TFolder
class description - source file - inheritance tree
private:
TFolder TFolder(const TFolder& folder)
void operator=(const TFolder&)
public:
TFolder TFolder()
TFolder TFolder(const char* name, const char* title)
virtual void ~TFolder()
virtual void Add(TObject* obj)
TFolder* AddFolder(const char* name, const char* title, TCollection* collection = 0)
virtual void Browse(TBrowser* b)
static TClass* Class()
virtual void Clear(Option_t* option)
virtual void Copy(TObject&) const
virtual const char* FindFullPathName(const char* name) const
virtual const char* FindFullPathName(const TObject* obj) const
virtual TObject* FindObject(const char* name) const
virtual TObject* FindObject(const TObject* obj) const
virtual TObject* FindObjectAny(const char* name) const
TCollection* GetListOfFolders() const
virtual TClass* IsA() const
virtual Bool_t IsFolder() const
Bool_t IsOwner() const
virtual void ls(Option_t* option = "*") const
virtual Int_t Occurence(const TObject* obj) const
virtual void RecursiveRemove(TObject* obj)
virtual void Remove(TObject* obj)
virtual void SaveAs(const char* filename)
virtual void SetOwner(Bool_t owner = kTRUE)
virtual void ShowMembers(TMemberInspector& insp, char* parent)
virtual void Streamer(TBuffer& b)
void StreamerNVirtual(TBuffer& b)
protected:
TCollection* fFolders pointer to the list of folders
Bool_t fIsOwner true if folder own its contained objects
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 analyzes 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.
/*
*/
TFolder() : TNamed()
default constructor used by the Input functions
This constructor should not be called by a user directly.
The normal way to create a folder is by calling TFolder::AddFolder
TFolder(const char *name, const char *title) : TNamed(name,title)
create a normal folder.
use Add or AddFolder to add objects or folders to this folder
TFolder(const TFolder &folder) : TNamed(folder)
~TFolder()
folder destructor. Remove all objects from its lists and delete
all its sub folders
void Add(TObject *obj)
Add object to this folder. obj must be a TObject or a TFolder
TFolder* AddFolder(const char *name, const char *title, TCollection *collection)
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.
void Browse(TBrowser *b)
Browse this folder
void Clear(Option_t *option)
Delete all objects from a folder list
const char* FindFullPathName(const char *name) const
return the full pathname corresponding to subpath name
The returned path will be re-used by the next call to GetPath().
const char* FindFullPathName(const TObject *) const
return the full pathname corresponding to subpath name
The returned path will be re-used by the next call to GetPath().
TObject* FindObject(const TObject *) const
find object in an folder
TObject* FindObject(const char *name) const
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
TObject* FindObjectAny(const char *name) const
return a pointer to the first object with name starting at this folder
Bool_t IsOwner() const
folder ownership has been set via
- TFolder::SetOwner
- TCollection::SetOwner on the collection specified to TFolder::AddFolder
void ls(Option_t *option) const
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 <regexp> will be used to match the name of the objects.
Int_t Occurence(const TObject *object) const
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;
void RecursiveRemove(TObject *obj)
Recursively remove object from a Folder
void Remove(TObject *obj)
Remove object from this folder. obj must be a TObject or a TFolder
void SaveAs(const char *filename)
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.
void SetOwner(Bool_t owner)
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
Inline Functions
void operator=(const TFolder&)
void Copy(TObject&) const
TCollection* GetListOfFolders() const
Bool_t IsFolder() const
TClass* Class()
TClass* IsA() const
void ShowMembers(TMemberInspector& insp, char* parent)
void Streamer(TBuffer& b)
void StreamerNVirtual(TBuffer& b)
Author: Rene Brun 02/09/2000
Last update: root/base:$Name: $:$Id: TFolder.cxx,v 1.22 2003/02/09 18:35:17 brun Exp $
Copyright (C) 1995-2000, Rene Brun and Fons Rademakers. *
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