Is it possible to draw an indicator using EA

Question

Say when using EA, and when I detect the current bar has the lowest price I have seen so far, I will draw a horizontal line below it, is it possible to achieve with EA rather than custom indicator?

Answer 1

yes, if your conditions are met - you can draw a horizontal line or trend line or update its price parameters. in order to draw a line, use the following function, for moving - ObjectSetDouble():

bool HLineCreate(const long            chart_ID=0,        // chart's ID
             const string          name="HLine",      // line name
             const int             sub_window=0,      // subwindow index
             double                price=0,           // line price
             const color           clr=clrRed,        // line color
             const ENUM_LINE_STYLE style=STYLE_SOLID, // line style
             const int             width=1,           // line width
             const bool            back=false,        // in the background
             const bool            selection=true,    // highlight to move
             const bool            hidden=true,       // hidden in the object list
             const long            z_order=0)         // priority for mouse click
 {
//--- if the price is not set, set it at the current Bid price level
 if(!price)
    price=SymbolInfoDouble(Symbol(),SYMBOL_BID);
//--- reset the error value
  ResetLastError();
//--- create a horizontal line
 if(!ObjectCreate(chart_ID,name,OBJ_HLINE,sub_window,0,price))
 {
  Print(__FUNCTION__,
        ": failed to create a horizontal line! Error code = ",GetLastError());
  return(false);
 }
//--- set line color
 ObjectSetInteger(chart_ID,name,OBJPROP_COLOR,clr);
//--- set line display style
 ObjectSetInteger(chart_ID,name,OBJPROP_STYLE,style);
//--- set line width
 ObjectSetInteger(chart_ID,name,OBJPROP_WIDTH,width);
//--- display in the foreground (false) or background (true)
 ObjectSetInteger(chart_ID,name,OBJPROP_BACK,back);
//--- enable (true) or disable (false) the mode of moving the line by mouse    
 ObjectSetInteger(chart_ID,name,OBJPROP_SELECTABLE,selection);
 ObjectSetInteger(chart_ID,name,OBJPROP_SELECTED,selection);
//--- hide (true) or display (false) graphical object name in the object list
 ObjectSetInteger(chart_ID,name,OBJPROP_HIDDEN,hidden);
//--- set the priority for receiving the event of a mouse click in the chart
 ObjectSetInteger(chart_ID,name,OBJPROP_ZORDER,z_order);
//--- successful execution
 return(true);
}