container.scm

#|
LambdaNative - a cross-platform Scheme framework
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|#
;; container widget
(define (glgui:container-input-drag g wgt type mx my)
  (let* ((xofs (glgui-widget-get-dyn g wgt 'xofs))
         (yofs (glgui-widget-get-dyn g wgt 'yofs))
         (w (glgui-widget-get-dyn g wgt 'w))
         (h (glgui-widget-get-dyn g wgt 'h))
         (cb (glgui-widget-get g wgt 'callback))
         (drag_oldx (glgui-widget-get g wgt 'drag_oldx))
         (drag_oldy (glgui-widget-get g wgt 'drag_oldy))
         (dragged? (glgui-widget-get g wgt 'dragged?))
         (draggable_x? (glgui-widget-get g wgt 'draggable_x?))
         (draggable_y? (glgui-widget-get g wgt 'draggable_y?))
         (drag_keep (glgui-widget-get g wgt 'drag_keep))
         (inside (and (> mx xofs) (< mx (+ xofs w)) (> my yofs) (< my (+ yofs h)))))
    (cond
      ((and (fx= type EVENT_MOTION) drag_oldx drag_oldy) ;; drag
        (if (or (> (abs (- mx drag_oldx)) 5) (> (abs (- my drag_oldy)) 5)) (begin
          (glgui-widget-set! g wgt 'dragged? #t)
          (if (and draggable_x?
                   (< (+ xofs (- mx drag_oldx)) (- (glgui-width-get) drag_keep))
                   (> (+ xofs (- mx drag_oldx) w) drag_keep))
            (glgui-widget-set! g wgt 'xofs (+ xofs (- mx drag_oldx)))
          )
          (if (and draggable_y?
                   (< (+ yofs (- my drag_oldy)) (- (glgui-height-get) drag_keep))
                   (> (+ yofs (- my drag_oldy) h) drag_keep))
            (glgui-widget-set! g wgt 'yofs (+ yofs (- my drag_oldy)))
          )
          (glgui-widget-set! g wgt 'drag_oldx (fix mx))
          (glgui-widget-set! g wgt 'drag_oldy (fix my))
        ))
      )
      ((and inside (fx= type EVENT_BUTTON1DOWN)) ;; touch down
        (glgui-widget-set! g wgt 'drag_oldx (fix mx))
        (glgui-widget-set! g wgt 'drag_oldy (fix my))
        (glgui-widget-set! g wgt 'dragged? #f)
      )
      ((and drag_oldx drag_oldy (fx= type EVENT_BUTTON1UP)) ;; touch release
       (if (and inside dragged?) (begin
          (glgui-widget-set! g wgt 'dragged? #f)
          (glgui-widget-set! g wgt 'drag_oldx #f))
          (glgui-widget-set! g wgt 'drag_oldy #f)
        )
      )
      (else (if (not inside) (begin
        (glgui-widget-set! g wgt 'drag_oldx #f)
        (glgui-widget-set! g wgt 'drag_oldy #f)
        ))
      )
    )
    ;; Make sure the widgets within get events passed too
    (if (not dragged?)
      (glgui:inputloop type mx my wgt)
      inside
    )
))

(define (glgui-container-update g wgt id val)
  (if (or (eq? id 'draggable_x?) (eq? id 'draggable_y?))
    (let ((draggable_x? (glgui-widget-get g wgt 'draggable_x?))
          (draggable_y? (glgui-widget-get g wgt 'draggable_y?)))
      (if (or val draggable_x? draggable_y?)
        (glgui-widget-set! g wgt 'input-handle glgui:container-input-drag)
        (glgui-widget-set! g wgt 'input-handle #f)
      )
    )
  )
)

;; Gets the topmost GUI by traversing parents
(define (glgui-container-gui-get wgt)
  (let ((parent (glgui-get wgt 'parent)))
    (if parent
        (glgui-container-gui-get parent)
        wgt)))

;; Given coordinates (x, y) in wgt,
;; get the same position in the frame of reference of
;; the topmost GUI
(define (glgui-container-gui-xy-get wgt x y)
  (let ((parent (glgui-get wgt 'parent))
        (wgt-x  (glgui-get wgt 'xofs))
        (wgt-y  (glgui-get wgt 'yofs)))
    (if parent
        (glgui-container-gui-xy-get parent (+ x wgt-x) (+ y wgt-y))
        (cons x y))))

(define (glgui-container g x y w h)
  (glgui-widget-add g
    'x 0
    'y 0
    'w w
    'h h
    'xofs x
    'yofs y
    'parent g
    'widget-list '()
    'widget-count 0
    'container #t
    'hidden #f
    'draw-handle #f
    'input-handle #f
    'draggable_x? #f
    'draggable_y? #f
    'drag_keep 10
    'update-handle glgui-container-update
  ))

;; eof