gimp/plug-ins/script-fu/scripts/palette-export.scm

; -----------------------------------------------------------------------------
; GIMP palette export toolkit -
; Written by Barak Itkin <lightningismyname@gmail.com>
;
; This script includes various exporters for GIMP palettes, and other
; utility function to help in exporting to other (text-based) formats.
; See instruction on adding new exporters at the end
;

; !!! Here run functions call script-fu-use-v3, to bind PDB returns succintly.

; -----------------------------------------------------------------------------
; Numbers and Math
; -----------------------------------------------------------------------------

; For all the operations below, this is the order of respectable digits:
(define conversion-digits (list "0" "1" "2" "3" "4" "5" "6" "7" "8" "9"
                                "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k"
				"l" "m" "n" "o" "p" "q" "r" "s" "t" "u" "v"
				"w" "x" "y" "z"))

; Converts a decimal number to another base. The returned number is a string
(define (convert-decimal-to-base num base)
  (if (< num base)
    (list-ref conversion-digits num)
    (let loop ((val num)
               (order (inexact->exact (truncate (/ (log num)
                                                   (log base)))))
               (result ""))
      (let* ((power (expt base order))
             (digit (quotient val power)))
        (if (zero? order)
          (string-append result (list-ref conversion-digits digit))
          (loop (- val (* digit power))
                (pred order)
                (string-append result (list-ref conversion-digits digit))))))))

; Convert a string representation of a number in some base, to a decimal number
(define (convert-base-to-decimal base num-str)
  (define (convert-char num-char)
    (if (char-numeric? num-char)
        (string->number (string num-char))
        (+ 10 (- (char->integer num-char) (char->integer #\a)))
        )
    )
  (define (calc base num-str num)
    (if (equal? num-str "")
        num
        (calc base
              (substring num-str 1)
              (+ (* num base) (convert-char (string-ref num-str 0)))
              )
        )
    )
  (calc base num-str 0)
  )

; If a string num-str is shorter then size, pad it with pad-str in the
; beginning until it's at least size long
(define (pre-pad-number num-str size pad-str)
  (if (< (string-length num-str) size)
      (pre-pad-number (string-append pad-str num-str) size pad-str)
      num-str
      )
  )

; -----------------------------------------------------------------------------
; Color converters
; -----------------------------------------------------------------------------

; The standard way for representing a color would be a list of red
; green and blue (GIMP's default)
(define color-get-red car)
(define color-get-green cadr)
(define color-get-blue caddr)

; Convert a color to a hexadecimal string
; '(255 255 255) => "#ffffff"

(define (color-rgb-to-hexa-decimal color)
  (string-append "#"
                 (pre-pad-number
		  (convert-decimal-to-base (color-get-red color) 16) 2 "0")
                 (pre-pad-number
		  (convert-decimal-to-base (color-get-green color) 16) 2 "0")
                 (pre-pad-number
		  (convert-decimal-to-base (color-get-blue color) 16) 2 "0")
                 )
  )

; Convert a color to a css color
; '(255 255 255) => "rgb(255, 255, 255)"
(define (color-rgb-to-css color)
  (string-append "rgb(" (number->string (color-get-red color))
                 ", " (number->string (color-get-green color))
                 ", " (number->string (color-get-blue color)) ");")
  )

; Convert a color to a simple pair of braces with comma separated values
; '(255 255 255) => "(255, 255, 255)"
(define (color-rgb-to-comma-separated-list color)
  (string-append "(" (number->string (color-get-red color))
                 ", " (number->string (color-get-green color))
                 ", " (number->string (color-get-blue color)) ")")
  )


; -----------------------------------------------------------------------------
; Export utils
; -----------------------------------------------------------------------------

; List of characters that should not appear in file names
(define illegal-file-name-chars (list #\\ #\/ #\: #\* #\? #\" #\< #\> #\|))

; A function to filter a list lst by a given predicate pred
(define (filter pred lst)
  (if (null? lst)
      '()
      (if (pred (car lst))
          (cons (car lst) (filter pred (cdr lst)))
          (filter pred (cdr lst))
          )
      )
  )

; A function to check if a certain value obj is inside a list lst
(define (contained? obj lst) (member obj lst))

; This functions filters a string to have only characters which are
; either alpha-numeric or contained in more-legal (which is a variable
; holding a list of characters)
(define (clean str more-legal)
  (list->string (filter (lambda (ch) (or (char-alphabetic? ch)
                                         (char-numeric? ch)
                                         (contained? ch more-legal)))
                        (string->list str)))
  )

; A function that receives the a file-name, and filters out all the
; character that shouldn't appear in file names. Then, it makes sure
; the remaining name isn't only white-spaces. If it's only
; white-spaces, the function returns false. Otherwise, it returns the
; fixed file-name
(define (valid-file-name name)
  (let* ((clean (list->string (filter (lambda (ch)
					(not (contained?
					      ch illegal-file-name-chars)))
                                      (string->list name))))
         (clean-without-spaces (list->string (filter (lambda (ch)
						       (not (char-whitespace?
							     ch)))
                                                     (string->list clean))))
         )
    (if (equal? clean-without-spaces "")
        #f
        clean
        )
    )
  )

(define (bad-file-name)
  (gimp-message (string-append _"The filename you entered is not a suitable name for a file."
			       "\n\n"
			       _"All characters in the name are either white-spaces or characters which can not appear in filenames.")))

