starting work on dataengines, datasource, datavisualizations, the plasma

app and applets ... doesn't compile atm as it's a work in progress off
the design concepts. but dinner becons and i don't want to lose progress
in case my laptop degrades further.

svn path=/trunk/KDE/kdebase/workspace/plasma/lib/; revision=529282

applet.cpp

@@ -19,12 +19,15 @@
 #include <QEvent>
 #include <QList>
 #include <QSize>
+#include <QStringList>
 #include <QTimer>
 
 #include <kstandarddirs.h>
 
 #include "applet.h"
 
+
+
 namespace Plasma
 {
 
@@ -40,9 +43,13 @@ class Applet::Private
               chain(appletChain)
         { }
 
-//         ~Private()
+        ~Private()
-//         {
+        {
-//         }
+            foreach (const QString& engine, loadedEngines)
+            {
+                Interface::interface()->unloadDataEngine(engine);
+            }
+        }
 
         int id;
         KSharedConfig::Ptr globalConfig;
@@ -50,6 +57,7 @@ class Applet::Private
         KService::Ptr appletDescription;
         QList<QObject*> watchedForFocus;
         AppletChain::Ptr chain;
+        QStringList loadedEngines;
 };
 
 Applet::Applet(QWidget* parent,
@@ -67,6 +75,19 @@ Applet::~Applet()
     delete d;
 }
 
+KSharedConfig::Ptr Applet::appletConfig() const
+{
+    if (!d->appletConfig)
+    {
+        QString file = locateLocal("appdata",
+                                   "applets/" + instanceName() + "rc",
+                                   true);
+        d->appletConfig = KSharedConfig::openConfig(file, false, true);
+    }
+
+    return d->appletConfig;
+}
+
 KSharedConfig::Ptr Applet::globalAppletConfig() const
 {
     if (!d->globalConfig)
@@ -80,17 +101,20 @@ KSharedConfig::Ptr Applet::globalAppletConfig() const
     return d->globalConfig;
 }
 
-KSharedConfig::Ptr Applet::appletConfig() const
+bool Applet::loadDataEngine(const QString& name)
 {
-    if (!d->appletConfig)
+    if (d->loadedEngines.indexOf(name) != -1)
     {
-        QString file = locateLocal("appdata",
+        return true;
-                                   "applets/" + instanceName() + "rc",
-                                   true);
-        d->appletConfig = KSharedConfig::openConfig(file, false, true);
     }
 
-    return d->appletConfig;
+    if (PlasmaAppInterface::self()->loadDataEngine(name))
+    {
+        d->loadedEngines.append(name);
+        return true;
+    }
+
+    return false;
 }
 
 const AppletChain::Ptr Applet::chain() const

applet.h

@@ -50,16 +50,29 @@ class KDE_EXPORT Applet : public QWidget
         * named \<appletname\>rc in the user's local %KDE directory.
         *
         * For normal applets this config object will write to an instance
-        * specific config file nameed \<appletname\>\<instanceid\>rc
+        * specific config file named \<appletname\>\<instanceid\>rc
         * in the user's local %KDE directory.
         **/
-        KSharedConfig::Ptr globalAppletConfig() const;
         KSharedConfig::Ptr appletConfig() const;
 
+        /**
+         * Returns a KConfig object to be shared by all applets of this type
+         * For unique applets, this will return the same config object as
+         * appletConfig()
+         */
+        KSharedConfig::Ptr globalAppletConfig() const;
+
+        /**
+         * Ensures that the DataEngine named name is loaded and ready to be used
+         *
+         * @return returns true on success, false on failure
+         */
+        bool loadDataEngine(const QString& name);
+
         const AppletChain::Ptr chain() const;
         void setChain(const AppletChain::Ptr);
 
-        /*
+        /**
          * called when any of the geometry constraints have been updated
          * this is always called prior to painting and should be used as an
          * opportunity to layout the widget, calculate sizings, etc.

dataengine.h

@@ -0,0 +1,93 @@
+/*
+ *   Copyright (C) 2006 Aaron Seigo <aseigo@kde.org>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License version 2 as
+ *   published by the Free Software Foundation
+ *
+ *   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_ENGINE_H
+#define PLASMA_ENGINE_H
+
+#include <QAtomic>
+#include <QHash>
+#include <QObject>
+#include <QStringList>
+
+namespace Plasma
+{
+
+class DataSource;
+class DataVisualization;
+
+class DataSource : public QObject
+{
+    Q_OBJECT
+
+    public:
+        typedef QHash<QString, DataSource*> Dict;
+        typedef QHash<QString, QVariant> Data;
+
+        DataSource(QObject* parent);
+        virtual ~DataSource();
+
+        QString name();
+
+    signals:
+        void data(const DataSource::Data&);
+
+    private:
+        class Private;
+        Private* d;
+};
+
+class DataEngine : public QObject
+{
+    Q_OBJECT
+
+    public:
+        typedef QHash<QString, DataEngine*> Dict;
+
+        DataEngine(QObject* parent);
+        virtual ~DataEngine();
+
+        virtual QStringList dataSources();
+        void connect(const QString& source, DataVisualization* visualization);
+        DataSource::Data query(const QString& source);
+
+        void ref();
+        void deref();
+
+    protected:
+        virtual void init();
+        virtual void cleanup();
+        virtual DataEngine* engine() = 0;
+        virtual
+
+    private:
+        QAtomic ref;
+        class Private;
+        Private* d;
+};
+
+} // Plasma namespace
+
+#define K_EXPORT_PLASMA_ENGINE(libname, classname)                       \
+        K_EXPORT_COMPONENT_FACTORY(                                      \
+                        plasmaengine_##libname,                          \
+                        KGenericFactory<classname>("libplasmaengine_" #libname))
+
+#endif // multiple inclusion guard
+
+
+#endif

datavisualization.h

@@ -0,0 +1,48 @@
+/*
+ *   Copyright (C) 2006 Aaron Seigo <aseigo@kde.org>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License version 2 as
+ *   published by the Free Software Foundation
+ *
+ *   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_DATAVISUALIZATION_H
+#define PLASMA_DATAVISUALIZATION_H
+
+#include <QObject>
+
+#include "dataengine.h"
+
+namespace Plasma
+{
+
+// this will end up being multiple-inherited?
+class DataVisualization : QObject
+{
+    Q_OBJECT
+
+    public:
+        DataVisualization(QObject* parent);
+        virtual ~DataVisualization();
+
+    public slots:
+        void data(const DataSource::Data&) = 0;
+
+    private:
+        class Private;
+        Private* d;
+};
+
+} // Plasma namespace
+
+#endif // multiple inclusion guard

interface.h

@@ -0,0 +1,40 @@
+/*
+ *   Copyright (C) 2006 Aaron Seigo <aseigo@kde.org>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License version 2 as
+ *   published by the Free Software Foundation
+ *
+ *   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_INTERFACE_H
+#define PLASMA_INTERFACE_H
+
+namespace Plasma
+{
+
+class Interface
+{
+    public:
+        static Interface* interface() { return m_interface; }
+
+        bool loadDataEngine(const QString& name) = 0;
+        bool unloadDataEngine(const QString& name) = 0;
+
+    protected:
+        Interface() : m_interface(0) {}
+        static Interface* m_interface;
+};
+
+} // Plasma namespace
+
+#endif // multiple inclusion guard