2231fb6647
Fixes during debugging: - Variable scope: loop's closing parens closed the let* prematurely, making children/is-row/pr/pb undefined in own-size calculation - gap NIL bug: make-layout-node passed :gap nil (from &key default) to make-instance, overriding :initform 0 → (* nil ...) crash - Child order: push (LIFO) in add-child reversed children order; changed to nconc (FIFO), removed the compensating reverse - Fixed distribute-sizes to base all children from their fixed size then apply grow/shrink on top, instead of treating fixed-size children as non-participating
189 lines
8.9 KiB
Common Lisp
189 lines
8.9 KiB
Common Lisp
;;; layout — Pure CL Flexbox layout engine
|
|
|
|
(defpackage :cl-tui.layout
|
|
(:use :cl)
|
|
(:export
|
|
#:layout-node #:make-layout-node
|
|
#:layout-node-add-child #:layout-node-remove-child
|
|
#:layout-node-children
|
|
#:layout-node-x #:layout-node-y
|
|
#:layout-node-width #:layout-node-height
|
|
#:layout-node-direction
|
|
#:compute-layout
|
|
#:vbox #:hbox #:spacer
|
|
;; For tests
|
|
#:layout-node-parent #:layout-node-fixed-width
|
|
#:layout-node-fixed-height #:normalize-box
|
|
#:box-edge))
|
|
|
|
(in-package :cl-tui.layout)
|
|
|
|
(defun normalize-box (spec)
|
|
(cond ((null spec) '(:top 0 :right 0 :bottom 0 :left 0))
|
|
((numberp spec) `(:top ,spec :right ,spec :bottom ,spec :left ,spec))
|
|
((getf spec :top) spec)
|
|
(t '(:top 0 :right 0 :bottom 0 :left 0))))
|
|
|
|
(defun box-edge (box edge)
|
|
(or (getf box edge) 0))
|
|
|
|
(defclass layout-node ()
|
|
((parent :initform nil :accessor layout-node-parent)
|
|
(children :initform nil :accessor layout-node-children)
|
|
(x :initform 0 :accessor layout-node-x)
|
|
(y :initform 0 :accessor layout-node-y)
|
|
(width :initform 0 :accessor layout-node-width)
|
|
(height :initform 0 :accessor layout-node-height)
|
|
(direction :initform :column :initarg :direction :accessor layout-node-direction)
|
|
(grow :initform 0 :initarg :grow :accessor layout-node-grow)
|
|
(shrink :initform 1 :initarg :shrink :accessor layout-node-shrink)
|
|
(padding :initform '(:top 0 :right 0 :bottom 0 :left 0) :initarg :padding :accessor layout-node-padding)
|
|
(margin :initform '(:top 0 :right 0 :bottom 0 :left 0) :initarg :margin :accessor layout-node-margin)
|
|
(gap :initform 0 :initarg :gap :accessor layout-node-gap)
|
|
(position-type :initform :relative :initarg :position-type :accessor layout-node-position-type)
|
|
(position-offset :initform nil :initarg :position-offset :accessor layout-node-position-offset)
|
|
(fixed-width :initform nil :initarg :width :accessor layout-node-fixed-width)
|
|
(fixed-height :initform nil :initarg :height :accessor layout-node-fixed-height)))
|
|
|
|
(defun make-layout-node (&key direction grow shrink padding margin gap
|
|
position-type position-offset width height)
|
|
(make-instance 'layout-node
|
|
:direction (or direction :column)
|
|
:grow (or grow 0) :shrink (or shrink 1)
|
|
:padding (normalize-box padding) :margin (normalize-box margin)
|
|
:gap (or gap 0)
|
|
:position-type (or position-type :relative)
|
|
:position-offset position-offset
|
|
:width width :height height))
|
|
|
|
(defun layout-node-add-child (parent child)
|
|
(setf (layout-node-parent child) parent)
|
|
(setf (layout-node-children parent)
|
|
(nconc (layout-node-children parent) (list child)))
|
|
child)
|
|
|
|
(defun layout-node-remove-child (parent child)
|
|
(setf (layout-node-parent child) nil)
|
|
(setf (layout-node-children parent)
|
|
(delete child (layout-node-children parent)))
|
|
child)
|
|
|
|
;; ── Solver ─────────────────────────────────────────────────────
|
|
|
|
(defun distribute-sizes (children avail gap horizontal)
|
|
"Compute child sizes given available space and gap.
|
|
HORIZONTAL is non-nil when distributing width (row layout).
|
|
Each child starts from its fixed size (if any). Remaining space
|
|
is distributed by grow ratio; overflow is reduced by shrink ratio."
