// RunJavaScript runs script asynchronously in the context of the current page
// in the WebView. Upon completion, resultCallback will be called with the
// result of evaluating the script, or with an error encountered during
// execution. To get the stack trace and other error logs, use the
// ::console-message signal.
//
// See also: webkit_web_view_run_javascript at
// http://webkitgtk.org/reference/webkit2gtk/stable/WebKitWebView.html#webkit-web-view-run-javascript
func (v *WebView) RunJavaScript(script string, resultCallback func(result *gojs.Value, err error)) {
var cCallback C.GAsyncReadyCallback
var userData C.gpointer
var err error
if resultCallback != nil {
callback := func(result *C.GAsyncResult) {
var jserr *C.GError
jsResult := C.webkit_web_view_run_javascript_finish(v.webView, result, &jserr)
if jsResult == nil {
defer C.g_error_free(jserr)
msg := C.GoString((*C.char)(jserr.message))
resultCallback(nil, errors.New(msg))
return
}
ctxRaw := gojs.RawGlobalContext(unsafe.Pointer(C.webkit_javascript_result_get_global_context(jsResult)))
jsValRaw := gojs.RawValue(unsafe.Pointer(C.webkit_javascript_result_get_value(jsResult)))
ctx := (*gojs.Context)(gojs.NewGlobalContextFrom(ctxRaw))
jsVal := ctx.NewValueFrom(jsValRaw)
resultCallback(jsVal, nil)
}
cCallback, userData, err = newGAsyncReadyCallback(callback)
if err != nil {
panic(err)
}
}
cScript := C.CString(script)
defer C.free(unsafe.Pointer(cScript))
C.webkit_web_view_run_javascript(v.webView, (*C.gchar)(cScript), nil, cCallback, userData)
}
//export go_genericGAsyncCallback
func go_genericGAsyncCallback(source *C.GObject, result *C.GAsyncResult, callbackId *C.char) {
key := C.GoString(callbackId)
if obj, ok := cgoget(key); ok {
switch obj.(type) {
case *RunJavaScriptResponse:
var jserr *C.GError
response := obj.(*RunJavaScriptResponse)
if response.Autoremove {
defer cgounregister(key)
}
if jsResult := C.webkit_web_view_run_javascript_finish(response.CWebView, result, &jserr); jsResult == nil {
defer C.g_error_free(jserr)
msg := C.GoString((*C.char)(jserr.message))
response.Reply(nil, errors.New(msg))
} else {
ctxRaw := gojs.RawGlobalContext(unsafe.Pointer(C.webkit_javascript_result_get_global_context(jsResult)))
jsValRaw := gojs.RawValue(unsafe.Pointer(C.webkit_javascript_result_get_value(jsResult)))
ctx := (*gojs.Context)(gojs.NewGlobalContextFrom(ctxRaw))
jsVal := ctx.NewValueFrom(jsValRaw)
response.Reply(jsVal, nil)
}
case *GetSnapshotAsImageResponse:
var snapErr *C.GError
response := obj.(*GetSnapshotAsImageResponse)
if response.Autoremove {
defer cgounregister(key)
}
if snapResult := C.webkit_web_view_get_snapshot_finish(response.CWebView, result, &snapErr); snapResult == nil {
defer C.g_error_free(snapErr)
msg := C.GoString((*C.char)(snapErr.message))
response.Reply(nil, errors.New(msg))
} else {
defer C.cairo_surface_destroy(snapResult)
if C.cairo_surface_get_type(snapResult) != cairoSurfaceTypeImage ||
C.cairo_image_surface_get_format(snapResult) != cairoImageSurfaceFormatARGB32 {
response.Reply(nil, errors.New("Snapshot in unexpected format"))
return
}
w := int(C.cairo_image_surface_get_width(snapResult))
h := int(C.cairo_image_surface_get_height(snapResult))
stride := int(C.cairo_image_surface_get_stride(snapResult))
data := unsafe.Pointer(C.cairo_image_surface_get_data(snapResult))
surfaceBytes := C.GoBytes(data, C.int(stride*h))
// convert from b,g,r,a or a,r,g,b(local endianness) to r,g,b,a
testint, _ := binary.ReadUvarint(bytes.NewBuffer([]byte{0x1, 0}))
if testint == 0x1 {
// Little: b,g,r,a -> r,g,b,a
for i := 0; i < w*h; i++ {
b := surfaceBytes[4*i+0]
r := surfaceBytes[4*i+2]
surfaceBytes[4*i+0] = r
surfaceBytes[4*i+2] = b
}
} else {
// Big: a,r,g,b -> r,g,b,a
for i := 0; i < w*h; i++ {
a := surfaceBytes[4*i+0]
r := surfaceBytes[4*i+1]
g := surfaceBytes[4*i+2]
b := surfaceBytes[4*i+3]
surfaceBytes[4*i+0] = r
surfaceBytes[4*i+1] = g
surfaceBytes[4*i+2] = b
surfaceBytes[4*i+3] = a
}
}
rgba := &image.RGBA{
Pix: surfaceBytes,
Stride: stride,
Rect: image.Rect(0, 0, w, h),
}
response.Reply(rgba, nil)
}
case *GetSnapshotAsCairoSurfaceResponse:
var snapErr *C.GError
response := obj.(*GetSnapshotAsCairoSurfaceResponse)
snapResult := C.webkit_web_view_get_snapshot_finish(response.CWebView, result, &snapErr)
if snapResult == nil {
defer C.g_error_free(snapErr)
msg := C.GoString((*C.char)(snapErr.message))
response.Reply(nil, errors.New(msg))
} else {
surface := cairo.NewSurface(uintptr(unsafe.Pointer(snapResult)), false)
if status := surface.Status(); status == cairo.STATUS_SUCCESS {
response.Reply(surface, nil)
} else {
response.Reply(nil, fmt.Errorf("Cairo surface error %d", status))
}
}
}
}
}