Init QQuickStyle's base URL to avoid creating temp QQmlEngine

Initialize the base URL from QtQuickControls2Plugin::registerTypes()
to avoid creating an unnecessary temporary instance of QQmlEngine. It
was used to list all known import paths, which were scanned for the
requested style folder. Now that we pass the base URL, the built-in
styles (a name without path to the style) can be looked up straight
from the base path.

Change-Id: I0d68d4c5bb90a4ab89660b5ce97f6433aeefc1ff
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

1 files changed, 14 insertions, 3 deletions

diff --git a/src/quickcontrols2/qquickstyle.cpp b/src/quickcontrols2/qquickstyle.cpp
index f432eded..bee837e9 100644
--- a/src/quickcontrols2/qquickstyle.cpp
+++ b/src/quickcontrols2/qquickstyle.cpp
@@ -35,6 +35,7 @@
 ****************************************************************************/
 
 #include "qquickstyle.h"
+#include "qquickstyle_p.h"
 #include "qquickstyleattached_p.h"
 
 #include <QtCore/qdir.h>
@@ -88,8 +89,6 @@ struct QQuickStyleSpec
 
     QString name()
     {
-        if (!resolved)
-            resolve();
         return style.mid(style.lastIndexOf(QLatin1Char('/')) + 1);
     }
 
@@ -110,7 +109,7 @@ struct QQuickStyleSpec
         resolve();
     }
 
-    void resolve()
+    void resolve(const QUrl &baseUrl = QUrl())
     {
         if (style.isEmpty())
             style = QGuiApplicationPrivate::styleOverride;
@@ -122,6 +121,13 @@ struct QQuickStyleSpec
                 style = settings->value(QStringLiteral("Style")).toString();
         }
 
+        if (baseUrl.isValid()) {
+            if (style.isEmpty())
+                style = baseUrl.toString(QUrl::StripTrailingSlash) + QLatin1Char('/');
+            else if (!style.contains(QLatin1Char('/')))
+                style = baseUrl.toString(QUrl::StripTrailingSlash) + QLatin1Char('/') + style;
+        }
+
         if (QGuiApplication::instance()) {
             if (!style.contains(QLatin1Char('/'))) {
                 const QString targetPath = QStringLiteral("QtQuick/Controls.2");
@@ -158,6 +164,11 @@ struct QQuickStyleSpec
 
 Q_GLOBAL_STATIC(QQuickStyleSpec, styleSpec)
 
+void QQuickStylePrivate::init(const QUrl &baseUrl)
+{
+    styleSpec()->resolve(baseUrl);
+}
+
 /*!
     Returns the name of the application style.