TExec is a utility class that can be used to execute a C++ command when some event happens in a pad.

The command in turn can invoke a C++ macro to paint graphics objects at positions depending on the histogram or graph contents.

Case 1:

The TExec object is in the list of pad primitives (after exec.Draw()). When the pad is drawn, the TExec::Paint function is called. This function will execute the specified command. The following example uses the services of the class Aclock created in $ROOTSYS/test/Aclock.cxx. This examples uses a TTimer to redraw a pad at regular intervals (clock). When the clock is updated, a string with the current date&time is drawn.

{
   gSystem->Load("$ROOTSYS/test/Aclock");
   Aclock ck(400);
   gPad->SetFillColor(5);
   TDatime dt;
   TText t(.5,.3,"t");
   t.SetTextAlign(22);
   t.SetTextSize(.07);
   t.SetTextColor(4);
   t.Draw();
   TExec ex("ex","dt.Set();t.SetTitle(dt.AsString())");
   ex.Draw();
}

Case 2:

The TExec object may be added to the list of functions of a TH1 or TGraph object via hist->GetListOfFunctions()->Add(exec). When the histogram (or graph) is drawn, the TExec will be executed. If the histogram is made persistent on a file, the TExec object is also saved with the histogram. When redrawing the histogram in a new session, the TExec will be executed.

Example:

Assume an histogram TH1F *h already filled.

TExec *ex1 = new TExec("ex1","DoSomething()");
TExec *ex2 = new TExec("ex2",".x macro.C");
h->GetListOfFunctions()->Add(ex1);
h->GetListOfFunctions()->Add(ex2);
h->Draw();

When the Paint function for the histogram will be called, the "DoSomething" function will be called (interpreted or compiled) and also the macro.C.

Case 3:

A TExec object is automatically generated when invoking TPad::AddExec. Each pad contains a TList of TExecs (0, 1 or more). When a mouse event (motion, click, etc) happens, the pad object executes sequentially this list of TExecs. In the code (interpreted or compiled) executed by the TExec referenced command, one can call the pad service functions such as TPad::GetEvent, TPad::GetEventX, TPad::GetEventY to find which type of event and the X,Y position of the mouse. By default, the list of TExecs is executed. This can be disabled via the canvas menu "Option". See $ROOTSYS/tutorials/hist/exec2.C for an example.

Root > TFile f("hsimple.root");
Root > hpxpy.Draw();
Root > c1.AddExec("ex2",".x exec2.C");

When moving the mouse in the canvas, a second canvas shows the projection along X of the bin corresponding to the Y position of the mouse. The resulting histogram is fitted with a gaussian. A "dynamic" line shows the current bin position in Y. This more elaborated example can be used as a starting point to develop more powerful interactive applications exploiting CINT as a development engine.

The 3 options above can be combined.

Definition at line 30 of file TExec.h.

Public Member Functions
	TExec ()

	TExec (const char name, const char command)
	Exec normal constructor. More...

	TExec (const TExec &text)
	Copy constructor. More...

virtual	~TExec ()
	Exec default destructor. More...

virtual void	Exec (const char *command="")
	Execute the command referenced by this object. More...

virtual void	Paint (Option_t *option="")
	Execute the command referenced by this object. More...

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

virtual void	SetAction (const char *action)

	ClassDef (TExec, 1)

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 void	Clear (Option_t *option="")
	Set name and title to empty strings (""). More...

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	Copy (TObject &named) const
	Copy this to obj. 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	ls (Option_t *option="") const
	List TNamed name and title. 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 void	Browse (TBrowser *b)
	Browse object. May be overridden for another default action. 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 TObject *	FindObject (const char *name) const
	Must be redefined in derived classes. More...

virtual TObject *	FindObject (const TObject *obj) const
	Must be redefined in derived classes. 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	IsFolder () const
	Returns kTRUE in case object contains browsable objects (like containers or lists of other objects). 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	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	RecursiveRemove (TObject *obj)
	Recursively remove this object from a list. More...

virtual void	SaveAs (const char filename="", Option_t option="") const
	Save this object in the file specified by filename. 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...

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...

Protected Attributes inherited from TNamed
TString	fName

TString	fTitle

#include <TExec.h>

Inheritance diagram for TExec:

[legend]

Constructor & Destructor Documentation

TExec::TExec ( )

TExec::TExec	(	const char *	name,
		const char *	command
	)

Exec normal constructor.

Definition at line 111 of file TExec.cxx.

TExec::TExec ( const TExec & text )

Copy constructor.

Definition at line 125 of file TExec.cxx.

TExec::~TExec ( )

virtual

Exec default destructor.

Definition at line 118 of file TExec.cxx.

Member Function Documentation

TExec::ClassDef	(	TExec	,
		1
	)

void TExec::Exec ( const char * command = "" )

virtual

Execute the command referenced by this object.

if command is given, this command is executed otherwise the default command of the object is executed

if the default command (in the exec title) is empty, an attempt is made to execute the exec name if it contains a "." or a "(", otherwise the command ".x execname.C" is executed. The function returns the result of the user function/script.

Definition at line 141 of file TExec.cxx.

Referenced by TPad::AutoExec(), TRef::GetObject(), and Paint().

void TExec::Paint ( Option_t * option = "" )

virtual

Execute the command referenced by this object.

Reimplemented from TObject.

Definition at line 159 of file TExec.cxx.

void TExec::SavePrimitive	(	std::ostream &	out,
		Option_t *	option = `""`
	)

virtual

Save primitive as a C++ statement(s) on output stream out.

Reimplemented from TObject.

Definition at line 167 of file TExec.cxx.

virtual void TExec::SetAction ( const char * action )

inlinevirtual

Definition at line 41 of file TExec.h.

Collaboration diagram for TExec:

[legend]

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

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

Case 1:

Case 2:

Case 3:

Public Member Functions

Additional Inherited Members

Constructor & Destructor Documentation

Member Function Documentation