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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 pat-
				      tern 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  containing  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 message is left in  the  interpreter's  result,  and
       nothing is stored at *dashPtr.

       The  first  possible  syntax is a list of integers. Each	element	repre-
       sents the number	of pixels of a line segment. Only the odd segments are
       drawn using the "outline" color.	The other segments are drawn transpar-
       ent.

       The second possible syntax is a character list containing only 5	possi-
       ble characters ".,-_ ".	The space can be used to enlarge the space be-
       tween 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
       multiplied  by  the  line  width	 before	display. This ensures that "."
       will always 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	avail-
       able; 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)

NAME | SYNOPSIS | ARGUMENTS | DESCRIPTION | SEE ALSO | KEYWORDS

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