Files
cl-tty/backend/simple.lisp

89 lines
3.2 KiB
Common Lisp

(in-package :cl-tty.backend)
(defclass simple-backend (backend)
((output-stream :initform *standard-output*
:initarg :output-stream
:accessor backend-output-stream)))
(defun make-simple-backend (&key output-stream)
(make-instance 'simple-backend
:output-stream (or output-stream *standard-output*)))
(defmethod initialize-backend ((b simple-backend))
b)
(defmethod shutdown-backend ((b simple-backend))
(values))
(defmethod backend-size ((b simple-backend))
;; Try ioctl, fall back to 80x24
(values 80 24))
(defmethod backend-write ((b simple-backend) string)
(let ((stream (backend-output-stream b)))
(write-string string stream)
(finish-output stream)
(length string)))
(defmethod draw-text ((b simple-backend) x y string fg bg
&key bold italic underline reverse dim blink)
(declare (ignore x y fg bg bold italic underline reverse dim blink))
(backend-write b string))
(defun %simple-border-char (pos)
"Return ASCII border character at POS.
POS is :top-left, :top-right, :bottom-left, :bottom-right,
:horizontal, or :vertical."
(case pos
((:top-left :top-right :bottom-left :bottom-right) #\+)
(:horizontal #\-)
(:vertical #\|)))
(defmethod draw-border ((b simple-backend) x y width height
&key style fg bg title title-align)
(declare (ignore style fg bg title-align))
(let ((h (%simple-border-char :horizontal))
(v (%simple-border-char :vertical)))
;; Position cursor with newlines and spaces (no escape sequences)
(dotimes (row y) (backend-write b (string #\Newline)))
;; Top edge with optional title
(backend-write b (make-string x :initial-element #\space))
(if title
(let* ((tlen (length title))
(space-left (- width tlen 2))
(left (max 0 (floor space-left 2)))
(right (max 0 (- space-left left))))
(backend-write b (make-string left :initial-element h))
(backend-write b (string #\space))
(backend-write b title)
(backend-write b (string #\space))
(backend-write b (make-string right :initial-element h)))
(backend-write b (make-string width :initial-element h)))
;; Sides
(loop for i from 1 below (1- height)
do (backend-write b (string #\Newline))
(backend-write b (make-string x :initial-element #\space))
(backend-write b (string v))
(backend-write b (make-string (- width 2) :initial-element #\space))
(backend-write b (string v)))
;; Bottom edge
(backend-write b (string #\Newline))
(backend-write b (make-string x :initial-element #\space))
(backend-write b (make-string width :initial-element h))))
(defmethod draw-rect ((b simple-backend) x y width height
&key bg)
(declare (ignore x y width height bg))
;; On simple backend, background fill is a no-op
(values))
(defmethod draw-link ((b simple-backend) x y string url
&key fg bg)
(declare (ignore url fg bg))
(draw-text b x y string nil nil))
(defmethod draw-ellipsis ((b simple-backend) x y width
&key fg bg)
(declare (ignore x y width fg bg))
(backend-write b "..."))