A TFolder object is a collection of objects and folders.

Folders have a name and a title and are identified in the folder hierarchy by a "Unix-like" naming mechanism. The root of all folders is //root. New folders can be dynamically added or removed to/from a folder. The folder hierarchy can be visualized via the TBrowser.

The Root folders hierarchy can be seen as a whiteboard where objects are posted. Other classes/tasks can access these objects by specifying only a string pathname. This whiteboard facility greatly improves the modularity of an application, minimizing the class relationship problem that penalizes large applications.

Pointers are efficient to communicate between classes. However, one has interest to minimize direct coupling between classes in the form of direct pointers. One better uses the naming and search service provided by the Root folders hierarchy. This makes the classes loosely coupled and also greatly facilitates I/O operations. In a client/server environment, this mechanism facilitates the access to any kind of object in //root stores running on different processes.

A TFolder is created by invoking the TFolder constructor. It is placed inside an existing folder via the TFolder::AddFolder method. One can search for a folder or an object in a folder using the FindObject method. FindObject analyses the string passed as its argument and searches in the hierarchy until it finds an object or folder matching the name.

When a folder is deleted, its reference from the parent folder and possible other folders is deleted.

If a folder has been declared the owner of its objects/folders via TFolder::SetOwner, then the contained objects are deleted when the folder is deleted. By default, a folder does not own its contained objects.

NOTE that folder ownership can be set

via TFolder::SetOwner
or via TCollection::SetOwner on the collection specified to TFolder::AddFolder

Standard Root objects are automatically added to the folder hierarchy. For example, the following folders exist: root/Files with the list of currently connected Root files root/Classes with the list of active classes root/Geometries with active geometries root/Canvases with the list of active canvases root/Styles with the list of graphics styles root/Colors with the list of active colors

For example, if a file "myFile.root" is added to the list of files, one can retrieve a pointer to the corresponding TFile object with a statement like:

TFile *myFile = (TFile*)gROOT->FindObject("//root/Files/myFile.root");

The above statement can be abbreviated to:

TFile *myFile = (TFile*)gROOT->FindObject("/Files/myFile.root");

or even to:

TFile *myFile = (TFile*)gROOT->FindObjectAny("myFile.root");

In this last case, the TROOT::FindObjectAny function will scan the folder hierarchy starting at //root and will return the first object named "myFile.root".

Because a string-based search mechanism is expensive, it is recommended to save the pointer to the object as a class member or local variable if this pointer is used frequently or inside loops.

Definition at line 32 of file TFolder.h.

Public Member Functions
	TFolder ()

	TFolder (const char name, const char title)
	Create a normal folder. More...

virtual	~TFolder ()
	Folder destructor. More...

virtual void	Add (TObject *obj)
	Add object to this folder. obj must be a TObject or a TFolder. More...

TFolder *	AddFolder (const char name, const char title, TCollection *collection=0)
	Create a new folder and add it to the list of folders of this folder, return a pointer to the created folder. More...

virtual void	Browse (TBrowser *b)
	Browse this folder. More...

virtual void	Clear (Option_t *option="")
	Delete all objects from a folder list. More...

virtual void	Copy (TObject &) const
	Copy this to obj. More...

virtual const char *	FindFullPathName (const char *name) const
	Return the full pathname corresponding to subpath name if the node is gROOT->GetRootFolder() and return a relative path otherwise. More...

virtual const char *	FindFullPathName (const TObject *obj) const
	Return the full pathname corresponding to subpath name. More...

virtual TObject *	FindObject (const char *name) const
	Search object identified by name in the tree of folders inside this folder. More...

virtual TObject *	FindObject (const TObject *obj) const
	Find object in an folder. More...

virtual TObject *	FindObjectAny (const char *name) const
	Return a pointer to the first object with name starting at this folder. More...

TCollection *	GetListOfFolders () const

Bool_t	IsFolder () const
	Returns kTRUE in case object contains browsable objects (like containers or lists of other objects). More...

