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Tk_GetDash(3)		      Tk Library Procedures		   Tk_GetDash(3)

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NAME
     Tk_GetDash - convert from string to valid dash structure.

SYNOPSIS
     #include <tk.h>

     int
     Tk_GetDash(interp, string, dashPtr)

ARGUMENTS
     Tcl_Interp *interp (in)	    Interpreter to use for error reporting.

     const char *string (in)	    Textual value to be converted.

     Tk_Dash *dashPtr (out)	    Points  to	place  to store the dash pattern
				    value converted from  string.  Must  not  be
				    NULL.
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DESCRIPTION
     These  procedure  parses  the string and fills in the result in the Tk_Dash
     structure. The string can be a list of integers or a character string  con-
     taining  only ".,-_" and spaces. If all goes well, TCL_OK is returned and a
     dash descriptor is stored in the variable pointed to by dashPtr.  If string
     does not have the proper syntax then TCL_ERROR is returned, an  error  mes-
     sage  is  left in the interpreter's result, and nothing is stored at *dash-
     Ptr.

     The first possible syntax is a list of integers.  Each  element  represents
     the number of pixels of a line segment. Only the odd segments are drawn us-
     ing the "outline" color. The other segments are drawn transparent.

     The  second  possible syntax is a character list containing only 5 possible
     characters ".,-_ ".  The space can be used to  enlarge  the  space  between
     other line elements, and can not occur in the first position of the string.
     Some examples:

		-dash .     = -dash {2 4}
		-dash -     = -dash {6 4}
		-dash -.    = -dash {6 4 2 4}
		-dash -..   = -dash {6 4 2 4 2 4}
		-dash {. }  = -dash {2 8}
		-dash ,     = -dash {4 4}

     The  main	difference  between  this  syntax  and the numeric is that it is
     shape-conserving. This means that all values in the dash list will be  mul-
     tiplied  by  the line width before display. This ensures that "."	will al-
     ways be displayed as a dot and "-" always as a dash regardless of the  line
     width.

     On systems where only a limited set of dash patterns, the dash pattern will
     be displayed as the most close dash pattern that is available. For example,
     on Windows only the first 4 of the above examples are available; the last 2
     examples will be displayed identically to the first one.

SEE ALSO
     canvas(n), Tk_CreateItemType(3)

KEYWORDS
     dash, conversion

Tk				       8.3			   Tk_GetDash(3)

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