--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/photosgallery/collectionframework/thumbnailcreator/inc/glxtntask.h	Thu Dec 17 08:45:44 2009 +0200
@@ -0,0 +1,220 @@
+/*
+* 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:    Base classes for multi-purpose tasks.
+*
+*/
+
+
+
+
+/**
+ * @internal reviewed 30/07/2007 by Simon Brooks
+ */
+
+#ifndef C_GLXTNTASK_H
+#define C_GLXTNTASK_H
+
+#include "glxtnstd.h"
+#include <glxmediaid.h>
+#include <e32base.h>
+
+// Forward declarations
+class CGlxtnTaskManager;
+class MGlxtnThumbnailCreatorClient;
+class MGlxtnThumbnailStorage;
+
+/**
+ *  Base class for thumbnail tasks.
+ *
+ * @ingroup glx_thumbnail_creator
+ */
+NONSHARABLE_CLASS(CGlxtnTask) : public CBase
+    {
+    friend class CGlxtnTaskManager;
+public:
+    /**
+    * Different state a task can go through
+    */
+    enum TState 
+        {
+        EIdle,      /**< Task is not ready to start */
+        EStarting,  /**< Task is ready to start */
+        ERunning,   /**< Task is currently running */
+        ECanceled,  /**< Task has been cancelled, and can be deleted */
+        EComplete   /**< Task has finished, and can be deleted */
+        };
+
+public:
+    CGlxtnTask(const TGlxtnTaskId& aId, const TGlxMediaId& aItemId,
+                MGlxtnThumbnailStorage* aStorage);
+    ~CGlxtnTask();
+	
+    /**
+     * Gets the current task specific state
+     * @returns TState The task current state.
+     */
+    inline TState State() const;
+
+    /**
+     * Gets the type of task this is.
+     * @returns TGlxtnTaskId Task type ID.
+     */
+    inline TGlxtnTaskId Id() const;
+
+    /**
+     * Gets the media ID of the item to which this task relates.
+     * @returns TGlxMediaId Media ID.
+     */
+    inline TGlxMediaId ItemId() const;
+
+    /**
+     * Sets the priority of the task. By default it is set to 
+     * EPriorityStandard.
+     */
+    inline void SetPriority(TInt aPriority);
+    /**
+     * Gets the task priority.
+     * @returns TInt Task priority.
+     */
+	inline TInt Priority() const;
+
+    /**
+     * Get thumbnail storage for the task to use, if any.
+     * @returns Pointer to thumbnail storage, or NULL if none.
+     */
+    inline MGlxtnThumbnailStorage* Storage() const;
+
+    /**
+     * Provides a pointer to the task manager.
+     * @param aManager Pointer to the task manager.
+     */
+    virtual void SetManager(CGlxtnTaskManager* aManager);
+
+private: // For CGlxTaskManager only
+    /**
+     * Starts the task 
+     */
+    void StartL(TRequestStatus& aStatus);
+
+	/**
+	 * Cancels the task
+	 */
+	void Cancel(); 
+	
+	/**
+	 * Runs a bit of the task
+	 */
+	void RunL(TRequestStatus& aStatus);
+
+	/**
+	 * Handle a leave in StartL or RunL.
+	 */
+    void RunError(TInt aError);
+
+protected:
+    /**
+     * Starts the task.
+     * @param aStatus Request status for asynchronous operations
+     * @returns -ETrue if the task has issued an asyncronous request.
+     *			CActive::SetActive() will be called in this case and the 
+     *			task state will be ERunning.
+     *			-EFalse if the task has not issued a request. 
+     *			SetActive will not be called and the task state will be 
+     *			EComplete.
+     */
+    virtual TBool DoStartL(TRequestStatus& aStatus) = 0;
+
+	/**
+	 * Cancels the task.  The task's state will be set to ECanceled.
+	 */
+	virtual void DoCancel() = 0; 
+
+	/**
+	 * Runs a bit of the task
+     * @param aStatus Request status for asynchronous operations
+     * @returns -ETrue if the task has issued an asyncronous request.
+     *			CActive::SetActive() will be called in this case and the 
+     *			task state will be ERunning.
+     *			-EFalse if the task has not issued a request. 
+     *			SetActive will not be called and the task state will be 
+     *			EComplete.
+	 */
+	virtual TBool DoRunL(TRequestStatus& aStatus) = 0;
+
+	/**
+	 * Handle a leave in StartL or RunL.
+     * @param aError The error that occurred.
+     * @returns -ETrue if the task has issued an asyncronous request.
+     *			CActive::SetActive() will be called in this case and the 
+     *			task state will be ERunning.
+     *			-EFalse if the task has not issued a request. 
+     *			SetActive will not be called and the task state will be 
+     *			EComplete.
+	 */
+    virtual TBool DoRunError(TInt aError) = 0;
+
+protected:
+	/**
+	 * Issues a request and sets the aStatus as KRequestPending
+	 * Use this to make a synchronous operation asynchronous.
+	 */
+	void SelfComplete(TRequestStatus& aStatus); 
+   
+private:
+    /** Task state */
+    TState iState;
+
+    /** Task id */
+    TGlxtnTaskId iId;
+
+    /** Media item id */
+    TGlxMediaId iItemId;
+
+    /**
+     * Priority of this task. 
+     * The task schedule will execute tasks based on this priority
+     * When this task is run, the execution priority in CActiveScheduler
+     * will be this priority. (So it is comparable to priorities of active 
+     * objects in the system.)
+     */
+    TInt iPriority; 
+
+    /** Thumbnail storage for the task to use (can be NULL) */
+    MGlxtnThumbnailStorage* iStorage;
+    };
+
+/**
+ *  Base class for thumbnail tasks which return results to a client.
+ *
+ * @ingroup glx_thumbnail_creator
+ */
+NONSHARABLE_CLASS(CGlxtnClientTask) : public CGlxtnTask
+    {
+protected:
+    CGlxtnClientTask(const TGlxtnTaskId& aId, const TGlxMediaId& aItemId,
+                MGlxtnThumbnailCreatorClient& aClient);
+
+    /**
+     * Get the client for this task.
+     */
+    inline MGlxtnThumbnailCreatorClient& Client();
+
+private:
+    /** Client for this task */
+    MGlxtnThumbnailCreatorClient& iClient;
+    };
+
+#include "glxtntask.inl"
+
+#endif // C_GLXTNTASK_H