From d4e4a25cde3067578be94cdf4e125ecdd2b7770c Mon Sep 17 00:00:00 2001
From: Tom Willemse <tom@ryuslash.org>
Date: Mon, 21 Oct 2019 00:41:19 -0700
Subject: [PATCH] Add documentation command for LSP
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The default way lsp (at least for Java) is displayed is annoying. I’m used to
calling documentation with a keybinding like in Emacs Lisp. This command makes
it more like that.
---
 oni-java.el | 13 +++++++++----
 oni-lsp.el  | 21 +++++++++++++++++----
 2 files changed, 26 insertions(+), 8 deletions(-)

diff --git a/oni-java.el b/oni-java.el
index e545a24..fb4fe42 100644
--- a/oni-java.el
+++ b/oni-java.el
@@ -4,8 +4,8 @@
 
 ;; Author: Tom Willemse <tom@ryuslash.org>
 ;; Keywords: local
-;; Version: 2019.1016.231834
-;; Package-Requires: (oni-fci oni-data-dir lsp-java company-lsp lsp-ui hydra)
+;; Version: 2019.1021.002901
+;; Package-Requires: (oni-fci oni-data-dir oni-lsp lsp-java company-lsp hydra)
 
 ;; 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
@@ -30,6 +30,7 @@
 (require 'hydra)
 (require 'lsp-java)
 (require 'oni-data-dir)
+(require 'oni-lsp)
 
 (defun oni-java-enable-buffer-formatting ()
   "Format the buffer before save."
@@ -50,6 +51,9 @@
   ("p" lsp-java-create-parameter "Create parameter")
   ("l" lsp-java-create-local "Create local"))
 
+(defhydra java-documentation-hydra (:color blue)
+  ("d" oni-lsp-show-doc "Show documentation"))
+
 (setq lsp-java-server-install-dir
       (oni-data-dir-locate "lsp-java/server/"))
 
@@ -74,14 +78,15 @@
 (add-to-list 'company-backends 'company-lsp)
 
 (define-key java-mode-map (kbd "C-c r") 'java-refactor-hydra/body)
+(define-key java-mode-map (kbd "C-c d") 'java-documentation-hydra/body)
 
 (add-to-list 'auto-insert-alist
              '("\\.java\\'"
                () "public class "
                (file-name-sans-extension
                 (file-name-nondirectory (buffer-file-name))) " {\n"
-                (indent-for-tab-command) _ "\n"
-                "}"))
+               (indent-for-tab-command) _ "\n"
+               "}"))
 
 ;;;###autoload(with-eval-after-load 'cc-mode (require 'oni-java))
 
diff --git a/oni-lsp.el b/oni-lsp.el
index 78581a4..312e294 100644
--- a/oni-lsp.el
+++ b/oni-lsp.el
@@ -4,7 +4,7 @@
 
 ;; Author: Tom Willemse <tom@ryuslash.org>
 ;; Keywords: local
-;; Version: 2019.1016.231222
+;; Version: 2019.1021.004102
 ;; Package-Requires: (lsp-mode lsp-ui)
 
 ;; This program is free software; you can redistribute it and/or modify
@@ -29,12 +29,25 @@
 (require 'lsp)
 (require 'lsp-ui)
 
+(defun oni-lsp-show-doc ()
+  "Show documentation string in a help buffer."
+  (interactive)
+  (let* ((position-params (lsp--text-document-position-params))
+         (response (lsp-request "textDocument/hover" position-params))
+         (contents (gethash "contents" response))
+         (help-string (lsp-ui-doc--extract contents))
+         (symbol (gethash "value" (pcase contents
+                                    ((pred arrayp) (aref contents 0))
+                                    (_ contents)))))
+    (with-help-window (help-buffer)
+      (princ symbol)
+      (princ "\n\n")
+      (princ help-string))))
+
 (setq lsp-prefer-flymake nil)
 
-(setq lsp-ui-doc-enable t)
+(setq lsp-ui-doc-enable nil)
 (setq lsp-ui-sideline-enable nil)
-(setq lsp-ui-doc-position 'at-point)
-(setq lsp-ui-doc-delay 1)
 
 (add-hook 'lsp-mode-hook 'lsp-lens-mode)