Provided by: tk8.4-doc_8.4.19-4_all bug


       Tk_GetDash - convert from string to valid dash structure.


       #include <tk.h>

       Tk_GetDash(interp, string, dashPtr)


       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.


       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  doesn't  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  represents  the  number  of
       pixels  of  a line segment. Only the odd segments are drawn using 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 as the first posibion 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 it 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 available. The last 2 examples will be displayed identically as
       the first one.


       dash, conversion