QDBusTrayIcon: Avoid needless initialization of a global var

TempFileTemplate is initialized each time an application starts.
It leads to the call of QStandardPaths::writableLocation(QStandardPaths::RuntimeLocation)
which is slow and can even change permissions of the runtime directory.
Use a static wrapper function to initialize this variable only when needed.

Change-Id: Ib620f9b842c88103c67f8dfab200f4d39c9981ee
Reviewed-by: Dmitry Shachnev <mitya57@gmail.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

1 files changed, 7 insertions, 2 deletions

diff --git a/src/platformsupport/themes/genericunix/dbustray/qdbustrayicon.cpp b/src/platformsupport/themes/genericunix/dbustray/qdbustrayicon.cpp
index 2153924ec8..e81d272d4f 100644
--- a/src/platformsupport/themes/genericunix/dbustray/qdbustrayicon.cpp
+++ b/src/platformsupport/themes/genericunix/dbustray/qdbustrayicon.cpp
@@ -90,12 +90,17 @@ static QString iconTempPath()
 
 static const QString KDEItemFormat = QStringLiteral("org.kde.StatusNotifierItem-%1-%2");
 static const QString KDEWatcherService = QStringLiteral("org.kde.StatusNotifierWatcher");
-static const QString TempFileTemplate = iconTempPath() + QLatin1String("/qt-trayicon-XXXXXX.png");
 static const QString XdgNotificationService = QStringLiteral("org.freedesktop.Notifications");
 static const QString XdgNotificationPath = QStringLiteral("/org/freedesktop/Notifications");
 static const QString DefaultAction = QStringLiteral("default");
 static int instanceCount = 0;
 
+static inline QString tempFileTemplate()
+{
+    static const QString TempFileTemplate = iconTempPath() + QLatin1String("/qt-trayicon-XXXXXX.png");
+    return TempFileTemplate;
+}
+
 /*!
     \class QDBusTrayIcon
     \internal
@@ -206,7 +211,7 @@ QTemporaryFile *QDBusTrayIcon::tempIcon(const QIcon &icon)
     if (!necessary)
         return nullptr;
     qreal dpr = qGuiApp->devicePixelRatio();
-    QTemporaryFile *ret = new QTemporaryFile(TempFileTemplate, this);
+    QTemporaryFile *ret = new QTemporaryFile(tempFileTemplate(), this);
     ret->open();
     icon.pixmap(QSize(22 * dpr, 22 * dpr)).save(ret);
     ret->close();