Object Properties

Graphical objects can have various properties depending on the object type. Values of object properties are set up and received by corresponding functions for working with graphical objects.

All objects used in technical analysis are bound to the time and price coordinates: trendline, channels, Fibonacci tools, etc. But there is a number of auxiliary objects intended to improve the user interface that are bound to the always visible part of a chart (main chart windows or indicator subwindows):

The following designations are used in the table:

• X/Y – coordinates of anchor points specified in pixels relative to a chart corner;
• Width/Height – objects have width and height. For “read only”, the width and height values are calculated only once the object is rendered on chart;
• Date/Price – anchor point coordinates are specified using the date and price values;
• OBJPROP_CORNER – defines the chart corner relative to which the anchor point coordinates are specified. Can be one of the 4 values of the ENUM_BASE_CORNER enumeration;
• OBJPROP_ANCHOR – defines the anchor point in object itself and can be one of the 9 values of the ENUM_ANCHOR_POINT enumeration. Coordinates in pixels are specified from this very point to selected chart corner;
• OBJPROP_ANGLE – defines the object rotation angle counterclockwise.

The functions defining the properties of graphical objects, as well as ObjectCreate() and ObjectMove() operations for creating and moving objects along the chart are actually used for sending commands to the chart. If these functions are executed successfully, the command is included in the common queue of the chart events. Visual changes in the properties of graphical objects are implemented when handling the queue of the chart events.

Thus, do not expect an immediate visual update of graphical objects after calling these functions. Generally, the graphical objects on the chart are updated automatically by the terminal following the change events - a new quote arrival, resizing the chart window, etc. Use ChartRedraw() function to forcefully update the graphical objects.

For functions ObjectSetInteger() and ObjectGetInteger()

ENUM_OBJECT_PROPERTY_INTEGER

When using chart operations for the “Chart” object (OBJ_CHART), the following limitations are imposed:

• It cannot be closed using ChartClose();
• Symbol/period cannot be changed using the ChartSetSymbolPeriod() function;
• The following properties are ineffective CHART_SCALE, CHART_BRING_TO_TOP, CHART_SHOW_DATE_SCALE and CHART_SHOW_PRICE_SCALE (ENUM_CHART_PROPERTY_INTEGER).

You can set a special mode of image display for OBJ_BITMAP_LABEL and OBJ_BITMAPobjects. In this mode, only part of an original image (at which a rectangular visible area is applied) is displayed, while the rest of the image becomes invisible. The size of this area should be set using the properties OBJPROP_XSIZE and OBJPROP_YSIZE. The visible area can be “moved” only within the original image using the properties OBJPROP_XOFFSET and OBJPROP_YOFFSET.

For the fixed-sized objects: OBJ_BUTTON, OBJ_RECTANGLE_LABEL, OBJ_EDIT and OBJ_CHART, properties OBJPROP_XDISTANCE and OBJPROP_YDISTANCE set the position of the top left point of the object relative to the chart corner (OBJPROP_CORNER), from which the X and Y coordinates will be counted in pixels.

For functions ObjectSetDouble() and ObjectGetDouble()

ENUM_OBJECT_PROPERTY_DOUBLE

For functions ObjectSetString() and ObjectGetString()

ENUM_OBJECT_PROPERTY_STRING

For the OBJ_RECTANGLE_LABEL object (“Rectangle label”) one of the three design modes can be set, to which the following values of ENUM_BORDER_TYPE correspond.

ENUM_BORDER_TYPE

For the OBJ_EDIT object (“Edit”) and for the ChartScreenShot() function, you can specify the horizontal alignment type using the values of the ENUM_ALIGN_MODE enumeration.

ENUM_ALIGN_MODE

Example:

#define  UP          "\x0431"
//+------------------------------------------------------------------+
//| Script program start function                                    |
//+------------------------------------------------------------------+
void OnStart()
  {
//---
   string label_name="my_OBJ_LABEL_object";
   if(ObjectFind(0,label_name)<0)
     {
      Print("Object ",label_name," not found. Error code = ",GetLastError());
      //--- create Label object
      ObjectCreate(0,label_name,OBJ_LABEL,0,0,0);
      //--- set X coordinate
      ObjectSetInteger(0,label_name,OBJPROP_XDISTANCE,200);
      //--- set Y coordinate
      ObjectSetInteger(0,label_name,OBJPROP_YDISTANCE,300);
      //--- define text color
      ObjectSetInteger(0,label_name,OBJPROP_COLOR,clrWhite);
      //--- define text for object Label
      ObjectSetString(0,label_name,OBJPROP_TEXT,UP);
      //--- define font
      ObjectSetString(0,label_name,OBJPROP_FONT,"Wingdings");
      //--- define font size
      ObjectSetInteger(0,label_name,OBJPROP_FONTSIZE,10);
      //--- 45 degrees rotation clockwise
      ObjectSetDouble(0,label_name,OBJPROP_ANGLE,-45);
      //--- disable for mouse selecting
      ObjectSetInteger(0,label_name,OBJPROP_SELECTABLE,false);
      //--- draw it on the chart
      ChartRedraw(0);
     }
  }