;; layers-delete.scm -*-scheme-*-

;; Alan Horkan, April 2004.  Copyright: Public Domain.  
;; You may do whatever you like with this script but please do share 
;; and try to let me know if you make any interesting changes.  
;;
;; Idea from Adobe Photoshop 7.0 
;; Layer, Delete: Layer, Linked Layers, Hidden Layers.  

; this script reuses parts of my layers-view script
; with better programming most of the code could be directly shared 

; failed to get it working using a straight list
; looked at copy-visible.scm for inspiration: answer use an array.  
; TODO learn more Scheme, read 'the Wizard book' again ;)

; ideally moving through the layer stack should be abstracted 
; and the specific function passed in a parameter as needed
; again must read 'the wizard book'


; delete the current (drawable if it is a) layer
(define (script-fu-layers-delete-layer image drawable) 
    (gimp-image-undo-group-start image) 
    ; drawable could be a channel, must check it.   
    (if (= 1 (car (gimp-drawable-is-layer drawable)))
        (gimp-image-remove-layer image drawable)
    )
    (gimp-displays-flush) 
    (gimp-image-undo-group-end image)
) 

(define (script-fu-layers-delete-linked image drawable)
  (let* (
      (layers (gimp-image-get-layers image))  
	(number-layers (car layers))
	(layer-array (cadr layers))
    )
  (gimp-image-undo-group-start image)
  (set! layer-count 0)
  (while (< layer-count number-layers)
      (set! layer (aref layer-array layer-count))
      ; delete all the linked layers  
      (if (= TRUE (car (gimp-drawable-get-linked layer)))
        (gimp-image-remove-layer image layer)
      ) 
      (set! layer-count (+ layer-count 1)))
  ) 
  (gimp-image-undo-group-end image) 
  (gimp-displays-flush) 
)

(define (script-fu-layers-delete-hidden image drawable) 
  (let* (
      (layers (gimp-image-get-layers image))  
	(number-layers (car layers))
	(layer-array (cadr layers))
    )
  (gimp-image-undo-group-start image)
  ; delete all the hidden layers
  (set! layer-count 0)
  (while (< layer-count number-layers)
      (set! layer (aref layer-array layer-count))
      (if (= (car (gimp-drawable-get-visible layer)) FALSE) 
        (gimp-image-remove-layer image layer)
      ) 
      (set! layer-count (+ layer-count 1)))
  ) 
  (gimp-image-undo-group-end image) 
  (gimp-displays-flush) 
)

;; register/add the various items to the menus, 
;; same menu positions and mnemonics used as Adobe Photoshop 7.0  

(set! authors "Alan Horkan.  ")
(set! copyrights "Alan Horkan, 2004.  Public Domain.  ") 
(set! date "2004 04 02 UTC")  

(script-fu-register "script-fu-layers-delete-layer"
    ; mnemonics are all 'l', extremely fast keybinding to use.  
    _"<Image>/Layer/Delete/_Layer" 
    "Delete the current Layer only.  "
    authors copyrights date "" ; strings set using variables, see above
    SF-IMAGE "Image" 0
    SF-DRAWABLE "Drawable" 0
)

(script-fu-register "script-fu-layers-delete-linked"
    _"<Image>/Layer/Delete/Lin_ked Layers" 
    "Delete all Linked Layers.  "
    authors copyrights date "" ; strings set using variables, see above
    SF-IMAGE "Image" 0
    SF-DRAWABLE "Drawable" 0
)

(script-fu-register "script-fu-layers-delete-hidden"
    _"<Image>/Layer/Delete/_Hidden Layers" 
    "Delete all Hidden Layers.  "
    authors copyrights date "" ; strings set using variables, see above
    SF-IMAGE "Image" 0
    SF-DRAWABLE "Drawable" 0
)