Symbian学习笔记(2) 照相 和 摄像 编程总结

//通过RApaLsSession的GetAllApps接口可以得到所有系统上应用程序的信息，包括UID，Full path name，Caption ,在其中一一比对系统摄像头所在的文件路径，找到其UID。 
_LIT(KCameraAppString , "z:\\sys\\bin\\cameraapp.exe") ; //Nokia 5800上测试通过，其他型号这个路径可能不一样 
class CApaDocument; 
class CEikonEnv; 
/**************************** 
// sylar 
// 2010.4.22 PM 12:18:21 
// cug@live.cn 
// CLaunchCamera 照相类 用于打开照相机和拍照后的处理 
//调用方法： 
// CLaunchCamera *camera_launcher = CLaunchCamera::NewL(CEikonEnv::Static()); 
camera_launcher->OpenCamera(); 
//当用户完成摄像功能后，会通过 MApaEmbeddedDocObserver 类的回调函数NotifyExit进行通知，所以这里进行继承 
****************************/ 
class CLaunchCamera: public MApaEmbeddedDocObserver 
{ 
public: CLaunchCamera(); 
virtual ~CLaunchCamera(); 
static CLaunchCamera * NewL(MCameraEvenCallBack * pEvenCallBack, CEikonEnv * pEikonEnv);
static CLaunchCamera * NewLC(MCameraEvenCallBack * pEvenCallBack, CEikonEnv * pEikonEnv);
TBool OpenCamera(); //启动照相机程序 //NOTE: some class functions should not be used in MCameraEvenCallBack, they lead crash void CloseCamera(); 
TBool EnableCloseCamera(); 
private: 
	void ConstructL(MCameraEvenCallBack * pEvenCallBack, CEikonEnv * pEikonEnv); //From MApaEmbeddedDocObserver 
	void NotifyExit(TExitMode aMode); //回调函数，照相后处理 
	void FindNewFile(); 
	TBool GetLastFile(TFileName & filePath, TTime & fileTime); 
	TBool GetLastNewFile(TFileName & filePath, TTime & fileTime); 
	TBool FindCamera(TApaAppInfo & appInfo); 
private: CEikonEnv * m_pEikonEnv; //MCameraEvenCallBack * m_pCallBack; 这个没用 
		 CApaDocument * m_pAppdoc; 
		 CEikProcess * m_pProcess; 
		 TBool m_bCloseCamera; 
};
/************************ 二级构造函数 &析构 *****************/ 
CLaunchCamera* CLaunchCamera::NewL(CEikonEnv * pEikonEnv) 
{
	CLaunchCamera* self = NewLC(pEikonEnv); 
	CleanupStack::Pop(self); return self; 
} 
CLaunchCamera* CLaunchCamera::NewLC(CEikonEnv * pEikonEnv) { 
	CLaunchCamera* self = new (ELeave) CLaunchCamera; 
	CleanupStack::PushL(self); 
	self->ConstructL(pEvenCallBack, pEikonEnv); 
	return self;
} 
void CLaunchCamera::ConstructL(MCameraEvenCallBack * pEvenCallBack, CEikonEnv * pEikonEnv)
{
	m_pProcess = NULL; 
	m_pAppdoc = NULL; 
	m_pCallBack = pEvenCallBack; 
	m_pEikonEnv = pEikonEnv; m_bCloseCamera = FALSE; 
} 
void CLaunchCamera::CloseCamera() {
	if (m_pProcess) {
		m_pProcess->DestroyDocument(m_pAppdoc); 
		m_pProcess = NULL;
		m_pAppdoc = NULL; 
	} 
	m_bCloseCamera = TRUE; 
} 

/************************ 函数作用：找到照相机对应的进程 *****************/
static TBool CLaunchCamera::FindCamera(TApaAppInfo & appInfo) {
	RApaLsSession apaTmpLs;
	User::LeaveIfError(apaTmpLs.Connect());
	CleanupClosePushL(apaTmpLs); //压入自动清理栈，请看symbian错误处理机制 
	User::LeaveIfError(apaTmpLs.GetAllApps()); 
	TBool bFindCamera = FALSE; 
	appInfo.iFullName.FillZ(appInfo.iFullName.MaxLength()); 
	appInfo.iFullName.Zero(); 
	while (apaTmpLs.GetNextApp(appInfo) == KErrNone) 
	{ 
		appInfo.iFullName.LowerCase(); 
		TInt nTmpID = appInfo.iFullName.Compare(KCameraAppString); 
		if (nTmpID == 0) 
		{
			bFindCamera = TRUE; //找到 
			break; 
		} 
		appInfo.iFullName.FillZ(appInfo.iFullName.MaxLength());
		appInfo.iFullName.Zero(); 
	} 
	CleanupStack::PopAndDestroy(); // 清理 
	return bFindCamera;
} 

