                            |
-| X                               | Y       |       |     |                                            |
-| Y                               | Y       |       |     |                                            |
-| Zoom                            |         |       |     |                                            |
-| ZoomControlEnabled              |         |       |     |                                            |
+| Feature                         | Windows | Linux | Mac | Notes                                             |
+|---------------------------------|---------|-------|-----|---------------------------------------------------|
+| Name                            |         |       |     |                                                   |
+| Title                           | Y       |       |     |                                                   |
+| Width                           | Y       | Y     |     |                                                   |
+| Height                          | Y       | Y     |     |                                                   |
+| AlwaysOnTop                     | Y       | Y     |     |                                                   |
+| URL                             | Y       |       |     |                                                   |
+| DisableResize                   | Y       | Y     |     |                                                   |
+| Frameless                       | Y       | Y     |     |                                                   |
+| MinWidth                        | Y       | Y     |     |                                                   |
+| MinHeight                       | Y       | Y     |     |                                                   |
+| MaxWidth                        | Y       | Y     |     |                                                   |
+| MaxHeight                       | Y       | Y     |     |                                                   |
+| StartState                      | Y       |       |     |                                                   |
+| Mac                             | -       | -     |     |                                                   |
+| BackgroundType                  |         |       |     | Acrylic seems to work but the others don't        |
+| BackgroundColour                | Y       | Y     |     |                                                   |
+| HTML                            | Y       | Y     |     |                                                   |
+| JS                              | Y       | Y     |     |                                                   |
+| CSS                             | Y       | Y     |     |                                                   |
+| X                               | Y       | Y     |     |                                                   |
+| Y                               | Y       | Y     |     |                                                   |
+| HideOnClose                     | Y       | Y     |     |                                                   |
+| FullscreenButtonEnabled         |         | ?     |     | [linux] How is this different from DisableResize? |
+| Hidden                          | Y       |       |     |                                                   |
+| EnableFraudulentWebsiteWarnings |         |       |     |                                                   |
+| Zoom                            |         | Y     |     |                                                   |
+| EnableDragAndDrop               | Y       | Y     |     |                                                   |
+| Windows                         | Y       | -     | -   |                                                   |
+| Focused                         | Y       |       |     |                                                   |
 
 ### Log
 
@@ -213,7 +211,7 @@ To log or not to log? System logger vs custom logger.
 
 | Event                    | Windows | Linux | Mac | Notes |
 |--------------------------|---------|-------|-----|-------|
-| Default Application Menu | Y       |       | Y   |       |
+| Default Application Menu | Y       | Y     | Y   |       |
 
 ## Tray Menus
 
@@ -286,10 +284,10 @@ Built-in plugin support:
 | Plugin          | Windows | Linux | Mac | Notes |
 |-----------------|---------|-------|-----|-------|
 | Browser         | Y       |       | Y   |       |
-| KV Store        | Y       |       | Y   |       |
-| Log             | Y       |       | Y   |       |
+| KV Store        | Y       | Y     | Y   |       |
+| Log             | Y       | Y     | Y   |       |
 | Single Instance | Y       |       | Y   |       |
-| SQLite          | Y       |       | Y   |       |
+| SQLite          | Y       | Y     | Y   |       |
 | Start at login  |         |       | Y   |       |
 | Server          |         |       |     |       |
 
@@ -308,10 +306,11 @@ Built-in plugin support:
 
 ## Frameless Windows
 
-| Feature | Windows | Linux | Mac | Notes |
-|---------|---------|-------|-----|-------|
-| Resize  |         |       |     |       |
-| Drag    |         |       |     |       |
+| Feature | Windows | Linux | Mac | Notes                                         |
+|---------|---------|-------|-----|-----------------------------------------------|
+| Resize  |         |       |     |                                               |
+| Drag    |         | Y     |     | Linux - can always drag with `Alt`+left mouse |
+
 
 ## Mac Specific
 

v3/go.mod

@@ -3,6 +3,7 @@ module github.com/wailsapp/wails/v3
 go 1.19
 
 require (
+	github.com/ebitengine/purego v0.3.2
 	github.com/bep/debounce v1.2.1
 	github.com/go-ole/go-ole v1.2.6
 	github.com/go-task/task/v3 v3.20.0
@@ -75,3 +76,5 @@ require (
 )
 
 replace github.com/wailsapp/wails/v2 => ../v2
+
+replace github.com/ebitengine/purego v0.3.2 => github.com/TotallyGamerJet/purego v0.2.0-alpha.0.20230404174033-5655abccca7e

v3/go.sum

@@ -11,6 +11,8 @@ github.com/MarvinJWendt/testza v0.2.12/go.mod h1:JOIegYyV7rX+7VZ9r77L/eH6CfJHHzX
 github.com/MarvinJWendt/testza v0.3.0/go.mod h1:eFcL4I0idjtIx8P9C6KkAuLgATNKpX4/2oUqKc6bF2c=
 github.com/MarvinJWendt/testza v0.4.2/go.mod h1:mSdhXiKH8sg/gQehJ63bINcCKp7RtYewEjXsvsVUPbE=
 github.com/MarvinJWendt/testza v0.5.1 h1:a9Fqx6vQrHQ4CyiaLhktfTTelwGotmFWy8MNhyaohw8=
+github.com/TotallyGamerJet/purego v0.2.0-alpha.0.20230404174033-5655abccca7e h1:wQ7ot+e0mwJYkbomtIX9tU0dOV9lFTmwAgUGqvQTIUg=
+github.com/TotallyGamerJet/purego v0.2.0-alpha.0.20230404174033-5655abccca7e/go.mod h1:iIjxzd6CiRiOG0UyXP+V1+jWqUXVjPKLAI0mRfJZTmQ=
 github.com/atomicgo/cursor v0.0.1/go.mod h1:cBON2QmmrysudxNBFthvMtN32r3jxVRIvzkUiF/RuIk=
 github.com/bep/debounce v1.2.1 h1:v67fRdBA9UQu2NhLFXrSg0Brw7CexQekrBwDMM8bzeY=
 github.com/bep/debounce v1.2.1/go.mod h1:H8yggRPQKLUhUoqrJC1bO2xNya7vanpDl7xR3ISbCJ0=

v3/pkg/application/application.go

@@ -333,7 +333,9 @@ func (a *App) error(message string, args ...any) {
 func (a *App) NewWebviewWindowWithOptions(windowOptions WebviewWindowOptions) *WebviewWindow {
 	newWindow := NewWindow(windowOptions)
 	id := newWindow.id
-
+	if a.windows == nil {
+		a.windows = make(map[uint]*WebviewWindow)
+	}
 	a.windowsLock.Lock()
 	a.windows[id] = newWindow
 	a.windowsLock.Unlock()

v3/pkg/application/application_darwin.go

@@ -185,6 +185,7 @@ func (m *macosApp) run() error {
 		C.setApplicationShouldTerminateAfterLastWindowClosed(C.bool(m.parent.options.Mac.ApplicationShouldTerminateAfterLastWindowClosed))
 		C.setActivationPolicy(C.int(m.parent.options.Mac.ActivationPolicy))
 		C.activateIgnoringOtherApps()
+		globalApplication.activate()
 	})
 	m.setupCommonEvents()
 	// setup event listeners

