QQuickStyleSelector: fix built-in file selectors

While selecting style files, the standard built-in platform and local
file selectors ("+linux", "+macos", "+windows"...) must be prefixed
with the standard file selector indicator ("+"). Previously the style
selector would not pick up platform-specific style files unless they
were supplied without the prefix.

[ChangeLog][Controls][Styles] Fixed the style selection mechanism so
that now it is possible to organize platform and locale-specific files
into sub-directories, such as "+linux", "+macos", and "+windows".

Change-Id: Ia44b6f14fd0247943486fd27609147827bda9666
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

1 files changed, 10 insertions, 2 deletions

diff --git a/src/quickcontrols2/qquickstyleselector.cpp b/src/quickcontrols2/qquickstyleselector.cpp
index 6d04c190..0e403dc1 100644
--- a/src/quickcontrols2/qquickstyleselector.cpp
+++ b/src/quickcontrols2/qquickstyleselector.cpp
@@ -65,13 +65,21 @@ static QString ensureSlash(const QString &path)
     return path + QLatin1Char('/');
 }
 
+static QStringList prefixedPlatformSelectors(const QChar &prefix)
+{
+    QStringList selectors = QFileSelectorPrivate::platformSelectors();
+    for (int i = 0; i < selectors.count(); ++i)
+        selectors[i].prepend(prefix);
+    return selectors;
+}
+
 static QStringList allSelectors(const QString &style = QString())
 {
-    static const QStringList platformSelectors = QFileSelectorPrivate::platformSelectors();
+    static const QStringList platformSelectors = prefixedPlatformSelectors(QLatin1Char('+'));
     QStringList selectors = platformSelectors;
     const QString locale = QLocale().name();
     if (!locale.isEmpty())
-        selectors += locale;
+        selectors += QLatin1Char('+') + locale;
     if (!style.isEmpty())
         selectors.prepend(style);
     return selectors;