//供外部调用 
TBool CLaunchCamera::OpenCamera() {
	if( m_pEikonEnv == NULL ) 
		return FALSE ; 
	TApaAppInfo appInfo; 
	if( FindCamera( appInfo) == FALSE ) 
		return FALSE ; 
	m_pProcess = m_pEikonEnv->Process(); 
	m_pAppdoc = m_pProcess->AddNewDocumentL(appInfo.iFullName, appInfo.iUid);//启动照相机 
	TApaDocCleanupItem cleanup(m_pProcess, m_pAppdoc); 
	CleanupStack::PushL(cleanup);
	m_pAppdoc->NewDocumentL(); 
	CleanupStack::Pop(); // cleanup 
	m_bCloseCamera = FALSE ;
	m_pAppdoc->EditL(this, EFalse ); 
	return TRUE ; 
} 

//这个是系统的回调函数，如果用户进行了拍照/摄像/取消操作之后都会运行到这里。 
static void CLaunchCamera::NotifyExit(TExitMode aMode) 
{
	if (aMode == EKeepChanges) //拍照或者摄像 
	{ 
		//不能在这里调，否则设备crash 
		//m_pProcess->DestroyDocument(m_pAppdoc) ; 
		FindNewFile(); 
	} 
	m_bCloseCamera = TRUE; 
} 

//下面的函数作用是找到照片所在的路径 
// Function name : CLaunchCamera::FindNewFile 
// Description : Search the last new files 
//if find the last new file, call Camera_HandleFile to caller
// Return type : void 
void CLaunchCamera::FindNewFile() {
	if (m_pCallBack == NULL) return; TFileName PhoneIamgePath; TFileName MemoryIamgePath; TFileName PhoneVideoPath; TFileName MemoryVideoPath; //需要查找的路径 
	PhoneIamgePath.Append(PathInfo::PhoneMemoryRootPath()); 
	PhoneIamgePath.Append(PathInfo::ImagesPath()); 
	MemoryIamgePath.Append(PathInfo::MemoryCardRootPath()); 
	MemoryIamgePath.Append(PathInfo::ImagesPath()); 
	PhoneVideoPath.Append(PathInfo::PhoneMemoryRootPath());
	PhoneVideoPath.Append(PathInfo::VideosPath()); 
	MemoryVideoPath.Append(PathInfo::MemoryCardRootPath()); 
	MemoryVideoPath.Append(PathInfo::VideosPath()); 
	TTime tFileTime(0); 
	TTime tLastFileTime(0); 
	TInt nIndex = -1; //查找最新时间的文件 
	//find phone card image 
	if (GetLastFile(PhoneIamgePath, tFileTime) == TRUE) 
	{ 
		if (tFileTime > tLastFileTime)
		{ 
			tLastFileTime = tFileTime; nIndex = 0; 
		}
	} 
	
	//find memory card image
	if (GetLastFile(MemoryIamgePath, tFileTime) == TRUE) 
	{
		if (tFileTime > tLastFileTime) 
		{
			tLastFileTime = tFileTime; nIndex = 1;
		} 
	} 
	
	//find phone memory video file 
	if (GetLastFile(PhoneVideoPath, tFileTime) == TRUE) { 
		if (tFileTime > tLastFileTime)
		{
			tLastFileTime = tFileTime; nIndex = 2; 
		}
	} 
	