v3/pkg/application/application_linux.go

@@ -0,0 +1,268 @@
+//go:build linux && !purego
+
+package application
+
+/*
+#cgo linux pkg-config: gtk+-3.0 webkit2gtk-4.0
+
+#include <gtk/gtk.h>
+#include <gdk/gdk.h>
+#include <webkit2/webkit2.h>
+#include <stdio.h>
+#include <limits.h>
+#include <stdint.h>
+
+typedef struct App {
+  void *app;
+} App;
+
+extern void processApplicationEvent(uint);
+
+extern void activateLinux(gpointer data);
+
+static void activate (GtkApplication* app, gpointer data) {
+   // FIXME: should likely emit a WAILS specific code
+   // events.Mac.EventApplicationDidFinishLaunching == 1032
+   //processApplicationEvent(1032);
+
+   activateLinux(data);
+}
+
+static GtkApplication* init(char* name) {
+   return gtk_application_new(name, G_APPLICATION_DEFAULT_FLAGS);
+}
+
+static int run(void *app, void *data) {
+  g_signal_connect (app, "activate", G_CALLBACK (activate), data);
+  g_application_hold(app);  // allows it to run without a window
+  int status = g_application_run (G_APPLICATION (app), 0, NULL);
+  g_application_release(app);
+  g_object_unref (app);
+  return status;
+}
+
+*/
+import "C"
+import (
+	"fmt"
+	"log"
+	"os"
+	"strings"
+	"sync"
+	"unsafe"
+
+	"github.com/wailsapp/wails/v3/pkg/events"
+)
+
+func init() {
+	// Set GDK_BACKEND=x11 if currently unset and XDG_SESSION_TYPE is unset, unspecified or x11 to prevent warnings
+	_ = os.Setenv("GDK_BACKEND", "x11")
+}
+
+type linuxApp struct {
+	application     unsafe.Pointer
+	applicationMenu unsafe.Pointer
+	parent          *App
+
+	startupActions []func()
+
+	// Native -> uint
+	windows     map[*C.GtkWindow]uint
+	windowsLock sync.Mutex
+}
+
+func getNativeApplication() *linuxApp {
+	return globalApplication.impl.(*linuxApp)
+}
+
+func (m *linuxApp) hide() {
+	windows := C.gtk_application_get_windows((*C.GtkApplication)(m.application))
+	for {
+		fmt.Println("hiding", windows.data)
+		C.gtk_widget_hide((*C.GtkWidget)(windows.data))
+		windows = windows.next
+		if windows == nil {
+			return
+		}
+	}
+}
+
+func (m *linuxApp) show() {
+	windows := C.gtk_application_get_windows((*C.GtkApplication)(m.application))
+	for {
+		fmt.Println("hiding", windows.data)
+		C.gtk_widget_show_all((*C.GtkWidget)(windows.data))
+		windows = windows.next
+		if windows == nil {
+			return
+		}
+	}
+}
+
+func (m *linuxApp) on(eventID uint) {
+	log.Println("linuxApp.on()", eventID)
+	// TODO: Setup signal handling as appropriate
+	// Note: GTK signals seem to be strings!
+}
+
+func (m *linuxApp) setIcon(icon []byte) {
+	/* // FIXME: WIP
+	   loader := C.gdk_pixbuf_loader_new()
+
+	   	if loader == nil {
+	   		return
+	   	}
+
+	   loaded := C.gdk_pixbuf_loader_write(loader, (*C.guchar)(&icon[0]), (C.gsize)(len(icon)), 0)
+
+	   	if loaded == C.bool(1) && C.gdk_pixbuf_loader_close(loader, 0) {
+	   		pixbuf := C.gdk_pixbuf_loader_get_pixbuf(loader)
+	   		if pixbuf != nil {
+	   			ww := m.parent.CurrentWindow()
+	   			window := ww.impl.window
+	   			C.gtk_window_set_icon(window, pixbuf)
+	   		}
+	   	}
+
+	   C.g_object_unref(loader)
+	*/
+}
+
+func (m *linuxApp) name() string {
+	// appName := C.getAppName()
+	// defer C.free(unsafe.Pointer(appName))
+	// return C.GoString(appName)
+	return ""
+}
+
+func (m *linuxApp) getCurrentWindowID() uint {
+	// TODO: Add extra metadata to window
+	window := (*C.GtkWindow)(C.gtk_application_get_active_window((*C.GtkApplication)(m.application)))
+	if window == nil {
+		return uint(1)
+	}
+	m.windowsLock.Lock()
+	defer m.windowsLock.Unlock()
+	identifier, ok := m.windows[window]
+	if ok {
+		return identifier
+	}
+	return uint(1)
+}
+
+func (m *linuxApp) setApplicationMenu(menu *Menu) {
+	if menu == nil {
+		// Create a default menu
+		menu = defaultApplicationMenu()
+	}
+	globalApplication.dispatchOnMainThread(func() {
+		fmt.Println("setApplicationMenu")
+
+		menu.Update()
+		m.applicationMenu = (menu.impl).(*linuxMenu).native
+	})
+}
+
+func (m *linuxApp) run() error {
+
+	// Add a hook to the ApplicationDidFinishLaunching event
+	// FIXME: add Wails specific events - i.e. Shouldn't platform specific ones be translated to Wails events?
+	m.parent.On(events.Mac.ApplicationDidFinishLaunching, func() {
+		// Do we need to do anything now?
+		fmt.Println("events.Mac.ApplicationDidFinishLaunching received!")
+	})
+
+	var app C.App
+	app.app = unsafe.Pointer(m)
+	C.run(m.application, m.application)
+	return nil
+}
+
+func (m *linuxApp) destroy() {
+	C.g_application_quit((*C.GApplication)(m.application))
+}
+
+// register our window to our parent mapping
+func (m *linuxApp) registerWindow(window *C.GtkWindow, id uint) {
+	m.windowsLock.Lock()
+	m.windows[window] = id
+	m.windowsLock.Unlock()
+}
+
+func newPlatformApp(parent *App) *linuxApp {
+	name := strings.ToLower(strings.Replace(parent.options.Name, " ", "", -1))
+	if name == "" {
+		name = "undefined"
+	}
+	nameC := C.CString(fmt.Sprintf("org.wails.%s", name))
+	app := &linuxApp{
+		parent:      parent,
+		application: unsafe.Pointer(C.init(nameC)),
+		//		name:        fmt.Sprintf("org.wails.%s", name),
+		windows: map[*C.GtkWindow]uint{},
+	}
+	C.free(unsafe.Pointer(nameC))
+	return app
+}
+
+// executeStartupActions is called by `activateLinux` below to execute
+// code which needs to be run after the 'activate' signal is received
+func (m *linuxApp) executeStartupActions() {
+	for _, fn := range m.startupActions {
+		fn()
+	}
+}
+
+//export activateLinux
+func activateLinux(data unsafe.Pointer) {
+	getNativeApplication().executeStartupActions()
+}
+
+//export processApplicationEvent
+func processApplicationEvent(eventID C.uint) {
+	// TODO: add translation to Wails events
+	//       currently reusing Mac specific values
+	applicationEvents <- uint(eventID)
+}
+
+//export processWindowEvent
+func processWindowEvent(windowID C.uint, eventID C.uint) {
+	windowEvents <- &WindowEvent{
+		WindowID: uint(windowID),
+		EventID:  uint(eventID),
+	}
+}
+
+//export processMessage
+func processMessage(windowID C.uint, message *C.char) {
+	windowMessageBuffer <- &windowMessage{
+		windowId: uint(windowID),
+		message:  C.GoString(message),
+	}
+}
+
+//export processDragItems
+func processDragItems(windowID C.uint, arr **C.char, length C.int) {
+	var filenames []string
+	// Convert the C array to a Go slice
+	goSlice := (*[1 << 30]*C.char)(unsafe.Pointer(arr))[:length:length]
+	for _, str := range goSlice {
+		filenames = append(filenames, C.GoString(str))
+	}
+	windowDragAndDropBuffer <- &dragAndDropMessage{
+		windowId:  uint(windowID),
+		filenames: filenames,
+	}
+}
+
+//export processMenuItemClick
+func processMenuItemClick(menuID C.uint) {
+	menuItemClicked <- uint(menuID)
+}
+
+func setIcon(icon []byte) {
+	if icon == nil {
+		return
+	}
+	//C.setApplicationIcon(unsafe.Pointer(&icon[0]), C.int(len(icon)))
+}