|
|
(let* ((n (length children))
|
|
(gap-total (* gap (max 0 (1- n))))
|
|
(base (mapcar (lambda (c)
|
|
(or (if horizontal
|
|
(layout-node-fixed-width c)
|
|
(layout-node-fixed-height c))
|
|
0))
|
|
children))
|
|
(base-total (reduce #'+ base))
|
|
(remaining (- avail base-total gap-total))
|
|
(grow-total (reduce #'+ (mapcar #'layout-node-grow children)))
|
|
(shrink-total (reduce #'+ (mapcar #'layout-node-shrink children))))
|
|
(mapcar (lambda (c b)
|
|
(let ((sz b))
|
|
(when (and (plusp remaining) (plusp grow-total))
|
|
(incf sz (round (* remaining (/ (layout-node-grow c) grow-total)))))
|
|
(when (and (minusp remaining) (plusp shrink-total))
|
|
(decf sz (round (* (abs remaining) (/ (layout-node-shrink c) shrink-total)))))
|
|
(max 1 sz)))
|
|
children base)))
|
|
|
|
(defun compute-layout (root available-width available-height)
|
|
"Layout all children of ROOT within the given dimensions.
|
|
Recursively computes position and size for every node."
|
|
(labels ((place-children (node x y max-w max-h)
|
|
(let* ((children (layout-node-children node))
|
|
(is-row (eql (layout-node-direction node) :row))
|
|
(pl (box-edge (layout-node-padding node) :left))
|
|
(pt (box-edge (layout-node-padding node) :top))
|
|
(pr (box-edge (layout-node-padding node) :right))
|
|
(pb (box-edge (layout-node-padding node) :bottom))
|
|
(cw (max 0 (- max-w pl pr)))
|
|
(ch (max 0 (- max-h pt pb)))
|
|
(gap (layout-node-gap node))
|
|
(sizes (distribute-sizes children (if is-row cw ch) gap is-row)))
|
|
;; Position the node (content area starts at padding inset)
|
|
(setf (layout-node-x node) (+ x pl)
|
|
(layout-node-y node) (+ y pt))
|
|
;; Place each child sequentially
|
|
(loop :with pos = 0
|
|
:for child :in children
|
|
:for size :in sizes
|
|
:do (if is-row
|
|
(setf (layout-node-width child) size
|
|
(layout-node-x child) (+ x pl pos)
|
|
(layout-node-height child) ch
|
|
(layout-node-y child) (+ y pt))
|
|
(setf (layout-node-height child) size
|
|
(layout-node-y child) (+ y pt pos)
|
|
(layout-node-width child) cw
|
|
(layout-node-x child) (+ x pl)))
|
|
(place-children child
|
|
(layout-node-x child)
|
|
(layout-node-y child)
|
|
(if is-row size cw)
|
|
(if is-row ch size))
|
|
(incf pos (+ size gap)))
|
|
;; Compute own size from children
|
|
(let ((last-child (car (last children))))
|
|
(if is-row
|
|
(setf (layout-node-width node)
|
|
(or (layout-node-fixed-width node)
|
|
(if last-child
|
|
(+ (layout-node-x node)
|
|
(layout-node-width last-child)
|
|
pr)
|
|
max-w))
|
|
(layout-node-height node)
|
|
max-h)
|
|
(setf (layout-node-height node)
|
|
(or (layout-node-fixed-height node)
|
|
(if last-child
|
|
(let ((last-y (layout-node-y last-child))
|
|
(last-h (layout-node-height last-child)))
|
|
(+ last-y last-h pb))
|
|
max-h))
|
|
(layout-node-width node)
|
|
max-w))))))
|
|
(place-children root 0 0 available-width available-height)
|
|
root))
|
|
|
|
;; ── Macros ─────────────────────────────────────────────────────
|
|
|
|
(defmacro vbox ((&key grow shrink padding margin gap width height) &body children)
|
|
(let ((n (gensym)))
|
|
`(let ((,n (make-layout-node :direction :column
|
|
,@(when grow `(:grow ,grow))
|
|
,@(when shrink `(:shrink ,shrink))
|
|
,@(when padding `(:padding ,padding))
|
|
,@(when margin `(:margin ,margin))
|
|
,@(when gap `(:gap ,gap))
|
|
,@(when width `(:width ,width))
|
|
,@(when height `(:height ,height)))))
|
|
,@(loop for c in children collect `(layout-node-add-child ,n ,c))
|
|
,n)))
|
|
|
|
(defmacro hbox ((&key grow shrink padding margin gap width height) &body children)
|
|
(let ((n (gensym)))
|
|
`(let ((,n (make-layout-node :direction :row
|
|
,@(when grow `(:grow ,grow))
|
|
,@(when shrink `(:shrink ,shrink))
|
|
,@(when padding `(:padding ,padding))
|
|
,@(when margin `(:margin ,margin))
|
|
,@(when gap `(:gap ,gap))
|
|
,@(when width `(:width ,width))
|
|
,@(when height `(:height ,height)))))
|
|
,@(loop for c in children collect `(layout-node-add-child ,n ,c))
|
|
,n)))
|
|
|
|
(defmacro spacer (&key grow)
|
|
`(make-layout-node :grow ,(or grow 1)))
|