132 lines
5.4 KiB
Racket
132 lines
5.4 KiB
Racket
|
#lang racket/base
|
||
|
|
||
|
(provide render-windows!)
|
||
|
|
||
|
(require racket/match)
|
||
|
|
||
|
(require "buffer.rkt")
|
||
|
(require "window.rkt")
|
||
|
(require "display.rkt")
|
||
|
(require "rope.rkt")
|
||
|
|
||
|
(define top-of-window-mtype (mark-type "top-of-window" 'right))
|
||
|
|
||
|
(define (newline? c) (equal? c #\newline))
|
||
|
(define (not-newline? c) (not (newline? c)))
|
||
|
|
||
|
;; Finseth's book defines a C routine, Framer(), which is intended to
|
||
|
;; ensure that the `top_of_window` mark, denoting the position where
|
||
|
;; display should begin for the current window, is in a sane position.
|
||
|
;; The mark is left alone unless the cursor is outside the currently
|
||
|
;; displayed window, either above or below. If the mark needs to be
|
||
|
;; moved, it is moved to a line such that the cursor, after redisplay,
|
||
|
;; will end up at a configurable percentage of the way down the
|
||
|
;; window.
|
||
|
;;
|
||
|
;; Buffer Nat -> Nat
|
||
|
;; Ensures the given mark is sanely positioned as a top-of-window mark
|
||
|
;; with respect to the given cursor position. Returns the
|
||
|
;; top-of-window position.
|
||
|
(define (frame-buffer! buf window-height
|
||
|
#:preferred-position-fraction [preferred-position-fraction 1/2])
|
||
|
(define old-top-of-window-pos (or (buffer-mark-pos buf top-of-window-mtype) 0))
|
||
|
(define preferred-distance-from-bottom (ceiling (* window-height (- 1 preferred-position-fraction))))
|
||
|
(let loop ((pos (buffer-findf buf newline? #:forward? #f))
|
||
|
(line-count 0)
|
||
|
(top-of-window-pos old-top-of-window-pos))
|
||
|
(define new-top-of-window-pos
|
||
|
(if (= line-count preferred-distance-from-bottom) pos top-of-window-pos))
|
||
|
(cond
|
||
|
[(<= pos old-top-of-window-pos)
|
||
|
old-top-of-window-pos]
|
||
|
[(= line-count window-height)
|
||
|
(buffer-mark! buf top-of-window-mtype #:position new-top-of-window-pos)
|
||
|
new-top-of-window-pos]
|
||
|
[else
|
||
|
(loop (buffer-findf buf newline? #:forward? #f #:position (- pos 1))
|
||
|
(+ line-count 1)
|
||
|
new-top-of-window-pos)])))
|
||
|
|
||
|
(define (tty-body-style t is-active?)
|
||
|
(tty-style t
|
||
|
#:foreground-color color-white
|
||
|
#:background-color color-blue
|
||
|
#:bold? #f))
|
||
|
|
||
|
(define (tty-statusline-style t is-active?)
|
||
|
(tty-style t
|
||
|
#:foreground-color color-black
|
||
|
#:background-color color-white))
|
||
|
|
||
|
(define (render-buffer! t b window-top window-height is-active?)
|
||
|
(define top-of-window-pos (frame-buffer! b window-height))
|
||
|
(define cursor-pos (buffer-pos b))
|
||
|
(tty-goto t window-top 0)
|
||
|
(tty-body-style t is-active?)
|
||
|
(define cursor-coordinates
|
||
|
(let loop ((line-count 0)
|
||
|
(sol-pos top-of-window-pos)
|
||
|
(cursor-coordinates #f))
|
||
|
(cond
|
||
|
[(>= line-count (- window-height 1))
|
||
|
cursor-coordinates]
|
||
|
[else
|
||
|
(define eol-pos (buffer-findf b newline? #:position sol-pos))
|
||
|
(define line (rope->string (buffer-region b #:point eol-pos #:mark sol-pos)))
|
||
|
(tty-display t line)
|
||
|
(tty-clear-to-eol t)
|
||
|
(tty-newline t)
|
||
|
(loop (+ line-count 1)
|
||
|
(+ eol-pos 1)
|
||
|
(if (<= sol-pos cursor-pos eol-pos)
|
||
|
(list (+ line-count window-top)
|
||
|
(- cursor-pos sol-pos))
|
||
|
cursor-coordinates))])))
|
||
|
(tty-statusline-style t is-active?)
|
||
|
(tty-display t (if is-active? "== " "-- ") (buffer-title b) " ")
|
||
|
(tty-display t (make-string (- (tty-columns t) 4 (string-length (buffer-title b)))
|
||
|
(if is-active? #\= #\-)))
|
||
|
cursor-coordinates)
|
||
|
|
||
|
(define (layout-windows ws total-height [minimum-height 4])
|
||
|
(define total-weight (foldl + 0 (map (lambda (e)
|
||
|
(match (cadr e)
|
||
|
[(absolute-size _) 0]
|
||
|
[(relative-size w) w])) ws)))
|
||
|
(define reserved-lines (foldl + 0 (map (lambda (e)
|
||
|
(match (cadr e)
|
||
|
[(absolute-size lines) lines]
|
||
|
[(relative-size _) 0])) ws)))
|
||
|
(define proportional-lines (- total-height reserved-lines))
|
||
|
(let loop ((ws ws) (offset 0) (remaining proportional-lines))
|
||
|
(match ws
|
||
|
['() '()]
|
||
|
[(cons (list w (absolute-size lines)) rest)
|
||
|
(cons (list w offset lines) (loop rest (+ offset lines) remaining))]
|
||
|
[(cons (list w (relative-size weight)) rest)
|
||
|
(define height (max minimum-height
|
||
|
(inexact->exact
|
||
|
(round (* proportional-lines (/ weight total-weight))))))
|
||
|
(if (>= remaining height)
|
||
|
(if (null? rest)
|
||
|
(list (list w offset remaining))
|
||
|
(cons (list w offset height) (loop rest (+ offset height) (- remaining height))))
|
||
|
(if (>= remaining minimum-height)
|
||
|
(list (list w offset remaining))
|
||
|
'()))])))
|
||
|
|
||
|
(define (render-windows! ws active-window)
|
||
|
(define t (stdin-tty))
|
||
|
(define layout (layout-windows ws (tty-rows t)))
|
||
|
(tty-body-style t #f)
|
||
|
(tty-clear t)
|
||
|
(define active-cursor-position
|
||
|
(for/fold [(cursor-position #f)] [(e layout)]
|
||
|
(match-define (list w window-top window-height) e)
|
||
|
(define is-active? (eq? w active-window))
|
||
|
(define b (window-buffer w))
|
||
|
(define window-cursor-position (render-buffer! t b window-top window-height is-active?))
|
||
|
(if is-active? window-cursor-position cursor-position)))
|
||
|
(when active-cursor-position
|
||
|
(tty-goto t (car active-cursor-position) (cadr active-cursor-position))))
|