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Tk_GetDash(3)                Tk Library Procedures               Tk_GetDash(3)




NAME

       Tk_GetDash - convert from string to valid dash structure.


SYNOPSIS

       #include <tk.h>

       int
       Tk_GetDash(interp, string, dashPtr)


ARGUMENTS

       Interpreter to use for error reporting.  Textual value to be converted.
       Points to place to store the dash pattern value converted from  string.



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 or spaces. If all goes well, TCL_OK is returned.
       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 color. The other segments are drawn transparent.

       The second possible syntax is a character list containing only 5 possi-
       ble characters The space can be used to enlarge the space between other
       line elements, and can not occur as the first position in  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  of  this  syntax with the previous 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 assures 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  as  the  first
       one.



KEYWORDS

       dash, conversion



Tk                                    8.3                        Tk_GetDash(3)

GetDash 8.5.4 - Generated Sat Aug 23 16:22:19 CDT 2008
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