Tk_GetPixelsFromObj, Tk_GetPixels, Tk_GetMMFromObj, Tk_GetScreenMM -
translate between strings and screen units
Tk_GetPixelsFromObj(interp, tkwin, objPtr, intPtr) |
Tk_GetPixels(interp, tkwin, string, intPtr)
Tk_GetMMFromObj(interp, tkwin, objPtr, doublePtr) |
Tk_GetScreenMM(interp, tkwin, string, doublePtr)
Tcl_Interp *interp (in) Interpreter to use for error report-
Tk_Window tkwin (in) Window whose screen geometry deter-
mines the conversion between absolute
units and pixels.
Tcl_Obj *objPtr (in/out) ||
String value specifies a distance on |
the screen; internal rep will be mod- |
ified to cache converted distance. |
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.
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_GetPixels- |
FromObj 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 pre- |
vents 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.
centimeters, convert, inches, millimeters, pixels, points, screen units
Tk 8.1 Tk_GetPixelsFromObj(3)
Man(1) output converted with