edraw-util.el

;;; edraw-util.el ---                                -*- lexical-binding: t; -*-

;; Copyright (C) 2021 AKIYAMA Kouhei

;; Author: AKIYAMA Kouhei <misohena.jp>
;; Keywords: Graphics, Drawing, SVG

;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with this program.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;; 

;;; Code:

(require 'cl-lib)
(require 'seq)
(require 'subr-x)
(require 'edraw-msg)

;;;; Customize

(defgroup edraw nil
  "A drawing environment that runs within Emacs."
  :tag "Edraw"
  :prefix "edraw-"
  :group 'multimedia)


;;;; Clipboard

(defvar edraw-clipboard-type-data nil)

(defun edraw-clipboard-set (type data)
  (setq edraw-clipboard-type-data (cons type data)))

(defun edraw-clipboard-empty-p ()
  (null edraw-clipboard-type-data))

(defun edraw-clipboard-type ()
  (car edraw-clipboard-type-data))

(defun edraw-clipboard-data ()
  (cdr edraw-clipboard-type-data))

;;;; gzip

(defconst edraw-detect-coding-system-p nil)

(defun edraw-decode-coding-region (begin end &optional coding-system)
  (decode-coding-region
   begin end
   (if edraw-detect-coding-system-p
       (detect-coding-region begin end t)
     (or coding-system 'utf-8))))

(defun edraw-shell-command-on-buffer (command)
  (let ((error-buffer "*edraw gzip error*"))
    (when (/= 0 (shell-command-on-region
                 (point-min) (point-max) command nil t error-buffer t))
      (error (format "%s error" command)))))

(defun edraw-gunzip-buffer (&optional coding-system)
  (when (edraw-buffer-gzip-p)
    (if (zlib-available-p)
        (progn
          (set-buffer-multibyte nil)
          (zlib-decompress-region (point-min) (point-max))
          (edraw-decode-coding-region (point-min) (point-max) coding-system)
          (set-buffer-multibyte t))
      (let ((coding-system-for-read 'no-conversion)
            (coding-system-for-write 'no-conversion))
        (edraw-shell-command-on-buffer "gunzip")
        (edraw-decode-coding-region (point-min) (point-max) coding-system)))))

(defun edraw-gzip-buffer (&optional coding-system)
  (let ((coding-system-for-read 'no-conversion)
        (coding-system-for-write (or coding-system 'utf-8)))
    (edraw-shell-command-on-buffer "gzip")))

(defun edraw-buffer-gzip-p ()
  ;; gzip's magic number 1f 8b
  (and
   (>= (- (point-max) (point-min)) 2)
   (= (multibyte-char-to-unibyte (char-after (+ (point-min) 0))) #x1f)
   (= (multibyte-char-to-unibyte (char-after (+ (point-min) 1))) #x8b)))

;;;; gzip & base64

(defun edraw-decode-buffer (base64-p &optional coding-system)
  (when base64-p
    (base64-decode-region (point-min) (point-max))
    (unless (edraw-buffer-gzip-p)
      (edraw-decode-coding-region (point-min) (point-max) coding-system)))
  (when (edraw-buffer-gzip-p)
    (edraw-gunzip-buffer)))

(defun edraw-encode-buffer (base64-p gzip-p &optional coding-system)
  (when gzip-p
    (edraw-gzip-buffer))
  (when base64-p
    (unless gzip-p
      (encode-coding-region (point-min) (point-max) (or coding-system 'utf-8)))
    (base64-encode-region (point-min) (point-max) t)))

(defun edraw-decode-string (data base64-p &optional coding-system)
  (with-temp-buffer
    (insert data)
    (edraw-decode-buffer base64-p coding-system)
    (buffer-string)))

(defun edraw-encode-string (data base64-p gzip-p coding-system)
  (with-temp-buffer
    (insert data)
    (edraw-encode-buffer base64-p gzip-p coding-system)
    (buffer-string)))