Bool_t	IsOwner () const
	Folder ownership has been set via. More...

virtual void	ls (Option_t *option="") const
	List folder contents. More...

virtual Int_t	Occurence (const TObject *obj) const
	Return occurence number of object in the list of objects of this folder. More...

virtual void	RecursiveRemove (TObject *obj)
	Recursively remove object from a folder. More...

virtual void	Remove (TObject *obj)
	Remove object from this folder. obj must be a TObject or a TFolder. More...

virtual void	SaveAs (const char filename="", Option_t option="") const
	Save all objects in this folder in filename. More...

virtual void	SetOwner (Bool_t owner=kTRUE)
	Set ownership. More...

Public Member Functions inherited from TNamed
	TNamed ()

	TNamed (const char name, const char title)

	TNamed (const TString &name, const TString &title)

	TNamed (const TNamed &named)

TNamed &	operator= (const TNamed &rhs)
	TNamed assignment operator. More...

virtual	~TNamed ()

virtual TObject *	Clone (const char *newname="") const
	Make a clone of an object using the Streamer facility. More...

virtual Int_t	Compare (const TObject *obj) const
	Compare two TNamed objects. More...

virtual void	FillBuffer (char *&buffer)
	Encode TNamed into output buffer. More...

virtual const char *	GetName () const
	Returns name of object. More...

virtual const char *	GetTitle () const
	Returns title of object. More...

virtual ULong_t	Hash () const
	Return hash value for this object. More...

virtual Bool_t	IsSortable () const

virtual void	SetName (const char *name)
	Change (i.e. More...

virtual void	SetNameTitle (const char name, const char title)
	Change (i.e. set) all the TNamed parameters (name and title). More...

virtual void	SetTitle (const char *title="")
	Change (i.e. set) the title of the TNamed. More...

virtual void	Print (Option_t *option="") const
	Print TNamed name and title. More...

virtual Int_t	Sizeof () const
	Return size of the TNamed part of the TObject. More...

Public Member Functions inherited from TObject
	TObject ()

	TObject (const TObject &object)
	TObject copy ctor. More...

TObject &	operator= (const TObject &rhs)
	TObject assignment operator. More...

virtual	~TObject ()
	TObject destructor. More...

virtual void	AppendPad (Option_t *option="")
	Append graphics object to current pad. More...

virtual const char *	ClassName () const
	Returns name of class to which the object belongs. More...

virtual void	Delete (Option_t *option="")
	Delete this object. More...

virtual Int_t	DistancetoPrimitive (Int_t px, Int_t py)
	Computes distance from point (px,py) to the object. More...

virtual void	Draw (Option_t *option="")
	Default Draw method for all objects. More...

virtual void	DrawClass () const
	Draw class inheritance tree of the class to which this object belongs. More...

virtual TObject *	DrawClone (Option_t *option="") const
	Draw a clone of this object in the current pad. More...

virtual void	Dump () const
	Dump contents of object on stdout. More...

virtual void	Execute (const char method, const char params, Int_t *error=0)
	Execute method on this object with the given parameter string, e.g. More...

virtual void	Execute (TMethod method, TObjArray params, Int_t *error=0)
	Execute method on this object with parameters stored in the TObjArray. More...

virtual void	ExecuteEvent (Int_t event, Int_t px, Int_t py)
	Execute action corresponding to an event at (px,py). More...

virtual Option_t *	GetDrawOption () const
	Get option used by the graphics system to draw this object. More...

virtual UInt_t	GetUniqueID () const
	Return the unique object id. More...

virtual const char *	GetIconName () const
	Returns mime type name of object. More...

virtual Option_t *	GetOption () const

virtual char *	GetObjectInfo (Int_t px, Int_t py) const
	Returns string containing info about the object at position (px,py). More...

virtual Bool_t	HandleTimer (TTimer *timer)
	Execute action in response of a timer timing out. More...

virtual Bool_t	InheritsFrom (const char *classname) const
	Returns kTRUE if object inherits from class "classname". More...

virtual Bool_t	InheritsFrom (const TClass *cl) const
	Returns kTRUE if object inherits from TClass cl. More...

virtual void	Inspect () const
	Dump contents of this object in a graphics canvas. More...

virtual Bool_t	IsEqual (const TObject *obj) const
	Default equal comparison (objects are equal if they have the same address in memory). More...

