--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ui/viewplugins/inc/qviewplugin.h	Fri Mar 19 09:28:59 2010 +0200
@@ -0,0 +1,116 @@
+/*
+* Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:   
+*
+*/
+
+
+
+#ifndef QVIEWPLUGIN_H_
+#define QVIEWPLUGIN_H_
+
+#include <QObject>
+
+class QGraphicsWidget;
+
+class QViewPlugin : public QObject {
+
+    Q_OBJECT
+
+public:
+	
+	/* COMMENT:
+	 * following two methods are kind of second-phase create & destroy. Rationale for this step is that
+	 * we need some way to promote lazy resources allocation (on application demand) and early resource
+	 * deallocation (again, on application direct command).
+	 */
+
+	/**
+	 * createView is the second operation (after plugin construction which is done somewhere 
+	 * in the plugin framework) executed in the application layer to make a fully operational 
+	 * View Plugin descendant.
+	 * I should allocate all of those resources that are required by plugin, but which are
+	 * too expensive to allocate in constructor (eg. in case of plugin prefetching).
+	 */
+	virtual void createView() = 0;	
+
+	/**
+	 * destroyView is an operation that should be executed just before plugin deletion.
+	 * Implementation should destroy all of resources allocated during createView execution.
+	 * It's reason d'etre is based on a fact, that application doesn't controll when exactly
+	 * plugin will be deleted, so destructor execution could be postponed still holding resources.
+	 */
+	virtual void destroyView() = 0;
+
+	/* COMMENT:
+	 * view activation and deactivation are reversible operations
+	 * that allows us to give up resources that we could temporary deallocate when that 
+	 * specific view plugin goes into background.
+	 */
+
+	/**
+	 * Called to notice view activation.
+	 */
+	virtual void activateView() = 0;
+
+	/**
+	 * Called to notice view deactivation.
+	 */
+	virtual void deactivateView() = 0;
+
+	/**
+	 * gives actual view component, ready to put somewhere into the app layout.
+	 * However, beware that calling to activate/deactivate in the meantime
+	 * can invalidate that pointer.
+	 * 
+	 * NOTE: Returned type is choosen to be as generic as possible, 
+	 * so please ensure that it fulfills all your needs (it was HbView* before)
+	 */
+	virtual QGraphicsWidget* getView() = 0;
+
+public slots:
+
+	/**
+	 * Signalled by application when orientation has changed.
+	 */	
+	virtual void orientationChange(Qt::Orientation orientation) = 0;
+
+	/**
+	 * Implementation should take care either to implement
+       * go-back operation internally or to emit proper
+	 * command signal to delegate that responsibility to
+	 * framework (eg. to switch to previous view).
+	 */	
+	virtual void back() = 0;
+
+signals:
+
+	/**
+	 * Command is the only way to notify from plugin to application
+	 * about action needed to be executed.
+	 *
+	 * @param aCommand  enumeration of command type. 
+	 * Currently supported are: ViewBack, CloseApp, GoToNowPlaying, GoToCollectionView.
+	 * NOTE: It should be specified how to determine between broadly supported operations 
+	 * (back, close etc.) and application/plugin specific (go to collection, go to now playing etc.)
+	 *
+	 * There is also one major issue here, that there is no guaranted order of command delivery,
+	 * so there is second option to use common observer pattern. Should be discussed.
+	 */	
+	void command(int aCommand);
+
+};
+
+    
+#endif /*QVIEWPLUGIN_H_*/