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A pad is like a window, except that it is not restricted by the screen
size, and is not necessarily associated with a particular part of the
screen. Pads can be used when a large window is needed, and only a
part of the window will be on the screen at one time. Automatic
refreshes of pads (e.g., from scrolling or echoing of input) do not
occur. It is not legal to call refresh with a pad as an
argument; the routines prefresh or pnoutrefresh should
be called instead. Note that these routines require additional
parameters to specify the part of the pad to be displayed and the
location on the screen to be used for the display.
The newpad routine creates and returns #<window> pad with the
given number of lines, nlines, and columns, ncols.
Returns #t if win is a pad. #f otherwise.
If the underlying ncurses implementation is not capable of reporting
whether a window is a pad, this function will always return #t.
This can happen in older versions of ncurses that were compiled with
the NCURSES_OPAQUE option enabled.
To see if this is-pad? procedure actually works, you can check
the constant %is-pad-broken, which will be #f is is-pad?
actually works.
The subpad routine creates and returns a pointer to a subwindow
within a pad with the given number of lines, nlines, and
columns, ncols. Unlike subwin, which uses screen
coordinates, the window is at position (begin-x, begin-y)
on the pad. The window is made in the middle of the window orig, so
that changes made to one window affect both windows. During the use
of this routine, it will often be necessary to call touchwin or
touchline on orig before calling prefresh.
The prefresh and pnoutrefresh routines are analogous to
refresh and noutrefresh except that they relate to pads
instead of windows. The additional parameters are needed to indicate
what part of the pad and screen are involved. pminrow and
pmincol specify the upper left-hand corner of the rectangle to
be displayed in the pad. sminrow, smincol, smaxrow,
and smaxcol specify the edges of the rectangle to be displayed
on the screen. The lower right-hand corner of the rectangle to be
displayed in the pad is calculated from the screen coordinates, since
the rectangles must be the same size. Both rectangles must be
entirely contained within their respective structures. Negative
values of pminrow, pmincol, sminrow, or
smincol are treated as if they were zero.
Returns #f upon failure and #t upon successful
The pechochar routine is functionally equivalent to a call to
addch followed by a call to refresh or a call to
addch followed by a call to prefresh. The knowledge
that only a single character is being output is taken into
consideration and, for non-control characters, a considerable
performance gain might be seen by using these routines instead of
their equivalents. In the case of pechochar, the last location
of the pad on the screen is reused for the arguments to
prefresh.
Returns #f upon failure and #t upon successful
completion.