--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/phonebookengines/mobcntmodel/inc/cntcache.h	Thu May 27 12:45:19 2010 +0300
@@ -0,0 +1,120 @@
+/*
+* Copyright (c) 2010 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: Class for asynchronously fetching and caching
+*              basic contact info for list views.
+*
+*/
+
+#ifndef CNTCACHE_H
+#define CNTCACHE_H
+
+#include <QObject>
+#include <QSharedData>
+#include <HbIcon>
+#include <qcontactmanager.h>
+#include <cntinfoprovider.h>
+
+class CntContactInfoData;
+class CntCacheThread;
+class CntInfoCacheItem;
+class CntIconCacheItem;
+
+QTM_USE_NAMESPACE
+
+/*
+   Info about one contact that can be used by listviews:
+   - the id
+   - the full name, properly formatted
+   - text, secondary information like phone number
+   - icon1, the main icon
+   - icon2, a secondary icon
+ */
+class CntContactInfo : public QObject
+{
+    Q_OBJECT
+public:
+    CntContactInfo();
+    CntContactInfo(int id, const QString& name, const QString& text, const HbIcon& icon1, const HbIcon& icon2);
+    ~CntContactInfo();
+
+    CntContactInfo(const CntContactInfo& other);
+    CntContactInfo& operator=(const CntContactInfo& other);
+
+    int id() const;
+    QString name() const;
+    QString text() const;
+    HbIcon icon1() const;
+    HbIcon icon2() const;
+
+private:
+    QSharedDataPointer<CntContactInfoData> d;
+};
+
+/*
+   Singleton class that acts as a proxy to get CntContactInfo objects for contacts.
+   It also implements caching for faster access. This is why the fetchContactInfo()
+   function takes a row number and the full list of contact IDs rather than just a
+   contact ID -- the former allows caching ahead.
+   
+   The usage pattern for clients is to call fetchContactInfo() to get at least the
+   name of the contact. If all the info is cached then it will be provided. If not,
+   then the uncached info is fetched asynchronously and contactInfoUpdated signals
+   are emitted as the pieces of information arrive -- up to three times per contact;
+   once for text, once for icon1 and once for icon2.
+ */
+class CntCache : public QObject
+{
+    Q_OBJECT
+public:
+    static CntCache* instance();
+    CntContactInfo fetchContactInfo(int row, const QList<QContactLocalId>& idList);
+
+public slots:
+    void clearCache();
+
+signals:
+    void contactInfoUpdated(QContactLocalId contactId);
+
+private:
+    CntCache();
+    ~CntCache();
+    bool fetchContactName(int contactId, QString& contactName);
+    void updateReadAheadCache(int mostRecentRow, const QList<QContactLocalId>& idList);
+    CntInfoCacheItem* createInfoCacheItem(int contactId);
+    CntIconCacheItem* createIconCacheItem(const QString& iconName);
+    void emitContactInfoUpdated(int contactId);
+
+private slots:
+    void onNewInfo(int contactId, const ContactInfoField& infoField, const QString& infoValue);
+    void onInfoCancelled(int contactId);
+    void onNewIcon(const QString& iconName, const HbIcon& icon);
+    void onIconCancelled(const QString& iconName);
+    void onShutdown();
+    void removeContactsFromCache(const QList<QContactLocalId>& contactIds);
+    void scheduleOneReadAheadItem();
+
+private:
+    static CntCache* mInstance;                   // the one and only instance of CntCache
+    QContactManager* mContactManager;             // for fetching contact names and for getting
+                                                  // notifications about changes to contacts
+    CntCacheThread* mWorker;                      // the background thread that does the actual fetching
+    QList<int> mReadAheadCache;                   // cache with set of IDs to prefetch (they are likely to be needed soon)
+    QHash<int,CntInfoCacheItem*> mInfoCache;      // cache with contact info, indexed by contact ids
+    QHash<QString,CntIconCacheItem*> mIconCache;  // cache with icons, indexed by icon name
+    int mNextInfoCacheOrder;                      // cache order for the next item to be updated/inserted in info cache
+    int mNextIconCacheOrder;                      // cache order for the next item to be updated/inserted in icon cache
+    int mEmittedContactId;                        // id of the last contact emitted to UI
+};
+
+#endif