Programmatically Refresh your charts
Hi folks!
I'm writing this article today because I've go a lot of requests asking me this mystery question "How do I programmatically refresh my charts?"
Every time I answer this question like that: "You can not use normal mql4 to fulfill this task, the only way is to use a keystuffer program, please give my Send Keyboard keys to MetaTrader! article a look! it's the only solution I guess!"
Today we are going to write an indicator that refreshes the chart every x seconds. Let's go!
Where do you go?
To refresh the chart there's only one manual method! you have to go to the Charts menu (in main menu - figure 1 - or the context menu - figure 2) and click Refresh command!
We need the code to do that for us! Our code will simulate the key storks of opening the Chart menu by click CTRL+C then click R for the Refresh command. Let's see how could we convert the normal MACD indicator to every 60 second self-refreshing indicator?
Figure 1
Figure 2
The code:
//+------------------------------------------------------------------+
//| Custom MACD.mq4 |
//| Copyright © 2004, MetaQuotes Software Corp. |
//| http://www.metaquotes.net/ |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2004, MetaQuotes Software Corp."
#property link "http://www.metaquotes.net/"
#import "user32.dll"
void keybd_event(int bVk,int bScan,int dwFlags,int dwExtraInfo);
#import
#define KEYEVENTF_EXTENDEDKEY 0x0001
#define KEYEVENTF_KEYUP 0x0002
#define VK_0 48
#define VK_1 49
#define VK_2 50
#define VK_3 51
#define VK_4 52
#define VK_5 53
#define VK_6 54
#define VK_7 55
#define VK_8 56
#define VK_9 57
#define VK_A 65
#define VK_B 66
#define VK_C 67
#define VK_D 68
#define VK_E 69
#define VK_F 70
#define VK_G 71
#define VK_H 72
#define VK_I 73
#define VK_J 74
#define VK_K 75
#define VK_L 76
#define VK_M 77
#define VK_N 78
#define VK_O 79
#define VK_P 80
#define VK_Q 81
#define VK_R 82
#define VK_S 83
#define VK_T 84
#define VK_U 85
#define VK_V 86
#define VK_W 87
#define VK_X 88
#define VK_Y 89
#define VK_Z 90
#define VK_LBUTTON 1 //Left mouse button
#define VK_RBUTTON 2 //Right mouse button
#define VK_CANCEL 3 //Control-break processing
#define VK_MBUTTON 4 //Middle mouse button (three-button mouse)
#define VK_BACK 8 //BACKSPACE key
#define VK_TAB 9 //TAB key
#define VK_CLEAR 12 //CLEAR key
#define VK_RETURN 13 //ENTER key
#define VK_SHIFT 16 //SHIFT key
#define VK_CONTROL 17 //CTRL key
#define VK_MENU 18 //ALT key
#define VK_PAUSE 19 //PAUSE key
#define VK_CAPITAL 20 //CAPS LOCK key
#define VK_ESCAPE 27 //ESC key
#define VK_SPACE 32 //SPACEBAR
#define VK_PRIOR 33 //PAGE UP key
#define VK_NEXT 34 //PAGE DOWN key
#define VK_END 35 //END key
#define VK_HOME 36 //HOME key
#define VK_LEFT 37 //LEFT ARROW key
#define VK_UP 38 //UP ARROW key
#define VK_RIGHT 39 //RIGHT ARROW key
#define VK_DOWN 40 //DOWN ARROW key
#define VK_PRINT 42 //PRINT key
#define VK_SNAPSHOT 44 //PRINT SCREEN key
#define VK_INSERT 45 //INS key
#define VK_DELETE 46 //DEL key
#define VK_HELP 47 //HELP key
#define VK_LWIN 91 //Left Windows key (Microsoft® Natural® keyboard)
#define VK_RWIN 92 //Right Windows key (Natural keyboard)
#define VK_APPS 93 //Applications key (Natural keyboard)
#define VK_SLEEP 95 //Computer Sleep key
#define VK_NUMPAD0 96 //Numeric keypad 0 key
#define VK_NUMPAD1 97 //Numeric keypad 1 key
#define VK_NUMPAD2 98 //Numeric keypad 2 key
#define VK_NUMPAD3 99 //Numeric keypad 3 key
#define VK_NUMPAD4 100 //Numeric keypad 4 key
#define VK_NUMPAD5 101 //Numeric keypad 5 key
#define VK_NUMPAD6 102 //Numeric keypad 6 key
#define VK_NUMPAD7 103 //Numeric keypad 7 key
#define VK_NUMPAD8 104 //Numeric keypad 8 key
#define VK_NUMPAD9 105 //Numeric keypad 9 key
#define VK_MULTIPLY 106 //Multiply key
#define VK_ADD 107 //Add key
#define VK_SEPARATOR 108 //Separator key
#define VK_SUBTRACT 109 //Subtract key
#define VK_DECIMAL 110 //Decimal key
#define VK_DIVIDE 111 //Divide key
#define VK_F1 112 //F1 key
#define VK_F2 113 //F2 key