v3/pkg/application/application_linux_purego.go

@@ -0,0 +1,253 @@
+//go:build linux && purego
+
+package application
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"strings"
+	"sync"
+
+	"github.com/ebitengine/purego"
+	"github.com/wailsapp/wails/v2/pkg/assetserver/webview"
+)
+
+const (
+	gtk3 = "libgtk-3.so"
+	gtk4 = "libgtk-4.so"
+)
+
+var (
+	gtk     uintptr
+	version int
+	webkit  uintptr
+)
+
+func init() {
+	// needed for GTK4 to function
+	_ = os.Setenv("GDK_BACKEND", "x11")
+	var err error
+	/*
+		gtk, err = purego.Dlopen(gtk4, purego.RTLD_NOW|purego.RTLD_GLOBAL)
+		if err == nil {
+			version = 4
+			return
+		}
+
+		log.Println("Failed to open GTK4: Falling back to GTK3")
+	*/
+	gtk, err = purego.Dlopen(gtk3, purego.RTLD_NOW|purego.RTLD_GLOBAL)
+	if err != nil {
+		panic(err)
+	}
+	version = 3
+
+	var webkit4 string = "libwebkit2gtk-4.1.so"
+	webkit, err = purego.Dlopen(webkit4, purego.RTLD_NOW|purego.RTLD_GLOBAL)
+	if err != nil {
+		panic(err)
+	}
+}
+
+type linuxApp struct {
+	appName         string
+	application     uintptr
+	applicationMenu uintptr
+	parent          *App
+
+	// Native -> uint
+	windows     map[uintptr]uint
+	windowsLock sync.Mutex
+}
+
+func getNativeApplication() *linuxApp {
+	return globalApplication.impl.(*linuxApp)
+}
+
+func (m *linuxApp) hide() {
+	//	C.hide()
+}
+
+func (m *linuxApp) show() {
+	//	C.show()
+}
+
+func (m *linuxApp) on(eventID uint) {
+	log.Println("linuxApp.on()", eventID)
+
+	// TODO: Setup signal handling as appropriate
+	// Note: GTK signals seem to be strings!
+}
+
+func (m *linuxApp) setIcon(icon []byte) {
+	//	C.setApplicationIcon(unsafe.Pointer(&icon[0]), C.int(len(icon)))
+}
+
+func (m *linuxApp) name() string {
+	return m.appName
+}
+
+func (m *linuxApp) getCurrentWindowID() uint {
+	var getCurrentWindow func(uintptr) uintptr
+	purego.RegisterLibFunc(&getCurrentWindow, gtk, "gtk_application_get_active_window")
+	window := getCurrentWindow(m.application)
+	if window == 0 {
+		return 1
+	}
+	m.windowsLock.Lock()
+	defer m.windowsLock.Unlock()
+	if identifier, ok := m.windows[window]; ok {
+		return identifier
+	}
+
+	return 1
+}
+
+func (m *linuxApp) setApplicationMenu(menu *Menu) {
+	if menu == nil {
+		// Create a default menu
+		menu = defaultApplicationMenu()
+	}
+	globalApplication.dispatchOnMainThread(func() {
+		menu.Update()
+		m.applicationMenu = (menu.impl).(*linuxMenu).native
+	})
+}
+
+func (m *linuxApp) activate() {
+	fmt.Println("linuxApp.activated!", m.application)
+	var hold func(uintptr)
+	purego.RegisterLibFunc(&hold, gtk, "g_application_hold")
+
+	hold(m.application)
+
+	//	time.Sleep(50 * time.Millisecond)
+	//	m.parent.activate()
+}
+
+func (m *linuxApp) run() error {
+	// Add a hook to the ApplicationDidFinishLaunching event
+	// FIXME: add Wails specific events - i.e. Shouldn't platform specific ones be translated to Wails events?
+	/*	m.parent.On(events.Mac.ApplicationDidFinishLaunching, func() {
+			// Do we need to do anything now?
+			fmt.Println("ApplicationDidFinishLaunching!")
+		})
+	*/
+	m.parent.OnWindowCreation(func(window *WebviewWindow) {
+		fmt.Println("OnWindowCreation: ", window)
+
+	})
+
+	var g_signal_connect func(uintptr, string, uintptr, uintptr, bool, int) int
+	purego.RegisterLibFunc(&g_signal_connect, gtk, "g_signal_connect_data")
+	g_signal_connect(m.application, "activate", purego.NewCallback(m.activate), m.application, false, 0)
+
+	var run func(uintptr, int, []string) int
+	purego.RegisterLibFunc(&run, gtk, "g_application_run")
+
+	// FIXME: Convert status to 'error' if needed
+	status := run(m.application, 0, []string{})
+	fmt.Println("status", status)
+
+	var release func(uintptr)
+	purego.RegisterLibFunc(&release, gtk, "g_application_release")
+	release(m.application)
+
+	purego.RegisterLibFunc(&release, gtk, "g_object_unref")
+	release(m.application)
+
+	return nil
+}
+
+func (m *linuxApp) destroy() {
+	var quit func(uintptr)
+	purego.RegisterLibFunc(&quit, gtk, "g_application_quit")
+	quit(m.application)
+}
+
+func (m *linuxApp) registerWindow(address uintptr, window uint) {
+	m.windowsLock.Lock()
+	m.windows[address] = window
+	m.windowsLock.Unlock()
+}
+
+func newPlatformApp(parent *App) *linuxApp {
+	name := strings.ToLower(parent.options.Name)
+	if name == "" {
+		name = "undefined"
+	}
+	identifier := fmt.Sprintf("org.wails.%s", strings.Replace(name, " ", "-", -1))
+
+	var gtkNew func(string, uint) uintptr
+	purego.RegisterLibFunc(&gtkNew, gtk, "gtk_application_new")
+	app := &linuxApp{
+		appName:     identifier,
+		parent:      parent,
+		application: gtkNew(identifier, 0),
+		windows:     map[uintptr]uint{},
+	}
+	return app
+}
+
+func processApplicationEvent(eventID uint) {
+	// TODO: add translation to Wails events
+	//       currently reusing Mac specific values
+	applicationEvents <- eventID
+}
+
+func processWindowEvent(windowID uint, eventID uint) {
+	windowEvents <- &WindowEvent{
+		WindowID: windowID,
+		EventID:  eventID,
+	}
+}
+
+func processMessage(windowID uint, message string) {
+	windowMessageBuffer <- &windowMessage{
+		windowId: windowID,
+		message:  message,
+	}
+}
+
+func processURLRequest(windowID uint, wkUrlSchemeTask uintptr) {
+	fmt.Println("processURLRequest", windowID, wkUrlSchemeTask)
+	webviewRequests <- &webViewAssetRequest{
+		Request:    webview.NewRequest(wkUrlSchemeTask),
+		windowId:   windowID,
+		windowName: globalApplication.getWindowForID(windowID).Name(),
+	}
+}
+
+func processDragItems(windowID uint, arr []string, length int) {
+	windowDragAndDropBuffer <- &dragAndDropMessage{
+		windowId:  windowID,
+		filenames: arr,
+	}
+}
+
+func processMenuItemClick(menuID uint) {
+	menuItemClicked <- menuID
+}
+
+func setIcon(icon []byte) {
+	if icon == nil {
+		return
+	}
+	fmt.Println("setIcon")
+	/*
+	   GdkPixbufLoader *loader = gdk_pixbuf_loader_new();
+	   if (!loader)
+	   {
+	       return;
+	   }
+	   if (gdk_pixbuf_loader_write(loader, buf, len, NULL) && gdk_pixbuf_loader_close(loader, NULL))
+	   {
+	       GdkPixbuf *pixbuf = gdk_pixbuf_loader_get_pixbuf(loader);
+	       if (pixbuf)
+	       {
+	           gtk_window_set_icon(window, pixbuf);
+	       }
+	   }
+	   g_object_unref(loader);*/
+}