;;;; Menu UI

(defun edraw-y-or-n-p (prompt)
  (x-popup-menu
   t
   (list prompt
         (cons ""
               (list (cons (edraw-msg "Yes") t)
                     (cons (edraw-msg "No") nil))))))

(defcustom edraw-popup-menu-style 'x
  "How to display menus."
  :group 'edraw
  :type '(choice (const :tag "Determine with `use-dialog-box-p'" nil)
                 (const :tag "Use `tmm-prompt'" tmm)
                 (const :tag "Use `x-popup-menu'" x)))

(defun edraw-popup-menu-style ()
  (if (memq edraw-popup-menu-style '(x tmm))
      edraw-popup-menu-style
    (if (if (fboundp 'use-dialog-box-p) ;; Emacs 28 or later
            (use-dialog-box-p)
          ;; Emacs 27 behavior
          (and (display-popup-menus-p)
               last-input-event
               (listp last-nonmenu-event)
               use-dialog-box))
        'x
      'tmm)))

(defun edraw-popup-menu (name items &rest args)
  (if (eq (edraw-popup-menu-style) 'tmm)
      (edraw-popup-menu--tmm name items args)
    (edraw-popup-menu--x name items args)))

(defun edraw-popup-menu--x-position ()
  (let* ((pos (event-start last-input-event))
         (xy (posn-x-y pos)))
    (list (list (car xy) (cdr xy)) (posn-window pos))))

(defun edraw-popup-menu--x (name items args)
  (let* ((menu-map (edraw-make-menu-map name items))
         (events (x-popup-menu (edraw-popup-menu--x-position) menu-map))
         (fn (lookup-key menu-map (apply 'vector events))))
    (cond
     ((commandp fn)
      (call-interactively fn))
     ((functionp fn)
      (apply fn args)))))

(defun edraw-popup-menu--tmm (name items args)
  (let* ((menu-map (edraw-make-menu-map name items))
         (fn (tmm-prompt menu-map nil nil t)))
    (cond
     ((commandp fn)
      (call-interactively fn))
     ((functionp fn)
      (apply fn args)))))


(defun edraw-popup-menu-call-interactively (name items)
  (let* ((menu-map (edraw-make-menu-map name items))
         (events (x-popup-menu t menu-map))
         (fn (lookup-key menu-map (apply 'vector events))))
    (when (functionp fn)
      (call-interactively fn))))

(defun edraw-make-menu-map (name items)
  ;; Support name=nil items=("Main Menu" ((item1) (item2)...)) format
  ;;   => name="Main Menu" items=((item1) (item2)...)
  (when (stringp (car items))
    (unless name
      (setq name (car items)))
    (setq items (cadr items)))

  (nconc
   (list 'keymap)
   ;; Menu Name
   (when name
     (list
      (if (and (consp name) (functionp (car name)))
          (eval name)
        name)))
   ;; Items
   (cl-loop with result = nil
            for (item-name binding . props) in items
            for id from 0
            for key = (intern (format "item%s" id))
            ;; Remove invisible item
            when (if-let ((visible (plist-member props :visible)))
                     (progn
                       ;; Remove :visible property
                       (setq props (edraw-plist-remove props :visible))
                       ;; Eval visible property
                       (eval (cadr visible)))
                   t)
            do
            (cond
             ;; ("--<???>" nil . <properties>) => Separator
             ((and (stringp item-name)
                   (string-prefix-p "--" item-name)
                   (null binding))
              (push (nconc (list key 'menu-item item-name binding) props)
                    result))
             ;; (<item-name> nil . <properties>) => Ignore
             ((null binding) )
             ;; (<item-name> <function> . <properties>)
             ((or (symbolp binding) (functionp binding))
              (push (nconc (list key 'menu-item item-name binding) props)
                    result))
             ;; (<item-name> <submenu> . <properties>)
             ((listp binding)
              (let ((sub-km (edraw-make-menu-map nil binding)))
                (when (cdr sub-km)
                  (push (nconc (list key 'menu-item item-name sub-km) props)
                        result))))
             (t (error "Unkonwn menu item binding %s"
                       (prin1-to-string binding))))
            finally return (nreverse result))))



