Is it possible to draw an indicator using EA - mql4

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);
}