v3/pkg/application/clipboard_linux.go

@@ -0,0 +1,33 @@
+//go:build linux
+
+package application
+
+import (
+	"sync"
+)
+
+var clipboardLock sync.RWMutex
+
+type linuxClipboard struct{}
+
+func (m linuxClipboard) setText(text string) bool {
+	clipboardLock.Lock()
+	defer clipboardLock.Unlock()
+	// cText := C.CString(text)
+	// success := C.setClipboardText(cText)
+	// C.free(unsafe.Pointer(cText))
+	success := false
+	return bool(success)
+}
+
+func (m linuxClipboard) text() string {
+	clipboardLock.RLock()
+	defer clipboardLock.RUnlock()
+	//	clipboardText := C.getClipboardText()
+	//	result := C.GoString(clipboardText)
+	return ""
+}
+
+func newClipboardImpl() *linuxClipboard {
+	return &linuxClipboard{}
+}

v3/pkg/application/dialogs_linux.go

@@ -0,0 +1,300 @@
+//go:build linux
+
+package application
+
+/*
+#cgo linux pkg-config: gtk+-3.0 webkit2gtk-4.0
+
+#include <gtk/gtk.h>
+#include <gdk/gdk.h>
+#include <stdio.h>
+
+static GtkWidget* new_about_dialog(GtkWindow *parent, const gchar *msg) {
+   // gtk_message_dialog_new is variadic!  Can't call from cgo
+   GtkWidget *dialog;
+   dialog = gtk_message_dialog_new(
+       parent,
+       GTK_DIALOG_MODAL | GTK_DIALOG_DESTROY_WITH_PARENT,
+	   GTK_MESSAGE_INFO,
+	   GTK_BUTTONS_CLOSE,
+       msg);
+
+   g_signal_connect_swapped (dialog,
+                             "response",
+                             G_CALLBACK (gtk_widget_destroy),
+                             dialog);
+   return dialog;
+};
+
+*/
+import "C"
+import (
+	"fmt"
+	"unsafe"
+)
+
+const AlertStyleWarning = C.int(0)
+const AlertStyleInformational = C.int(1)
+const AlertStyleCritical = C.int(2)
+
+var alertTypeMap = map[DialogType]C.int{
+	WarningDialog:  AlertStyleWarning,
+	InfoDialog:     AlertStyleInformational,
+	ErrorDialog:    AlertStyleCritical,
+	QuestionDialog: AlertStyleInformational,
+}
+
+func setWindowIcon(window *C.GtkWindow, icon []byte) {
+	fmt.Println("setWindowIcon", len(icon))
+	loader := C.gdk_pixbuf_loader_new()
+	if loader == nil {
+		return
+	}
+	written := C.gdk_pixbuf_loader_write(
+		loader,
+		(*C.uchar)(&icon[0]),
+		C.ulong(len(icon)),
+		nil)
+	if written == 0 {
+		fmt.Println("failed to write icon")
+		return
+	}
+	C.gdk_pixbuf_loader_close(loader, nil)
+	pixbuf := C.gdk_pixbuf_loader_get_pixbuf(loader)
+	if pixbuf != nil {
+		fmt.Println("gtk_window_set_icon", window)
+		C.gtk_window_set_icon((*C.GtkWindow)(window), pixbuf)
+	}
+	C.g_object_unref(C.gpointer(loader))
+}
+
+func (m *linuxApp) showAboutDialog(title string, message string, icon []byte) {
+	globalApplication.dispatchOnMainThread(func() {
+		parent := C.gtk_application_get_active_window((*C.GtkApplication)(m.application))
+		cMsg := C.CString(message)
+		cTitle := C.CString(title)
+		defer C.free(unsafe.Pointer(cMsg))
+		defer C.free(unsafe.Pointer(cTitle))
+		dialog := C.new_about_dialog(parent, cMsg)
+		C.gtk_window_set_title(
+			(*C.GtkWindow)(unsafe.Pointer(dialog)),
+			cTitle)
+		//		setWindowIcon((*C.GtkWindow)(dialog), icon)
+		C.gtk_dialog_run((*C.GtkDialog)(unsafe.Pointer(dialog)))
+
+	})
+}
+
+type linuxDialog struct {
+	dialog *MessageDialog
+
+	//nsDialog unsafe.Pointer
+}
+
+func (m *linuxDialog) show() {
+	globalApplication.dispatchOnMainThread(func() {
+
+		// Mac can only have 4 Buttons on a dialog
+		if len(m.dialog.Buttons) > 4 {
+			m.dialog.Buttons = m.dialog.Buttons[:4]
+		}
+
+		// if m.nsDialog != nil {
+		// 	//C.releaseDialog(m.nsDialog)
+		// }
+		// var title *C.char
+		// if m.dialog.Title != "" {
+		// 	title = C.CString(m.dialog.Title)
+		// }
+		// var message *C.char
+		// if m.dialog.Message != "" {
+		// 	message = C.CString(m.dialog.Message)
+		// }
+		// var iconData unsafe.Pointer
+		// var iconLength C.int
+		// if m.dialog.Icon != nil {
+		// 	iconData = unsafe.Pointer(&m.dialog.Icon[0])
+		// 	iconLength = C.int(len(m.dialog.Icon))
+		// } else {
+		// 	// if it's an error, use the application Icon
+		// 	if m.dialog.DialogType == ErrorDialog {
+		// 		iconData = unsafe.Pointer(&globalApplication.options.Icon[0])
+		// 		iconLength = C.int(len(globalApplication.options.Icon))
+		// 	}
+		// }
+
+		// alertType, ok := alertTypeMap[m.dialog.DialogType]
+		// if !ok {
+		// 	alertType = AlertStyleInformational
+		// }
+
+		//		m.nsDialog = C.createAlert(alertType, title, message, iconData, iconLength)
+
+		// Reverse the Buttons so that the default is on the right
+		reversedButtons := make([]*Button, len(m.dialog.Buttons))
+		var count = 0
+		for i := len(m.dialog.Buttons) - 1; i >= 0; i-- {
+			//button := m.dialog.Buttons[i]
