14 KiB
14 KiB
OBJ_TREND
Trend Line.
Note
For Trend Line, it is possible to specify the mode of continuation of its display to the right and/or left (OBJPROP_RAY_RIGHT and OBJPROP_RAY_LEFT properties accordingly).
Example
The following script creates and moves the trend line on the chart. Special functions have been developed to create and change graphical object's properties. You can use these functions "as is" in your own applications.
//--- description
#property description "Script draws \"Trend Line\" graphical object."
#property description "Anchor point coordinates are set in percentage of"
#property description "the chart window size."
//--- display window of the input parameters during the script's launch
#property script_show_inputs
//--- input parameters of the script
input string InpName="Trend"; // Line name
input int InpDate1=35; // 1 st point's date, %
input int InpPrice1=60; // 1 st point's price, %
input int InpDate2=65; // 2 nd point's date, %
input int InpPrice2=40; // 2 nd point's price, %
input color InpColor=clrRed; // Line color
input ENUM_LINE_STYLE InpStyle=STYLE_DASH; // Line style
input int InpWidth=2; // Line width
input bool InpBack=false; // Background line
input bool InpSelection=true; // Highlight to move
input bool InpRayLeft=false; // Line's continuation to the left
input bool InpRayRight=false; // Line's continuation to the right
input bool InpHidden=true; // Hidden in the object list
input long InpZOrder=0; // Priority for mouse click
//+------------------------------------------------------------------+
//| Create a trend line by the given coordinates |
//+------------------------------------------------------------------+
bool TrendCreate(const long chart_ID=0, // chart's ID
const string name="TrendLine", // line name
const int sub_window=0, // subwindow index
datetime time1=0, // first point time
double price1=0, // first point price
datetime time2=0, // second point time
double price2=0, // second point 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 ray_left=false, // line's continuation to the left
const bool ray_right=false, // line's continuation to the right
const bool hidden=true, // hidden in the object list
const long z_order=0) // priority for mouse click
{
//--- set anchor points' coordinates if they are not set
ChangeTrendEmptyPoints(time1,price1,time2,price2);
//--- reset the error value
ResetLastError();
//--- create a trend line by the given coordinates
if(!ObjectCreate(chart_ID,name,OBJ_TREND,sub_window,time1,price1,time2,price2))
{
Print(__FUNCTION__,
": failed to create a trend 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
//--- when creating a graphical object using ObjectCreate function, the object cannot be
//--- highlighted and moved by default. Inside this method, selection parameter
//--- is true by default making it possible to highlight and move the object
ObjectSetInteger(chart_ID,name,OBJPROP_SELECTABLE,selection);
ObjectSetInteger(chart_ID,name,OBJPROP_SELECTED,selection);
//--- enable (true) or disable (false) the mode of continuation of the line's display to the left
ObjectSetInteger(chart_ID,name,OBJPROP_RAY_LEFT,ray_left);
//--- enable (true) or disable (false) the mode of continuation of the line's display to the right
ObjectSetInteger(chart_ID,name,OBJPROP_RAY_RIGHT,ray_right);
//--- 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);
}
//+------------------------------------------------------------------+
//| Move trend line anchor point |
//+------------------------------------------------------------------+
bool TrendPointChange(const long chart_ID=0, // chart's ID
const string name="TrendLine", // line name
const int point_index=0, // anchor point index
datetime time=0, // anchor point time coordinate
double price=0) // anchor point price coordinate
{
//--- if point position is not set, move it to the current bar having Bid price
if(!time)
time=TimeCurrent();
if(!price)
price=SymbolInfoDouble(Symbol(),SYMBOL_BID);
//--- reset the error value
ResetLastError();
//--- move trend line's anchor point
if(!ObjectMove(chart_ID,name,point_index,time,price))
{
Print(__FUNCTION__,
": failed to move the anchor point! Error code = ",GetLastError());
return(false);
}
//--- successful execution
return(true);
}
//+------------------------------------------------------------------+
//| The function deletes the trend line from the chart. |
//+------------------------------------------------------------------+
bool TrendDelete(const long chart_ID=0, // chart's ID
