Automatic Arrowhead lines on MT4

Perhaps this indicator will be of use to somebody.

It will automatically put an arrowhead on any Trendline by Angle that is generated while the indicator is running.

If you move the line or change its color, the arrowhead will be updated.

Please Note: this is a workaround for an inherent shortcoming of MetaTrader 4. Therefore, please do not expect perfection. You must have the font "Wingdings 3" installed on your computer (most Windows PCs should have this font installed).

thanks mate , let me try it

Thanks honestknave this is still working.

Thanks! This works perfectly.

Is it possible to have the mq4 file?

I'm trying to program an indicator like this, but using trendlines instead of trendbyangles, which don't change when you resize the chart. I have a problem: here is the code. Why doesn't it recognize the value of the price2 always returning 0? some advice? Thanks in advance

#property copyright "Copyright 2018, MetaQuotes Software Corp."
#property link "https://www.mql5.com"
#property version "1.00"
#property strict
#property indicator_chart_window
//+------------------------------------------------------------------+
//| Custom indicator initialization function |
//+------------------------------------------------------------------+
int OnInit()
{
//--- indicator buffers mapping

//---
return(INIT_SUCCEEDED);
}
//+------------------------------------------------------------------+
//| Custom indicator iteration function |
//+------------------------------------------------------------------+
int OnCalculate(const int rates_total,
const int prev_calculated,
const datetime &time[],
const double &open[],
const double &high[],
const double &low[],
const double &close[],
const long &tick_volume[],
const long &volume[],
const int &spread[])
{
//---

//--- return value of prev_calculated for next call
return(rates_total);
}
//+------------------------------------------------------------------+
//| ChartEvent function |
//+------------------------------------------------------------------+
void OnChartEvent(const int id, // Event identifier
const long& lparam, // Event parameter of long type
const double& dparam, // Event parameter of double type
const string& sparam) // Event parameter of string type
{
if(id==CHARTEVENT_OBJECT_CREATE){

string objname = sparam;
int objtype = ObjectType(objname);
if (objtype == OBJ_TRENDBYANGLE){
datetime time1 = ObjectGet(objname,OBJPROP_TIME1);
double price1 = ObjectGet(objname,OBJPROP_PRICE1);
datetime time2 = ObjectGet(objname,OBJPROP_TIME2);
double price2 = ObjectGet(objname,OBJPROP_PRICE2);
double angle = MathRound(ObjectGet(objname,OBJPROP_ANGLE));

ObjectCreate ("cntr", OBJ_LABEL, 0, 0, 0);
ObjectSet ("cntr", OBJPROP_CORNER, 1);
ObjectSet ("cntr", OBJPROP_XDISTANCE, 381);
ObjectSet ("cntr", OBJPROP_YDISTANCE, 12);
ObjectSetText ("cntr", time1+"|"+price1+"|"+time2+"|"+price2+"|"+angle,10,0,Black);
}

}
}
//+------------------------------------------------------------------+

You're still using OBJ_TRENDBYANGLE (and not trend lines) in your code?!

OBJ_TRENDBYANGLE - MQL4 Documentation shows TrendByAngleCreate contains one price/time and one angle. (from here)

yes, trendbyangle is the starting object, because I need the angle to set the arrow. Then I would like to replace it with a normal trendline, but I can't do it without the value of price2. Is only the first part of the code, but I can't go on and I don't understand why I don't get the value of the second price. My request for help was for this.

Drawing a trendline and get the "angle" (better slope) from that object isn't an option? (link)

OBJ_TRENDBYANGLE doesn't have the OBJPROP_PRICE2 property. It is a ray, not a line segment. Which means an object OBJ_TRENDBYANGLE is fully defined by OBJPROP_TIME1, OBJPROP_PRICE1 and OBJPROP_ANGLE.

Thanks to both of you

In the end I opted for writing a script.
it works like this:
draw a trendline by angle, launch the script (perhaps through a hotkey is more practical), the trendline by angle will be replaced by a normal trendline with arrowhead; at this point if the trendline is moved or deleted, calling the script everything will be updated.
Note:
- the trendlines will be blue, because the arrows are only blue;
- arrows will be drawn only for the angle from 90 ° to 270 °, so to speak towards the right side of the graph;
- the images of the arrows must be saved in the images folder of the platform.
I enclose everything maybe it can be useful to someone.
Thanks for collaboration.

Doing it this way is really limited (to a white background, always the need for runnig the script again, ...) and the need for >180 bmp files is insane

I thought more about using "Wingdings 3" font (as honestknave is doing it with his indicator), using the letters p and q with the correct angle for example

unfortunately I know it, three hours of my life
How can I set these characters as a bmp file? What is the path?

No bmp.... you only add a text object with the mentioned fontname and using "p" / "q" as text. That's all!

Thank you very much for your advice, as you may have guessed I am not a programmer, even if I can untangle myself a little with the codes. English is not my language and finding information is not always easy even using a translator. However I have readjusted the code with your welcome explanations.
Now draw arrows in all directions and based on the color of the trendline by angle.
The choice of a limiting script, instead of an indicator, is given by the fact that I keep many graphics open with various ea and indicators and sometimes the platform slows down. For this reason it is preferable for me to write a script only when I need it, also because I am not continuously shooting arrows .
Many thanks again.