+			//C.alertAddButton(m.nsDialog, C.CString(button.Label), C.bool(button.IsDefault), C.bool(button.IsCancel))
+			reversedButtons[count] = m.dialog.Buttons[i]
+			count++
+		}
+
+		buttonPressed := int(0) //C.dialogRunModal(m.nsDialog))
+		if len(m.dialog.Buttons) > buttonPressed {
+			button := reversedButtons[buttonPressed]
+			if button.callback != nil {
+				button.callback()
+			}
+		}
+	})
+
+}
+
+func newDialogImpl(d *MessageDialog) *linuxDialog {
+	return &linuxDialog{
+		dialog: d,
+	}
+}
+
+type linuxOpenFileDialog struct {
+	dialog *OpenFileDialog
+}
+
+func newOpenFileDialogImpl(d *OpenFileDialog) *linuxOpenFileDialog {
+	return &linuxOpenFileDialog{
+		dialog: d,
+	}
+}
+
+func toCString(s string) *C.char {
+	if s == "" {
+		return nil
+	}
+	return C.CString(s)
+}
+
+func (m *linuxOpenFileDialog) show() ([]string, error) {
+	openFileResponses[m.dialog.id] = make(chan string)
+	//	nsWindow := unsafe.Pointer(nil)
+	if m.dialog.window != nil {
+		// get NSWindow from window
+		//nsWindow = m.dialog.window.impl.(*macosWebviewWindow).nsWindow
+	}
+
+	// Massage filter patterns into macOS format
+	// We iterate all filter patterns, tidy them up and then join them with a semicolon
+	// This should produce a single string of extensions like "png;jpg;gif"
+	// 	var filterPatterns string
+	// if len(m.dialog.filters) > 0 {
+	// 	var allPatterns []string
+	// 	for _, filter := range m.dialog.filters {
+	// 		patternComponents := strings.Split(filter.Pattern, ";")
+	// 		for i, component := range patternComponents {
+	// 			filterPattern := strings.TrimSpace(component)
+	// 			filterPattern = strings.TrimPrefix(filterPattern, "*.")
+	// 			patternComponents[i] = filterPattern
+	// 		}
+	// 		allPatterns = append(allPatterns, strings.Join(patternComponents, ";"))
+	// 	}
+	// 	filterPatterns = strings.Join(allPatterns, ";")
+	// }
+
+	// C.showOpenFileDialog(C.uint(m.dialog.id),
+	// 	C.bool(m.dialog.canChooseFiles),
+	// 	C.bool(m.dialog.canChooseDirectories),
+	// 	C.bool(m.dialog.canCreateDirectories),
+	// 	C.bool(m.dialog.showHiddenFiles),
+	// 	C.bool(m.dialog.allowsMultipleSelection),
+	// 	C.bool(m.dialog.resolvesAliases),
+	// 	C.bool(m.dialog.hideExtension),
+	// 	C.bool(m.dialog.treatsFilePackagesAsDirectories),
+	// 	C.bool(m.dialog.allowsOtherFileTypes),
+	// 	toCString(filterPatterns),
+	// 	C.uint(len(filterPatterns)),
+	// 	toCString(m.dialog.message),
+	// 	toCString(m.dialog.directory),
+	// 	toCString(m.dialog.buttonText),
+	// 	nsWindow)
+	var result []string
+	for filename := range openFileResponses[m.dialog.id] {
+		result = append(result, filename)
+	}
+	return result, nil
+}
+
+//export openFileDialogCallback
+func openFileDialogCallback(cid C.uint, cpath *C.char) {
+	path := C.GoString(cpath)
+	id := uint(cid)
+	channel, ok := openFileResponses[id]
+	if ok {
+		channel <- path
+	} else {
+		panic("No channel found for open file dialog")
+	}
+}
+
+//export openFileDialogCallbackEnd
+func openFileDialogCallbackEnd(cid C.uint) {
+	id := uint(cid)
+	channel, ok := openFileResponses[id]
+	if ok {
+		close(channel)
+		delete(openFileResponses, id)
+		freeDialogID(id)
+	} else {
+		panic("No channel found for open file dialog")
+	}
+}
+
+type linuxSaveFileDialog struct {
+	dialog *SaveFileDialog
+}
+
+func newSaveFileDialogImpl(d *SaveFileDialog) *linuxSaveFileDialog {
+	return &linuxSaveFileDialog{
+		dialog: d,
+	}
+}
+
+func (m *linuxSaveFileDialog) show() (string, error) {
+	saveFileResponses[m.dialog.id] = make(chan string)
+	//	nsWindow := unsafe.Pointer(nil)
+	if m.dialog.window != nil {
+		// get NSWindow from window
+		//		nsWindow = m.dialog.window.impl.(*linuxWebviewWindow).nsWindow
+	}
+
+	// C.showSaveFileDialog(C.uint(m.dialog.id),
+	// 	C.bool(m.dialog.canCreateDirectories),
+	// 	C.bool(m.dialog.showHiddenFiles),
+	// 	C.bool(m.dialog.canSelectHiddenExtension),
+	// 	C.bool(m.dialog.hideExtension),
+	// 	C.bool(m.dialog.treatsFilePackagesAsDirectories),
+	// 	C.bool(m.dialog.allowOtherFileTypes),
+	// 	toCString(m.dialog.message),
+	// 	toCString(m.dialog.directory),
+	// 	toCString(m.dialog.buttonText),
+	// 	toCString(m.dialog.filename),
+	// 	nsWindow)
+	return <-saveFileResponses[m.dialog.id], nil
+}
+
+//export saveFileDialogCallback
+func saveFileDialogCallback(cid C.uint, cpath *C.char) {
+	// Covert the path to a string
+	path := C.GoString(cpath)
+	id := uint(cid)
+	// put response on channel
+	channel, ok := saveFileResponses[id]
+	if ok {
+		channel <- path
+		close(channel)
+		delete(saveFileResponses, id)
+		freeDialogID(id)
+
+	} else {
+		panic("No channel found for save file dialog")
+	}
+}

