TCanvas


class description - source file - inheritance tree

class TCanvas : public TPad

    private:
TCanvas TCanvas(const TCanvas& canvas) void Build() virtual void CopyPixmaps() void DrawEventStatus(Int_t button, Int_t x, Int_t y, TObject* selected) TCanvas& operator=(const TCanvas& rhs) void RunAutoExec() protected:
void Constructor() void Constructor(const char* name, const char* title, Int_t form) void Constructor(const char* name, const char* title, Int_t ww, Int_t wh) void Constructor(const char* name, const char* title, Int_t wtopx, Int_t wtopy, Int_t ww, Int_t wh) void Destructor() virtual void ExecuteEvent(Int_t event, Int_t px, Int_t py) public:
TCanvas TCanvas() TCanvas TCanvas(const char* name, const char* title, Int_t form = 1) TCanvas TCanvas(const char* name, const char* title, Int_t ww, Int_t wh) TCanvas TCanvas(const char* name, const char* title, Int_t wtopx, Int_t wtopy, Int_t ww, Int_t wh) TCanvas TCanvas(const char* name, Int_t ww, Int_t wh, Int_t winid) virtual void ~TCanvas() virtual void cd(Int_t subpadnumber = 0) TClass* Class() virtual void Clear(Option_t* option) virtual void Close(Option_t* option) virtual void Draw(Option_t* option) virtual void DrawClone(Option_t* option) virtual void EditorBar() void EnterLeave(TPad* prevSelPad, TObject* prevSelObj) void FeedbackMode(Bool_t set) void Flush() void ForceUpdate() Bool_t GetAutoExec() const virtual Int_t GetCanvasID() const TCanvasImp* GetCanvasImp() virtual void GetCanvasPar(Int_t& wtopx, Int_t& wtopy, UInt_t& ww, UInt_t& wh) TContextMenu* GetContextMenu() const char* GetDISPLAY() const Int_t GetDoubleBuffer() TControlBar* GetEditorBar() virtual Int_t GetEvent() const virtual Int_t GetEventX() const virtual Int_t GetEventY() const virtual Color_t GetHighLightColor() const virtual void* GetPadDivision(Int_t xdivision = 1, Int_t ydivision = 1) virtual TVirtualPad* GetPadSave() const virtual TObject* GetSelected() Option_t* GetSelectedOpt() const virtual TVirtualPad* GetSelectedPad() const Bool_t GetShowEventStatus() virtual UInt_t GetWh() UInt_t GetWindowHeight() const Int_t GetWindowTopX() Int_t GetWindowTopY() UInt_t GetWindowWidth() const virtual UInt_t GetWw() Size_t GetXsizeReal() Size_t GetXsizeUser() Size_t GetYsizeReal() Size_t GetYsizeUser() virtual void HandleInput(EEventType button, Int_t x, Int_t y) Bool_t HasMenuBar() const void Iconify() virtual TClass* IsA() const virtual Bool_t IsBatch() virtual Bool_t IsRetained() virtual void ls(Option_t* option) void MakeDefCanvas() void MoveOpaque(Int_t set = 1) virtual Bool_t OpaqueMoving() const virtual Bool_t OpaqueResizing() const virtual void Paint(Option_t* option) virtual void Resize(Option_t* option) void ResizeOpaque(Int_t set = 1) void SaveSource(const char* filename, Option_t* option) virtual void SetBatch(Bool_t batch = kTRUE) virtual void SetCanvasSize(UInt_t ww, UInt_t wh) virtual void SetCursor(ECursor cursor) virtual void SetDoubleBuffer(Int_t mode = 1) void SetHighLightColor(Color_t col) void SetRetained(Bool_t retained = kTRUE) virtual void SetSelected(TObject* obj) virtual void SetTitle(const char* title) void SetWindowPosition(Int_t x, Int_t y) void SetWindowSize(UInt_t ww, UInt_t wh) void Show() virtual void ShowMembers(TMemberInspector& insp, char* parent) virtual void Size(Float_t xsizeuser = 0, Float_t ysizeuser = 0) virtual void Streamer(TBuffer& b) virtual void ToggleAutoExec() virtual void ToggleEventStatus() virtual void Update() virtual void UseCurrentStyle()