;;;; Emacs UI Utility

;;
;;

(defun edraw-track-dragging (down-event on-move
                                        &optional on-up on-leave target
                                        allow-pointer-shape-change-p
                                        allow-out-of-target-p)
  (if (not (memq 'down (event-modifiers down-event)))
      (error "down-event is not down event. %s" (event-modifiers down-event)))
  (let* ((down-basic-type (event-basic-type down-event))
         (down-position (event-start down-event)))

    (track-mouse
      (unless allow-pointer-shape-change-p
        (setq track-mouse 'dragging))
      (let (result)
        (while (null result)
          (let ((event (let (;; Suppress display of events
                             ;; (e.g. down-mouse-1-) in echo area
                             (echo-keystrokes 0))
                         (read-event))))
            (cond
             ;; Ignore switch-frame event
             ;; (For Ubuntu 22/Emacs 27.1, To allow dragging in child frames)
             ((eq (car-safe event) 'switch-frame))
             ;; mouse move
             ((mouse-movement-p event)
              ;; check same object
              (if (or allow-out-of-target-p
                      (edraw-posn-same-object-p (event-start event)
                                                down-position
                                                target))
                  (if on-move (funcall on-move event))
                ;; out of target
                (if on-up (funcall on-leave event))
                (setq result event)))
             ;; mouse up
             ((and (eq (event-basic-type event) down-basic-type)
                   (or (memq 'click (event-modifiers event))
                       (memq 'drag (event-modifiers event))))
              (if on-up (funcall on-up event))
              (setq result event))
             ;; otherwise
             (t
              (if on-up (funcall on-up event))
              (setq result event)
              (push (cons t event) unread-command-events)))))
        result))))

(defun edraw-posn-same-object-p (pos1 pos2 &optional target)
  (and (eq (posn-window pos1)
           (posn-window pos2))
       (if (memq target '(point object nil))
           (equal (posn-point pos1)
                  (posn-point pos2))
         t)
       (if (memq target '(object nil))
           (eq (car (posn-object pos1)) ;;ex: 'image
               (car (posn-object pos2))) ;;ex: 'image
         t)))

;;;; Input Event Coordinates

(defun edraw-posn-x-y-on-frame (position &optional default-inside-window-p)
  "Convert POSITION to frame coordinates.

POSITION should be a list of the form returned by `event-start'
and `event-end'.

If area of POSITION is an unknown location and
DEFAULT-INSIDE-WINDOW-P is non-nil, the event is assumed to be
within window and the result is returned. If it is nil, it
returns nil."
  (let* ((window-or-frame (posn-window position))
         (window (and (windowp window-or-frame) window-or-frame))
         (area (posn-area position))
         (xy (posn-x-y position))
         (x (car xy))
         (y (cdr xy)))
    (cond
     (window
      (let ((edges (cond
                    ((null area)
                     (window-inside-pixel-edges window))
                    ((memq area '(horizontal-scroll-bar
                                  mode-line header-line tab-line))
                     (window-pixel-edges window))
                    ((memq area '(left-margin
                                  left-fringe
                                  ;; Right
                                  right-fringe
                                  right-margin
                                  vertical-line
                                  vertical-scroll-bar))
                     (let ((win (window-pixel-edges window))
                           (ins (window-inside-pixel-edges window)))
                       ;; Just to make sure, do the processing when
                       ;; x is not a number.
                       (unless (numberp x)
                         (setq x (if (memq area '(left-margin left-fringe))
                                     (nth 0 ins)
                                   (nth 2 ins))))
                       ;; x=win, y=ins
                       ;; NOTE: Elisp manual says "x does not have
                       ;; meaningful data" But at least in
                       ;; MS-Windows x means the coordinate from the
                       ;; left edge of the window.
                       (list (nth 0 win) (nth 1 ins)
                             (nth 2 win) (nth 3 ins))))
                    (default-inside-window-p
                     (window-inside-pixel-edges window)))))
        (when edges
          (cons (+ x (car edges))
                (+ y (cadr edges))))))
     ((framep window-or-frame)
      xy))))