; Return path to a file, or abort with error to Gimp.
;
; IN filename is from a string widget.
; A user entered the filename.  It could be strange characters, empty, etc.
; Valid: see valid-file-name, which may be overly strict for some platforms.
;
; IN directory-name is from a GtkFileChooser widget in mode "choose folder"
; When empty, returned path is just the in filename.
; When not empty, returned path is to the filename in that directory.
; The file at that path might exist already.
;
; FUTURE a proper widget for choosing a file destination.

(define (get-path-or-abort directory-name filename)
  (let* ((validated-file-name (valid-file-name filename))
         (result-path ""))
    (if (not validated-file-name)
      (begin
        (bad-file-name) ; gimp-message w translated text
        (quit -1)))
      ; FUTURE: The above should be (error "Invalid file name"))
      ; with the existing translated text,  when ScriptFu error is fixed.

    (set! result-path
      (if (> (string-length directory-name) 0)
        ; result is full path
        (string-append directory-name DIR-SEPARATOR validated-file-name)
        ; result is just the filename
        validated-file-name))

    ; Side effect.
    ; Tell the user the mangled path, might be different than user entered.
    ; The user should not need to search for the file.
    (gimp-message (string-append _"Exported palette to file: " result-path))

    result-path))


; Filters a string from all the characters which are not alpha-numeric
; (this also removes whitespaces)
(define (name-alpha-numeric str)
  (clean str '())
  )

; This function does the same as name-alpha-numeric, with an added
; operation - it removes any numbers from the beginning
(define (name-standard str)
  (let ((cleaned (clean str '())))
    (while (char-numeric? (string-ref cleaned 0))
           (set! cleaned (substring cleaned 1))
           )
    cleaned
    )
  )

(define name-no-conversion (lambda (obj) obj))
(define color-none (lambda (x) ""))
(define name-none (lambda (x) ""))

(define displayln (lambda (obj) (display obj) (display "\n")))

; The loop for exporting all the colors
(define (export-palette palette ; since v3, palette is numeric ID
                        color-convertor name-convertor
                        start name-pre name-after name-color-seperator
                        color-pre color-after entry-seperator end)

  (define (write-color-line index)
    (display name-pre)
    (display (name-convertor (gimp-palette-entry-get-name palette index)))
    (display name-after)
    (display name-color-seperator)
    (display color-pre)
    (display (color-convertor (gimp-palette-entry-get-color palette index)))
    (display color-after)
    )

  (let ((color-count (gimp-palette-get-color-count palette))
        (i 0))

    (display start)

    (while (< i (- color-count 1))
           (begin
             (write-color-line i)
             (display entry-seperator)
             (set! i (+ 1 i))
             )
           )

    (write-color-line i)
    (display end)
    )
  )

; -----------
; Methods for getting palette and its name from context.
; These plugins are in the RMB pop-up menu of the Palettes dockable.
; User clicking RMB on a palette puts it in the Gimp context i.e chooses it.
; The palette is not actually passed as an arg to these plugins.
; -----------

; Return numeric ID of palette in context.
(define (palette-in-context) (gimp-context-get-palette))

; Return name of palette in context.
; Since v3, resources in ScriptFu have numeric ID, not a string
(define (palette-name-in-context)(gimp-resource-get-name (palette-in-context)))


; -----------
; Register exporter as run-function of a plugin.
; -----------

(define (register-palette-exporter
	        export-type export-name file-type description author copyright date)
  (script-fu-register (string-append "gimp-palette-export-" export-type)
                      export-name
                      description
                      author
                      copyright
                      date
                      ""
                      SF-DIRNAME _"Folder for the output file" ""
                      SF-STRING _"The name of the file to create (if a file with this name already exist, it will be replaced)"
                      (string-append "palette." file-type)
                      )
  (script-fu-menu-register (string-append "gimp-palette-export-" export-type)
                           "<Palettes>/Palettes Menu/Export as")
  )

; -----------------------------------------------------------------------------
; Exporters
; Run functions of the plugins.
; -----------------------------------------------------------------------------

