Add SetHtml (#60)

Author: gizmo-ds

common.go

@@ -58,6 +58,10 @@ type WebView interface {
 	// properly, webview will re-encode it for you.
 	Navigate(url string)
 
+	// SetHtml sets the webview HTML directly.
+	// The origin of the page is `about:blank`.
+	SetHtml(html string)
+
 	// Init injects JavaScript code at the initialization of the new page. Every
 	// time the webview will open a the new page - this initialization code will
 	// be executed. It is guaranteed that code is executed before window.onload.

pkg/edge/chromium.go

@@ -120,6 +120,13 @@ func (e *Chromium) Navigate(url string) {
 	)
 }
 
+func (e *Chromium) NavigateToString(htmlContent string) {
+	_, _, _ = e.webview.vtbl.NavigateToString.Call(
+		uintptr(unsafe.Pointer(e.webview)),
+		uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(htmlContent))),
+	)
+}
+
 func (e *Chromium) Init(script string) {
 	_, _, _ = e.webview.vtbl.AddScriptToExecuteOnDocumentCreated.Call(
 		uintptr(unsafe.Pointer(e.webview)),

webview.go

@@ -39,6 +39,7 @@ type browser interface {
 	Embed(hwnd uintptr) bool
 	Resize()
 	Navigate(url string)
+	NavigateToString(htmlContent string)
 	Init(script string)
 	Eval(script string)
 	NotifyParentWindowPositionChanged() error
@@ -389,6 +390,10 @@ func (w *webview) Navigate(url string) {
 	w.browser.Navigate(url)
 }
 
+func (w *webview) SetHtml(html string) {
+	w.browser.NavigateToString(html)
+}
+
 func (w *webview) SetTitle(title string) {
 	_title, err := windows.UTF16FromString(title)
 	if err != nil {