Golang webkit_javascript_result_get_value Examples

Example #1

File: webview.go Project: visionect/go-webkit2

// 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)
}

Example #2

File: callbacks.go Project: auroralaboratories/go-webkit2

//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))
				}
			}
		}
	}
}