Bool_t	IsOnHeap () const

Bool_t	IsZombie () const

virtual Bool_t	Notify ()
	This method must be overridden to handle object notification. More...

virtual void	Paint (Option_t *option="")
	This method must be overridden if a class wants to paint itself. More...

virtual void	Pop ()
	Pop on object drawn in a pad to the top of the display list. More...

virtual Int_t	Read (const char *name)
	Read contents of object with specified name from the current directory. More...

virtual void	SavePrimitive (std::ostream &out, Option_t *option="")
	Save a primitive as a C++ statement(s) on output stream "out". More...

virtual void	SetDrawOption (Option_t *option="")
	Set drawing option for object. More...

virtual void	SetUniqueID (UInt_t uid)
	Set the unique object id. More...

virtual void	UseCurrentStyle ()
	Set current style settings in this object This function is called when either TCanvas::UseCurrentStyle or TROOT::ForceStyle have been invoked. More...

virtual Int_t	Write (const char *name=0, Int_t option=0, Int_t bufsize=0)
	Write this object to the current directory. More...

virtual Int_t	Write (const char *name=0, Int_t option=0, Int_t bufsize=0) const
	Write this object to the current directory. More...

void *	operator new (size_t sz)

void *	operator new[] (size_t sz)

void *	operator new (size_t sz, void *vp)

void *	operator new[] (size_t sz, void *vp)

void	operator delete (void *ptr)
	Operator delete. More...

void	operator delete[] (void *ptr)
	Operator delete []. More...

void	SetBit (UInt_t f, Bool_t set)
	Set or unset the user status bits as specified in f. More...

void	SetBit (UInt_t f)

void	ResetBit (UInt_t f)

Bool_t	TestBit (UInt_t f) const

Int_t	TestBits (UInt_t f) const

void	InvertBit (UInt_t f)

virtual void	Info (const char method, const char msgfmt,...) const
	Issue info message. More...

virtual void	Warning (const char method, const char msgfmt,...) const
	Issue warning message. More...

virtual void	Error (const char method, const char msgfmt,...) const
	Issue error message. More...

virtual void	SysError (const char method, const char msgfmt,...) const
	Issue system error message. More...

virtual void	Fatal (const char method, const char msgfmt,...) const
	Issue fatal error message. More...

void	AbstractMethod (const char *method) const
	Use this method to implement an "abstract" method that you don't want to leave purely abstract. More...

void	MayNotUse (const char *method) const
	Use this method to signal that a method (defined in a base class) may not be called in a derived class (in principle against good design since a child class should not provide less functionality than its parent, however, sometimes it is necessary). More...

void	Obsolete (const char method, const char asOfVers, const char *removedFromVers) const
	Use this method to declare a method obsolete. More...

Protected Attributes
TCollection *	fFolders

Bool_t	fIsOwner

Protected Attributes inherited from TNamed
TString	fName

TString	fTitle

Private Member Functions
	TFolder (const TFolder &folder)
	Copy constructor. More...

void	operator= (const TFolder &)

Additional Inherited Members
Public Types inherited from TObject
enum	EStatusBits { kCanDelete = BIT(0), kMustCleanup = BIT(3), kObjInCanvas = BIT(3), kIsReferenced = BIT(4), kHasUUID = BIT(5), kCannotPick = BIT(6), kNoContextMenu = BIT(8), kInvalidObject = BIT(13) }

enum	{ kIsOnHeap = 0x01000000, kNotDeleted = 0x02000000, kZombie = 0x04000000, kBitMask = 0x00ffffff }

enum	{ kSingleKey = BIT(0), kOverwrite = BIT(1), kWriteDelete = BIT(2) }

Static Public Member Functions inherited from TObject
static Long_t	GetDtorOnly ()
	Return destructor only flag. More...