Data Members

protected:
TString fDISPLAY Name of destination screen Int_t fDoubleBuffer Double buffer flag (0=off, 1=on) Bool_t fRetained Retain structure flag Size_t fXsizeUser User specified size of canvas along X in CM Size_t fYsizeUser User specified size of canvas along Y in CM Size_t fXsizeReal Current size of canvas along X in CM Size_t fYsizeReal Current size of canvas along Y in CM Int_t fCanvasID Canvas identifier Int_t fWindowTopX Top X position of window (in pixels) Int_t fWindowTopY Top Y position of window (in pixels) UInt_t fWindowWidth Width of window (including borders, etc.) UInt_t fWindowHeight Height of window (including menubar, borders, etc.) UInt_t fCw Width of the canvas along X (pixels) UInt_t fCh Height of the canvas along Y (pixels) TAttCanvas fCatt Canvas attributes TObject* fSelected Currently selected object TString fSelectedOpt Drawing option of selected object TVirtualPad* fSelectedPad Pad containing currently selected object TVirtualPad* fPadSave Pointer to saved pad in HandleInput Int_t fEvent Type of current or last handled event Int_t fEventX Last X mouse position in canvas Int_t fEventY Last Y mouse position in canvas Bool_t fShowEventStatus Show event status panel Bool_t fAutoExec To auto exec the list of pad TExecs TControlBar* fEditorBar Editor control bar TCanvasImp* fCanvasImp Window system specific canvas implementation Bool_t fMoveOpaque Move objects in opaque mode Bool_t fResizeOpaque Resize objects in opaque mode Color_t fHighLightColor Highlight color of active pad Bool_t fBatch True when in batchmode Bool_t fMenuBar False if no menubar is displayed TContextMenu* fContextMenu Context menu pointer


See also

TDialogCanvas, TInspectCanvas, TTreeViewer

Class Description

   A Canvas is an area mapped to a window directly under
   the control of the display manager.
   A ROOT session may have several canvases open at any given time.

   A Canvas may be subdivided into independent graphical areas: the PADs
   A canvas has a default pad which has the name of the canvas itself.
   An example of a Canvas layout is sketched in the picture below.

   ***********************************************************************
   *          Tool Bar menus    for Canvas                               *
   ***********************************************************************
   *                                                                     *
   *  ************************************    *************************  *
   *  *                                  *    *                       *  *
   *  *                                  *    *                       *  *
   *  *                                  *    *                       *  *
   *  *                                  *    *                       *  *
   *  *                                  *    *                       *  *
   *  *                                  *    *                       *  *
   *  *              P1                  *    *        P2             *  *
   *  *                                  *    *                       *  *
   *  *                                  *    *                       *  *
   *  *                                  *    *                       *  *
   *  *                                  *    *                       *  *
   *  *                                  *    *                       *  *
   *  *                                  *    *                       *  *
   *  ************************************    *************************  *
   *                                                                     *
   ***********************************************************************

   This canvas contains two pads named P1 and P2.
   Both Canvas, P1 and P2 can be moved, grown, shrinked using the
   normal rules of the Display manager.
   A copy of a real canvas with 4 pads is shown in the picture below.

/*

*/


  Once objects have been drawn in a canvas, they can be edited/moved
  by pointing directly to them. The cursor shape is changed
  to suggest the type of action that one can do on this object.
  Clicking with the right mouse button on an object pops-up
  a contextmenu with a complete list of actions possible on this object.

  A graphical editor may be started from the canvas "Edit" menu.
  Select the "Editor" item. This will show the following editor menu.

/*

*/

  For example, to draw a new TText primitive, select the option Text,
  then click at the position where you want to draw the text. Type <CR>
  when you have finished typing the string.

  A canvas may be automatically divided into pads via TPad::Divide.


TCanvas() : TPad()
 Canvas default constructor.

void Constructor()
 Canvas default constructor

TCanvas(const char *name, Int_t ww, Int_t wh, Int_t winid)
 Create an embedded canvas, i.e. a canvas that is in a TGCanvas widget
 which is placed in a TGFrame. This ctor is only called via the
 TRootEmbeddedCanvas class.

TCanvas(const char *name, const char *title, Int_t form) : TPad()
  Create a new canvas with a predefined size form.
  If form < 0  the menubar is not shown.

  form = 1    700x500 at 10,10 (set by TStyle::SetCanvasDefH,W,X,Y)
  form = 2    500x500 at 20,20
  form = 3    500x500 at 30,30
  form = 4    500x500 at 40,40
  form = 5    500x500 at 50,50

void Constructor(const char *name, const char *title, Int_t form)
  Create a new canvas with a predefined size form.
  If form < 0  the menubar is not shown.

  form = 1    700x500 at 10,10 (set by TStyle::SetCanvasDefH,W,X,Y)
  form = 2    500x500 at 20,20
  form = 3    500x500 at 30,30
  form = 4    500x500 at 40,40
  form = 5    500x500 at 50,50

TCanvas(const char *name, const char *title, Int_t ww, Int_t wh) : TPad()
  Create a new canvas at a random position.

  ww is the canvas size in pixels along X
      (if ww < 0  the menubar is not shown)
  wh is the canvas size in pixels along Y

void Constructor(const char *name, const char *title, Int_t ww, Int_t wh)
  Create a new canvas at a random position.

  ww is the canvas size in pixels along X
      (if ww < 0  the menubar is not shown)
  wh is the canvas size in pixels along Y