v3/pkg/application/dialogs_linux_purego.go

@@ -0,0 +1,220 @@
+//go:build linux && purego
+
+package application
+
+const AlertStyleWarning = 0
+const AlertStyleInformational = 1
+const AlertStyleCritical = 2
+
+var alertTypeMap = map[DialogType]int{
+	WarningDialog:  AlertStyleWarning,
+	InfoDialog:     AlertStyleInformational,
+	ErrorDialog:    AlertStyleCritical,
+	QuestionDialog: AlertStyleInformational,
+}
+
+func (m *linuxApp) showAboutDialog(title string, message string, icon []byte) {
+	//	var iconData unsafe.Pointer
+	// if icon != nil {
+	// 	iconData = unsafe.Pointer(&icon[0])
+	// }
+	//C.showAboutBox(C.CString(title), C.CString(message), iconData, C.int(len(icon)))
+}
+
+type linuxDialog struct {
+	dialog *MessageDialog
+
+	//nsDialog unsafe.Pointer
+}
+
+func (m *linuxDialog) show() {
+	globalApplication.dispatchOnMainThread(func() {
+
+		// Mac can only have 4 Buttons on a dialog
+		if len(m.dialog.Buttons) > 4 {
+			m.dialog.Buttons = m.dialog.Buttons[:4]
+		}
+
+		// if m.nsDialog != nil {
+		// 	//C.releaseDialog(m.nsDialog)
+		// }
+		// var title *C.char
+		// if m.dialog.Title != "" {
+		// 	title = C.CString(m.dialog.Title)
+		// }
+		// var message *C.char
+		// if m.dialog.Message != "" {
+		// 	message = C.CString(m.dialog.Message)
+		// }
+		// var iconData unsafe.Pointer
+		// var iconLength C.int
+		// if m.dialog.Icon != nil {
+		// 	iconData = unsafe.Pointer(&m.dialog.Icon[0])
+		// 	iconLength = C.int(len(m.dialog.Icon))
+		// } else {
+		// 	// if it's an error, use the application Icon
+		// 	if m.dialog.DialogType == ErrorDialog {
+		// 		iconData = unsafe.Pointer(&globalApplication.options.Icon[0])
+		// 		iconLength = C.int(len(globalApplication.options.Icon))
+		// 	}
+		// }
+
+		// alertType, ok := alertTypeMap[m.dialog.DialogType]
+		// if !ok {
+		// 	alertType = AlertStyleInformational
+		// }
+
+		//		m.nsDialog = C.createAlert(alertType, title, message, iconData, iconLength)
+
+		// Reverse the Buttons so that the default is on the right
+		reversedButtons := make([]*Button, len(m.dialog.Buttons))
+		var count = 0
+		for i := len(m.dialog.Buttons) - 1; i >= 0; i-- {
+			//button := m.dialog.Buttons[i]
+			//C.alertAddButton(m.nsDialog, C.CString(button.Label), C.bool(button.IsDefault), C.bool(button.IsCancel))
+			reversedButtons[count] = m.dialog.Buttons[i]
+			count++
+		}
+
+		buttonPressed := int(0) //C.dialogRunModal(m.nsDialog))
+		if len(m.dialog.Buttons) > buttonPressed {
+			button := reversedButtons[buttonPressed]
+			if button.callback != nil {
+				button.callback()
+			}
+		}
+	})
+
+}
+
+func newDialogImpl(d *MessageDialog) *linuxDialog {
+	return &linuxDialog{
+		dialog: d,
+	}
+}
+
+type linuxOpenFileDialog struct {
+	dialog *OpenFileDialog
+}
+
+func newOpenFileDialogImpl(d *OpenFileDialog) *linuxOpenFileDialog {
+	return &linuxOpenFileDialog{
+		dialog: d,
+	}
+}
+
+func (m *linuxOpenFileDialog) show() ([]string, error) {
+	openFileResponses[m.dialog.id] = make(chan string)
+	//	nsWindow := unsafe.Pointer(nil)
+	if m.dialog.window != nil {
+		// get NSWindow from window
+		//nsWindow = m.dialog.window.impl.(*macosWebviewWindow).nsWindow
+	}
+
+	// Massage filter patterns into macOS format
+	// We iterate all filter patterns, tidy them up and then join them with a semicolon
+	// This should produce a single string of extensions like "png;jpg;gif"
+	// 	var filterPatterns string
+	// if len(m.dialog.filters) > 0 {
+	// 	var allPatterns []string
+	// 	for _, filter := range m.dialog.filters {
+	// 		patternComponents := strings.Split(filter.Pattern, ";")
+	// 		for i, component := range patternComponents {
+	// 			filterPattern := strings.TrimSpace(component)
+	// 			filterPattern = strings.TrimPrefix(filterPattern, "*.")
+	// 			patternComponents[i] = filterPattern
+	// 		}
+	// 		allPatterns = append(allPatterns, strings.Join(patternComponents, ";"))
+	// 	}
+	// 	filterPatterns = strings.Join(allPatterns, ";")
+	// }
+
+	// C.showOpenFileDialog(C.uint(m.dialog.id),
+	// 	C.bool(m.dialog.canChooseFiles),
+	// 	C.bool(m.dialog.canChooseDirectories),
+	// 	C.bool(m.dialog.canCreateDirectories),
+	// 	C.bool(m.dialog.showHiddenFiles),
+	// 	C.bool(m.dialog.allowsMultipleSelection),
+	// 	C.bool(m.dialog.resolvesAliases),
+	// 	C.bool(m.dialog.hideExtension),
+	// 	C.bool(m.dialog.treatsFilePackagesAsDirectories),
+	// 	C.bool(m.dialog.allowsOtherFileTypes),
+	// 	toCString(filterPatterns),
+	// 	C.uint(len(filterPatterns)),
+	// 	toCString(m.dialog.message),
+	// 	toCString(m.dialog.directory),
+	// 	toCString(m.dialog.buttonText),
+	// 	nsWindow)
+	var result []string
+	for filename := range openFileResponses[m.dialog.id] {
+		result = append(result, filename)
+	}
+	return result, nil
+}
+
+func openFileDialogCallback(id uint, path string) {
+	channel, ok := openFileResponses[id]
+	if ok {
+		channel <- path
+	} else {
+		panic("No channel found for open file dialog")
+	}
+}
+
+func openFileDialogCallbackEnd(id uint) {
+	channel, ok := openFileResponses[id]
+	if ok {
+		close(channel)
+		delete(openFileResponses, id)
+		freeDialogID(id)
+	} else {
+		panic("No channel found for open file dialog")
+	}
+}
+
+type linuxSaveFileDialog struct {
+	dialog *SaveFileDialog
+}
+
+func newSaveFileDialogImpl(d *SaveFileDialog) *linuxSaveFileDialog {
+	return &linuxSaveFileDialog{
+		dialog: d,
+	}
+}
+
+func (m *linuxSaveFileDialog) show() (string, error) {
+	saveFileResponses[m.dialog.id] = make(chan string)
+	//	nsWindow := unsafe.Pointer(nil)
+	if m.dialog.window != nil {
+		// get NSWindow from window
+		//		nsWindow = m.dialog.window.impl.(*linuxWebviewWindow).nsWindow
+	}
+
+	// C.showSaveFileDialog(C.uint(m.dialog.id),
+	// 	C.bool(m.dialog.canCreateDirectories),
+	// 	C.bool(m.dialog.showHiddenFiles),
+	// 	C.bool(m.dialog.canSelectHiddenExtension),
+	// 	C.bool(m.dialog.hideExtension),
+	// 	C.bool(m.dialog.treatsFilePackagesAsDirectories),
+	// 	C.bool(m.dialog.allowOtherFileTypes),
+	// 	toCString(m.dialog.message),
+	// 	toCString(m.dialog.directory),
+	// 	toCString(m.dialog.buttonText),
+	// 	toCString(m.dialog.filename),
+	// 	nsWindow)
+	return <-saveFileResponses[m.dialog.id], nil
+}
+
+func saveFileDialogCallback(cid uint, path string) {
+	// put response on channel
+	channel, ok := saveFileResponses[cid]
+	if ok {
+		channel <- path
+		close(channel)
+		delete(saveFileResponses, cid)
+		freeDialogID(cid)
+
+	} else {
+		panic("No channel found for save file dialog")
+	}
+}

v3/pkg/application/mainthread_linux.go

@@ -0,0 +1,51 @@
+//go:build linux
+
+package application
+
+/*
+#cgo linux pkg-config: gtk+-3.0
+
+#include <stdio.h>
+#include "gtk/gtk.h"
+
+typedef struct CallbackID
+{
+    unsigned int value;
+} CallbackID;
+
+extern void dispatchOnMainThreadCallback(unsigned int);
+
+static gboolean dispatchCallback(gpointer data) {
+    struct CallbackID *args = data;
+    unsigned int cid = args->value;
+    dispatchOnMainThreadCallback(cid);
+    free(args);
+
+    return G_SOURCE_REMOVE;
+};
+
+static void dispatchOnMainThread(unsigned int id) {
+    CallbackID *args = malloc(sizeof(CallbackID));
+    args->value = id;
+    g_idle_add((GSourceFunc)dispatchCallback, (gpointer)args);
+}
+
+*/
+import "C"
+
+func (m *linuxApp) dispatchOnMainThread(id uint) {
+	C.dispatchOnMainThread(C.uint(id))
+}
+
+//export dispatchOnMainThreadCallback
+func dispatchOnMainThreadCallback(callbackID C.uint) {
+	mainThreadFunctionStoreLock.RLock()
+	id := uint(callbackID)
+	fn := mainThreadFunctionStore[id]
+	if fn == nil {
+		Fatal("dispatchCallback called with invalid id: %v", id)
+	}
+	delete(mainThreadFunctionStore, id)
+	mainThreadFunctionStoreLock.RUnlock()
+	fn()
+}

