Add DNS prefetching

Turns out we did no have DNS prefetching. It requires an extra
component. The same component can also do pre-connect, but we do not
enable that, as it requires a predictive browsing backend.

[ChangeLog][Settings] DnsPrefetchEnabled added, but disabled by default.

Change-Id: Ieb036435b9f1a72a7be302e38e89e0c347c7176b
Reviewed-by: Jüri Valdmann <juri.valdmann@qt.io>

1 files changed, 22 insertions, 0 deletions

diff --git a/src/webengine/api/qquickwebenginesettings.cpp b/src/webengine/api/qquickwebenginesettings.cpp
index 6203f20f1..6e96e76cf 100644
--- a/src/webengine/api/qquickwebenginesettings.cpp
+++ b/src/webengine/api/qquickwebenginesettings.cpp
@@ -443,6 +443,20 @@ bool QQuickWebEngineSettings::javascriptCanPaste() const
 }
 
 /*!
+    \qmlproperty bool WebEngineSettings::dnsPrefetchEnabled
+    \since QtWebEngine 1.8
+
+    Enables speculative prefetching of DNS records for HTML links before
+    they are activated.
+
+    Disabled by default.
+*/
+bool QQuickWebEngineSettings::dnsPrefetchEnabled() const
+{
+    return d_ptr->testAttribute(WebEngineSettings::DnsPrefetchEnabled);
+}
+
+/*!
     \qmlproperty string WebEngineSettings::defaultTextEncoding
     \since QtWebEngine 1.2
 
@@ -692,6 +706,14 @@ void QQuickWebEngineSettings::setJavascriptCanPaste(bool on)
         Q_EMIT javascriptCanPasteChanged();
 }
 
+void QQuickWebEngineSettings::setDnsPrefetchEnabled(bool on)
+{
+    bool wasOn = d_ptr->testAttribute(WebEngineSettings::DnsPrefetchEnabled);
+    d_ptr->setAttribute(WebEngineSettings::DnsPrefetchEnabled, on);
+    if (wasOn != on)
+        Q_EMIT dnsPrefetchEnabledChanged();
+}
+
 void QQuickWebEngineSettings::setUnknownUrlSchemePolicy(QQuickWebEngineSettings::UnknownUrlSchemePolicy policy)
 {
     WebEngineSettings::UnknownUrlSchemePolicy oldPolicy = d_ptr->unknownUrlSchemePolicy();