TCanvas(const char *name, const char *title, Int_t wtopx, Int_t wtopy, Int_t ww, Int_t wh) : TPad()
  Create a new canvas.

  wtopx,wtopy are the pixel coordinates of the top left corner of
  the canvas (if wtopx < 0) the menubar is not shown)
  ww is the canvas size in pixels along X
  wh is the canvas size in pixels along Y

void Constructor(const char *name, const char *title, Int_t wtopx, Int_t wtopy, Int_t ww, Int_t wh)
  Create a new canvas.

  wtopx,wtopy are the pixel coordinates of the top left corner of
  the canvas (if wtopx < 0) the menubar is not shown)
  ww is the canvas size in pixels along X
  wh is the canvas size in pixels along Y

void Build()
 Build a canvas. Called by all constructors.

~TCanvas()
 Canvas destructor

void Destructor()
 Actual canvas destructor.

void cd(Int_t subpadnumber)
*-*-*-*-*-*-*-*-*-*-*-*Set current canvas & pad*-*-*-*-*-*-*-*-*-*-*-*-*
*-*                    ========================

    see TPad::cd for explanation of parameter

void Clear(Option_t *option)
*-*-*-*-*-*-*-*-*-*-*-*Clear canvas*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
*-*                    ============
  Remove all primitives in default pad
  Remove all pads (except default pad)


void Close(Option_t *option)
*-*-*-*-*-*-*-*-*-*-*-*Close canvas*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
*-*                    ============
  Delete window/pads data structure


void CopyPixmaps()
*-*-*-*-*-*-*-*-*Copy the canvas pixmap of the pad to the canvas*-*-*-*-*-*-*
*-*              ===============================================

void Draw(Option_t *)
  Draw a canvas.
  If a canvas with the name is already on the screen, the canvas is repainted.
  This function is useful when a canvas object has been saved in a Root file.
  One can then do:
     Root > Tfile f("file.root");
     Root > canvas.Draw();

void DrawClone(Option_t *option)
 Draw a clone of this canvas

void DrawEventStatus(Int_t event, Int_t px, Int_t py, TObject *selected)
*-*-*-*-*-*-*Report name and title of primitive below the cursor*-*-*-*-*-*
*-*          ===================================================

    This function is called when the option "Event Status"
    in the canvas menu "Options" is selected.


void EditorBar()
*-*-*-*-*-*-*-*-*-*-*Create the Editor Controlbar*-*-*-*-*-*-*-*-*-*
*-*                  ============================

void EnterLeave(TPad *prevSelPad, TObject *prevSelObj)
 Generate kMouseEnter and kMouseLeave events depending on the previously
 selected object and the currently selected object. Does nothing if the
 selected object does not change.

void ExecuteEvent(Int_t event, Int_t px, Int_t py)
*-*-*-*-*-*-*-*-*-*-*Execute action corresponding to one event*-*-*-*
*-*                  =========================================
  This member function must be implemented to realize the action
  corresponding to the mouse click on the object in the canvas

  Only handle mouse motion events in TCanvas, all other events are
  ignored for the time being


void FeedbackMode(Bool_t set)
*-*-*-*-*-*-*-*-*Turn rubberband feedback mode on or off*-*-*-*-*-*-*-*-*-*-*
*-*              =======================================

void Flush()
*-*-*-*-*-*-*-*-*Flush canvas buffers*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
*-*              ====================

void UseCurrentStyle()
*-*-*-*-*-*Force a copy of current style for all objects in canvas*-*-*-*-*
*-*        =======================================================

void* GetPadDivision(Int_t, Int_t)
*-*-*-*-*-*-*-*-*Return pad corresponding to one canvas division*-*-*-*-*
*-*              ===============================================

Int_t GetWindowTopX()
 Returns current top x position of window on screen.

Int_t GetWindowTopY()
 Returns current top y position of window on screen.

void HandleInput(EEventType event, Int_t px, Int_t py)
*-*-*-*-*-*-*-*-*-*Handle Input Events*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
*-*                ===================
  Handle input events, like button up/down in current canvas.


void ls(Option_t *option)
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*List all pads*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
*-*                          =============

void MakeDefCanvas()
*-*-*-*-*-*-*Static function to build a default canvas*-*-*-*-*-*-*-*-*-*-*
*-*          =========================================

void MoveOpaque(Int_t set)
*-*-*-*-*-*-*-*-*Set option to move objects/pads in a canvas*-*-*-*-*-*-*-*
*-*              ===========================================

  if set = 1 (default) graphics objects are moved in opaque mode
         = 0 only the outline of objects is drawn when moving them
  The option opaque produces the best effect. It requires however a
  a reasonably fast workstation or response time.