static void	SetDtorOnly (void *obj)
	Set destructor only flag. More...

static Bool_t	GetObjectStat ()
	Get status of object stat flag. More...

static void	SetObjectStat (Bool_t stat)
	Turn on/off tracking of objects in the TObjectTable. More...

Protected Member Functions inherited from TObject
void	MakeZombie ()

virtual void	DoError (int level, const char location, const char fmt, va_list va) const
	Interface to ErrorHandler (protected). More...

#include <TFolder.h>

Inheritance diagram for TFolder:

Collaboration diagram for TFolder:

Constructor & Destructor Documentation

TFolder::TFolder ( const TFolder & folder )

private

Copy constructor.

Definition at line 126 of file TFolder.cxx.

TFolder::TFolder ( )

Referenced by AddFolder().

TFolder::TFolder	(	const char *	name,
		const char *	title
	)

Create a normal folder.

Use Add or AddFolder to add objects or folders to this folder.

Definition at line 116 of file TFolder.cxx.

TFolder::~TFolder ( )

virtual

Folder destructor.

Remove all objects from its lists and delete all its sub folders.

Definition at line 135 of file TFolder.cxx.

Member Function Documentation

void TFolder::Add ( TObject * obj )

virtual

Add object to this folder. obj must be a TObject or a TFolder.

Definition at line 168 of file TFolder.cxx.

Referenced by TRootSniffer::AccessField(), and TRootSniffer::RegisterObject().

TFolder * TFolder::AddFolder	(	const char *	name,
		const char *	title,
		TCollection *	collection = `0`
	)

Create a new folder and add it to the list of folders of this folder, return a pointer to the created folder.

Note that a folder can be added to several folders.

If collection is non NULL, the pointer fFolders is set to the existing collection, otherwise a default collection (Tlist) is created. Note that the folder name cannot contain slashes.

Definition at line 184 of file TFolder.cxx.

Referenced by TRootSniffer::GetItem(), and TROOT::TROOT().

void TFolder::Browse ( TBrowser * b )

virtual

Browse this folder.

Reimplemented from TObject.

Definition at line 215 of file TFolder.cxx.

void TFolder::Clear ( Option_t * option = "" )

virtual

Delete all objects from a folder list.

Reimplemented from TNamed.

Definition at line 223 of file TFolder.cxx.

virtual void TFolder::Copy ( TObject & named ) const

inlinevirtual

Copy this to obj.

Reimplemented from TNamed.

Definition at line 51 of file TFolder.h.

const char * TFolder::FindFullPathName ( const char * name ) const

virtual

Return the full pathname corresponding to subpath name if the node is gROOT->GetRootFolder() and return a relative path otherwise.

The returned path will be re-used by the next call to FindFullPathName().

Definition at line 233 of file TFolder.cxx.

Referenced by FindFullPathName().

const char * TFolder::FindFullPathName ( const TObject * obj ) const

virtual

Return the full pathname corresponding to subpath name.

The returned path will be re-used by the next call to FindFullPathName().

Definition at line 278 of file TFolder.cxx.

TObject * TFolder::FindObject ( const char * name ) const

virtual

Search object identified by name in the tree of folders inside this folder.

Name may be of the forms:

A. Specify a full pathname starting at the top ROOT folder //root/xxx/yyy/name

B. Specify a pathname starting with a single slash. //root is assumed /xxx/yyy/name

C. Specify a pathname relative to this folder xxx/yyy/name name

Reimplemented from TObject.

Definition at line 308 of file TFolder.cxx.

Referenced by FindFullPathName(), FindObjectAny(), TRootSniffer::GetItem(), and TEveManager::GetMacro().

