Simplify the style plugins code a bit

QQuickProxyTheme's destructor restores platform_theme,
so keep proxy theme around and destroy it when we don't need it anymore.

Change-Id: I2fef7c295251af1cd944cea27531c1c117d34d51
Reviewed-by: J-P Nurmi <jpnurmi@theqtcompany.com>

1 files changed, 6 insertions, 13 deletions

diff --git a/src/imports/controls/universal/qtquickuniversalstyleplugin.cpp b/src/imports/controls/universal/qtquickuniversalstyleplugin.cpp
index 952f0302..371b94ed 100644
--- a/src/imports/controls/universal/qtquickuniversalstyleplugin.cpp
+++ b/src/imports/controls/universal/qtquickuniversalstyleplugin.cpp
@@ -62,12 +62,12 @@ class QtQuickUniversalStylePlugin: public QQmlExtensionPlugin
 
 public:
     QtQuickUniversalStylePlugin(QObject *parent = nullptr);
-    ~QtQuickUniversalStylePlugin();
+
     void registerTypes(const char *uri) override;
     void initializeEngine(QQmlEngine *engine, const char *uri) override;
 
 private:
-    QQuickProxyTheme *theme;
+    QScopedPointer<QQuickProxyTheme> theme;
 };
 
 QtQuickUniversalStylePlugin::QtQuickUniversalStylePlugin(QObject *parent) : QQmlExtensionPlugin(parent)
@@ -75,15 +75,6 @@ QtQuickUniversalStylePlugin::QtQuickUniversalStylePlugin(QObject *parent) : QQml
     initResources();
 }
 
-QtQuickUniversalStylePlugin::~QtQuickUniversalStylePlugin()
-{
-    if (theme) {
-        QPlatformTheme *old = theme->theme();
-        QGuiApplicationPrivate::platform_theme = old;
-        delete theme;
-    }
-}
-
 void QtQuickUniversalStylePlugin::registerTypes(const char *uri)
 {
     qmlRegisterUncreatableType<QQuickUniversalStyle>(uri, 1, 0, "Universal", tr("Universal is an attached property"));
@@ -91,8 +82,10 @@ void QtQuickUniversalStylePlugin::registerTypes(const char *uri)
 
 void QtQuickUniversalStylePlugin::initializeEngine(QQmlEngine *engine, const char *uri)
 {
-    if (QQuickStyle::name().compare(QLatin1String("universal"), Qt::CaseInsensitive) == 0)
-        QGuiApplicationPrivate::platform_theme = new QQuickUniversalTheme;
+    if (QQuickStyle::name().compare(QLatin1String("universal"), Qt::CaseInsensitive) == 0) {
+        theme.reset(new QQuickUniversalTheme);
+        QGuiApplicationPrivate::platform_theme = theme.data();
+    }
 
     engine->addImageProvider(QStringLiteral("universal"), new QQuickColorImageProvider(QStringLiteral(":/qt-project.org/imports/Qt/labs/controls/universal/images")));