Let QPlatformTheme decide which engine QIcon::fromTheme uses

By default we still use QIconLoaderEngine but now platform theme plugins
have the opportunity to override that. It is in particular planned to be
used in a WIP platform theme plugin for KDE sessions.

Change-Id: I07a82dc91daea44709b3a790f3f6e2a7a090d108
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: David Faure (KDE) <faure@kde.org>
Reviewed-by: Samuel Rødal <samuel.rodal@digia.com>
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@digia.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/src/gui/image/qicon.cpp b/src/gui/image/qicon.cpp
index dce902301c..6b91ead666 100644
--- a/src/gui/image/qicon.cpp
+++ b/src/gui/image/qicon.cpp
@@ -60,6 +60,7 @@
 
 #include "private/qhexstring_p.h"
 #include "private/qguiapplication_p.h"
+#include "qpa/qplatformtheme.h"
 
 #ifndef QT_NO_ICON
 QT_BEGIN_NAMESPACE
@@ -986,7 +987,10 @@ QIcon QIcon::fromTheme(const QString &name, const QIcon &fallback)
     if (qtIconCache()->contains(name)) {
         icon = *qtIconCache()->object(name);
     } else {
-        QIcon *cachedIcon  = new QIcon(new QIconLoaderEngine(name));
+        QPlatformTheme * const platformTheme = QGuiApplicationPrivate::platformTheme();
+        QIconEngine * const engine = platformTheme ? platformTheme->createIconEngine(name)
+                                                   : new QIconLoaderEngine(name);
+        QIcon *cachedIcon  = new QIcon(engine);
         qtIconCache()->insert(name, cachedIcon);
         icon = *cachedIcon;
     }