init

eglot-doc.el

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+;;; eglot-doc.el --- Display documentation in childframe      -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2018  Yuan Fu
+
+;; Author: Yuan Fu <casouri@gmail.com>
+
+;;; This file is NOT part of GNU Emacs
+
+;;; 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.
+
+;;; Commentary:
+;;
+
+;;; Code:
+;;
+
+;;;; Userland
+;;;;; Variable
+
+(defvar eglot-doc-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 eglot-doc-max-pixel-width 800
+  "Maximum width of doc childframw in pixel.")
+(defvar eglot-doc-max-pixel-height 1400
+  "Maximum height of doc childframw in pixel.")
+
+;;;;; Function
+
+(defun eglot-doc-help-at-point ()
+  "Display hover info at point in a childframe."
+  (interactive)
+  (eglot--dbind ((Hover) contents range)
+      (jsonrpc-request (eglot--current-server-or-lose) :textDocument/hover
+                       (eglot--TextDocumentPositionParams))
+    (when (seq-empty-p contents) (eglot--error "No hover info here"))
+    (eglot-doc--display (eglot--hover-info contents range))))
+
+(defun eglot-doc-quit-frame ()
+  "Hide childframe used by eglot doc."
+  (interactive)
+  ;; TODO
+  (when eglot-doc--frame
+    (delete-frame eglot-doc--frame t)))
+
+;;;; Backstage
+;;;;; Variable
+
+(defvar eglot-doc--frame nil
+  "The frame to display doc.")
+
+(defvar eglot-doc--buffer "*eglot-doc*"
+  "The buffer used to display eglot doc.")
+
+;;;;; Function
+
+(defun eglot-doc--display (str)
+  "Display STR in childframe."
+  (let ((doc-buffer (get-buffer-create eglot-doc--buffer)))
+    (with-current-buffer doc-buffer
+      (setq mode-line-format nil)
+      (erase-buffer)
+      (insert str)
+      (eglot-doc--get-frame doc-buffer))
+    (eglot-doc--inject-quit-func)))
+
+(defun eglot-doc-quit-hook ()
+  "Quit eglot doc childframe and remove self from hook."
+  (eglot-doc-quit-frame)
+  (remove-hook 'pre-command-hook #'eglot-doc-quit-hook t))
+
+(defun eglot-doc--inject-quit-func ()
+  "Inject quit function into `pre-command-hook' so doing anything will quit eglot doc childframe."
+  (add-hook 'pre-command-hook #'eglot-doc-quit-hook t t))
+
+(defun eglot-doc--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 eglot-doc--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 eglot-doc-frame-parameters
+                            `((default-minibuffer-frame . ,(selected-frame))
+                              (minibuffer . ,(minibuffer-window))
+                              (left-fringe . ,(frame-char-width)))))
+         (window (display-buffer-in-child-frame
+                  buffer
+                  `((child-frame-parameters . ,parameter))))
+         (frame (window-frame window))
+         (main-frame (selected-frame)))
+    (set-window-dedicated-p window t)
+    (redirect-frame-focus frame (frame-parent frame))
+    ;; set size
+    (let* ((size
+            (window-text-pixel-size
+             window nil nil
+             eglot-doc-max-pixel-width
+             eglot-doc-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 (eglot-doc--window-side) ; x position
+                                  ;; display doc on right
+                                  ('left (- (frame-outer-width main-frame) width))
+                                  ;; display doc on left
+                                  ('right 0))
+                          ;; y position
+                          0))
+    (setq eglot-doc--frame frame)))
+
+;;;;; ElDoc
+(defun eglot-doc--eldoc-message-function (str &rest args)
+  "Frontend for eldoc. Display STR in childframe and ARGS works like `message'."
+  (when str
+    (eglot-doc-quit-frame)
+    (eglot-doc--display (apply #'format str args))))
+
+(define-minor-mode eglot-doc-hover-mode
+  "Displays hover documentations in a childframe. This mode is buffer local."
+  :lighter " EGLOT-DOC"
+  (if eglot-doc-hover-mode
+      (setq-local eldoc-message-function #'eglot-doc--eldoc-message-function)
+    (setq-local eldoc-message-function #'eldoc-minibuffer-message)))
+
+(provide 'eglot-doc)
+
+;;; eglot-doc.el ends here