CCheckGroup returns ''array out of range'' when trying to check items not visible

[dcstoyanov]

This is the same example from the library https://www.mql5.com/en/docs/standardlibrary/controls/ccheckgroup with the highlighted lines changed in order to produce the issue in question.

I'm trying to initialize all the check-boxes as checked, even those not visible (you have to scroll the chek-group to see them).

//+------------------------------------------------------------------+
//|                                           ControlsCheckGroup.mq5 |
//|                         Copyright 2000-2024, MetaQuotes Ltd. |
//|                                             https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2017, MetaQuotes Software Corp."
#property link      "https://www.mql5.com"
#property version   "1.00"
#property description "Control Panels and Dialogs. Demonstration class CCheckGroup"
#include <Controls\Dialog.mqh>
#include <Controls\CheckGroup.mqh>
//+------------------------------------------------------------------+
//| defines                                                          |
//+------------------------------------------------------------------+
//--- indents and gaps
#define INDENT_LEFT                         (11)      // indent from left (with allowance for border width)
#define INDENT_TOP                          (11)      // indent from top (with allowance for border width)
#define INDENT_RIGHT                        (11)      // indent from right (with allowance for border width)
#define INDENT_BOTTOM                       (11)      // indent from bottom (with allowance for border width)
#define CONTROLS_GAP_X                      (5)       // gap by X coordinate
#define CONTROLS_GAP_Y                      (5)       // gap by Y coordinate
//--- for buttons
#define BUTTON_WIDTH                        (100)     // size by X coordinate
#define BUTTON_HEIGHT                       (20)      // size by Y coordinate
//--- for the indication area
#define EDIT_HEIGHT                         (20)      // size by Y coordinate
//--- for group controls
#define GROUP_WIDTH                         (150)     // size by X coordinate
#define LIST_HEIGHT                         (179)     // size by Y coordinate
#define RADIO_HEIGHT                        (56)      // size by Y coordinate
#define CHECK_HEIGHT                        (63)      // size by Y coordinate
//+------------------------------------------------------------------+
//| Class CControlsDialog                                            |
//| Usage: main dialog of the Controls application                   |
//+------------------------------------------------------------------+
class CControlsDialog : public CAppDialog
  {
private:
   CCheckGroup       m_check_group;                   // CCheckGroup object
 
public:
                     CControlsDialog(void);
                    ~CControlsDialog(void);
   //--- create
   virtual bool      Create(const long chart,const string name,const int subwin,const int x1,const int y1,const int x2,const int y2);
   //--- chart event handler
   virtual bool      OnEvent(const int id,const long &lparam,const double &dparam,const string &sparam);
 
