Tk_GetPixelsFromObj(3TK) Tk Library Procedures Tk_GetPixelsFromObj(3TK)
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NAME
Tk_GetPixelsFromObj, Tk_GetPixels, Tk_GetMMFromObj, Tk_GetScreenMM - translate between strings and screen units
SYNOPSIS
#include <tk.h>
int |
Tk_GetPixelsFromObj(interp, tkwin, objPtr, intPtr) |
int
Tk_GetPixels(interp, tkwin, string, intPtr)
int |
Tk_GetMMFromObj(interp, tkwin, objPtr, doublePtr) |
int
Tk_GetScreenMM(interp, tkwin, string, doublePtr)
ARGUMENTS
Tcl_Interp *interp (in) Interpreter to use for error reporting.
Tk_Window tkwin (in) Window whose screen geometry determines the conversion between absolute units and pixels.
Tcl_Obj *objPtr (in/out) |
String value specifies a distance on the screen; internal rep will be modified to cache converted dis- |
tance. |
CONST char *string (in) |
Same as objPtr except specification of distance is passed as a string.
int *intPtr (out) Pointer to location in which to store converted distance in pixels.
double *doublePtr (out) Pointer to location in which to store converted distance in millimeters.
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DESCRIPTION
These procedures take as argument a specification of distance on the screen (objPtr or string) and compute the corresponding distance |
either in integer pixels or floating-point millimeters. In either case, objPtr or string specifies a screen distance as a floating-point |
number followed by one of the following characters that indicates units:
<none> The number specifies a distance in pixels.
c The number specifies a distance in centimeters on the screen.
i The number specifies a distance in inches on the screen.
m The number specifies a distance in millimeters on the screen.
p The number specifies a distance in printer's points (1/72 inch) on the screen.
Tk_GetPixelsFromObj converts the value of objPtr to the nearest even number of pixels and stores that value at *intPtr. It returns TCL_OK |
under normal circumstances. If an error occurs (e.g. objPtr contains a number followed by a character that isn't one of the ones above) |
then TCL_ERROR is returned and an error message is left in interp's result if interp isn't NULL. Tk_GetPixelsFromObj caches information |
about the return value in objPtr, which speeds up future calls to Tk_GetPixelsFromObj with the same objPtr. |
Tk_GetPixels is identical to Tk_GetPixelsFromObj except that the screen distance is specified with a string instead of an object. This |
prevents Tk_GetPixels from caching the return value, so Tk_GetAnchor is less efficient than Tk_GetPixelsFromObj. |
Tk_GetMMFromObj and Tk_GetScreenMM are similar to Tk_GetPixelsFromObj and Tk_GetPixels (respectively) except that they convert the screen |
distance to millimeters and store a double-precision floating-point result at *doublePtr.
KEYWORDS
centimeters, convert, inches, millimeters, pixels, points, screen units
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Availability | SUNWTk |
+--------------------+-----------------+
|Interface Stability | Uncommitted |
+--------------------+-----------------+
NOTES
Source for Tk is available on http://opensolaris.org.
Tk 8.1 Tk_GetPixelsFromObj(3TK)