simple way to fetch the correct files from l&f

a little class that loads files from the configured l&f package
with fallback to the default one
provides a signal when the theme changes, for things that need to react at runtime

ksplash/ksplashqml/CMakeLists.txt

@@ -6,6 +6,7 @@ set(ksplashqml_SRCS
     main.cpp
     SplashApp.cpp
     SplashWindow.cpp
+    ../../lookandfeelaccess/lookandfeelaccess.cpp
    )
 
 add_executable(ksplashqml ${ksplashqml_SRCS})

ksplash/ksplashqml/SplashWindow.cpp

@@ -18,6 +18,7 @@
  */
 
 #include "SplashWindow.h"
+#include "../../lookandfeelaccess/lookandfeelaccess.h"
 
 #include <QQmlContext>
 #include <QQuickItem>
@@ -26,7 +27,6 @@
 #include <QTimer>
 #include <QStandardPaths>
 #include <QSurfaceFormat>
-#include <shellpluginloader.h>
 
 SplashWindow::SplashWindow(bool testing, bool window)
     : QQuickView(),
@@ -85,10 +85,8 @@ void SplashWindow::setGeometry(const QRect& rect)
     QQuickView::setGeometry(rect);
 
     if (oldGeometryEmpty) {
-        ShellPluginLoader::init();
-        Plasma::Package pkg = Plasma::PluginLoader::self()->loadPackage("Plasma/LookAndFeel");
-        pkg.setPath("org.kde.lookandfeel");
+        LookAndFeelAccess access;
 
-        setSource(QUrl::fromLocalFile(pkg.filePath("splashmainscript")));
+        setSource(QUrl::fromLocalFile(access.filePath("splashmainscript")));
     }
 }

lookandfeelaccess/lookandfeelaccess.cpp

@@ -0,0 +1,120 @@
+/*
+ *   Copyright 2014 Marco Martin <notmart@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.
+ */
+
+
+#include "lookandfeelaccess.h"
+
+#include "shellpluginloader.h"
+
+#include <QDebug>
+#include <KDirWatch>
+#include <KSharedConfig>
+
+class LookAndFeelAccessPrivate
+{
+public:
+    LookAndFeelAccessPrivate(LookAndFeelAccess *access)
+        : q(access)
+    {
+    }
+
+    void settingsFileChanged();
+
+
+    LookAndFeelAccess *q;
+    Plasma::Package package;
+    Plasma::Package defaultPackage;
+    KSharedConfig::Ptr config;
+};
+
+void LookAndFeelAccessPrivate::settingsFileChanged()
+{
+    config->reparseConfiguration();
+    KConfigGroup cg(config, "KDE");
+
+    const QString packageName = cg.readEntry("LookAndFeelPackage", QString());
+    const QString oldPackageName = package.isValid() ? package.metadata().pluginName() : QString();
+
+    if (packageName == oldPackageName) {
+        return;
+    }
+
+    //Invalid
+    if (packageName.isEmpty() && !oldPackageName.isEmpty()) {
+        package = Plasma::Package();
+    } else if (!packageName.isEmpty()) {
+        package = Plasma::PluginLoader::self()->loadPackage("Plasma/LookAndFeel");
+        package.setPath(packageName);
+    }
+
+    emit q->packageChanged();
+}
+
+LookAndFeelAccess::LookAndFeelAccess(QObject *parent)
+    : QObject(parent),
+      d(new LookAndFeelAccessPrivate(this))
+{
+    ShellPluginLoader::init();
+    d->defaultPackage = Plasma::PluginLoader::self()->loadPackage("Plasma/LookAndFeel");
+    d->defaultPackage.setPath("org.kde.lookandfeel");
+
+    d->config = KSharedConfig::openConfig("kdeglobals");
+    KConfigGroup cg(d->config, "KDE");
+    const QString packageName = cg.readEntry("LookAndFeelPackage", QString());
+    if (!packageName.isEmpty()) {
+        d->package = Plasma::PluginLoader::self()->loadPackage("Plasma/LookAndFeel");
+        d->package.setPath(packageName);
+    }
+
+    const QString configFile = QStandardPaths::writableLocation(QStandardPaths::GenericConfigLocation) + "/kdeglobals";
+    KDirWatch::self()->addFile(configFile);
+
+    // Catch both, direct changes to the config file ...
+    connect(KDirWatch::self(), SIGNAL(dirty()), this, SLOT(settingsFileChanged()));
+    // ... but also remove/recreate cycles, like KConfig does it
+    connect(KDirWatch::self(), SIGNAL(created()), this, SLOT(settingsFileChanged()));
+}
+
+LookAndFeelAccess::~LookAndFeelAccess()
+{
+}
+
+
+QString LookAndFeelAccess::filePath(const char *key, const QString &filename) const
+{
+    const QString path = d->package.filePath(key, filename);
+
+    if (!path.isEmpty()) {
+        return path;
+    } else {
+        return d->defaultPackage.filePath(key, filename);
+    }
+}
+
+KPluginInfo LookAndFeelAccess::metadata() const
+{
+    if (d->package.isValid()) {
+        return d->package.metadata();
+    } else {
+        return d->defaultPackage.metadata();
+    }
+}
+
+
+#include "moc_lookandfeelaccess.cpp"

lookandfeelaccess/lookandfeelaccess.h

@@ -0,0 +1,64 @@
+/*
+ *   Copyright 2014 Marco Martin <notmart@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 LOOKANDFEELACCESS_H
+#define LOOKANDFEELACCESS_H
+
+#include <QtCore/QObject>
+
+#include <KPluginInfo>
+
+class LookAndFeelAccessPrivate;
+
+class LookAndFeelAccess : public QObject
+{
+    Q_OBJECT
+
+public:
+    LookAndFeelAccess(QObject *parent = 0);
+    ~LookAndFeelAccess();
+
+    /**
+     * Get the path to a given file based on the key and an optional filename.
+     * Example: finding the main script in a scripting package:
+     *      filePath("mainscript")
+     *
+     * Example: finding a specific image in the images directory:
+     *      filePath("images", "myimage.png")
+     *
+     * @param key the key of the file type to look for,
+     * @param filename optional name of the file to locate within the package
+     * @return path to the file on disk. QString() if not found.
+     **/
+    QString filePath(const char *key, const QString &filename = QString()) const;
+
+    /**
+      * @return the package metadata object.
+      */
+    KPluginInfo metadata() const;
+
+Q_SIGNALS:
+    void packageChanged();
+
+private:
+    LookAndFeelAccessPrivate *const d;
+    Q_PRIVATE_SLOT(d, void settingsFileChanged())
+};
+
+#endif