abstract the bit of data engine management code out into a small class that the private classes can then subclass, and add dataEngine(const QString &) to Wallpaper

svn path=/trunk/KDE/kdelibs/; revision=947636

applet.cpp

@@ -574,17 +574,7 @@ ConfigLoader *Applet::configScheme() const
 
 DataEngine *Applet::dataEngine(const QString &name) const
 {
-    int index = d->loadedEngines.indexOf(name);
-    if (index != -1) {
-        return DataEngineManager::self()->engine(name);
-    }
-
-    DataEngine *engine = DataEngineManager::self()->loadEngine(name);
-    if (engine->isValid()) {
-        d->loadedEngines.append(name);
-    }
-
-    return engine;
+    return d->dataEngine(name);
 }
 
 const Package *Applet::package() const
@@ -2035,10 +2025,6 @@ AppletPrivate::~AppletPrivate()
         activationAction->forgetGlobalShortcut();
     }
 
-    foreach (const QString &engine, loadedEngines) {
-        DataEngineManager::self()->unloadEngine(engine);
-    }
-
     if (extender) {
         delete extender;
         extender = 0;

private/applet_p.h

@@ -26,6 +26,8 @@
 
 #include <kactioncollection.h>
 
+#include "plasma/private/dataengineconsumer_p.h"
+
 class KKeySequenceWidget;
 
 namespace Plasma
@@ -51,7 +53,7 @@ protected Q_SLOTS:
     void overlayAnimationComplete();
 };
 
-class AppletPrivate
+class AppletPrivate : public DataEngineConsumer
 {
 public:
     AppletPrivate(KService::Ptr service, int uniqueID, Applet *applet);
@@ -107,7 +109,6 @@ public:
     AppletOverlayWidget *messageOverlay;
     Plasma::BusyWidget *busyWidget;
     QSet<QGraphicsItem*> registeredAsDragHandle;
-    QStringList loadedEngines;
     Plasma::FrameSvg *background;
     AppletScript *script;
     QVariantList args;

private/dataengineconsumer_p.h

@@ -0,0 +1,65 @@
+/*
+ *   Copyright 2005 by Aaron Seigo <aseigo@kde.org>
+ *   Copyright 2007 by Riccardo Iaconelli <riccardo@kde.org>
+ *   Copyright 2008 by Ménard Alexis <darktears31@gmail.com>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License as
+ *   published by the Free Software Foundation; either version 2, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details
+ *
+ *   You should have received a copy of the GNU Library General Public
+ *   License along with this program; if not, write to the
+ *   Free Software Foundation, Inc.,
+ *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#ifndef PLASMA_DATAENGINECONSUMER_H
+#define PLASMA_DATAENGINECONSUMER_H
+
+#include <QtCore/QStringList>
+
+#include "plasma/dataenginemanager.h"
+
+namespace Plasma
+{
+
+class DataEngineConsumer
+{
+public:
+    ~DataEngineConsumer()
+    {
+        foreach (const QString &engine, m_loadedEngines) {
+            DataEngineManager::self()->unloadEngine(engine);
+        }
+    }
+
+    DataEngine *dataEngine(const QString &name)
+    {
+        int index = m_loadedEngines.indexOf(name);
+        if (index != -1) {
+            return DataEngineManager::self()->engine(name);
+        }
+
+        DataEngine *engine = DataEngineManager::self()->loadEngine(name);
+        if (engine->isValid()) {
+            m_loadedEngines.append(name);
+        }
+
+        return engine;
+    }
+
+private:
+    QStringList m_loadedEngines;
+};
+
+} // namespace Plasma
+
+#endif
+
+

wallpaper.cpp

@@ -25,10 +25,12 @@
 
 #include <version.h>
 
+#include "plasma/private/dataengineconsumer_p.h"
+
 namespace Plasma
 {
 
-class WallpaperPrivate
+class WallpaperPrivate : public DataEngineConsumer
 {
 public:
     WallpaperPrivate(KService::Ptr service, Wallpaper *wallpaper) :
@@ -109,6 +111,7 @@ Wallpaper *Wallpaper::load(const QString &wallpaperName, const QVariantList &arg
     if (!wallpaper) {
         kDebug() << "Couldn't load wallpaper \"" << wallpaperName << "\"! reason given: " << error;
     }
+
     return wallpaper;
 }
 
@@ -237,6 +240,11 @@ void Wallpaper::wheelEvent(QGraphicsSceneWheelEvent *event)
     Q_UNUSED(event)
 }
 
+DataEngine *Wallpaper::dataEngine(const QString &name) const
+{
+    return d->dataEngine(name);
+}
+
 } // Plasma namespace
 
 #include "wallpaper.moc"

wallpaper.h

@@ -28,6 +28,8 @@
 
 namespace Plasma
 {
+
+class DataEngine;
 class WallpaperPrivate;
 
 /**
@@ -204,6 +206,25 @@ class PLASMA_EXPORT Wallpaper : public QObject
          */
         virtual void wheelEvent(QGraphicsSceneWheelEvent *event);
 
+        /**
+         * Loads the given DataEngine
+         *
+         * Tries to load the data engine given by @p name.  Each engine is
+         * only loaded once, and that instance is re-used on all subsequent
+         * requests.
+         *
+         * If the data engine was not found, an invalid data engine is returned
+         * (see DataEngine::isValid()).
+         *
+         * Note that you should <em>not</em> delete the returned engine.
+         *
+         * @param name Name of the data engine to load
+         * @return pointer to the data engine if it was loaded,
+         *         or an invalid data engine if the requested engine
+         *         could not be loaded
+         */
+        Q_INVOKABLE DataEngine *dataEngine(const QString &name) const;
+
     Q_SIGNALS:
         /**
          * This signal indicates that wallpaper needs to be repainted.