QNI: Add a convenience method for loading the default plugin

We have some official plugins, we may as well treat them as default
and give a convenient function which loads those.

Change-Id: I6251c77ac042b795bcf24b86e510e960ee4bab54
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

3 files changed, 65 insertions, 2 deletions

diff --git a/src/network/kernel/qnetworkinformation.cpp b/src/network/kernel/qnetworkinformation.cpp
index 79375dee81..4f0b1405ef 100644
--- a/src/network/kernel/qnetworkinformation.cpp
+++ b/src/network/kernel/qnetworkinformation.cpp
@@ -604,11 +604,62 @@ QNetworkInformation::Features QNetworkInformation::supportedFeatures() const
 }
 
 /*!
+    \since 6.3
+
+    Attempts to load the platform-default backend.
+
+    This platform-to-plugin mapping is as follows:
+
+    \table
+    \header
+        \li Platform
+        \li Plugin-name
+    \row
+        \li Windows
+        \li networklistmanager
+    \row
+        \li Apple (macOS/iOS)
+        \li scnetworkreachability
+    \row
+        \li Android
+        \li android
+    \row
+        \li Linux
+        \li networkmanager
+    \endtable
+
+    This function is provided for convenience where the default for a given
+    platform is good enough. If you are not using the default plugins you must
+    use one of the other load() overloads.
+
+    Returns \c true if it managed to load the backend or if it was already
+    loaded. Returns \c false otherwise.
+
+    \sa instance
+*/
+bool QNetworkInformation::load()
+{
+    int index = -1;
+#ifdef Q_OS_WIN
+    index = QNetworkInformationBackend::PluginNamesWindowsIndex;
+#elif defined(Q_OS_DARWIN)
+    index = QNetworkInformationBackend::PluginNamesAppleIndex;
+#elif defined(Q_OS_ANDROID)
+    index = QNetworkInformationBackend::PluginNamesAndroidIndex;
+#elif defined(Q_OS_LINUX)
+    index = QNetworkInformationBackend::PluginNamesLinuxIndex;
+#endif
+    if (index == -1)
+        return false;
+    return load(QNetworkInformationBackend::PluginNames[index]);
+}
+
+/*!
     Attempts to load a backend whose name matches \a backend
     (case insensitively).
 
     Returns \c true if it managed to load the requested backend or
-    if it was already loaded. Returns \c false otherwise
+    if it was already loaded. Returns \c false otherwise.
 
     \sa instance
 */
@@ -622,7 +673,7 @@ bool QNetworkInformation::load(QStringView backend)
     Load a backend which supports \a features.
 
     Returns \c true if it managed to load the requested backend or
-    if it was already loaded. Returns \c false otherwise
+    if it was already loaded. Returns \c false otherwise.
 
     \sa instance
 */
diff --git a/src/network/kernel/qnetworkinformation.h b/src/network/kernel/qnetworkinformation.h
index febf5bbc8f..e280894fef 100644
--- a/src/network/kernel/qnetworkinformation.h
+++ b/src/network/kernel/qnetworkinformation.h
@@ -96,6 +96,7 @@ public:
     bool supports(Features features) const;
     Features supportedFeatures() const;
 
+    static bool load();
     static bool load(QStringView backend);
     static bool load(Features features);
     static QStringList availableBackends();
diff --git a/src/network/kernel/qnetworkinformation_p.h b/src/network/kernel/qnetworkinformation_p.h
index ba07870be3..971340b6e3 100644
--- a/src/network/kernel/qnetworkinformation_p.h
+++ b/src/network/kernel/qnetworkinformation_p.h
@@ -67,6 +67,17 @@ class Q_NETWORK_EXPORT QNetworkInformationBackend : public QObject
     using TransportMedium = QNetworkInformation::TransportMedium;
 
 public:
+    static inline const char16_t PluginNames[4][22] = {
+        { u"networklistmanager" },
+        { u"scnetworkreachability" },
+        { u"android" },
+        { u"networkmanager" },
+    };
+    static constexpr int PluginNamesWindowsIndex = 0;
+    static constexpr int PluginNamesAppleIndex = 1;
+    static constexpr int PluginNamesAndroidIndex = 2;
+    static constexpr int PluginNamesLinuxIndex = 3;
+
     QNetworkInformationBackend() = default;
     ~QNetworkInformationBackend() override;