Pick the default style name at runtime instead of compile time

Instead of a naïve OS-based compile time check, we check which platform
plugin is in use at runtime. This should give a more accurate mapping,
especially on desktop OSes using alternative platform plugins where the
Desktop style is not useful.

The minimum Android SDK version is 16 now, so the check is removed.

Change-Id: Ie7af3a8ce5fd031256f5eba9706f24ab50a23bf9
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@qt.io>

1 files changed, 24 insertions, 12 deletions

diff --git a/src/controls/Private/qquickcontrolsettings.cpp b/src/controls/Private/qquickcontrolsettings.cpp
index d8cfdaed..95c656b2 100644
--- a/src/controls/Private/qquickcontrolsettings.cpp
+++ b/src/controls/Private/qquickcontrolsettings.cpp
@@ -58,19 +58,31 @@ QT_BEGIN_NAMESPACE
 
 static QString defaultStyleName()
 {
-    //Only enable QStyle support when we are using QApplication
-#if defined(QT_WIDGETS_LIB) && !defined(Q_OS_IOS) && !defined(Q_OS_ANDROID) && !defined(Q_OS_BLACKBERRY) && !defined(Q_OS_QNX) && !defined(Q_OS_WINRT)
-    if (QCoreApplication::instance()->inherits("QApplication"))
-        return QLatin1String("Desktop");
-#elif defined(Q_OS_ANDROID) && !defined(Q_OS_ANDROID_EMBEDDED)
-    if (QtAndroidPrivate::androidSdkVersion() >= 11)
-        return QLatin1String("Android");
-#elif defined(Q_OS_IOS)
-    return QLatin1String("iOS");
-#elif defined(Q_OS_WINRT) && 0 // Enable once style is ready
-    return QLatin1String("WinRT");
+    static const QMap<QString, QString> styleMap {
+#if defined(QT_WIDGETS_LIB)
+        {QLatin1String("cocoa"), QLatin1String("Desktop")},
+        {QLatin1String("wayland"), QLatin1String("Desktop")},
+        {QLatin1String("windows"), QLatin1String("Desktop")},
+        {QLatin1String("xcb"), QLatin1String("Desktop")},
 #endif
-    return QLatin1String("Base");
+        {QLatin1String("android"), QLatin1String("Android")},
+        {QLatin1String("ios"), QLatin1String("iOS")},
+#if 0 // Enable once style is ready
+        {QLatin1String("winrt"), QLatin1String("WinRT")},
+#endif
+    };
+
+    QGuiApplication *app = static_cast<QGuiApplication *>(
+        QCoreApplication::instance());
+    const QString styleName = styleMap.value(app->platformName(), QLatin1String("Base"));
+
+#if defined(QT_WIDGETS_LIB)
+    // Only enable QStyle support when we are using QApplication
+    if (styleName == QLatin1String("Desktop") && !app->inherits("QApplication"))
+        return QLatin1String("Base");
+#endif
+
+    return styleName;
 }
 
 static QString styleEnvironmentVariable()