library: libGraf #include "TLegend.h"

# TLegend

class description - source file - inheritance tree (.ps)

## class TLegend : public TPave, public TAttText

| Inheritance Chart:

`TObject`

`TAttLine`

`TAttFill`

<-

`TBox`

<-

`TPave`

`TAttText`

<-

`TLegend`

        public:

                              TLegend()
                              TLegend(Double_t x1, Double_t y1, Double_t x2, Double_t y2, const char* header, Option_t* option = "brNDC")
                              TLegend(const TLegend& legend)
                      virtual ~TLegend()
                TLegendEntry* AddEntry(TObject* obj, const char* label, Option_t* option = "lpf")
                TLegendEntry* AddEntry(const char* name, const char* label, Option_t* option = "lpf")
               static TClass* Class()
                 virtual void Clear(Option_t* option)
                 virtual void Copy(TObject& obj) const
                 virtual void DeleteEntry()
                 virtual void Draw(Option_t* option)
                 virtual void EditEntryAttFill()
                 virtual void EditEntryAttLine()
                 virtual void EditEntryAttMarker()
                 virtual void EditEntryAttText()
                TLegendEntry* GetEntry() const
                      Float_t GetEntrySeparation() const
          virtual const char* GetHeader() const
                       TList* GetListOfPrimitives() const
                      Float_t GetMargin() const
                 virtual void InsertEntry(const char* objectName, const char* label, Option_t* option = "lpf")
              virtual TClass* IsA() const
                     TLegend& operator=(const TLegend&)
                 virtual void Paint(Option_t* option)
                 virtual void PaintPrimitives()
                 virtual void Print(Option_t* option) const
                 virtual void RecursiveRemove(TObject* obj)
                 virtual void SavePrimitive(ofstream& out, Option_t* option)
                         void SetDefaults()
                 virtual void SetEntryLabel(const char* label)
                 virtual void SetEntryOption(Option_t* option)
                         void SetEntrySeparation(Float_t entryseparation)
                 virtual void SetHeader(const char* header)
                         void SetMargin(Float_t margin)
                 virtual void ShowMembers(TMemberInspector& insp, char* parent)
                 virtual void Streamer(TBuffer& b)
                         void StreamerNVirtual(TBuffer& b)

### Data Members

        protected:

           TList* fPrimitives       list of TLegendEntries
          Float_t fEntrySeparation  separation between entries, as a fraction of
          Float_t fMargin           fraction of total width used for symbol

## Class Description

     TLegend   Matthew.Adam.Dobbs@Cern.CH, September 1999
     Legend of markers/lines/boxes to represent objects with marker/line/fill
       attributes
       (the methods employed are very similar to those in TPaveText class)

TLegend(): TPave(), TAttText()

     TPadLegend do-nothing default constructor

TLegend( Double_t x1, Double_t y1,Double_t x2, Double_t y2, const char *header, Option_t *option) :TPave(x1,y1,x2,y2,4,option), TAttText(12,0,1,42,0)

    ___________________________________
     TLegend normal Contructor
     A TLegend is a Pave with several TLegendEntry(s)
     The pave is defined with default coords, bordersize and option
     x1,y1,x2,y2 are the coordinates of the Legend in the current pad
     (in NDC by default!)
     text is left adjusted and vertically centered = 12
          Angle=0 (degrees), color=1 (black)
          helvetica-medium-r-normal scalable font = 42
          (will use bold = 62 for header)
          size =0 (calculate this later when number of entries is known)
     header is the "title" that will be displayed at the top of the legend
       it is treated like a regular entry and supports TLatex. The default
       is no header (header = 0).
     Options are the same as for TPave Default = "brNDC"

     Here's an example of a Legend created with TLegend

/* */

     The Legend part of this plot was created as follows:

        leg = new TLegend(0.4,0.6,0.89,0.89);
        leg->AddEntry(fun1,"One Theory","l");
        leg->AddEntry(fun3,"Another Theory","f");
        leg->AddEntry(gr,"The Data","p");
        leg->Draw();
        // oops we forgot the blue line... add it after
        leg->AddEntry(fun2,"#sqrt{2#pi} P_{T} (#gamma)  latex formula","f");
        // and add a header (or "title") for the legend
        leg->SetHeader("The Legend Title");
        leg->Draw();

     where fun1,fun2,fun3 and gr are pre-existing functions and graphs

     You can edit the TLegend by right-clicking on it.

