essentials.h

《UIQ 3 The Complete Guide》书的源代码

// Copyright (C) UIQ Technology AB, 2007
//
// This material is provided "as is" without any warranty to its performance or functionality. 
// In no event shall UIQ Technology be liable for any damages whatsoever arising out of the
// use or inabilty to use this material. 

#ifndef __ESSENTIALS_H__
#define __ESSENTIALS_H__

#include <f32file.h>

class MPolygon
	{
public:
	virtual TInt CalculateNumberOfVerticesL() =0;
	virtual ~MPolygon();
	};

class CSquare : public CBase, public MPolygon
	{
public:
	static CSquare* NewL();
	virtual TInt CalculateNumberOfVerticesL();
	virtual ~CSquare();
private:
	CSquare();
	};

class CNotifyChange : public CActive
	{
public:
	~CNotifyChange();
	static CNotifyChange* NewL(const TDesC& aPath);
	void StartFilesystemMonitor();
protected:
	CNotifyChange();
	void ConstructL(const TDesC& aPath);
protected: // From CActive
	virtual void RunL();
	virtual void DoCancel();
	virtual TInt RunError(TInt aError);
private:
	RFs iFs;
	HBufC* iPath;
	TInt iChanges;
	};

class TLongRunningCalculation
	{
public:
	TLongRunningCalculation() {iState=EWaiting;};
	void StartCalculation();  	// Initialization before starting the task
	void DoTaskStep(); 			// Perform a short task step
	TBool ContinueTask();     	// Destroy intermediate data
	void CancelCalculation() {iState=EWaiting;};
	enum TCalcState { EWaiting, EBeginState, EIntermediateState, EFinalState };
	TCalcState iState;
	};

class CBackgroundTask : public CActive
 	{
public:
	static CBackgroundTask* NewLC();
	~CBackgroundTask(){};
public:
	void PerformRecalculation(TRequestStatus& aStatus);
	void CancelTask();
protected:
	CBackgroundTask();
	void ConstructL();
	void SelfComplete();
protected: // From CActive
	virtual void RunL();
	virtual void DoCancel();
private:
	TLongRunningCalculation iCalc;
	TBool iMoreToDo;
	TRequestStatus* iCallerStatus; // To notify caller on completion
	};
	
class CExampleActive : public CActive
	{
public:
	static CExampleActive* NewLC(CBackgroundTask& aTask);
	~CExampleActive(){Cancel();};
protected:
	CExampleActive(CBackgroundTask& aTask);
	void ConstructL();
protected: // From CActive
	void RunL();
	void DoCancel();
private:
	CBackgroundTask& iTask;
	};
  
#endif  // __ESSENTIALS_H__