Minor Indicator Tweak / Code Review: Hotkeys_Slim

Hi all

I could do with a bit of a favour.

I use this indicator on a daily basis to rapidly change time frames, but whenever there's any order management EA attached to the chart, MT4 freezes up for a few seconds.

Is there anything in this code that would cause MT4 to lock up if there's an EA attached?

I can happily blast through the time frames normally with the EA's attached to the chart without issue. It's definitely something to do with this code.

Any ideas would be great.

Cheers

Here's the code. It seems fairly basic but there's something causing MT4 to crash when there's an EA attached to the chart.

//+------------------------------------------------------------------+
//| hotKeys.mq4 |
//| Copyright 2015, Mohit Marwaha |
//| [email protected] |
//+------------------------------------------------------------------+
#property copyright "Copyright 2015, Mohit Marwaha"
#property link "[email protected]"
#property version "1.00"
#property strict
#property indicator_chart_window
#property description "[email protected]"
#property description "The indicator will change the timeframe of the chart with key press"
#property description "M - Monthly, W - Weekly, D - Daily, 4 - 4Hr, 1 - 1Hr, 3 - 30Mins, f - 15Mins, 5 - 5Mins"
#define KEY_MONTHLY 57
#define KEY_WEEKLY 56
#define KEY_DAILY 55
#define KEY_4HOUR 54
#define KEY_1HOUR 53
#define KEY_5MIN 50
#define KEY_30MIN 52
#define KEY_15MIN 51
#define KEY_1MIN 49
#define KEY_CHARTFIX 48
#define KEY_P 80
//+------------------------------------------------------------------+
//| Custom indicator initialization function |
//+------------------------------------------------------------------+
int OnInit()
{
//---
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(rates_total);
}
//+------------------------------------------------------------------+
//| ChartEvent function |
//+------------------------------------------------------------------+
void OnChartEvent(const int id,
const long &lparam,
const double &dparam,
const string &sparam)
{
//---
if(id==CHARTEVENT_KEYDOWN)
{
switch(int(lparam))
{
case KEY_MONTHLY:ChartSetSymbolPeriod(0,NULL,43200);
break;
case KEY_WEEKLY:ChartSetSymbolPeriod(0,NULL,10080);
break;
case KEY_DAILY:ChartSetSymbolPeriod(0,NULL,1440);
break;
case KEY_4HOUR:ChartSetSymbolPeriod(0,NULL,240);
break;
case KEY_1HOUR:ChartSetSymbolPeriod(0,NULL,60);
break;
case KEY_5MIN:ChartSetSymbolPeriod(0,NULL,5);
break;
case KEY_30MIN:ChartSetSymbolPeriod(0,NULL,30);
break;
case KEY_15MIN:ChartSetSymbolPeriod(0,NULL,15);
break;
case KEY_1MIN:ChartSetSymbolPeriod(0,NULL,1);
break;
case KEY_CHARTFIX:
{
bool isFixed=ChartGetInteger(0,CHART_SCALEFIX,true);
if(!isFixed)
{
ChartSetInteger(0,CHART_SCALEFIX,true);
}
else
{
ChartSetInteger(0,CHART_SCALEFIX,false);
}
}
break;
case KEY_P:
{
bool isFixed=ChartGetInteger(0,CHART_SHOW_PRICE_SCALE,true);
if(!isFixed)
{
ChartSetInteger(0,CHART_SHOW_PRICE_SCALE,true);
}
else
{
ChartSetInteger(0,CHART_SHOW_PRICE_SCALE,false);
}
}
break;
}
ChartRedraw();
}
}
//+------------------------------------------------------------------+
int deinit()
{
return(0);
}
//+------------------------------------------------------------------+

Ok found a workaround with another script I can map to hotkeys to change a timeframe on a single chart only.

Just one problem, how to get rid of this pop up when applying it to a chart?

try now.

Cheers, didn't fix the problem but I can see the tweaks made sense to try. Much appreciated.

It must be just the way this indicator works causing issues with some EAs I guess....

There's one very important thing you really need to understand about MT, and that is all MT programs (EA, indi, etc.) can only run on a chart instances, and whenever you change a chart's timeframe it is the same thing as closing and reopening the chart and reapplying your programs. This means that all program get reinitialized, and that's why you are getting errors. This is incredibly dangerous unless you have built a super rock-solid EA that can recover and handle errors, and even then you should not be changing messing with the running instance of an EA.

In summary, if you are using someone else's EA and you don't have/understand the source code then under no circumstances should you never change the chart, and if you are running your own recovery system then ........ you don't change the freakin' chart!!! Only mess with charts that do not have active EAs.

Sounds like a plan. I can't trade without a ridiculous amount of time-frame hopping so will stick with Hotkeys_Slim.