TLegend( const TLegend &legend ) : TPave(legend), TAttText(legend)

     copy constuctor

~TLegend()

     TLegend default destructor

TLegendEntry* AddEntry(TObject *obj, const char *label, Option_t *option)

     Add a new entry to this legend
     obj is the object to be represented
     label is the text you wish to associate with obj in the legend
     Options are:
        L draw line associated w/ TAttLine if obj inherits from TAttLine
        P draw polymarker assoc. w/ TAttMarker if obj inherits from TAttMarker
        F draw a box with fill associated w/ TAttFill if obj inherits TAttFill

TLegendEntry* AddEntry(const char *name, const char *label, Option_t *option)

     Add a new entry to this legend
     name is the name of an object in the pad to be represented
     label is the text you wish to associate with obj in the legend
     Options are:
        L draw line associated w/ TAttLine if obj inherits from TAttLine
        P draw polymarker assoc. w/ TAttMarker if obj inherits from TAttMarker
        F draw a box with fill associated w/ TAttFill if obj inherits TAttFill

void Clear( Option_t *)

     Clear all entries in this legend --- including the header!

void Copy( TObject &obj ) const

     copy this legend into obj

void DeleteEntry()

     Delete entry at the mouse position

void Draw( Option_t *option )

     Draw this legend with its current attributes

void EditEntryAttFill()

     Edit the fill attributes for the entry pointed by the mouse

void EditEntryAttLine()

     Edit the line attributes for the entry pointed by the mouse

void EditEntryAttMarker()

     Edit the marker attributes for the entry pointed by the mouse

void EditEntryAttText()

     Edit the text attributes for the entry pointed by the mouse

TLegendEntry* GetEntry() const

     Get entry pointed to by the mouse
     This method is mostly a tool for other methods inside this class

const char* GetHeader() const

     returns the header, which is the title that appears at the top
      of the legend

void InsertEntry( const char* objectName, const char* label, Option_t* option)

     Add a new entry before the entry at the mouse position

void Paint( Option_t* option )

     Paint this legend with its current attributes

void PaintPrimitives()

     Paint the entries (list of primitives) for this legend

     NOTE: if we want an     Int_t mode
           it can be added later... but I understand whyaas

void Print( Option_t* option ) const

     dump this TLegend and its contents

void RecursiveRemove(TObject *obj)

      Reset TLegendEntrys pointing to obj

void SavePrimitive( ofstream &out, Option_t* )

     Save this legend as C++ statements on output stream out
      to be used with the SaveAs .C option

void SetEntryLabel( const char* label )

     edit the label of the entry pointed to by the mouse

void SetEntryOption( Option_t* option )

     edit the option of the entry pointed to by the mouse

void SetHeader( const char *header )

     Sets the header, which is the "title" that appears at the top of the
      TLegend

### Inline Functions

                Float_t GetEntrySeparation() const
                 TList* GetListOfPrimitives() const
                Float_t GetMargin() const
                   void SetDefaults()
                   void SetEntrySeparation(Float_t entryseparation)
                   void SetMargin(Float_t margin)
                TClass* Class()
                TClass* IsA() const
                   void ShowMembers(TMemberInspector& insp, char* parent)
                   void Streamer(TBuffer& b)
                   void StreamerNVirtual(TBuffer& b)
               TLegend& operator=(const TLegend&)

Author: Matthew.Adam.Dobbs 06/09/99
Last update: root/graf:$Name: $:$Id: TLegend.cxx,v 1.20 2003/11/17 17:18:07 brun Exp $
Copyright (C) 1995-2000, Rene Brun and Fons Rademakers. *