;;; guix-buffer.el --- Buffer interface for displaying data -*- lexical-binding: t -*- ;; Copyright © 2014, 2015 Alex Kost <alezost@gmail.com> ;; This file is part of GNU Guix. ;; GNU Guix 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. ;; GNU Guix 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 <http://www.gnu.org/licenses/>. ;;; Commentary: ;; This file provides a general 'buffer' interface for displaying an ;; arbitrary data. ;;; Code: (require 'cl-lib) (require 'guix-history) (require 'guix-utils) (defvar guix-buffer-map (let ((map (make-sparse-keymap))) (define-key map (kbd "l") 'guix-history-back) (define-key map (kbd "r") 'guix-history-forward) (define-key map (kbd "g") 'revert-buffer) (define-key map (kbd "R") 'guix-buffer-redisplay) map) "Parent keymap for Guix buffer modes.") ;;; Buffer item (cl-defstruct (guix-buffer-item (:constructor nil) (:constructor guix-buffer-make-item (entries buffer-type entry-type args)) (:copier nil)) entries buffer-type entry-type args) (defvar-local guix-buffer-item nil "Data (structure) for the current Guix buffer. The structure consists of the following elements: - `entries': list of the currently displayed entries. Each element of the list is an alist with an entry data of the following form: ((PARAM . VAL) ...) PARAM is a name of the entry parameter. VAL is a value of this parameter. - `entry-type': type of the currently displayed entries. - `buffer-type': type of the current buffer. - `args': search arguments used to get the current entries.") (put 'guix-buffer-item 'permanent-local t) (defmacro guix-buffer-with-item (item &rest body) "Evaluate BODY using buffer ITEM. The following local variables are available inside BODY: `%entries', `%buffer-type', `%entry-type', `%args'. See `guix-buffer-item' for details." (declare (indent 1) (debug t)) (let ((item-var (make-symbol "item"))) `(let ((,item-var ,item)) (let ((%entries (guix-buffer-item-entries ,item-var)) (%buffer-type (guix-buffer-item-buffer-type ,item-var)) (%entry-type (guix-buffer-item-entry-type ,item-var)) (%args (guix-buffer-item-args ,item-var))) ,@body)))) (defmacro guix-buffer-with-current-item (&rest body) "Evaluate BODY using `guix-buffer-item'. See `guix-buffer-with-item' for details." (declare (indent 0) (debug t)) `(guix-buffer-with-item guix-buffer-item ,@body)) (defmacro guix-buffer-define-current-item-accessor (name) "Define `guix-buffer-current-NAME' function to access NAME element of `guix-buffer-item' structure. NAME should be a symbol." (let* ((name-str (symbol-name name)) (accessor (intern (concat "guix-buffer-item-" name-str))) (fun-name (intern (concat "guix-buffer-current-" name-str))) (doc (format "\ Return '%s' of the current Guix buffer. See `guix-buffer-item' for details." name-str))) `(defun ,fun-name () ,doc (and guix-buffer-item (,accessor guix-buffer-item))))) (defmacro guix-buffer-define-current-item-accessors (&rest names) "Define `guix-buffer-current-NAME' functions for NAMES. See `guix-buffer-define-current-item-accessor' for details." `(progn ,@(mapcar (lambda (name) `(guix-buffer-define-current-item-accessor ,name)) names))) (guix-buffer-define-current-item-accessors entries entry-type buffer-type args) (defmacro guix-buffer-define-current-args-accessor (n prefix name) "Define `PREFIX-NAME' function to access Nth element of 'args' field of `guix-buffer-item' structure. PREFIX and NAME should be strings." (let ((fun-name (intern (concat prefix "-" name))) (doc (format "\ Return '%s' of the current Guix buffer. '%s' is the element number %d in 'args' of `guix-buffer-item'." name name n))) `(defun ,fun-name () ,doc (nth ,n (guix-buffer-current-args))))) (defmacro guix-buffer-define-current-args-accessors (prefix &rest names) "Define `PREFIX-NAME' functions for NAMES. See `guix-buffer-define-current-args-accessor' for details." `(progn ,@(cl-loop for name