--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/photosgallery/viewframework/medialists/inc/glxcache.h	Thu Dec 17 08:45:44 2009 +0200
@@ -0,0 +1,183 @@
+/*
+* Copyright (c) 2008-2009 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:    Cache implementation for media items sharing the same Id space
+*
+*/
+
+
+
+
+#ifndef C_GLXCACHE_H
+#define C_GLXCACHE_H
+
+#include <e32base.h>
+
+#include "glxmediaid.h"
+
+// Forward declarations
+class CMPXMedia;
+class CGlxMedia;
+class T_CacheTestHelpers;
+class TMPXAttribute;
+class CGlxCacheManager;
+
+/**
+ *  CGlxCache
+ *
+ *  Individual cache of media items sharing the same Id space
+ */
+NONSHARABLE_CLASS( CGlxCache ) : public CBase
+	{
+public:
+    /**
+     * Constructor
+     * @param aIdSpaceId The id of the id address space of this cache 
+	 * @param aCacheManager Instance of cachemanager to cleanup the media
+     */
+    CGlxCache( const TGlxIdSpaceId& aIdSpaceId, CGlxCacheManager* aCacheManager );
+    
+    /**
+     * Destructor
+     */
+    ~CGlxCache();
+
+    /**
+     * Returns the Id space covered by this cache
+     * @return The Id space covered by this cache    
+     */
+    TGlxIdSpaceId IdSpaceId() const;    
+
+    /**
+     * Notify the cache that attributes have changed on media item(s)
+     * @param aMedia The updated media item or array of updated media items
+     */
+    void MediaUpdatedL( const CMPXMedia& aMedia );
+
+    /**
+     * Update media item
+     *
+     * @param aMedia The updated media item
+     */
+    void UpdateMediaL( const CMPXMedia& aMedia );
+
+    /**
+     * Cleanup the media of the given media id: broadcast this to all observers
+	 * @param aMediaId The media id of the item
+     */ 
+    void CleanupMedia(const TGlxMediaId& aMediaId);
+
+    /**
+     * Handles modifications of item in cache
+     *
+     * @param aId Media item id
+     * @param aAttributes Attributes that have been modified
+     */
+    void HandleItemModified( const TGlxMediaId& aId, const RArray<TMPXAttribute>& aAttributes );
+
+    /**
+     * Access to the items stored in the cache: return the item matching the given media Id
+     * @param aId The media Id
+     * @return The media item, or NULL if not found
+     */
+    CGlxMedia* Media( const TGlxMediaId& aId ) const;
+
+    /**
+     * Access to the items stored in the cache: return the item matching the given media Id.
+     * If not found, a new item is created
+     * @param aId The media Id
+     * @return The media item
+     */
+    CGlxMedia* FindItemForceCreateL( const TGlxMediaId& aId );
+    
+    /**
+     * Number of items in cache
+     * @return Number of items in cache
+     */
+    TInt Count();
+    
+    /**
+     * Cached item by index
+     * @param aIndex index of the item
+     * @return Cached item
+     */
+    CGlxMedia& Media( TInt aIndex );
+    
+    /**
+     * Delete an item at index from the cache.
+     * @param aIndex Index of the item to delete
+     */
+    void Delete( TInt aIndex );
+    
+    /**
+     * Reserve space for a number of users, for all items in the cache
+     *
+     * @param aCount The number of users to reserve space for
+     */
+    void ReserveUsersL( TInt aCount );
+    
+    /**
+	 * Finds the media index present in cache
+	 * @returns the index of media
+	 */    
+    TInt FindMediaIndexInCache(TGlxMediaId aMediaId);
+
+private:
+    /**
+     * Copy the new and modified attributes from aSource to aTarget
+     * @param aTarget The target media item
+     * @param aSource The source media item
+     * @param aNewAttributes The new and modified attributes
+     */
+    void CopyNewAndModifiedL( CGlxMedia& aTarget, const CMPXMedia& aSource, 
+        RArray<TMPXAttribute>& aNewAttributes );
+
+    /**
+     * Function for TLinearOrder() for comparing two CGlxMedias 
+     * Used from ordering the iItemPool by id
+     * @param aItem1 The first item to compare
+     * @param aItem2 The second item to compare
+     * @return -1 if aItem1 < aItem2; 1 if aItem1 > aItem2; 0 if aItem1 == aItem2
+     */
+    static TInt MediaItemOrderById( const CGlxMedia& aItem1, const CGlxMedia& aItem2 );
+    
+    /**
+     * Function for comparing a TGlxMediaId with a CGlxMedia 
+     * Used from ordering iItemPool by media id
+     * @param aMediaId The media id to compare against aItem2
+     * @param aItem2 The second item to compare
+     * @return -1 if aMediaId < aItem2.Id(); 1 if aMediaId > aItem2.Id(); 0 if aMediaId == aItem2.Id()
+     */
+    static TInt MediaItemOrderByKey( const TGlxMediaId* aMediaId, const CGlxMedia& aItem2 );
+
+    /**
+     * Create and add an item to the item pool
+     * @param aId Id for the new item
+     * @return Pointer to the created item
+     */
+    CGlxMedia* CreateItemL( const TGlxMediaId& aId );
+    
+private:
+    /// Id space that this cache covers
+    TGlxIdSpaceId iIdSpaceId;
+    
+    /// Pool of media items. Owned
+    RPointerArray<CGlxMedia> iItemPool; 
+    
+    ///Instance of cacheManager to cleanup cache
+    CGlxCacheManager* iCacheManager;
+
+    friend class T_CacheTestHelpers;
+    };
+
+#endif // C_GLXCACHE_H