void Paint(Option_t *option)
*-*-*-*-*-*-*-*-*Paint canvas*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
*-*              ============

void Resize(Option_t *)
*-*-*-*-*-*-*Recompute canvas parameters following a X11 Resize*-*-*-*-*-*-*
*-*          ==================================================

void RunAutoExec()
 Execute the list of TExecs in the current pad.

void SaveSource(const char *filename, Option_t *option)
*-*-*-*-*-*-*Save primitives in this canvas as a C++ macro file*-*-*-*-*-*
*-*          ==================================================

void SetBatch(Bool_t batch)
 Toggle batch mode. However, if the canvas is created without a window
 then batch mode always stays set.

void SetCanvasSize(UInt_t ww, UInt_t wh)
 Set Width and Height of canvas to ww and wh respectively
 If ww and/or wh are greater than the current canvas window
 a scroll bar is automatically generated.
 Use this function to zoom in a canvas and naviguate via
 the scroll bars.

void SetCursor(ECursor cursor)
*-*-*-*-*-*-*-*-*-*-*Set cursor*-*-**-*-*-*-*-*-*-*-*-*-*-*-*
*-*                  ==========

void SetDoubleBuffer(Int_t mode)
*-*-*-*-*-*-*-*-*-*-*Set Double Buffer On/Off*-*-**-*-*-*-*-*-*-*-*-*-*-*-*
*-*                  ========================

void SetTitle(const char *title)
*-*-*-*-*-*-*-*-*-*-*Set Canvas title*-*-**-*-*-*-*-*-*-*-*-*-*-*-*
*-*                  ===============

void Size(Float_t xsize, Float_t ysize)
*-*-*-*-*-*-*Set the canvas scale in centimeters*-*-*-*-*-*-*-*-*-*-*-*-*-*
*-*          ===================================
  This information is used by PostScript to set the page size.
  xsize  = size of the canvas in centimeters along X
  ysize  = size of the canvas in centimeters along Y
   if xsize and ysize are not equal to 0, then the scale factors will
   be computed to keep the ratio ysize/xsize independently of the canvas
   size (parts of the physical canvas will be unused).

   if xsize = 0 and ysize is not zero, then xsize will be computed
      to fit to the current canvas scale. If the canvas is resized,
      a new value for xsize will be recomputed. In this case the aspect
      ratio is not preserved.

   if both xsize = 0 and ysize = 0, then the scaling is automatic.
   the largest dimension will be allocated a size of 20 centimeters.


void Streamer(TBuffer &b)
*-*-*-*-*-*-*-*-*Stream a class object*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
*-*              =========================================

void ToggleAutoExec()
 Toggle pad auto execution of list of TExecs.

void ToggleEventStatus()
 Toggle event statusbar.

void Update()
 Update canvas pad buffers



Inline Functions


             TCanvas& operator=(const TCanvas& rhs)
              TCanvas TCanvas(const char* name, Int_t ww, Int_t wh, Int_t winid)
                 void ForceUpdate()
          const char* GetDISPLAY() const
        TContextMenu* GetContextMenu()
                Int_t GetDoubleBuffer()
         TControlBar* GetEditorBar()
                Int_t GetEvent() const
                Int_t GetEventX() const
                Int_t GetEventY() const
              Color_t GetHighLightColor() const
         TVirtualPad* GetPadSave() const
             TObject* GetSelected()
            Option_t* GetSelectedOpt() const
         TVirtualPad* GetSelectedPad() const
               Bool_t GetShowEventStatus()
               Bool_t GetAutoExec() const
               Size_t GetXsizeUser()
               Size_t GetYsizeUser()
               Size_t GetXsizeReal()
               Size_t GetYsizeReal()
                Int_t GetCanvasID() const
          TCanvasImp* GetCanvasImp()
               UInt_t GetWindowWidth() const
               UInt_t GetWindowHeight() const
               UInt_t GetWw()
               UInt_t GetWh()
                 void GetCanvasPar(Int_t& wtopx, Int_t& wtopy, UInt_t& ww, UInt_t& wh)
               Bool_t HasMenuBar() const
                 void Iconify()
               Bool_t IsBatch()
               Bool_t IsRetained()
               Bool_t OpaqueMoving() const
               Bool_t OpaqueResizing() const
                 void ResizeOpaque(Int_t set = 1)
                 void SetWindowPosition(Int_t x, Int_t y)
                 void SetWindowSize(UInt_t ww, UInt_t wh)
                 void SetHighLightColor(Color_t col)
                 void SetSelected(TObject* obj)
                 void Show()
                 void SetRetained(Bool_t retained = kTRUE)
              TClass* Class()
              TClass* IsA() const
                 void ShowMembers(TMemberInspector& insp, char* parent)


Author: Rene Brun 12/12/94
Last update: 2.23/12 31/01/2000 20.11.02 by Fons Rademakers
Copyright (c) 1995-1999, The ROOT System, All rights reserved. *


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