Identify selected object

[ZetaTrader]

I'd like to identify a trend line when clicked.

The chart would then display additional info & lines related to it, so that the chart isn't too clustered in the normal state.

I know how to do the rest, but Is there a way to get the object's name or any info when it is selected?

Thank you for the help.

[William Roeder]

Go through the list of objects, get the name, check if it is a trend line and selected.

[ZetaTrader]

whroeder1:
Go through the list of objects, get the name, check if it is a trend line and selected.

Thanks again for the quick help!

That should be the proper code then (not tested yet):

EDIT: Tested now, I used OBJPROP_SELECTED but that actually does not return whether the object is currently selected, it return true if the object is allowed to be selected in general.

EDIT: 2 As pointed out below by whroeder1 OBJPROP_SELECTED is the correct property, but my check for -1 was wrong, it is updated now.

void OnChartEvent(const int id, const long& lparam, const double& dparam, const string& sparam) {
   if (id == CHARTEVENT_OBJECT_CLICK) {
      for (int i = 0; i < ObjectsTotal(0, 0, OBJ_TREND); i++) {
         string objectName = ObjectName(0, i, 0, OBJ_TREND);
        
         if (ObjectGet(objectName, OBJPROP_SELECTED) == 1) {   //fixed this, no longer checking for > -1
            // This object is selected.
            double price = ObjectGetDouble(0, objectName, OBJPROP_PRICE);
            int startTime = ObjectGet(objectName, OBJPROP_TIME1);
           
            Print("Trend line starts at " + TimeToStr(startTime) + " at " + DoubleToStr(price, 2));
         }
      }
   }
}

[Mladen Rakic]

ZetaTrader:

Thanks again for the quick help!

That should be the proper code then (not tested yet):

void OnChartEvent(const int id, const long& lparam, const double& dparam, const string& sparam) {
   if (id == CHARTEVENT_OBJECT_CLICK) {
      for (int i = 0; i < ObjectsTotal(0, 0, OBJ_TREND); i++) {
         string objectName = ObjectName(0, i, 0, OBJ_TREND);
        
         if (ObjectGet(objectName, OBJPROP_SELECTED) > -1) {
            // This object is selected.
            double price = ObjectGetDouble(0, objectName, OBJPROP_PRICE);
            int startTime = ObjectGet(objectName, OBJPROP_TIME1);
           
            Print("Trend line starts at " + TimeToStr(startTime) + " at " + DoubleToStr(price, 2));
         }
      }
   }
}

sparam will give you the name of the object that caused that event - why don't you use that instead of looping through the objects?

[nicholish en]

Mladen Rakic:
sparam will give you the name of the object that caused that event - why don't you use that instead of looping through the objects?

Exactly, this.

if(id == CHARTEVENT_OBJECT_CLICK && OBJ_TREND == (ENUM_OBJECT)ObjectGetInteger(0,sparam,OBJPROP_TYPE))

[ZetaTrader]

Mladen Rakic:
sparam will give you the name of the object that caused that event - why don't you use that instead of looping through the objects?

nicholishen:

Exactly, this.

Awesome! Thanks, it works great! I didn't realise the function would provide these parameters, I've rarely used OnChartEvent before.

As edited in my above post, the code I posted does not work as intended. EDIT: The code is updated to work now!

[William Roeder]

ZetaTrader: EDIT: Tested now, I used OBJPROP_SELECTED but that actually does not return whether the object is currently selected, it return true if the object is allowed to be selected in general.

         if (ObjectGet(objectName, OBJPROP_SELECTED) > -1) {
            // This object is selected.

That isn't true. Your if test is bogus. It is a boolean. Zero is False and One is True.  Greater than minus one is always true.

         if ( (bool)ObjectGet(objectName, OBJPROP_SELECTED) ) {
            // This object is selected.

Identifier	Description	Property Type
OBJPROP_SELECTED	Object is selected	bool
OBJPROP_SELECTABLE	Object availability	bool

          Object Properties - Objects Constants - Standard Constants, Enumerations and Structures - MQL4 Reference

[ZetaTrader]

whroeder1:
That isn't true. Your if test is bogus. It is a boolean. Zero is False and One is True.  Greater than minus one is always true.

Identifier	Description	Property Type
OBJPROP_SELECTED	Object is selected	bool
OBJPROP_SELECTABLE	Object availability	bool

          Object Properties - Objects Constants - Standard Constants, Enumerations and Structures - MQL4 Reference

Oops! My fault! Mixed it up with if statements checking for NULL.

Thanks for clearing that up, I'll edit my above post!