(defun edraw-posn-delta-xy-frame-to-object (down-pos)
  "Calculate coordinate delta from frame to image."
  (let* ((down-xy-on-frame (edraw-posn-x-y-on-frame down-pos))
         (down-xy-on-object (posn-object-x-y down-pos)))
    (and down-xy-on-frame
         (cons (- (car down-xy-on-object) (car down-xy-on-frame))
               (- (cdr down-xy-on-object) (cdr down-xy-on-frame))))))


;;;; Input Event Modifiers

(defun edraw-event-mouse-modifiers (event)
  (seq-remove (lambda (m) (not (memq m '(click double triple drag down))))
              (event-modifiers event)))

(defun edraw-event-key-modifiers (event)
  (seq-remove (lambda (m) (not (memq m '(meta control shift hyper super alt))))
              (event-modifiers event)))

(defun edraw-event-key-modifiers-equal (event modifiers)
  (seq-set-equal-p
   (edraw-event-key-modifiers event)
   modifiers))

(defun edraw-event-modifiers-symbol (event)
  (edraw-make-event-modifiers-symbol (event-modifiers event)))

(defun edraw-make-event-modifiers-symbol (modifiers)
  (let ((modifier-symbols '(alt control hyper meta shift super
                                double triple
                                drag down click))
        (modifier-strings '("A" "C" "H" "M" "S" "s"
                            "double" "triple" "drag" "down" "click"))
        (code 0))
    (cl-loop for m in modifiers
             for pos = (seq-position modifier-symbols m #'eq)
             when pos do (setq code (logior code (ash 1 pos))))
    (when (/= code 0)
      (intern
       (cl-loop with str = nil
                for s in modifier-strings
                for bit = 1 then (ash bit 1)
                when (/= (logand code bit) 0)
                if str do (setq str (concat str "-" s)) else do (setq str s)
                finally return str)))))



;;;; Hook Utility

;; - Hooks deleted during callback will never be called.
;; - Hooks added during the callback will never be called until next time.
;; - To determine the equivalence when removing the hook, use the eq function
;;  to determine the combination of the function and additional arguments.

(defun edraw-hook-make ()
  (cons 0 nil)) ;;(re-entry-count . function-list)

(defun edraw-hook-add (hook function &rest args)
  ;; push front only
  (setcdr hook (cons (cons function args) (cdr hook))))

(defun edraw-hook-remove (hook function &rest args)
  (edraw-hook-mark-delete hook (cons function args))
  (edraw-hook-sweep hook))

(defun edraw-hook-length (hook)
  (length (cdr hook)))

(defun edraw-hook-mark-delete (hook function-args)
  (let ((p (cdr hook)))
    (while p
      ;; eq function and eq args
      (when (and (= (length function-args) (length (car p)))
                 (cl-every 'eq function-args (car p)))
        (setcar p nil))
      (setq p (cdr p)))))

(defun edraw-hook-sweep (hook)
  (when (= (car hook) 0)
    (setcdr hook (delq nil (cdr hook)))))

(defun edraw-hook-call (hook &rest args)
  (cl-incf (car hook))
  (unwind-protect
      (let ((p (cdr hook)))
        (while p
          (when (car p)
            (apply (caar p) (append (cdar p) args)))
          (setq p (cdr p))))
    (cl-decf (car hook)))
  (edraw-hook-sweep hook))



;;;; List Structure

(cl-defstruct (edraw-list
               (:constructor edraw-list-construct))
  (data nil))

(defun edraw-list (&optional list)
  (edraw-list-construct :data (mapcar #'identity list)))

(cl-defmethod edraw-assign ((list edraw-list) sequence)
  (setf (edraw-list-data list) (mapcar #'identity sequence))
  list)