v3/pkg/application/mainthread_linux_purego.go

@@ -0,0 +1,30 @@
+//go:build linux && purego
+
+package application
+
+import "github.com/ebitengine/purego"
+
+const (
+	G_SOURCE_REMOVE = 0
+)
+
+func (m *linuxApp) dispatchOnMainThread(id uint) {
+	var dispatch func(uintptr)
+	purego.RegisterLibFunc(&dispatch, gtk, "g_idle_add")
+	dispatch(purego.NewCallback(func(uintptr) int {
+		dispatchOnMainThreadCallback(id)
+		return G_SOURCE_REMOVE
+	}))
+}
+
+func dispatchOnMainThreadCallback(callbackID uint) {
+	mainThreadFunctionStoreLock.RLock()
+	id := uint(callbackID)
+	fn := mainThreadFunctionStore[id]
+	if fn == nil {
+		Fatal("dispatchCallback called with invalid id: %v", id)
+	}
+	delete(mainThreadFunctionStore, id)
+	mainThreadFunctionStoreLock.RUnlock()
+	fn()
+}

v3/pkg/application/menu_linux.go

@@ -0,0 +1,200 @@
+//go:build linux
+
+package application
+
+/*
+#cgo linux pkg-config: gtk+-3.0 webkit2gtk-4.0
+
+#include <gtk/gtk.h>
+#include <gdk/gdk.h>
+
+void handleClick(void*);
+*/
+import "C"
+import (
+	"fmt"
+	"unsafe"
+)
+
+var (
+	gtkSignalHandlers   map[*C.GtkWidget]C.gulong
+	gtkSignalToMenuItem map[*C.GtkWidget]*MenuItem
+)
+
+func init() {
+	gtkSignalHandlers = map[*C.GtkWidget]C.gulong{}
+	gtkSignalToMenuItem = map[*C.GtkWidget]*MenuItem{}
+}
+
+//export handleClick
+func handleClick(idPtr unsafe.Pointer) {
+	id := (*C.GtkWidget)(idPtr)
+	item, ok := gtkSignalToMenuItem[id]
+	if !ok {
+		return
+	}
+
+	//impl := (item.impl).(*linuxMenuItem)
+
+	switch item.itemType {
+	case text, checkbox:
+		processMenuItemClick(C.uint(item.id))
+	case radio:
+		menuItem := (item.impl).(*linuxMenuItem)
+		if menuItem.isChecked() {
+			processMenuItemClick(C.uint(item.id))
+		}
+	}
+}
+
+type linuxMenu struct {
+	menu   *Menu
+	native unsafe.Pointer
+}
+
+func newMenuImpl(menu *Menu) *linuxMenu {
+	result := &linuxMenu{
+		menu:   menu,
+		native: unsafe.Pointer(C.gtk_menu_bar_new()),
+	}
+	return result
+}
+
+func (m *linuxMenu) update() {
+	//	fmt.Println("linuxMenu.update()")
+	// if m.native != nil {
+	// 	C.gtk_widget_destroy((*C.GtkWidget)(m.native))
+	// 	m.native = unsafe.Pointer(C.gtk_menu_new())
+	// }
+	m.processMenu(m.menu)
+}
+
+func (m *linuxMenu) processMenu(menu *Menu) {
+	if menu.impl == nil {
+		menu.impl = &linuxMenu{
+			menu:   menu,
+			native: unsafe.Pointer(C.gtk_menu_new()),
+		}
+	}
+	var currentRadioGroup *C.GSList
+
+	for _, item := range menu.items {
+		// drop the group if we have run out of radio items
+		if item.itemType != radio {
+			currentRadioGroup = nil
+		}
+
+		switch item.itemType {
+		case submenu:
+			menuItem := newMenuItemImpl(item)
+			item.impl = menuItem
+			m.processMenu(item.submenu)
+			m.addSubMenuToItem(item.submenu, item)
+			m.addMenuItem(menu, item)
+		case text, checkbox:
+			menuItem := newMenuItemImpl(item)
+			item.impl = menuItem
+			m.addMenuItem(menu, item)
+		case radio:
+			menuItem := newRadioItemImpl(item, currentRadioGroup)
+			item.impl = menuItem
+			m.addMenuItem(menu, item)
+			currentRadioGroup = C.gtk_radio_menu_item_get_group((*C.GtkRadioMenuItem)(menuItem.native))
+		case separator:
+			m.addMenuSeparator(menu)
+		}
+
+	}
+
+	for _, item := range menu.items {
+		if item.callback != nil {
+			m.attachHandler(item)
+		}
+	}
+
+}
+
+func (m *linuxMenu) attachHandler(item *MenuItem) {
+	signal := C.CString("activate")
+	defer C.free(unsafe.Pointer(signal))
+
+	impl := (item.impl).(*linuxMenuItem)
+	widget := impl.native
+	flags := C.GConnectFlags(0)
+	handlerId := C.g_signal_connect_object(
+		C.gpointer(widget),
+		signal,
+		C.GCallback(C.handleClick),
+		C.gpointer(widget),
+		flags)
+
+	id := (*C.GtkWidget)(widget)
+	gtkSignalToMenuItem[id] = item
+	gtkSignalHandlers[id] = handlerId
+	impl.handlerId = handlerId
+}
+
+func (m *linuxMenu) addSubMenuToItem(menu *Menu, item *MenuItem) {
+	if menu.impl == nil {
+		menu.impl = &linuxMenu{
+			menu:   menu,
+			native: unsafe.Pointer(C.gtk_menu_new()),
+		}
+	}
+
+	C.gtk_menu_item_set_submenu(
+		(*C.GtkMenuItem)((item.impl).(*linuxMenuItem).native),
+		(*C.GtkWidget)((menu.impl).(*linuxMenu).native))
+
+	if item.role == ServicesMenu {
+		// FIXME: what does this mean?
+	}
+}
+
+func (m *linuxMenu) addMenuItem(parent *Menu, menu *MenuItem) {
+	//	fmt.Println("addMenuIteam", fmt.Sprintf("%+v", parent), fmt.Sprintf("%+v", menu))
+	C.gtk_menu_shell_append(
+		(*C.GtkMenuShell)((parent.impl).(*linuxMenu).native),
+		(*C.GtkWidget)((menu.impl).(*linuxMenuItem).native),
+	)
+	/*
+		C.gtk_menu_item_set_submenu(
+			(*C.struct__GtkMenuItem)((menu.impl).(*linuxMenuItem).native),
+			(*C.struct__GtkWidget)((parent.impl).(*linuxMenu).native),
+		)
+	*/
+}
+
+func (m *linuxMenu) addMenuSeparator(menu *Menu) {
+	//	fmt.Println("addMenuSeparator", fmt.Sprintf("%+v", menu))
+	sep := C.gtk_separator_menu_item_new()
+	native := (menu.impl).(*linuxMenu).native
+	C.gtk_menu_shell_append((*C.GtkMenuShell)(native), sep)
+}
+
+func (m *linuxMenu) addServicesMenu(menu *Menu) {
+	fmt.Println("addServicesMenu - not implemented")
+	//C.addServicesMenu(unsafe.Pointer(menu.impl.(*linuxMenu).nsMenu))
+}
+
+func (l *linuxMenu) createMenu(name string, items []*MenuItem) *Menu {
+	impl := newMenuImpl(&Menu{label: name})
+	menu := &Menu{
+		label: name,
+		items: items,
+		impl:  impl,
+	}
+	impl.menu = menu
+	return menu
+}
+
+func defaultApplicationMenu() *Menu {
+	menu := NewMenu()
+	menu.AddRole(AppMenu)
+	menu.AddRole(FileMenu)
+	menu.AddRole(EditMenu)
+	menu.AddRole(ViewMenu)
+	menu.AddRole(WindowMenu)
+	menu.AddRole(HelpMenu)
+	return menu
+}

