;;; eldoc-box.el --- Display documentation in childframe -*- lexical-binding: t; -*-
;; Copyright (C) 2017 Sebastien Chapuis
;; Version: 1.0
;; Author: Sebastien Chapuis <sebastien@chapu.is>
;; Yuan Fu <casouri@gmail.com> made a lot of change to use it for ElDoc
;; URL: https://github.com/casouri/eldoc-box
;; Package-Requires: ((emacs "26.1"))
;;; License
;;
;; 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, 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; see the file COPYING. If not, write to
;; the Free Software Foundation, Inc., 51 Franklin Street, Fifth
;; Floor, Boston, MA 02110-1301, USA.
;;; This file is NOT part of GNU Emacs
;;; Commentary:
;;
;;; Code:
;;
(require 'cl-lib)
;;;; Userland
;;;;; Variable
(defface eldoc-box-border '((((background dark)) . (:background "white"))
(((background light)) . (:background "black")))
"The border color used in childframe.")
(defface eldoc-box-body '((t . (:background nil)))
"Body face used in eglot doc childframe. Only :background is used.")
(defvar eldoc-box-only-multi-line nil
"If non-nil, only use childframe when there are more than one line.")
(defvar eldoc-box-frame-parameters
'(
;; (left . -1)
(no-accept-focus . t)
(no-focus-on-map . t)
(min-width . 0)
;; (width . 0)
(min-height . 0)
;; (height . 0)
(internal-border-width . 1)
(vertical-scroll-bars . nil)
(horizontal-scroll-bars . nil)
(right-fringe . 0)
(menu-bar-lines . 0)
(tool-bar-lines . 0)
(line-spacing . 0)
(unsplittable . t)
(undecorated . t)
;; (top . -1)
(visibility . nil)
(mouse-wheel-frame . nil)
(no-other-frame . t)
(cursor-type . nil)
(inhibit-double-buffering . t)
(drag-internal-border . t)
(no-special-glyphs . t)
(desktop-dont-save . t))
"Frame parameters used to create the frame.")
(defvar eldoc-box-max-pixel-width 800
"Maximum width of doc childframw in pixel.")
(defvar eldoc-box-max-pixel-height 1400
"Maximum height of doc childframw in pixel.")
;;;;; Function
(defun eldoc-box-help-at-point ()
"Display hover info at point in a childframe."
(interactive)
(let ((doc (funcall eldoc-documentation-function)))
(if doc
(progn
(eldoc-box--display doc)
(eldoc-box--inject-quit-func))
(message "No documentation available"))))
(defun eldoc-box-quit-frame ()
"Hide childframe used by eglot doc."
(interactive)
;; TODO
(when eldoc-box--frame
(make-frame-invisible eldoc-box--frame t)))
;;;; Backstage
;;;;; Variable
(defvar eldoc-box--frame nil
"The frame to display doc.")
(defvar eldoc-box--buffer "*eldoc-box*"
"The buffer used to display eglot doc.")
;;;;; Function
(defun eldoc-box--display (str)
"Display STR in childframe."
(let ((doc-buffer (get-buffer-create eldoc-box--buffer)))
(with-current-buffer doc-buffer
(setq mode-line-format nil)
(erase-buffer)
(insert str)
(eldoc-box--get-frame doc-buffer))))
(defun eldoc-box-quit-hook ()
"Quit eglot doc childframe and remove self from hook."
(eldoc-box-quit-frame)
(remove-hook 'pre-command-hook #'eldoc-box-quit-hook t))
(defun eldoc-box--inject-quit-func ()
"Inject quit function into `pre-command-hook' so doing anything will quit eglot doc childframe."
(add-hook 'pre-command-hook #'eldoc-box-quit-hook t t))
(defun eldoc-box--window-side ()
"Return 'left if the selected window is on the left,
'right if on the right. Return 'left if there is only one window."
(let ((left-window(window-at 0 0)))
(if (eq left-window (selected-window))
'left
'right)))
(defun eldoc-box--get-frame (buffer)
"Return a childframe displaying BUFFER.
Checkout `lsp-ui-doc--make-frame', `lsp-ui-doc--move-frame'."
(let* ((after-make-frame-functions nil)
(before-make-frame-hook nil)
(parameter (append eldoc-box-frame-parameters
`((default-minibuffer-frame . ,(selected-frame))
(minibuffer . ,(minibuffer-window))
(left-fringe . ,(frame-char-width)))))
(window (or (and eldoc-box--frame (frame-selected-window eldoc-box--frame))
(display-buffer-in-child-frame
buffer
`((child-frame-parameters . ,parameter)))))
(frame (window-frame window))
(main-frame (selected-frame)))
(make-frame-visible frame)
(set-window-dedicated-p window t)
(redirect-frame-focus frame (frame-parent frame))
(set-face-attribute 'internal-border frame :inherit 'eldoc-box-border)
(set-face-attribute 'default frame :background (face-attribute 'eldoc-box-body :background main-frame))
;; set size
(let* ((size
(window-text-pixel-size
window nil nil
eldoc-box-max-pixel-width
eldoc-box-max-pixel-height t))
(width (car size))
(height (cdr size))
(width (+ width (frame-char-width frame))) ; add margin
(frame-resize-pixelwise t))
(set-frame-size frame width height t)
;; move position
(set-frame-position frame (pcase (eldoc-box--window-side) ; x position + a little padding (16)
;; display doc on right
('left (- (frame-outer-width main-frame) width 16))
;; display doc on left
('right 16))
;; y position + a little padding (16)
16))
(setq eldoc-box--frame frame)))
;;;;; ElDoc
(defvar eldoc-box--cleanup-timer nil
"The timer used to cleanup childframe after ElDoc.")
(defun eldoc-box--maybe-cleanup ()
"Clean up after ElDOc."
;; timer is global, so this function will be called outside
;; the buffer with `eldoc-box-hover-mode' enabled
(if eldoc-box-hover-mode
;; if eldoc-last-message is nil, the childframe is cleared
(eldoc-box--eldoc-message-function eldoc-last-message)
;; sometimes you switched buffer when childframe is on.
;; it wouldn't go away unless you goes back and let eldoc
;; shut it off. this code can save you
;; this is gold, right here, you know it my friend?
(when (frame-parameter eldoc-box--frame 'visibility)
(eldoc-box-quit-frame))))
(defun eldoc-box--eldoc-message-function (str &rest args)
"Frontend for eldoc. Display STR in childframe and ARGS works like `message'."
(if (stringp str)
(let ((doc (apply #'format str args)))
(if (and eldoc-box-only-multi-line (eq (cl-count ?\n doc) 0))
(apply #'eldoc-minibuffer-message str args)
(eldoc-box--display (apply #'format str args))))
(eldoc-box-quit-frame)))
(define-minor-mode eldoc-box-hover-mode
"Displays hover documentations in a childframe. This mode is buffer local."
:lighter " ELDOC-BOX"
(if eldoc-box-hover-mode
(progn
;; Why a timer? ElDoc is mainly use in minibuffer,
;; where the text is constantly being flushed by other commands
;; so ElDoc doesn't try very hard to cleanup
(setq eldoc-box--cleanup-timer (run-with-idle-timer 1 t #'eldoc-box--maybe-cleanup))
(setq-local eldoc-message-function #'eldoc-box--eldoc-message-function))
(setq-local eldoc-message-function #'eldoc-minibuffer-message)
(when eldoc-box--cleanup-timer (cancel-timer eldoc-box--cleanup-timer))
;; if minor mode is turned off when childframe is visible
;; hide it
(eldoc-box-quit-frame)))
(provide 'eldoc-box)
;;; eldoc-box.el ends here