(cl-defmethod edraw-clear ((list edraw-list))
  (setf (edraw-list-data list) nil)
  list)

(cl-defmethod edraw-length ((list edraw-list))
  (length (edraw-list-data list)))

(cl-defmethod edraw-empty-p ((list edraw-list))
  (null (edraw-list-data list)))

(cl-defmethod edraw-push-front ((list edraw-list) element)
  (push element (edraw-list-data list))
  element)

(cl-defmethod edraw-pop-front ((list edraw-list))
  (pop (edraw-list-data list)))

(cl-defmethod edraw-front ((list edraw-list))
  (car (edraw-list-data list)))

(cl-defmethod edraw-shrink ((list edraw-list) n)
  (if (< n 1)
      (edraw-clear list)
    (when-let ((cell (nthcdr (1- n) (edraw-list-data list))))
      (setcdr cell nil)))
  list)

(cl-defmethod edraw-resize ((list edraw-list) n)
  (if (< n 1)
      (edraw-clear list)
    (let ((size (edraw-length list)))
      (cond
       ((< n size)
        (setcdr (nthcdr (1- n) (edraw-list-data list)) nil))
       ((> n size)
        (nconc (edraw-list-data list) (make-list (- n size) nil))))))
  list)

(cl-defmethod edraw-remove-if ((list edraw-list) predicate)
  (setf (edraw-list-data list)
        (cl-remove-if predicate (edraw-list-data list)))
  list)

(cl-defmethod edraw-nth ((list edraw-list) n)
  (nth n (edraw-list-data list)))



;;;; Property List

(defun edraw-plist-take-while (plist pred)
  (cl-loop for (k v) on plist by #'cddr
           while (funcall pred k v)
           collect k collect v))

(defun edraw-plist-remove (plist prop &optional predicate)
  "Return a property list with the property PROP removed from PLIST.

The original PLIST will not be modified.

The rest of the PLIST after the modified part is shared with the
returned list.

If there are multiple PROPs, the first one is removed.

If you want to make destructive changes to the list, consider
using `cl-remf'."
  (unless predicate (setq predicate #'eq))
  (if-let ((head (plist-member plist prop)))
      (nconc
       (edraw-plist-take-while plist (lambda (k _)
                                       (not (funcall predicate k prop))))
       (cddr head))
    plist))

(defun edraw-plist-put (plist prop value &optional predicate)
  "Return a plist with the PROP of PLIST changed to VALUE.
This is a non-destructive version of `plist-put'."
  (cons
   prop
   (cons
    value
    (edraw-plist-remove plist prop predicate))))

(defun edraw-plist-append (&rest plists)
  "Return a new plist by concatenating PLISTS and removing duplicates.

For duplicate properties, the first occurrence takes precedence.
Therefore, the following evaluation results will be the same:

- (plist-get (edraw-plist-append PLIST1 PLIST2) PROP)
- (plist-get (append PLIST1 PLIST2) PROP)"
  (let* ((head (cons nil nil))
         (last head))
    (cl-loop for plist in plists
             do (cl-loop for (key value) on plist by #'cddr
                         unless (plist-member (cdr head) key)
                         do (progn
                              (setcdr last (cons key (cons value nil)))
                              (setq last (cddr last)))))
    (cdr head)))
;; TEST: (edraw-plist-append) => nil
;; TEST: (edraw-plist-append  '(:a 1 :b 2 :a 3)) => (:a 1 :b 2)
;; TEST: (edraw-plist-append '(:a 1 :b 2) '(:c 3 :d 4)) => (:a 1 :b 2 :c 3 :d 4)
;; TEST: (edraw-plist-append '(:a 1 :b 2) '(:a 3 :d 4)) => (:a 1 :b 2 :d 4)
;; TEST: (edraw-plist-append nil '(:a 11 :b 22 :c 33 :d 44)) => (:a 11 :b 22 :c 33 :d 44)

(defun edraw-plist-to-alist (plist)
  (cl-loop for (prop value) on plist by #'cddr
           collect (cons prop value)))
;; TEST: (edraw-plist-to-alist nil) => nil
;; TEST: (edraw-plist-to-alist '(a 1 b 2)) => ((a . 1) (b . 2))

;;;; Association List

(defun edraw-alist-append (&rest alists)
  "Return a new alist by concatenating ALISTS and removing duplicates.

