8.16.0.4
4 Single Cell Handling🔗ℹ
This module encapsulates the low-level handling of single cell
handling with respect to drawing a character to the buffer.
Puts a character into ub at specified position using
given attributes colors. By if update-dirty? is
#t it sets modified cell’s dirty bit if the target cell
was modified.
The character char can be one or two cells wide and this
information is passed on transparently into the underlying cell
attributes. If the character is two cells wide, it obscures the
next character to the right on the same row if printed onto a
terminal.
Both foreground fg and background bg colors can
be either indexed or truecolor. See the color support module for
details.
The bold and italic attributes can either be
#f or #t - disabling or enabling given visual
variant.
The underline attribute can be one of #f,
'single or 'double.
The blink attribute can be one of #f,
'slow or 'fast.
Updates cell starting at index idx of the cells
vector. If char differs to what is in the cells, it gets
updated. The same applies for fg and bg colors and
the attributes flags.
If update-dirty? is #t, then this procedure sets the
tcf-dirty-true in the flags if anything changed.
Convenience procedure to pack user interface attributes’ values into a
single flags value.
(define-from-ubuf ub x y maybe-binding ...)
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| maybe-binding | | = | | | | | | | | | #:char char-id | | | | | | | #:fg fg-id | | | | | | | #:bg bg-id | | | | | | | #:flags flags-id | | | | | | | #:bold bold-id | | | | | | | #:underline underline-id | | | | | | | #:italic italic-id | | | | | | | #:blink blink-id | | | | | | | #:dirty dirty-id | | | | | | | #:wide wide-id |
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A special form for defining any attributes of any cell in the buffer
as new binding. It can be seen as a reverse operation to
ubuf-putchar!.
This example retrieves a character at position (1,1) from buffer
ub and stores it in a binding ch:
(define-from-ubuf ub 1 1 #:char ch)
The #:char binding binds either a valid char? or
#f to the identifier provided. For all bindings, if given
coordinates are out of bounds, #f is supplied as value.
The #:fg, #:bg and #:flags all return
fixnum? value of given cell attribute.
The #:bold, #:italic, #:dirty and
#:wide all return boolean? value.
The #:underline returns one of #f, 'single
or 'double.
The #:blink returns one of #f, 'slow or
'fast.