	//find memory card video files 
	if (GetLastFile(MemoryVideoPath, tFileTime) == TRUE)
	{
		if (tFileTime > tLastFileTime)
		{ 
			tLastFileTime = tFileTime; 
			nIndex = 3;
		}
	} 
	//判断是那个目录下的文件 
	switch (nIndex) { 
case 0: m_pCallBack->Camera_HandleFile(CFT_Image, PhoneIamgePath);
	////想怎么处理就怎么处理去把。就是把图片传给了另一个类m_pCallBack的方法Camera_HandleFile去处理而已。不用想的太麻烦 
	break; 
case 1: m_pCallBack->Camera_HandleFile(CFT_Image, MemoryIamgePath); 
	break; 
case 2: m_pCallBack->Camera_HandleFile(CFT_Video, PhoneVideoPath); break; case 3: m_pCallBack->Camera_HandleFile(CFT_Video, MemoryVideoPath); 
	break; 
default: m_pCallBack->Camera_HandleFile(CFT_NoFind, TFileName(0)); break; } } 



//////////////////////////////////////////////////////////////////////////
//查找最新的图像文件,只查找到二级目录
//
//////////////////////////////////////////////////////////////////////////
TBool CLaunchCamera::GetLastFile(TFileName & filePath , TTime & fileTime)
{
	RFs sessionRFs;
	User::LeaveIfError(sessionRFs.Connect());
	CDir* FileList;
	CDir* dirList ;
	//读出文件夹下文件信息,并对所有的文件进行降序排列
	TInt nError = sessionRFs.GetDir(filePath,KEntryAttNormal, ESortByDate|EDescending , FileList , dirList);
	if( nError != KErrNone )
	{
		sessionRFs.Close() ;
		return FALSE;
	}       
	else if( nError == KErrNone )
	{
		TFileName  tmpFileName(0) ;
		TTime tmpTime(0) ;
		TTime  tLastFileTime(0) ;
		TFileName tLastFile(0) ;
		//file
		if( FileList->Count() > 0 )
		{
			tmpFileName.FillZ(KMaxFileName) ;
			tmpFileName.Zero() ;
			tmpFileName.Append(filePath) ;
			tmpFileName.Append((*FileList)[0].iName) ;
			//get file modification time
			sessionRFs.Modified(tmpFileName , tmpTime ) ;
			if( tmpTime > tLastFileTime )
			{
				tLastFileTime = tmpTime ;
				tLastFile.FillZ(KMaxFileName) ;
				tLastFile.Zero() ;
				tLastFile.Append(tmpFileName) ;
			}
		}
		delete FileList ;
		//dir
		TInt nDirCount = dirList->Count() ;
		for( int i = 0 ; i< nDirCount ; i++ )
		{
			tmpFileName.FillZ(KMaxFileName) ;
			tmpFileName.Zero() ;
			tmpFileName.Append(filePath) ;
			tmpFileName.Append((*dirList)[i].iName) ;
			tmpFileName.Append(_L("\\")) ;
			if( GetLastNewFile( tmpFileName , tmpTime ) == TRUE )
			{
				if( tmpTime > tLastFileTime )
				{
					tLastFileTime = tmpTime ;
					tLastFile.FillZ(KMaxFileName) ;
					tLastFile.Zero() ;
					tLastFile.Append(tmpFileName) ;
				}
			}               
		}       
		delete dirList;
		//是否找到新的文件
		if( tLastFileTime > TTime(0) )
		{
			filePath.FillZ(KMaxFileName) ;
			filePath.Zero() ;
			filePath.Append(tLastFile) ;
			fileTime = tLastFileTime ;
		}
		else
		{
			sessionRFs.Close() ;
			return FALSE ;
		}
	}
	sessionRFs.Close() ;
	return TRUE ;
}


//用KEntryAttNormal只查找目录中的文件
TBool CLaunchCamera::GetLastNewFile(TFileName & filePath , TTime & fileTime)
{
	RFs sessionRFs;
	User::LeaveIfError(sessionRFs.Connect());
	CDir* dirList;
	//读出文件夹下文件信息,并对所有的文件进行降序排列
	TInt nError = sessionRFs.GetDir(filePath,KEntryAttNormal, ESortByDate|EDescending,dirList);
	if( nError != KErrNone )
	{
		sessionRFs.Close() ;
		return FALSE;
	}       
	else if( dirList->Count() > 0 )
	{
		//get filename
		filePath.Append((*dirList)[0].iName) ;
		//get file modification time
		sessionRFs.Modified(filePath , fileTime ) ;                       
		delete dirList;
	}
	else
	{
		sessionRFs.Close() ;
		return FALSE;
	}
	sessionRFs.Close() ;
	return TRUE ;
}