const string name="TrendLine") // line name
{
//--- reset the error value
ResetLastError();
//--- delete a trend line
if(!ObjectDelete(chart_ID,name))
{
Print(__FUNCTION__,
": failed to delete a trend line! Error code = ",GetLastError());
return(false);
}
//--- successful execution
return(true);
}
//+------------------------------------------------------------------+
//| Check the values of trend line's anchor points and set default |
//| values for empty ones |
//+------------------------------------------------------------------+
void ChangeTrendEmptyPoints(datetime &time1,double &price1,
datetime &time2,double &price2)
{
//--- if the first point's time is not set, it will be on the current bar
if(!time1)
time1=TimeCurrent();
//--- if the first point's price is not set, it will have Bid value
if(!price1)
price1=SymbolInfoDouble(Symbol(),SYMBOL_BID);
//--- if the second point's time is not set, it is located 9 bars left from the second one
if(!time2)
{
//--- array for receiving the open time of the last 10 bars
datetime temp[10];
CopyTime(Symbol(),Period(),time1,10,temp);
//--- set the second point 9 bars left from the first one
time2=temp[0];
}
//--- if the second point's price is not set, it is equal to the first point's one
if(!price2)
price2=price1;
}
//+------------------------------------------------------------------+
//| Script program start function |
//+------------------------------------------------------------------+
void OnStart()
{
//--- check correctness of the input parameters
if(InpDate1<0 || InpDate1>100 || InpPrice1<0 || InpPrice1>100 ||
InpDate2<0 || InpDate2>100 || InpPrice2<0 || InpPrice2>100)
{
Print("Error! Incorrect values of input parameters!");
return;
}
//--- number of visible bars in the chart window
int bars=(int)ChartGetInteger(0,CHART_VISIBLE_BARS);
//--- price array size
int accuracy=1000;
//--- arrays for storing the date and price values to be used
//--- for setting and changing line anchor points' coordinates
datetime date[];
double price[];
//--- memory allocation
ArrayResize(date,bars);
ArrayResize(price,accuracy);
//--- fill the array of dates
ResetLastError();
if(CopyTime(Symbol(),Period(),0,bars,date)==-1)
{
Print("Failed to copy time values! Error code = ",GetLastError());
return;
}
//--- fill the array of prices
//--- find the highest and lowest values of the chart
double max_price=ChartGetDouble(0,CHART_PRICE_MAX);
double min_price=ChartGetDouble(0,CHART_PRICE_MIN);
//--- define a change step of a price and fill the array
double step=(max_price-min_price)/accuracy;
for(int i=0;i<accuracy;i++)
price[i]=min_price+i*step;
//--- define points for drawing the line
int d1=InpDate1*(bars-1)/100;
int d2=InpDate2*(bars-1)/100;
int p1=InpPrice1*(accuracy-1)/100;
int p2=InpPrice2*(accuracy-1)/100;
//--- create a trend line
if(!TrendCreate(0,InpName,0,date[d1],price[p1],date[d2],price[p2],InpColor,InpStyle,
InpWidth,InpBack,InpSelection,InpRayLeft,InpRayRight,InpHidden,InpZOrder))
{
return;
}
//--- redraw the chart and wait for 1 second
ChartRedraw();
Sleep(1000);
//--- now, move the line's anchor points
//--- loop counter
int v_steps=accuracy/5;
//--- move the first anchor point vertically
for(int i=0;i<v_steps;i++)
{
//--- use the following value
if(p1>1)
p1-=1;
//--- move the point
if(!TrendPointChange(0,InpName,0,date[d1],price[p1]))
return;
//--- check if the script's operation has been forcefully disabled
if(IsStopped())
return;
//--- redraw the chart
ChartRedraw();
}
//--- move the second anchor point vertically
for(int i=0;i<v_steps;i++)
{
//--- use the following value
if(p2<accuracy-1)
p2+=1;
//--- move the point
if(!TrendPointChange(0,InpName,1,date[d2],price[p2]))
return;
//--- check if the script's operation has been forcefully disabled
if(IsStopped())
return;
//--- redraw the chart
ChartRedraw();
}
//--- half a second of delay
Sleep(500);
//--- loop counter
int h_steps=bars/2;
//--- move both anchor points horizontally at the same time
for(int i=0;i<h_steps;i++)
{
//--- use the following values
if(d1<bars-1)
d1+=1;
if(d2>1)
d2-=1;
//--- shift the points
if(!TrendPointChange(0,InpName,0,date[d1],price[p1]))
return;
if(!TrendPointChange(0,InpName,1,date[d2],price[p2]))
return;
//--- check if the script's operation has been forcefully disabled
if(IsStopped())
return;
//--- redraw the chart
ChartRedraw();
// 0.03 seconds of delay
Sleep(30);
}
//--- 1 second of delay
Sleep(1000);
//--- delete a trend line
TrendDelete(0,InpName);
ChartRedraw();
//--- 1 second of delay
Sleep(1000);
//---
}