#define VK_F3 114 //F3 key
#define VK_F4 115 //F4 key
#define VK_F5 116 //F5 key
#define VK_F6 117 //F6 key
#define VK_F7 118 //F7 key
#define VK_F8 119 //F8 key
#define VK_F9 120 //F9 key
#define VK_F10 121 //F10 key
#define VK_F11 122 //F11 key
#define VK_F12 123 //F12 key
#define VK_F13 124 //F13 key
#define VK_NUMLOCK 144 //NUM LOCK key
#define VK_SCROLL 145 //SCROLL LOCK key
#define VK_LSHIFT 160 //Left SHIFT key
#define VK_RSHIFT 161 //Right SHIFT key
#define VK_LCONTROL 162 //Left CONTROL key
#define VK_RCONTROL 163 //Right CONTROL key
#define VK_LMENU 164 //Left MENU key
#define VK_RMENU 165 //Right MENU key
//---- indicator settings
#property indicator_separate_window
#property indicator_buffers 2
#property indicator_color1 Silver
#property indicator_color2 Red
//---- indicator parameters
extern int FastEMA=12;
extern int SlowEMA=26;
extern int SignalSMA=9;
extern int SecondsToRefresh = 60;
//---- indicator buffers
double ind_buffer1[];
double ind_buffer2[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function |
//+------------------------------------------------------------------+
int init()
{
//---- drawing settings
SetIndexStyle(0,DRAW_HISTOGRAM,STYLE_SOLID,3);
SetIndexDrawBegin(1,SignalSMA);
IndicatorDigits(MarketInfo(Symbol(),MODE_DIGITS)+1);
//---- indicator buffers mapping
if(!SetIndexBuffer(0,ind_buffer1) && !SetIndexBuffer(1,ind_buffer2))
Print("cannot set indicator buffers!");
//---- name for DataWindow and indicator subwindow label
IndicatorShortName("MACD("+FastEMA+","+SlowEMA+","+SignalSMA+")");
SetIndexLabel(0,"MACD");
SetIndexLabel(1,"Signal");
//---- initialization done
return(0);
}
//+------------------------------------------------------------------+
//| Moving Averages Convergence/Divergence |
//+------------------------------------------------------------------+
int start()
{
int limit;
int counted_bars=IndicatorCounted();
//---- check for possible errors
if(counted_bars<0) return(-1);
//---- last counted bar will be recounted
if(counted_bars>0) counted_bars--;
limit=Bars-counted_bars;
//---- macd counted in the 1-st buffer
for(int i=0; i<limit; i++)
ind_buffer1[i]=iMA(NULL,0,FastEMA,0,MODE_EMA,PRICE_CLOSE,i)-iMA(NULL,0,SlowEMA,0,MODE_EMA,PRICE_CLOSE,i);
//---- signal line counted in the 2-nd buffer
for(i=0; i<limit; i++)
ind_buffer2[i]=iMAOnArray(ind_buffer1,Bars,SignalSMA,0,MODE_SMA,i);
//---- done
Refresh(SecondsToRefresh);
return(0);
}
void Refresh(int seconds = 60)
{
datetime cur = CurTime();
static datetime last = 0;
if (last == 0) {last = cur;}
if (cur > last + seconds)
{
last = cur;
SendKey (VK_MENU);
SendKey (VK_C);
ReleaseKey(VK_MENU);
ReleaseKey(VK_C);
SendKey (VK_R);
ReleaseKey(VK_R);
}
}
void SendKey(int key,bool release = false)
{
keybd_event (key, 0, 0, 0);
if(release)
keybd_event (key, 0, KEYEVENTF_KEYUP, 0);
}
void ReleaseKey(int key)
{
keybd_event (key, 0, KEYEVENTF_KEYUP, 0);
}
Code explained:
The first thing we have added is the code to call the keybd_event windows function by importing it from the user32.dll. Then all the #define are from the constants used with the keybd_event function.
The real works starts with the varaible SecondsToRefresh which we set it to the x seconds we want the indicator to use it to refresh the chart (i.e. refresh the chart every 60 seconds).
The function which you use to refresh the chart is Refresh() function which take x seconds to refresh the chart. This function compares the current time with the last saved time (time algorism) to work every x seconds.
Every x seconds the function will send the keys ALT+C (To open the Charts menu) then sends R key to select Refresh command from the menu!
Caution:
This program will sends the keys ALT+C and R to any activated window! So, you have to be sure that the activated window is MetaTrader window and the chart you want to refresh!
I know this is odd but it's the only way to Refresh the chart programmatically!
Hope you find it a helpful article/code/crack!