in names for i from 0 collect `(guix-buffer-define-current-args-accessor ,i ,prefix ,name)))) ;;; Wrappers for defined variables (defvar guix-buffer-data nil "Alist with 'buffer' data. This alist is filled by `guix-buffer-define-interface' macro.") (defun guix-buffer-value (buffer-type entry-type symbol) "Return SYMBOL's value for BUFFER-TYPE/ENTRY-TYPE from `guix-buffer-data'." (symbol-value (guix-assq-value guix-buffer-data buffer-type entry-type symbol))) (defun guix-buffer-get-entries (buffer-type entry-type args) "Return ENTRY-TYPE entries. Call an appropriate 'get-entries' function from `guix-buffer' using ARGS as its arguments." (apply (guix-buffer-value buffer-type entry-type 'get-entries) args)) (defun guix-buffer-mode-enable (buffer-type entry-type) "Turn on major mode to display ENTRY-TYPE ENTRIES in BUFFER-TYPE buffer." (funcall (guix-buffer-value buffer-type entry-type 'mode))) (defun guix-buffer-mode-initialize (buffer-type entry-type) "Set up the current BUFFER-TYPE buffer to display ENTRY-TYPE entries." (let ((fun (guix-buffer-value buffer-type entry-type 'mode-init))) (when fun (funcall fun)))) (defun guix-buffer-insert-entries (entries buffer-type entry-type) "Show ENTRY-TYPE ENTRIES in the current BUFFER-TYPE buffer." (funcall (guix-buffer-value buffer-type entry-type 'insert-entries) entries)) (defun guix-buffer-show-entries-default (entries buffer-type entry-type) "Show ENTRY-TYPE ENTRIES in the current BUFFER-TYPE buffer." (let ((inhibit-read-only t)) (erase-buffer) (guix-buffer-mode-enable buffer-type entry-type) (guix-buffer-insert-entries entries buffer-type entry-type) (goto-char (point-min)))) (defun guix-buffer-show-entries (entries buffer-type entry-type) "Show ENTRY-TYPE ENTRIES in the current BUFFER-TYPE buffer." (funcall (guix-buffer-value buffer-type entry-type 'show-entries) entries)) (defun guix-buffer-message (entries buffer-type entry-type args) "Display a message for BUFFER-ITEM after showing entries." (let ((fun (guix-buffer-value buffer-type entry-type 'message))) (when fun (apply fun entries args)))) (defun guix-buffer-name (buffer-type entry-type args) "Return name of BUFFER-TYPE buffer for displaying ENTRY-TYPE entries." (let ((str-or-fun (guix-buffer-value buffer-type entry-type 'buffer-name))) (if (stringp str-or-fun) str-or-fun (apply str-or-fun args)))) (defun guix-buffer-param-title (buffer-type entry-type param) "Return PARAM title for BUFFER-TYPE/ENTRY-TYPE." (or (guix-assq-value (guix-buffer-value buffer-type entry-type 'titles) param) ;; Fallback to a title defined in 'info' interface. (unless (eq buffer-type 'info) (guix-assq-value (guix-buffer-value 'info entry-type 'titles) param)) (guix-symbol-title param))) (defun guix-buffer-history-size (buffer-type entry-type) "Return history size for BUFFER-TYPE/ENTRY-TYPE." (guix-buffer-value buffer-type entry-type 'history-size)) (defun guix-buffer-revert-confirm? (buffer-type entry-type) "Return 'revert-confirm' value for BUFFER-TYPE/ENTRY-TYPE." (guix-buffer-value buffer-type entry-type 'revert-confirm)) ;;; Displaying entries (defun guix-buffer-display (buffer) "Switch to a Guix BUFFER." (pop-to-buffer buffer '((display-buffer-reuse-window display-buffer-same-window)))) (defun guix-buffer-history-item (buffer-item) "Make and return a history item for displaying BUFFER-ITEM." (list #'guix-buffer-set buffer-item)) (defun guix-buffer-set (buffer-item &optional history) "Set up the current buffer for displaying BUFFER-ITEM. HISTORY should be one of the following: `nil' - do not save BUFFER-ITEM in history, `add' - add it to history, `replace' - replace the current history item." (guix-buffer-with-item buffer-item (when %entries ;; Set buffer item before showing entries, so that its value can ;; be used by the code for displaying entries. (setq guix-buffer-item buffer-item) (guix-buffer-show-entries %entries %buffer-type %entry-type) (when history (funcall (cl-ecase history (add #'guix-history-add) (replace #'guix-history-replace)) (guix-buffer-history-item buffer-item)))) (guix-buffer-message %entries %buffer-type %entry-type %args))) (defun guix-buffer-display-entries-current (entries buffer-type entry-type args &optional history) "Show ENTRIES in the current Guix buffer. See `guix-buffer-item' for the meaning of BUFFER-TYPE, ENTRY-TYPE and ARGS, and `guix-buffer-set' for the meaning of HISTORY." (let ((item (guix-buffer-make-item entries buffer-type entry-type args))) (guix-buffer-set item history))) (defun guix-buffer-get-display-entries-current (buffer-type entry-type args &optional history) "Search for entries and show them in the current Guix buffer. See `guix-buffer-display-entries-current' for details." (guix-buffer-display-entries-current (guix-buffer-get-entries buffer-type entry-type args) buffer-type entry-type args history)) (defun guix-buffer-display-entries (entries buffer-type entry-type args &optional history) "Show ENTRIES in a BUFFER-TYPE buffer. See `guix-buffer-display-entries-current' for details." (let ((buffer (get-buffer-create (guix-buffer-name buffer-type entry-type args)))) (with-current-buffer buffer (guix-buffer-display-entries-current entries buffer-type entry-type args history)) (when entries (guix-buffer-display buffer)))) (defun guix-buffer-get-display-entries (buffer-type entry-type args &optional history) "Search for entries and show them in a BUFFER-TYPE buffer. See `guix-buffer-display-entries-current' for details." (guix-buffer-display-entries (guix-buffer-get-entries buffer-type entry-type args) buffer-type entry-type args history)) (defun guix-buffer-revert (_ignore-auto noconfirm) "Update the data in the current Guix buffer. This function is suitable for `revert-buffer-function'. See `revert-buffer' for the meaning of NOCONFIRM." (guix-buffer-with-current-item (when (or noconfirm (not (guix-buffer-revert-confirm? %buffer-type %entry-type)) (y-or-n-p "Update the current buffer? ")) (guix-buffer-get-display-entries-current %buffer-type %entry-type %args 'replace)))) (defvar guix-buffer-after-redisplay-hook nil "Hook run by `guix-buffer-redisplay'. This hook is called before seting up a window position.") (defun guix-buffer-redisplay () "Redisplay the current Guix buffer. Restore the point and window positions after redisplaying. This function does not update the buffer data, use '\\[revert-buffer]' if you want the full update." (interactive) (let* ((old-point (point)) ;; For simplicity, ignore an unlikely case when multiple ;; windows display the same buffer. (window (car (get-buffer-window-list (current-buffer) nil t))) (window-start (and window (window-start window)))) (guix-buffer-set guix-buffer-item) (goto-char old-point) (run-hooks 'guix-buffer-after-redisplay-hook) (when window (set-window-point window (point)) (set-window-start window window-start)))) (defun guix-buffer-redisplay-goto-button () "Redisplay the current buffer and go to the next button, if needed." (let ((guix-buffer-after-redisplay-hook (cons (lambda () (unless (button-at (point)) (forward-button 1))) guix-buffer-after-redisplay-hook))) (guix-buffer-redisplay))) ;;; Interface definers (defmacro guix-define-groups (type &rest args) "Define `guix-TYPE' and `guix-TYPE-faces' custom groups. Remaining arguments (ARGS) should have a form [KEYWORD VALUE] ... Optional keywords: - `:parent-group' - name of a parent custom group. - `:parent-faces-group' - name of a parent custom faces group. - `:group-doc' - docstring of a `guix-TYPE' group. - `:faces-group-doc' - docstring of a `guix-TYPE-faces' group." (declare (indent 1)) (let* ((type-str (symbol-name type)) (prefix (concat "guix-" type-str)) (group (intern prefix)) (faces-group (intern (concat prefix "-faces")))) (guix-keyword-args-let args ((parent-group :parent-group 'guix) (parent-faces-group :parent-faces-group 'guix-faces) (group-doc :group-doc (format "Settings for '%s' buffers." type-str)) (faces-group-doc :faces-group-doc (format "Faces for '%s' buffers." type-str))) `(progn (defgroup ,group nil ,group-doc :group ',parent-group) (defgroup ,faces-group nil ,faces-group-doc :group ',group :group ',parent-faces-group))))) (defmacro guix-define-entry-type (entry-type &rest args) "Define general code for ENTRY-TYPE. See `guix-define-groups'." (declare (indent 1)) `(guix-define-groups ,entry-type ,@args)) (defmacro guix-define-buffer-type (buffer-type &rest args) "Define general code for BUFFER-TYPE. See `guix-define-groups'." (declare (indent 1)) `(guix-define-groups ,buffer-type ,@args)) (defmacro guix-buffer-define-interface (buffer-type entry-type &rest args) "Define BUFFER-TYPE interface for displaying ENTRY-TYPE entries. Remaining arguments (ARGS) should have a form [KEYWORD VALUE] ... In the following description TYPE means ENTRY-TYPE-BUFFER-TYPE. Required keywords: - `:buffer-name' - default value of the generated `guix-TYPE-buffer-name' variable. - `:get-entries-function' - default value of the generated `guix-TYPE-get-function' variable. - `:show-entries-function' - default value of the generated `guix-TYPE-show-function' variable. Alternatively, if `:show-entries-function' is not specified, a default `guix-TYPE-show-entries' will be generated, and the following keyword should be specified instead: - `:insert-entries-function' - default value of the generated `guix-TYPE-insert-function' variable. Optional keywords: - `:message-function' - default value of the generated `guix-TYPE-message-function' variable. - `:titles' - default value of the generated `guix-TYPE-titles' variable. - `:history-size' - default value of the generated `guix-TYPE-history-size' variable. - `:revert-confirm?' - default value of the generated `guix-TYPE-revert-confirm' variable. - `:mode-name' - name (a string appeared in the mode-line) of the generated `guix-TYPE-mode'. - `:mode-init-function' - default value of the generated `guix-TYPE-mode-initialize-function' variable. - `:reduced?' - if non-nil, generate only group, faces group and titles variable (if specified); all keywords become optional." (declare (indent 2)) (let* ((entry-type-str (symbol-name entry-type)) (buffer-type-str (symbol-name buffer-type)) (prefix (concat "guix-" entry-type-str "-" buffer-type-str)) (group (intern prefix)) (faces-group (intern (concat prefix "-faces"))) (get-entries-var (intern (concat prefix "-get-function"))) (show-entries-var (intern (concat prefix "-show-function"))) (show-entries-fun (intern (concat prefix "-show-entries"))) (message-var (intern (concat prefix "-message-function"))) (buffer-name-var (intern (concat prefix "-buffer-name"))) (titles-var (intern (concat prefix "-titles"))) (history-size-var (intern (concat prefix "-history-size"))) (revert-confirm-var (intern (concat prefix "-revert-confirm")))) (guix-keyword-args-let args ((get-entries-val :get-entries-function) (show-entries-val :show-entries-function) (insert-entries-val :insert-entries-function) (mode-name :mode-name (capitalize prefix)) (mode-init-val :mode-init-function) (message-val :message-function) (buffer-name-val :buffer-name) (titles-val :titles) (history-size-val :history-size 20) (revert-confirm-val :revert-confirm? t) (reduced? :reduced?)) `(progn (defgroup ,group nil ,(format "Displaying '%s' entries in '%s' buffer." entry-type-str buffer-type-str) :group ',(intern (concat "guix-" entry-type-str)) :group ',(intern (concat "guix-" buffer-type-str))) (defgroup ,faces-group nil ,(format "Faces for displaying '%s' entries in '%s' buffer." entry-type-str buffer-type-str) :group ',group :group ',(intern (concat "guix-" entry-type-str "-faces")) :group ',(intern (concat "guix-" buffer-type-str "-faces"))) (defcustom ,titles-var ,titles-val ,(format "Alist of titles of '%s' parameters." entry-type-str) :type '(alist :key-type symbol :value-type string) :group ',group) ,(unless reduced? `(progn (defvar ,get-entries-var ,get-entries-val ,(format "\ Function used to receive '%s' entries for '%s' buffer." entry-type-str buffer-type-str)) (defvar ,show-entries-var ,(or show-entries-val `',show-entries-fun) ,(format "\ Function used to show '%s' entries in '%s' buffer." entry-type-str buffer-type-str)) (defvar ,message-var ,message-val ,(format "\ Function used to display a message after showing '%s' entries. If nil, do not display messages." entry-type-str)) (defcustom ,buffer-name-var ,buffer-name-val ,(format "\ Default name of '%s' buffer for displaying '%s' entries. May be a string or a function returning a string. The function is called with the same arguments as `%S'." buffer-type-str entry-type-str get-entries-var) :type '(choice string function) :group ',group) (defcustom ,history-size-var ,history-size-val ,(format "\ Maximum number of items saved in history of `%S' buffer. If 0, the history is disabled." buffer-name-var) :type 'integer :group ',group) (defcustom ,revert-confirm-var ,revert-confirm-val ,(format "\ If non-nil, ask to confirm for reverting `%S' buffer." buffer-name-var) :type 'boolean :group ',group) (guix-alist-put! '((get-entries . ,get-entries-var) (show-entries . ,show-entries-var) (message . ,message-var) (buffer-name . ,buffer-name-var) (history-size . ,history-size-var) (revert-confirm . ,revert-confirm-var)) 'guix-buffer-data ',buffer-type ',entry-type) ,(unless show-entries-val `(defun ,show-entries-fun (entries) ,(format "\ Show '%s' ENTRIES in the current '%s' buffer." entry-type-str buffer-type-str) (guix-buffer-show-entries-default entries ',buffer-type ',entry-type))) ,(when (or insert-entries-val (null show-entries-val)) (let ((insert-entries-var (intern (concat prefix "-insert-function")))) `(progn (defvar ,insert-entries-var ,insert-entries-val ,(format "\ Function used to print '%s' entries in '%s' buffer." entry-type-str buffer-type-str)) (guix-alist-put! ',insert-entries-var 'guix-buffer-data ',buffer-type ',entry-type 'insert-entries)))) ,(when (or mode-name mode-init-val (null show-entries-val)) (let* ((mode-str (concat prefix "-mode")) (mode-map-str (concat mode-str "-map")) (mode (intern mode-str)) (parent-mode (intern (concat "guix-" buffer-type-str "-mode"))) (mode-var (intern (concat mode-str "-function"))) (mode-init-var (intern (concat mode-str "-initialize-function")))) `(progn (defvar ,mode-var ',mode ,(format "\ Major mode for displaying '%s' entries in '%s' buffer." entry-type-str buffer-type-str)) (defvar ,mode-init-var ,mode-init-val ,(format "\ Function used to set up '%s' buffer for displaying '%s' entries." buffer-type-str entry-type-str)) (define-derived-mode ,mode ,parent-mode ,mode-name ,(format "\ Major mode for displaying '%s' entries in '%s' buffer. \\{%s}" entry-type-str buffer-type-str mode-map-str) (setq-local revert-buffer-function 'guix-buffer-revert) (setq-local guix-history-size (guix-buffer-history-size ',buffer-type ',entry-type)) (guix-buffer-mode-initialize ',buffer-type ',entry-type)) (guix-alist-put! ',mode-var 'guix-buffer-data ',buffer-type ',entry-type 'mode) (guix-alist-put! ',mode-init-var 'guix-buffer-data ',buffer-type ',entry-type 'mode-init)))))) (guix-alist-put! ',titles-var 'guix-buffer-data ',buffer-type ',entry-type 'titles))))) (defvar guix-buffer-font-lock-keywords (eval-when-compile `((,(rx "(" (group (or "guix-buffer-with-item" "guix-buffer-with-current-item" "guix-buffer-define-interface" "guix-define-groups" "guix-define-entry-type" "guix-define-buffer-type")) symbol-end) . 1)))) (font-lock-add-keywords 'emacs-lisp-mode guix-buffer-font-lock-keywords) (provide 'guix-buffer) ;;; guix-buffer.el ends here