protected:
   //--- create dependent controls
   bool              CreateCheckGroup(void);
   //--- handlers of the dependent controls events
   void              OnChangeCheckGroup(void);
  };
//+------------------------------------------------------------------+
//| Event Handling                                                   |
//+------------------------------------------------------------------+
EVENT_MAP_BEGIN(CControlsDialog)
ON_EVENT(ON_CHANGE,m_check_group,OnChangeCheckGroup)
EVENT_MAP_END(CAppDialog)
//+------------------------------------------------------------------+
//| Constructor                                                      |
//+------------------------------------------------------------------+
CControlsDialog::CControlsDialog(void)
  {
  }
//+------------------------------------------------------------------+
//| Destructor                                                       |
//+------------------------------------------------------------------+
CControlsDialog::~CControlsDialog(void)
  {
  }
//+------------------------------------------------------------------+
//| Create                                                           |
//+------------------------------------------------------------------+
bool CControlsDialog::Create(const long chart,const string name,const int subwin,const int x1,const int y1,const int x2,const int y2)
  {
   if(!CAppDialog::Create(chart,name,subwin,x1,y1,x2,y2))
      return(false);
//--- create dependent controls
   if(!CreateCheckGroup())
      return(false);
//--- succeed
   return(true);
  }
//+------------------------------------------------------------------+
//| Create the "CheckGroup" element                                  |
//+------------------------------------------------------------------+
bool CControlsDialog::CreateCheckGroup(void)
  {
//--- coordinates
   int x1=INDENT_LEFT;
   int y1=INDENT_TOP+(EDIT_HEIGHT+CONTROLS_GAP_Y)+
          (BUTTON_HEIGHT+CONTROLS_GAP_Y)+
          (EDIT_HEIGHT+CONTROLS_GAP_Y)+
          (EDIT_HEIGHT+CONTROLS_GAP_Y)+
          (RADIO_HEIGHT+CONTROLS_GAP_Y);
   int x2=x1+GROUP_WIDTH;
   int y2=y1+CHECK_HEIGHT;
//--- create
   if(!m_check_group.Create(m_chart_id,m_name+"CheckGroup",m_subwin,x1,y1,x2,y2))
      return(false);
   if(!Add(m_check_group))
      return(false);
//--- fill out with strings
   for(int i=0;i<5;i++) {
      if(!m_check_group.AddItem("Item "+IntegerToString(i),1<<i))
         return(false);
      m_check_group.Check(i,1<<i);
   }
   Comment(__FUNCTION__+" : Value="+IntegerToString(m_check_group.Value()));
//--- succeed
   return(true);
  }
//+------------------------------------------------------------------+
//| Event handler                                                    |
//+------------------------------------------------------------------+
void CControlsDialog::OnChangeCheckGroup(void)
  {
   Comment(__FUNCTION__+" : Value="+IntegerToString(m_check_group.Value()));
  }
//+------------------------------------------------------------------+
//| Global Variables                                                 |
//+------------------------------------------------------------------+
CControlsDialog ExtDialog;
//+------------------------------------------------------------------+
//| Expert initialization function                                   |
//+------------------------------------------------------------------+
int OnInit()
  {
//--- create application dialog
   if(!ExtDialog.Create(ChartID(),"Controls",0,40,40,380,344))
      return(INIT_FAILED);
//--- run application
   ExtDialog.Run();
//--- succeed
   return(INIT_SUCCEEDED);
  }
//+------------------------------------------------------------------+
//| Expert deinitialization function                                 |
//+------------------------------------------------------------------+
void OnDeinit(const int reason)
  {
//---
   Comment("");
//--- destroy dialog
   ExtDialog.Destroy(reason);
  }
//+------------------------------------------------------------------+
//| Expert chart event function                                      |
//+------------------------------------------------------------------+
void OnChartEvent(const int id,         // event ID  
                  const long& lparam,   // event parameter of the long type
                  const double& dparam, // event parameter of the double type
                  const string& sparam) // event parameter of the string type
  {
   ExtDialog.ChartEvent(id,lparam,dparam,sparam);
  }

It returns the error:

array out of range in 'CheckGroup.mqh' (222,17)

which is inside the method:

bool CCheckGroup::Check(const int idx,const int value)
  {
//--- check
   if(idx>=m_values.Total())
      return(false);
//---
   bool res=(m_states.Update(idx,value) && Redraw());
//--- change value
   if(res && idx<64)
     {
      if(m_rows[idx].Checked())
         Value(m_value|m_values.At(idx));
      else
         Value(m_value&(~m_values.At(idx)));
     }
//---
   return(res);
  }

I don't know why it is idx<64.

If it is changed in idx<m_total_view no error is raised and all the check-boxes, even those not visible, are checked.

[[Deleted]]

Your topic has been moved to the section: Expert Advisors and Automated Trading
Please consider which section is most appropriate — https://www.mql5.com/en/forum/172166/page6#comment_49114893

[dcstoyanov]

Fernando Carreiro #:
Your topic has been moved to the section: Expert Advisors and Automated Trading
Please consider which section is most appropriate — https://www.mql5.com/en/forum/172166/page6#comment_49114893

I thought the section "Library comments" was good since this is exactly a comment on a strange behaviour (bug?) of the Standard Library.

[[Deleted]]

dcstoyanov #: I thought the section "Library comments" was good since this is exactly a comment on a strange behaviour (bug?) of the Standard Library.

That section is only for automatically created discussion threads about Articles and CodeBase Library publications.