v3/pkg/application/menu_linux_purego.go

@@ -0,0 +1,179 @@
+//go:build linux && purego
+
+package application
+
+import (
+	"fmt"
+
+	"github.com/ebitengine/purego"
+)
+
+type linuxMenu struct {
+	menu   *Menu
+	native uintptr
+}
+
+func newMenuImpl(menu *Menu) *linuxMenu {
+	var newMenuBar func() uintptr
+	purego.RegisterLibFunc(&newMenuBar, gtk, "gtk_menu_bar_new")
+	result := &linuxMenu{
+		menu:   menu,
+		native: newMenuBar(),
+	}
+	return result
+}
+
+func (m *linuxMenu) update() {
+	m.processMenu(m.menu)
+}
+
+func (m *linuxMenu) processMenu(menu *Menu) {
+	var newMenu func() uintptr
+	purego.RegisterLibFunc(&newMenu, gtk, "gtk_menu_new")
+	if menu.impl == nil {
+		menu.impl = &linuxMenu{
+			menu:   menu,
+			native: newMenu(),
+		}
+	}
+	var currentRadioGroup uintptr
+
+	for _, item := range menu.items {
+		// drop the group if we have run out of radio items
+		if item.itemType != radio {
+			currentRadioGroup = 0
+		}
+
+		switch item.itemType {
+		case submenu:
+			menuItem := newMenuItemImpl(item)
+			item.impl = menuItem
+			m.processMenu(item.submenu)
+			m.addSubMenuToItem(item.submenu, item)
+			m.addMenuItem(menu, item)
+		case text, checkbox:
+			menuItem := newMenuItemImpl(item)
+			item.impl = menuItem
+			m.addMenuItem(menu, item)
+		case radio:
+			menuItem := newRadioItemImpl(item, currentRadioGroup)
+			item.impl = menuItem
+			m.addMenuItem(menu, item)
+
+			var radioGetGroup func(uintptr) uintptr
+			purego.RegisterLibFunc(&radioGetGroup, gtk, "gtk_radio_menu_item_get_group")
+
+			currentRadioGroup = radioGetGroup(menuItem.native)
+		case separator:
+			m.addMenuSeparator(menu)
+		}
+
+	}
+
+	for _, item := range menu.items {
+		if item.callback != nil {
+			m.attachHandler(item)
+		}
+	}
+
+}
+
+func (m *linuxMenu) attachHandler(item *MenuItem) {
+	impl := (item.impl).(*linuxMenuItem)
+	widget := impl.native
+	flags := 0
+
+	var handleClick = func() {
+		item := item
+		switch item.itemType {
+		case text, checkbox:
+			processMenuItemClick(item.id)
+		case radio:
+			menuItem := (item.impl).(*linuxMenuItem)
+			if menuItem.isChecked() {
+				processMenuItemClick(item.id)
+			}
+		default:
+			fmt.Println("handleClick", item.itemType, item.id)
+		}
+	}
+
+	var signalConnectObject func(uintptr, string, uintptr, uintptr, int) uint
+	purego.RegisterLibFunc(&signalConnectObject, gtk, "g_signal_connect_object")
+	handlerId := signalConnectObject(
+		widget,
+		"activate",
+		purego.NewCallback(handleClick),
+		widget,
+		flags)
+
+	impl.handlerId = handlerId
+}
+
+func (m *linuxMenu) addSubMenuToItem(menu *Menu, item *MenuItem) {
+	var newMenu func() uintptr
+	purego.RegisterLibFunc(&newMenu, gtk, "gtk_menu_new")
+	if menu.impl == nil {
+		menu.impl = &linuxMenu{
+			menu:   menu,
+			native: newMenu(),
+N		}
+	}
+	var itemSetSubmenu func(uintptr, uintptr)
+	purego.RegisterLibFunc(&itemSetSubmenu, gtk, "gtk_menu_item_set_submenu")
+
+	itemSetSubmenu(
+		(item.impl).(*linuxMenuItem).native,
+		(menu.impl).(*linuxMenu).native)
+
+	if item.role == ServicesMenu {
+		// FIXME: what does this mean?
+	}
+}
+
+func (m *linuxMenu) addMenuItem(parent *Menu, menu *MenuItem) {
+	var shellAppend func(uintptr, uintptr)
+	purego.RegisterLibFunc(&shellAppend, gtk, "gtk_menu_shell_append")
+	shellAppend(
+		(parent.impl).(*linuxMenu).native,
+		(menu.impl).(*linuxMenuItem).native,
+	)
+}
+
+func (m *linuxMenu) addMenuSeparator(menu *Menu) {
+	var newSeparator func() uintptr
+	purego.RegisterLibFunc(&newSeparator, gtk, "gtk_separator_menu_item_new")
+	var shellAppend func(uintptr, uintptr)
+	purego.RegisterLibFunc(&shellAppend, gtk, "gtk_menu_shell_append")
+
+	sep := newSeparator()
+	native := (menu.impl).(*linuxMenu).native
+	shellAppend(native, sep)
+}
+
+func (m *linuxMenu) addServicesMenu(menu *Menu) {
+	fmt.Println("addServicesMenu - not implemented")
+	//C.addServicesMenu(unsafe.Pointer(menu.impl.(*linuxMenu).nsMenu))
+}
+
+func (l *linuxMenu) createMenu(name string, items []*MenuItem) *Menu {
+	impl := newMenuImpl(&Menu{label: name})
+	menu := &Menu{
+		label: name,
+		items: items,
+		impl:  impl,
+	}
+	impl.menu = menu
+	return menu
+}
+
+func defaultApplicationMenu() *Menu {
+	menu := NewMenu()
+	menu.AddRole(AppMenu)
+	menu.AddRole(FileMenu)
+	menu.AddRole(EditMenu)
+	menu.AddRole(ViewMenu)
+	menu.AddRole(WindowMenu)
+	menu.AddRole(HelpMenu)
+	return menu
+}

v3/pkg/application/menuitem.go

@@ -203,7 +203,9 @@ func (m *MenuItem) handleClick() {
 	if m.itemType == radio {
 		for _, member := range m.radioGroupMembers {
 			member.checked = false
-			member.impl.setChecked(false)
+			if member.impl != nil {
+				member.impl.setChecked(false)
+			}
 		}
 		m.checked = true
 		ctx.withChecked(true)