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Diffstat (limited to 'tools/emacs-pkgs/notable/notable.el')
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diff --git a/tools/emacs-pkgs/notable/notable.el b/tools/emacs-pkgs/notable/notable.el new file mode 100644 index 0000000000..4668dd333c --- /dev/null +++ b/tools/emacs-pkgs/notable/notable.el @@ -0,0 +1,251 @@ +;;; notable.el --- a simple note-taking app -*- lexical-binding: t; -*- +;; +;; Copyright (C) 2020 The TVL Contributors +;; +;; Author: Vincent Ambo <mail@tazj.in> +;; Version: 1.0 +;; Package-Requires: (cl-lib dash f rx s subr-x) +;; +;;; Commentary: +;; +;; This package provides a simple note-taking application which can be +;; invoked from anywhere in Emacs, with several interactive +;; note-taking functions included. +;; +;; As is tradition for my software, the idea here is to reduce +;; friction which I see even with tools like `org-capture', because +;; `org-mode' does a ton of things I don't care about. +;; +;; Notable stores its notes in simple JSON files in the folder +;; specified by `notable-note-dir'. + +(require 'cl-lib) +(require 'dottime) +(require 'f) +(require 'ht) +(require 'rx) +(require 's) +(require 'subr-x) + +;; User-facing customisation options + +(defgroup notable nil + "Simple note-taking application." + :group 'applications) + +;; TODO(tazjin): Use whatever the XDG state dir thing is for these by +;; default. +(defcustom notable-note-dir (expand-file-name "~/.notable/") + "File path to the directory containing notable's notes." + :type 'string + :group 'notable) + +;; Package internal definitions + +(cl-defstruct (notable--note (:constructor notable--make-note)) + "Structure containing the fields of a single notable note." + time ;; UNIX timestamp at which the note was taken + content ;; Textual content of the note + ) + +(defvar notable--note-lock (make-mutex "notable-notes") + "Exclusive lock for note operations with shared state.") + +(defvar notable--note-regexp + (rx "note-" + (group (one-or-more (any num))) + ".json") + "Regular expression to match note file names.") + +(defvar notable--next-note + (let ((next 0)) + (dolist (file (f-entries notable-note-dir)) + (when-let* ((match (string-match notable--note-regexp file)) + (id (string-to-number + (match-string 1 file))) + (larger (> id next))) + (setq next id))) + (+ 1 next)) + "Next ID to use for notes. Initial value is determined based on + the existing notes files.") + +(defun notable--serialize-note (note) + "Serialise NOTE into JSON format." + (check-type note notable--note) + (json-serialize (ht ("time" (notable--note-time note)) + ("content" (notable--note-content note))))) + +(defun notable--deserialize-note (json) + "Deserialise JSON into a notable note." + (check-type json string) + (let ((parsed (json-parse-string json))) + (unless (and (ht-contains? parsed "time") + (ht-contains-p parsed "content")) + (error "Missing required keys in note structure!")) + (notable--make-note :time (ht-get parsed "time") + :content (ht-get parsed "content")))) + +(defun notable--next-id () + "Return the next note ID and increment the counter." + (with-mutex notable--note-lock + (let ((id notable--next-note)) + (setq notable--next-note (+ 1 id)) + id))) + +(defun notable--note-path (id) + (check-type id integer) + (f-join notable-note-dir (format "note-%d.json" id))) + +(defun notable--archive-path (id) + (check-type id integer) + (f-join notable-note-dir (format "archive-%d.json" id))) + +(defun notable--add-note (content) + "Add a note with CONTENT to the note store." + (let* ((id (notable--next-id)) + (note (notable--make-note :time (time-convert nil 'integer) + :content content)) + (path (notable--note-path id))) + (when (f-exists? path) (error "Note file '%s' already exists!" path)) + (f-write-text (notable--serialize-note note) 'utf-8 path) + (message "Saved note %d" id))) + +(defun notable--archive-note (id) + "Archive the note with ID." + (check-type id integer) + + (unless (f-exists? (notable--note-path id)) + (error "There is no note with ID %d." id)) + + (when (f-exists? (notable--archive-path id)) + (error "Oh no, a note with ID %d has already been archived!" id)) + + (f-move (notable--note-path id) (notable--archive-path id)) + (message "Archived note with ID %d." id)) + +(defun notable--list-note-ids () + "List all note IDs (not contents) from `notable-note-dir'" + (cl-loop for file in (f-entries notable-note-dir) + with res = nil + if (string-match notable--note-regexp file) + do (push (string-to-number (match-string 1 file)) res) + finally return res)) + +(defun notable--get-note (id) + (let ((path (notable--note-path id))) + (unless (f-exists? path) + (error "No note with ID %s in note storage!" id)) + (notable--deserialize-note (f-read-text path 'utf-8)))) + +;; Note view buffer implementation + +(defvar-local notable--buffer-note nil "The note ID displayed by this buffer.") + +(define-derived-mode notable-note-mode fundamental-mode "notable-note" + "Major mode displaying a single Notable note." + (set (make-local-variable 'scroll-preserve-screen-position) t) + (setq truncate-lines t) + (setq buffer-read-only t) + (setq buffer-undo-list t)) + +(setq notable-note-mode-map + (let ((map (make-sparse-keymap))) + (define-key map "q" 'kill-current-buffer) + map)) + +(defun notable--show-note (id) + "Display a single note in a separate buffer." + (check-type id integer) + + (let ((note (notable--get-note id)) + (buffer (get-buffer-create (format "*notable: %d*" id))) + (inhibit-read-only t)) + (with-current-buffer buffer + (notable-note-mode) + (erase-buffer) + (setq notable--buffer-note id) + (setq header-line-format + (format "Note from %s" + (dottime-format + (seconds-to-time (notable--note-time note)))))) + (switch-to-buffer buffer) + (goto-char (point-min)) + (insert (notable--note-content note)))) + +(defun notable--show-note-at-point () + (interactive) + (notable--show-note (get-text-property (point) 'notable-note-id))) + +(defun notable--archive-note-at-point () + (interactive) + (notable--archive-note (get-text-property (point) 'notable-note-id))) + +;; Note list buffer implementation + +(define-derived-mode notable-list-mode fundamental-mode "notable" + "Major mode displaying the Notable note list." + ;; TODO(tazjin): `imenu' functions? + + (set (make-local-variable 'scroll-preserve-screen-position) t) + (setq truncate-lines t) + (setq buffer-read-only t) + (setq buffer-undo-list t) + (hl-line-mode t)) + +(setq notable-list-mode-map + (let ((map (make-sparse-keymap))) + (define-key map "a" 'notable--archive-note-at-point) + (define-key map "q" 'kill-current-buffer) + (define-key map "g" 'notable-list-notes) + (define-key map (kbd "RET") 'notable--show-note-at-point) + map)) + +(defun notable--render-note (id note) + (check-type id integer) + (check-type note notable--note) + + (let* ((start (point)) + (date (dottime-format (seconds-to-time + (notable--note-time note)))) + (first-line (truncate-string-to-width + (car (s-lines (notable--note-content note))) + ;; Length of the window, minus the date prefix: + (- (window-width) (+ 2 (length date))) + nil nil 1))) + (insert (propertize (s-concat date " " first-line) + 'notable-note-id id)) + (insert "\n"))) + +(defun notable--render-notes (notes) + "Retrieve each note in NOTES by ID and insert its contents into +the list buffer. + +For larger notes only the first line is displayed." + (dolist (id notes) + (notable--render-note id (notable--get-note id)))) + +;; User-facing functions + +(defun notable-take-note (content) + "Interactively prompt the user for a note that should be stored +in Notable." + (interactive "sEnter note: ") + (check-type content string) + (notable--add-note content)) + +(defun notable-list-notes () + "Open a buffer listing all active notes." + (interactive) + + (let ((buffer (get-buffer-create "*notable*")) + (notes (notable--list-note-ids)) + (inhibit-read-only t)) + (with-current-buffer buffer + (notable-list-mode) + (erase-buffer) + (setq header-line-format "Notable notes")) + (switch-to-buffer buffer) + (goto-char (point-min)) + (notable--render-notes notes))) + +(provide 'notable) |