Ben / Nujel

;;; Nujel - Copyright (C) 2020-2021 - Benjamin Vincent Schulenburg
;;; This project uses the MIT license, a copy should be included under /LICENSE
;;;

(defclass TermAppVerticalSplit
  :export

  (defn new (self parent left-child right-child)
        (def s (:get-size parent))
        (def ret { :parent parent
                   :width s.width
                   :height s.height
                   :left-child left-child
                   :right-child right-child
                   :right-child-focus? #f
                   :right-child-active? #f
                   :split-pos (div/int s.width 2)
                   :prototype* self })
        (:set-parent! left-child ret)
        (:set-parent! right-child ret)
        (:clear-screen ret)
        ret)

  (defn child-offset (self)
        (if self.right-child-active?
            self.split-pos
            0))

  (defn windmove-left (self)
        (if self.right-child-focus?
            (do (set! self.right-child-focus? #f)
                (:handle-event self.right-child {:T :blur})
                (:handle-event self.left-child {:T :focus}))
            (:windmove-left self.parent)))

  (defn windmove-right (self)
        (if self.right-child-focus?
            (:windmove-right self.parent)
            (do (set! self.right-child-focus? #t)
                (:handle-event self.left-child {:T :blur})
                (:handle-event self.right-child {:T :focus}))))

  (defn child-width (self)
        (if self.right-child-active?
            (- self.width self.split-pos)
            (inc self.split-pos)))

  (defn split-window-right (self right-child)
        (def new (:new TermAppVerticalSplit
                       self
                       (if self.right-child-active?
                           self.right-child
                           self.left-child)
                       right-child))
        (if self.right-child-active?
            (set! self.right-child new)
            (set! self.left-child new))
        (:handle-event new {:T :resize :width self.width :height self.height}))

  (defn run (self child)
        (if self.right-child-active?
            (set! self.right-child child)
            (set! self.left-child child))
        (child {:T :resize :width (:child-width self) :height s.height})
        (child {:T :draw}))

  (defn stop (self) (:stop self.parent))
  (defn flip (self) (:flip self.parent))
  (defn draw-char (self char x y color)
        (when (or (>= x (:child-width self))
                  (>= y self.height)
                  (< x 0)
                  (< y 0))
          (return))
        (:draw-char self.parent char (+ (:child-offset self) x) y color))

  (defn set-cursor (self x y)
        (when (= self.right-child-active? self.right-child-focus?)
                  (def child-offset (if self.right-child-active?
                                        self.split-pos
                                        0))
                  (:set-cursor self.parent (+ x child-offset) y)))

  (defn draw-text (self text x y w h color)
        (set! x (max 0 x))
        (set! y (max 0 y))
        (set! w (min (- (:child-width self) x) w))
        (set! h (min (- self.height y) (- h 1)))
        (:draw-text self.parent text (+ x (:child-offset self)) y w h color))

  (defn stop (self)
        (:stop self.parent))

  (defn set-parent! (self parent)
        (set! self.parent parent))

  (defn run (self child)
        (if self.right-child-active?
            (set! self.right-child child)
            (set! self.left-child child)))

  (defn clear-screen (self)
        (:clear-screen self.parent))

  (defn handle-event (self event)
        (when (= :resize event.T)
          (set! self.right-child-active? #f)
          (:handle-event self.left-child {:T :resize :width (:child-width self) :height self.height})
          (set! self.right-child-active? #t)
          (:handle-event self.right-child {:T :resize :width (:child-width self) :height self.height})
          (return))
        (when (= :draw event.T)
          (set! self.right-child-active? #f)
          (:handle-event self.left-child event)
          (set! self.right-child-active? #t)
          (:handle-event self.right-child event)
          (return))

        (set! self.right-child-active? self.right-child-focus?)
        (:handle-event (if self.right-child-focus? self.right-child self.left-child) event))

  (defn get-size (self)
        (def child-width )
        { :width (:child-width self)
          :height self.height }))