Add proof-of-concept support for keyboardButtonWebView.

Telegram/SourceFiles/facades.cpp

@@ -222,7 +222,14 @@ void activateBotCommand(
 	} break;
 
 	case ButtonType::WebView: {
-
+		if (const auto m = CheckMainWidget(&msg->history()->session())) {
+			if (const auto bot = msg->getMessageBot()) {
+				m->controller()->requestAttachWebview(
+					bot,
+					bot,
+					button->data);
+			}
+		}
 	} break;
 	}
 }

Telegram/SourceFiles/window/window_session_controller.cpp

@@ -429,12 +429,14 @@ void SessionNavigation::resolveAttachWebview(
 
 void SessionNavigation::requestAttachWebview(
 		not_null<PeerData*> peer,
-		not_null<UserData*> bot) {
+		not_null<UserData*> bot,
+		const QByteArray &url) {
+	using Flag = MTPmessages_RequestWebView::Flag;
 	_api.request(MTPmessages_RequestWebView(
-		MTP_flags(0),
+		MTP_flags(url.isEmpty() ? Flag(0) : Flag::f_url),
 		peer->input,
 		bot->inputUser,
-		MTPstring(), // start_param
+		MTP_bytes(url),
 		MTPDataJSON() // theme_params
 	)).done([=](const MTPWebViewResult &result) {
 		result.match([&](const MTPDwebViewResultUrl &data) {

Telegram/SourceFiles/window/window_session_controller.h

@@ -208,6 +208,10 @@ public:
 	void resolveAttachWebview(
 		not_null<PeerData*> peer,
 		const QString &botUsername);
+	void requestAttachWebview(
+		not_null<PeerData*> peer,
+		not_null<UserData*> bot,
+		const QByteArray &url = QByteArray());
 	[[nodiscard]] auto inlineResultConfirmed() const
 		-> rpl::producer<InlineBots::ResultSelected>;
 
@@ -278,9 +282,6 @@ private:
 		not_null<PeerData*> peer,
 		const PeerByLinkInfo &info);
 
-	void requestAttachWebview(
-		not_null<PeerData*> peer,
-		not_null<UserData*> bot);
 	void requestAddToMenu(not_null<UserData*> bot, Fn<void()> callback);
 	void showAttachWebview(
 		not_null<PeerData*> peer,