For duplicate keys, the first occurrence takes precedence.
Therefore, the following evaluation results will be the same:

- (alist-get (edraw-alist-append ALIST1 ALIST2) KEY)
- (alist-get (append ALIST1 ALIST2) PROP)"
  (let (result)
    (cl-loop for alist in alists
             do (cl-loop for cell in alist
                         unless (assq (car cell) result)
                         do (push cell result)))
    (nreverse result)))
;; TEST: (edraw-alist-append) => nil
;; TEST: (edraw-alist-append '((a . 1) (b . 2))) => ((a . 1) (b . 2))
;; TEST: (edraw-alist-append '((a . 1) (b . 2) (c . 3)) '((a . 11) (b . 22) (d . 44))) => ((a . 1) (b . 2) (c . 3) (d . 44))

(defun edraw-alist-to-plist (alist)
  (cl-loop for (key . value) in alist
           collect key collect value))
;; TEST (edraw-alist-to-plist nil) => nil
;; TEST (edraw-alist-to-plist '((a . 1) (b . 2))) => (a 1 b 2)


;;;; Max Image Size

(defun edraw-max-image-width ()
  "Return max image width in pixels."
  (defvar max-image-size)
  (let ((size max-image-size))
    (cond
     ((integerp size) size)
     ((floatp size) (round (* size (frame-pixel-width))))
     (t 1024))))

(defun edraw-max-image-height ()
  "Return max image height in pixels."
  (defvar max-image-size)
  (let ((size max-image-size))
    (cond
     ((integerp size) size)
     ((floatp size) (round (* size (frame-pixel-height))))
     (t 1024))))

;;;; Misc

(defun edraw-alist-get-as-number (key alist default)
  (let ((value (alist-get key alist default nil (if (stringp key) #'equal))))
    (if (stringp value)
        (string-to-number value)
      value)))

(cl-defmethod edraw-to-string ((str string))
  str)

(cl-defmethod edraw-to-string ((sym symbol))
  (symbol-name sym))

(cl-defmethod edraw-cast (obj type)
  (when (cl-typep obj type)
    obj))

(defun edraw-read-string-or-nil (prompt &optional initial-input)
  (let ((input (read-string prompt (or initial-input ""))))
    (if (string-empty-p input) nil input)))

(defun edraw-read-integer-or-nil (prompt &optional initial-input)
  (edraw-read-number prompt initial-input t t))

(defun edraw-read-number-or-nil (prompt &optional initial-input)
  (edraw-read-number prompt initial-input nil t))

(defun edraw-read-integer (prompt &optional initial-input)
  (edraw-read-number prompt initial-input t nil))

(defun edraw-read-number (prompt &optional initial-input integer-p nullable-p)
  (let ((pred (if integer-p #'integerp #'numberp))
        result)
    (while (let ((input (read-string
                         prompt
                         (format "%s" (or initial-input "")))))
             (not
              (if (string-empty-p input)
                  nullable-p
                (let ((value (ignore-errors (read input))))
                  (when (funcall pred value)
                    (setq result value)
                    t)))))
      (message
       (if nullable-p
           (if integer-p
               (edraw-msg "Please enter a integer or empty.")
             (edraw-msg "Please enter a number or empty."))
         (if integer-p
             (edraw-msg "Please enter a integer.")
           (edraw-msg "Please enter a number."))))
      (sit-for 1))
    result))

(defvar edraw-minibuffer-default-prompt-format
  (if (boundp 'minibuffer-default-prompt-format)
      minibuffer-default-prompt-format ;; Emacs 28.1~
    " (default %s)"))