TObject * TFolder::FindObject ( const TObject * obj ) const

virtual

Find object in an folder.

Reimplemented from TObject.

Definition at line 287 of file TFolder.cxx.

TObject * TFolder::FindObjectAny ( const char * name ) const

virtual

Return a pointer to the first object with name starting at this folder.

Definition at line 350 of file TFolder.cxx.

Referenced by FindObjectAny(), and TROOT::FindObjectAny().

TCollection* TFolder::GetListOfFolders ( ) const

inline

Definition at line 57 of file TFolder.h.

Referenced by TRootSniffer::AccessField(), TTree::Branch(), TRootSniffer::GetItem(), and TRootSniffer::ScanRoot().

Bool_t TFolder::IsFolder ( ) const

inlinevirtual

Returns kTRUE in case object contains browsable objects (like containers or lists of other objects).

Reimplemented from TObject.

Definition at line 58 of file TFolder.h.

Bool_t TFolder::IsOwner ( ) const

Folder ownership has been set via.

TFolder::SetOwner
TCollection::SetOwner on the collection specified to TFolder::AddFolder

Definition at line 376 of file TFolder.cxx.

void TFolder::ls ( Option_t * option = "" ) const

virtual

List folder contents.

If option contains "dump", the Dump function of contained objects is called.

If option contains "print", the Print function of contained objects is called.

By default the ls function of contained objects is called.

Indentation is used to identify the folder tree.

The if option contains a <regexp> it be used to match the name of the objects.

Reimplemented from TNamed.

Definition at line 395 of file TFolder.cxx.

Int_t TFolder::Occurence ( const TObject * object ) const

virtual

Return occurence number of object in the list of objects of this folder.

The function returns the number of objects with the same name as object found in the list of objects in this folder before object itself. If only one object is found, return 0.

Definition at line 434 of file TFolder.cxx.

Referenced by TTree::Branch().

void TFolder::operator= ( const TFolder & )

private

void TFolder::RecursiveRemove ( TObject * obj )

virtual

Recursively remove object from a folder.

Reimplemented from TObject.

Definition at line 456 of file TFolder.cxx.

Referenced by TRootSniffer::UnregisterObject().

void TFolder::Remove ( TObject * obj )

virtual

Remove object from this folder. obj must be a TObject or a TFolder.

Definition at line 464 of file TFolder.cxx.

Referenced by TRootSniffer::AccessField().

void TFolder::SaveAs	(	const char *	filename = `""`,
		Option_t *	option = `""`
	)		const

virtual

Save all objects in this folder in filename.

Each object in this folder will have a key in the file where the name of the key will be the name of the object.

Reimplemented from TObject.

Definition at line 475 of file TFolder.cxx.

void TFolder::SetOwner ( Bool_t owner = kTRUE )

virtual

Set ownership.

If the folder is declared owner, when the folder is deleted, all the objects added via TFolder::Add are deleted via TObject::Delete, otherwise TObject::Clear is called.

NOTE that folder ownership can be set:

via TFolder::SetOwner
or via TCollection::SetOwner on the collection specified to TFolder::AddFolder

Definition at line 490 of file TFolder.cxx.

Member Data Documentation

TCollection* TFolder::fFolders

protected

Definition at line 35 of file TFolder.h.

Referenced by Add(), AddFolder(), Browse(), Clear(), FindFullPathName(), FindObject(), FindObjectAny(), GetListOfFolders(), IsOwner(), ls(), Occurence(), RecursiveRemove(), Remove(), SetOwner(), TFolder(), and ~TFolder().

Bool_t TFolder::fIsOwner

protected

Definition at line 36 of file TFolder.h.

Referenced by TFolder().

The documentation for this class was generated from the following files:

core/base/inc/TFolder.h
core/base/src/TFolder.cxx

Public Member Functions

Protected Attributes

Private Member Functions

Additional Inherited Members

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation