emacs/lisp/tty-tip.el

209 lines
6.7 KiB
EmacsLisp

;;; -*- lexical-binding: t; symbol-packages: t; -*-
;;; tty-tip.el --- Display help in kind of tooltips on ttys
;; Copyright (C) 2024 Free Software Foundation, Inc.
;; This file is part of GNU Emacs.
;; GNU Emacs 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 Emacs 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 GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;; This uses tty child frames to display help which looks and feels much
;; like using tooltips (but they really aren't).
;; Use `tty-tip-mode' to activate or toggle this feature.
;;
;; You can customize face `tooltip', `tooltip-short-delay',
;; `tooltip-delay', `tooltip-recent-seconds'.
(require 'tooltip)
(defvar tty-tip--frame nil)
(defun tty-tip--make-buffer (text)
(with-current-buffer
(get-buffer-create " *tty-tip*")
;; Redirect focus to parent.
(add-hook 'pre-command-hook #'tty-tip--delete-frame nil t)
;; Use an empty keymap.
(use-local-map (make-keymap))
(dolist (var '((mode-line-format . nil)
(header-line-format . nil)
(tab-line-format . nil)
(tab-bar-format . nil) ;; Emacs 28 tab-bar-format
(frame-title-format . "")
(truncate-lines . t)
(cursor-in-non-selected-windows . nil)
(cursor-type . nil)
(show-trailing-whitespace . nil)
(display-line-numbers . nil)
(left-fringe-width . nil)
(right-fringe-width . nil)
(left-margin-width . 0)
(right-margin-width . 0)
(fringes-outside-margins . 0)
(buffer-read-only . t)))
(set (make-local-variable (car var)) (cdr var)))
(let ((inhibit-modification-hooks t)
(inhibit-read-only t))
(erase-buffer)
(insert text)
(goto-char (point-min)))
(current-buffer)))
(defvar tty-tip-frame-parameters
`((visibility . nil)
(background-color . "lightyellow")
(foreground-color . "black")
(width . 0) (height . 0)
(min-width . t) (min-height . t)
(no-accept-focus . t)
(no-focus-on-map . t)
(border-width . 0)
(child-frame-border-width . 1)
(left-fringe . 0)
(right-fringe . 0)
(vertical-scroll-bars . nil)
(horizontal-scroll-bars . nil)
(menu-bar-lines . 0)
(tool-bar-lines . 0)
(tab-bar-lines . 0)
(no-other-frame . t)
(no-other-window . t)
(no-delete-other-windows . t)
(unsplittable . t)
(undecorated . t)
(cursor-type . nil)
(no-special-glyphs . t)
(desktop-dont-save . t)))
(defun tty-tip--frame-parameters ()
(let ((params (copy-sequence tty-tip-frame-parameters))
(fg (face-attribute 'tooltip :foreground))
(bg (face-attribute 'tooltip :background)))
(when (stringp fg)
(setf (alist-get 'foreground-color params) fg))
(when (stringp bg)
(setf (alist-get 'background-color params) bg))
params))
(defvar tty-tip--help-message nil)
(defvar tty-tip--hide-time nil)
(defvar tty-tip--show-timer nil)
(defvar tty-tip--hide-timer nil)
(defun tty-tip--delete-frame ()
(when tty-tip--frame
(when tty-tip--hide-timer
(cancel-timer tty-tip--hide-timer)
(setq tty-tip--hide-timer nil))
(delete-frame tty-tip--frame)
(setq tty-tip--frame nil)
t))
(defun tty-tip--compute-position ()
(let* ((pos (mouse-position))
(mouse-x (car (cdr pos)))
(mouse-y (cdr (cdr pos)))
(x (+ mouse-x 1))
(y (+ mouse-y 1))
(tip-width (frame-width tty-tip--frame))
(tip-height (frame-height tty-tip--frame))
(tty-width (display-pixel-width))
(tty-height (display-pixel-height)))
(when (> (+ x tip-width) tty-width)
(setq x (max 0 (- x tip-width 1))))
(when (> (+ y tip-height) tty-height)
(setq y (max 0 (- y tip-height 1))))
(cons x y)))
(defun tty-tip--create-frame (text)
(let* ((minibuffer (minibuffer-window (window-frame)))
(buffer (tty-tip--make-buffer text))
(window-min-height 1)
(window-min-width 1)
after-make-frame-functions
(text-lines (string-lines text)))
(setq tty-tip--frame
(make-frame
`((parent-frame . ,(car (mouse-position)))
(minibuffer . ,minibuffer)
,@(tty-tip--frame-parameters))))
(let ((win (frame-root-window tty-tip--frame)))
(set-window-buffer win buffer)
(set-window-dedicated-p win t)
(set-frame-size tty-tip--frame
(apply #'max (mapcar #'string-width text-lines))
(length text-lines))
(let* ((pos (tty-tip--compute-position))
(x (car pos))
(y (cdr pos)))
(set-frame-position tty-tip--frame x y))
(make-frame-visible tty-tip--frame)
(setq tty-tip--hide-timer
(run-with-timer tooltip-hide-delay nil
#'tty-tip--delete-frame)))))
(defun tty-tip--delay ()
(if (and tty-tip--hide-time
(time-less-p (time-since tty-tip--hide-time)
tooltip-recent-seconds))
tooltip-short-delay
tooltip-delay))
(defun tty-tip--cancel-delayed-tip ()
(when tty-tip--show-timer
(cancel-timer tty-tip--show-timer)
(setq tty-tip--show-timer nil)))
(defun tty-tip--start-delayed-tip ()
(setq tty-tip--show-timer
(run-with-timer (tty-tip--delay) nil
(lambda ()
(tty-tip--create-frame
tty-tip--help-message)))))
(defun tty-tip--hide (&optional _ignored-arg)
(tty-tip--cancel-delayed-tip)
(when (tty-tip--delete-frame)
(setq tty-tip--hide-time (float-time))))
(defun tty-tip--show-help (msg)
(let ((previous-help tty-tip--help-message))
(setq tty-tip--help-message msg)
(cond ((null msg)
(tty-tip--hide))
((equal previous-help msg)
nil)
(t
(tty-tip--hide)
(tty-tip--start-delayed-tip)))))
;;;###autoload
(define-minor-mode tty-tip-mode
"Global minor mode for displaying help in tty child frames."
:global t :group 'help
(unless (display-graphic-p)
(cond (tty-tip-mode
(setq show-help-function #'tty-tip--show-help)
(add-hook 'pre-command-hook #'tty-tip--hide))
(t
(setq show-help-function nil)
(remove-hook 'pre-command-hook #'tty-tip--hide)))))
(provide 'tty-tip)
;;; End