Refactor the callback mechanism used by runJavaScript

This prepares the way for other API made async like toHtml and
toPlainText.

Use a callback class with an implicit templated constructor to carry
the functor across the API boundary and avoid the intermediate helper
method as the ABI that we have to maintain.

Also pass the callback result through WebContentsAdapterClient using
a bookkeeping ID instead of transferring the callback to
WebContentsAdapter. This will allow other calls, which might not
already allow passing a callback functor, to use a consisten way
of carrying back the result to the top API layer.

Change-Id: Ia923767b9c1021a108c26da17d4c41878ef7cb95
Reviewed-by: Pierre Rossi <pierre.rossi@gmail.com>

1 files changed, 8 insertions, 12 deletions

diff --git a/src/webenginewidgets/api/qwebenginepage.cpp b/src/webenginewidgets/api/qwebenginepage.cpp
index 54abb4384..8192f38ed 100644
--- a/src/webenginewidgets/api/qwebenginepage.cpp
+++ b/src/webenginewidgets/api/qwebenginepage.cpp
@@ -146,6 +146,11 @@ void QWebEnginePagePrivate::close()
     Q_EMIT q->windowCloseRequested();
 }
 
+void QWebEnginePagePrivate::didRunJavaScript(const QVariant& result, quint64 requestId)
+{
+    (*m_variantCallbacks.take(requestId))(result);
+}
+
 void QWebEnginePagePrivate::updateAction(QWebEnginePage::WebAction action) const
 {
 #ifdef QT_NO_ACTION
@@ -490,20 +495,11 @@ void QWebEnginePage::runJavaScript(const QString &scriptSource, const QString &x
     d->adapter->runJavaScript(scriptSource, xPath);
 }
 
-namespace {
-struct JSCallbackFunctor : public JSCallbackBase {
-    JSCallbackFunctor(QtWebEnginePrivate::FunctorBase *functor) : m_func(functor) { }
-    ~JSCallbackFunctor() { delete m_func; }
-    void call(const QVariant &value) { (*m_func)(value); }
-private:
-    QtWebEnginePrivate::FunctorBase *m_func;
-};
-}
-
-void QWebEnginePage::runJavaScriptHelper(const QString &source, QtWebEnginePrivate::FunctorBase *functor, const QString &xPath)
+void QWebEnginePage::runJavaScript(const QString& scriptSource, const QWebEngineCallback<const QVariant &> &resultCallback, const QString &xPath)
 {
     Q_D(QWebEnginePage);
-    d->adapter->runJavaScript(source, xPath, new JSCallbackFunctor(functor));
+    quint64 requestId = d->adapter->runJavaScriptCallbackResult(scriptSource, xPath);
+    d->m_variantCallbacks.insert(requestId, resultCallback.d);
 }
 
 QWebEnginePage *QWebEnginePage::createWindow(WebWindowType type)