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- wheezy 8.4.19-5
Tk_GetDash(3tk) | Tk Library Procedures | Tk_GetDash(3tk) |
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.
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 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.
KEYWORDS¶
dash, conversion8.3 | Tk |