Import Tk 8.5.15 (as of svn r89086)

doc/GetDash.3

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+'\"
+'\" Copyright (c) 1989-1993 The Regents of the University of California.
+'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
+'\"
+'\" See the file "license.terms" for information on usage and redistribution
+'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
+'\" 
+.so man.macros
+.TH Tk_GetDash 3 8.3 Tk "Tk Library Procedures"
+.BS
+.SH NAME
+Tk_GetDash \- convert from string to valid dash structure.
+.SH SYNOPSIS
+.nf
+\fB#include <tk.h>\fR
+.sp
+int
+\fBTk_GetDash\fR(\fIinterp, string, dashPtr\fR)
+.SH ARGUMENTS
+.AS Tk_Dash *dashPtr
+.AP Tcl_Interp *interp in
+Interpreter to use for error reporting.
+.AP "const char *" string in
+Textual value to be converted.
+.AP Tk_Dash *dashPtr out
+Points to place to store the dash pattern
+value converted from \fIstring\fR.
+.BE
+
+.SH DESCRIPTION
+.PP
+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
+.QW \fB.,\-_\fR
+or spaces. If all
+goes well, \fBTCL_OK\fR is returned. If \fIstring\fR does not have the
+proper syntax then \fBTCL_ERROR\fR is returned, an error message is left
+in the interpreter's result, and nothing is stored at *\fIdashPtr\fR.
+.PP
+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
+.QW outline
+color. The other segments are drawn transparent.
+.PP
+The second possible syntax is a character list containing only
+5 possible characters
+.QW "\fB.,\-_ \fR" .
+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:
+.CS
+    \-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}
+.CE
+.PP
+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
+.QW .
+will always be displayed as a dot and
+.QW \-
+always as a dash regardless of the line width.
+.PP
+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.
+
+.SH KEYWORDS
+dash, conversion