ROOT 6.08/07 Reference Guide |
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
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:
The above statement can be abbreviated to:
or even to:
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.
Public Member Functions | |
TFolder () | |
Default constructor used by the Input functions. More... | |
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 copy ctor. 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 |
TNamed & | operator= (const TNamed &rhs) |
TNamed assignment operator. More... | |
virtual void | Print (Option_t *option="") const |
Print TNamed name and title. More... | |
virtual void | SetName (const char *name) |
Set the name of the TNamed. More... | |
virtual void | SetNameTitle (const char *name, const char *title) |
Set all the TNamed parameters (name and title). More... | |
virtual void | SetTitle (const char *title="") |
Set the title of the TNamed. More... | |
virtual Int_t | Sizeof () const |
Return size of the TNamed part of the TObject. More... | |
Public Member Functions inherited from TObject | |
TObject () | |
TObject constructor. More... | |
TObject (const TObject &object) | |
TObject copy ctor. More... | |
virtual | ~TObject () |
TObject destructor. 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... | |
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 | Error (const char *method, const char *msgfmt,...) const |
Issue error message. 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 void | Fatal (const char *method, const char *msgfmt,...) const |
Issue fatal error message. More... | |
virtual Option_t * | GetDrawOption () const |
Get option used by the graphics system to draw this object. More... | |
virtual const char * | GetIconName () const |
Returns mime type name of object. More... | |
virtual char * | GetObjectInfo (Int_t px, Int_t py) const |
Returns string containing info about the object at position (px,py). More... | |
virtual Option_t * | GetOption () const |
virtual UInt_t | GetUniqueID () const |
Return the unique object id. More... | |
virtual Bool_t | HandleTimer (TTimer *timer) |
Execute action in response of a timer timing out. More... | |
virtual void | Info (const char *method, const char *msgfmt,...) const |
Issue info message. 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... | |
void | InvertBit (UInt_t f) |
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 |
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... | |
virtual Bool_t | Notify () |
This method must be overridden to handle object notification. More... | |
void | Obsolete (const char *method, const char *asOfVers, const char *removedFromVers) const |
Use this method to declare a method obsolete. More... | |
void | operator delete (void *ptr) |
Operator delete. More... | |
void | operator delete[] (void *ptr) |
Operator delete []. More... | |
void * | operator new (size_t sz) |
void * | operator new (size_t sz, void *vp) |
void * | operator new[] (size_t sz) |
void * | operator new[] (size_t sz, void *vp) |
TObject & | operator= (const TObject &rhs) |
TObject assignment operator. 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... | |
void | ResetBit (UInt_t f) |
virtual void | SavePrimitive (std::ostream &out, Option_t *option="") |
Save a primitive as a C++ statement(s) on output stream "out". 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) |
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 | SysError (const char *method, const char *msgfmt,...) const |
Issue system error message. More... | |
Bool_t | TestBit (UInt_t f) const |
Int_t | TestBits (UInt_t f) const |
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 void | Warning (const char *method, const char *msgfmt,...) const |
Issue warning message. 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... | |
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 | { kIsOnHeap = 0x01000000, kNotDeleted = 0x02000000, kZombie = 0x04000000, kBitMask = 0x00ffffff } |
enum | { kSingleKey = BIT(0), kOverwrite = BIT(1), kWriteDelete = BIT(2) } |
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) } |
Static Public Member Functions inherited from TObject | |
static Long_t | GetDtorOnly () |
Return destructor only flag. More... | |
static Bool_t | GetObjectStat () |
Get status of object stat flag. More... | |
static void | SetDtorOnly (void *obj) |
Set destructor only flag. More... | |
static void | SetObjectStat (Bool_t stat) |
Turn on/off tracking of objects in the TObjectTable. More... | |
Protected Member Functions inherited from TObject | |
virtual void | DoError (int level, const char *location, const char *fmt, va_list va) const |
Interface to ErrorHandler (protected). More... | |
void | MakeZombie () |
#include <TFolder.h>
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private |
Copy constructor.
Definition at line 128 of file TFolder.cxx.
TFolder::TFolder | ( | ) |
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.
Definition at line 108 of file TFolder.cxx.
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 118 of file TFolder.cxx.
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virtual |
Folder destructor.
Remove all objects from its lists and delete all its sub folders.
Definition at line 137 of file TFolder.cxx.
Add object to this folder. obj must be a TObject or a TFolder.
Definition at line 170 of file TFolder.cxx.
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 186 of file TFolder.cxx.
Delete all objects from a folder list.
Reimplemented from TNamed.
Definition at line 225 of file TFolder.cxx.
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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 235 of file TFolder.cxx.
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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 280 of file TFolder.cxx.
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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 310 of file TFolder.cxx.
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virtual |
Return a pointer to the first object with name starting at this folder.
Definition at line 352 of file TFolder.cxx.
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inline |
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inlinevirtual |
Bool_t TFolder::IsOwner | ( | ) | const |
Folder ownership has been set via.
Definition at line 378 of file TFolder.cxx.
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 397 of file TFolder.cxx.
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 436 of file TFolder.cxx.
Recursively remove object from a folder.
Reimplemented from TObject.
Definition at line 458 of file TFolder.cxx.
Remove object from this folder. obj must be a TObject or a TFolder.
Definition at line 466 of file TFolder.cxx.
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 477 of file TFolder.cxx.
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:
Definition at line 492 of file TFolder.cxx.
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protected |