(define (gimp-palette-export-css directory-name file-name)
  (script-fu-use-v3)
  (let ((path (get-path-or-abort directory-name file-name)))
    (with-output-to-file path
      (lambda () (export-palette (palette-in-context)
                                  color-rgb-to-css
                                  name-alpha-numeric        ; name-convertor
                                  "/* Generated with GIMP Palette Export */\n" ; start
                                  "."                       ; name-pre
                                  ""                        ; name-after
                                  " { "                     ; name-color-seperator
                                  "color: "                 ; color-pre
                                  " }"                      ; color-after
                                  "\n"                      ; entry-seperator
                                  ""                        ; end
                                  )))))

(register-palette-exporter "css" _"_CSS stylesheet..." "css"
                           (string-append _"Export the active palette as a CSS stylesheet with the color entry name as their class name, and the color itself as the color attribute")
                           "Barak Itkin" "Barak Itkin" "May 15, 2009")

(define (gimp-palette-export-php directory-name file-name)
  (script-fu-use-v3)
  (let ((path (get-path-or-abort directory-name file-name)))
    (with-output-to-file path
      (lambda () (export-palette (palette-in-context)
                                  color-rgb-to-hexa-decimal
                                  name-standard             ; name-convertor
                                  "<?php\n/* Generated with GIMP Palette Export */\n$colors={\n" ; start
                                  "'"                       ; name-pre
                                  "'"                       ; name-after
                                  " => "                    ; name-color-seperator
                                  "'"                       ; color-pre
                                  "'"                       ; color-after
                                  ",\n"                     ; entry-seperator
                                  "}\n?>"                 ; end
                                  )))))

(register-palette-exporter "php" _"P_HP dictionary..." "php"
                           _"Export the active palette as a PHP dictionary (name => color)"
                           "Barak Itkin" "Barak Itkin" "May 15, 2009")

(define (gimp-palette-export-python directory-name file-name)
  (script-fu-use-v3)
  (let ((path (get-path-or-abort directory-name file-name)))
    (with-output-to-file path
      (lambda ()
        (displayln "# Generated with GIMP Palette Export")
        (displayln (string-append
          "# Based on the palette " (palette-name-in-context)))
        (export-palette (palette-in-context)
                        color-rgb-to-hexa-decimal
                        name-standard             ; name-convertor
                        "colors={\n"              ; start
                        "'"                       ; name-pre
                        "'"                       ; name-after
                        ": "                      ; name-color-seperator
                        "'"                       ; color-pre
                        "'"                       ; color-after
                        ",\n"                     ; entry-seperator
                        "}"                       ; end
                        )))))

(register-palette-exporter "python" _"_Python dictionary..." "py"
                           _"Export the active palette as a Python dictionary (name: color)"
                           "Barak Itkin" "Barak Itkin" "May 15, 2009")

(define (gimp-palette-export-text directory-name file-name)
  (script-fu-use-v3)
  (let ((path (get-path-or-abort directory-name file-name)))
    (with-output-to-file path
      (lambda ()
        (export-palette (palette-in-context)
                        color-rgb-to-hexa-decimal
                        name-none                 ; name-convertor
                        ""                        ; start
                        ""                        ; name-pre
                        ""                        ; name-after
                        ""                        ; name-color-seperator
                        ""                        ; color-pre
                        ""                        ; color-after
                        "\n"                      ; entry-seperator
                        ""                        ; end
                        )))))

(register-palette-exporter "text" _"_Text file..." "txt"
                           _"Write all the colors in a palette to a text file, one hexadecimal value per line (no names)"
                           "Barak Itkin" "Barak Itkin" "May 15, 2009")

(define (gimp-palette-export-java directory-name file-name)
  (script-fu-use-v3)
  (let ((path (get-path-or-abort directory-name file-name)))
    (with-output-to-file path
      (lambda ()
        (let ((palette-name (palette-name-in-context)))
          (displayln "")
          (displayln "import java.awt.Color;")
          (displayln "import java.util.Hashtable;")
          (displayln "")
          (displayln "// Generated with GIMP palette Export ")
          (displayln (string-append
            "// Based on the palette " palette-name))
          (displayln (string-append
              "public class "
              (name-standard palette-name) " {"))
          (displayln "")
          (displayln "    Hashtable<String, Color> colors;")
          (displayln "")
          (displayln (string-append
            "    public "
            (name-standard palette-name) "() {"))
          (export-palette (palette-in-context)
                          color-rgb-to-comma-separated-list
                          name-no-conversion
                          "        colors = new Hashtable<String,Color>();\n" ; start
                          "        colors.put(\""                             ; name-pre
                          "\""                                                ; name-after
                          ", "                                                ; name-color-seperator
                          "new Color"                                         ; color-pre
                          ");"                                                ; color-after
                          "\n"                                                ; entry-seperator
                          "\n    }"                                           ; end
                          )
          (display "\n}"))))))

(register-palette-exporter "java" _"J_ava map..." "java"
                           _"Export the active palette as a java.util.Hashtable&lt;String,Color&gt;"
                           "Barak Itkin" "Barak Itkin" "May 15, 2009")