(defconst edraw-minibuffer-number-regexp
  (concat "\\(?:"
          "[-+]?"
          ;; Valid: 12  12.34  .34  12.
          "\\(?:[0-9]+\\(?:\\.[0-9]*\\)?\\|\\.[0-9]+\\)"
          "\\(?:[eE][-+]?[0-9]+\\)?"
          "\\)"))

(defun edraw-read-number-with-unit--convert (input-string default units pred
                                                          regexp)
  (cond
   ((and default (string-empty-p input-string))
    default)
   ((string-match regexp input-string)
    (let ((num (string-to-number (match-string 1 input-string)))
          (unit (match-string 2 input-string)))
      ;; Unit conversion
      (when unit
        (let ((conv (alist-get unit units nil nil #'equal)))
          (cond
           ((numberp conv)
            (setq num (* conv num)))
           ((functionp conv)
            (setq num (funcall conv num default)))
           (t
            (error (edraw-msg "Unsupported unit"))))))
      ;; Validation
      (when (and num pred (not (funcall pred num)))
        (error (edraw-msg "Invalid number")))
      num))
   (t
    (error (edraw-msg "Not a number")))))

(defun edraw-read-number-with-unit--read (prompt default units pred regexp)
  "Almost the same as read-string, but with a preview of the result."
  (let* (overlay
         (on-post-command
          (lambda ()
            (let* ((curr-input
                    (minibuffer-contents-no-properties))
                   (curr-result
                    (format
                     "%s"
                     (condition-case err
                         (edraw-read-number-with-unit--convert
                          curr-input default units pred regexp)
                       (error (error-message-string err))))))
              (overlay-put
               overlay 'before-string
               (if (or (equal curr-input curr-result)
                       (string-empty-p curr-input))
                   nil
                 (propertize
                  (concat curr-result " <= ")
                  'face 'font-lock-comment-face))))))
         (on-minibuffer-setup
          (lambda ()
            (setq overlay (make-overlay (minibuffer-prompt-end)
                                        (point-max)
                                        nil nil t))
            (add-hook 'post-command-hook on-post-command nil t)))
         (minibuffer-setup-hook (cons on-minibuffer-setup
                                      minibuffer-setup-hook)))
    (unwind-protect
        (read-from-minibuffer prompt nil nil nil nil
                              (when default (number-to-string default)))
      (when overlay
        (delete-overlay overlay)))))

(defun edraw-read-number-with-unit (prompt &optional default units pred)
  (let ((result nil)
        (regexp (concat "\\`\\(" edraw-minibuffer-number-regexp "\\)"
                        (when units
                          (concat
                           "\\(" (mapconcat #'car units "\\|") "\\)?\\'")))))

    (when default
      (string-match "\\(?:\\(\\):\\)?\\([ \t]*\\)\\'" prompt)
      (setq prompt
            (replace-match
             (format edraw-minibuffer-default-prompt-format default) t t prompt
             (if (match-beginning 1) 1 0))))

    (while
        (null
         (setq result
               (let ((str (edraw-read-number-with-unit--read
                           prompt default units pred regexp)))
                 (condition-case err
                     (edraw-read-number-with-unit--convert str default units
                                                           pred regexp)
                   (error
                    (message "%s" (error-message-string err))
                    (sit-for 1)
                    nil))))))
    result))
;; Example: (edraw-read-number-with-unit "Length (px, %): " 640 '(("%" . (lambda (n def) (round (/ (* n def) 100.0)))) ("px" . (lambda (n _) n))) (lambda (n) (or (integerp n) (error "Not a integer"))))


(defun edraw-where-is-string (definition &optional keymap firstonly)
  (when-let ((keys (where-is-internal definition keymap firstonly)))
    (if (listp keys)
        (mapcar #'key-description keys)
      (key-description keys))))

(provide 'edraw-util)
;;; edraw-util.el ends here