Display cheatsheet in a separate buffer

CHANGELOG.md

@@ -4,6 +4,9 @@
 
 ### New features
 
+- [#3681](https://github.com/clojure-emacs/cider/pull/3681): Add an alternative way to display cheatsheet in a buffer and make it the default.
+  - Current `cider-cheatsheet` command is renamed to `cider-cheatsheet-select`.
+  - New way to display cheatsheet in a buffer is available with `cider-cheatsheet` command.
 - [#3632](https://github.com/clojure-emacs/cider/pull/3623): Add new configuration variable `cider-clojure-cli-global-aliases`.
 - [#3366](https://github.com/clojure-emacs/cider/pull/3366): Support display of error overlays with `#dbg!` and `#break!` reader macros.
 - [#3622](https://github.com/clojure-emacs/cider/pull/3461): Basic support for using CIDER from [clojure-ts-mode](https://github.com/clojure-emacs/clojure-ts-mode).

cider-cheatsheet.el

@@ -29,6 +29,7 @@
 ;;; Code:
 
 (require 'cider-doc)
+(require 'cl-lib)
 (require 'seq)
 
 (defconst cider-cheatsheet-hierarchy
@@ -555,7 +556,7 @@ The list can hold one or more lists inside - one per each namespace."
     (cider-doc-lookup (completing-read "Select var: " namespaced-vars))))
 
 ;;;###autoload
-(defun cider-cheatsheet ()
+(defun cider-cheatsheet-select ()
   "Navigate `cider-cheatsheet-hierarchy' with `completing-read'.
 
 When you make it to a Clojure var its doc buffer gets displayed."
@@ -568,6 +569,38 @@ When you make it to a Clojure var its doc buffer gets displayed."
         (setq cheatsheet-data (cdr section-data))))
     (cider-cheatsheet--select-var cheatsheet-data)))
 
+(cl-defun cider-cheatsheet--insert-hierarchy (hierarchy &optional (level 0))
+  "Insert HIERARCHY with visual indentation for LEVEL."
+  (dolist (node hierarchy)
+    (if (stringp (car node))
+        (progn
+          (insert (make-string (* level 2) ?\s) (car node) "\n")
+          (cider-cheatsheet--insert-hierarchy (cdr node) (1+ level)))
+      (dolist (var (cider-cheatsheet--expand-vars node))
+        (insert (make-string (* level 2) ?\s))
+        (insert-text-button var
+                            'var var
+                            'action (lambda (btn)
+                                      (cider-doc-lookup (button-get btn 'var)))
+                            'help-echo (format "Show documentation for %s" var))
+        (insert "\n")))))
+
+(defun cider-cheatsheet--buffer-contents ()
+  "Generate cheatsheet buffer contents based on the cheatsheet hierarchy."
+  (with-temp-buffer
+    (cider-cheatsheet--insert-hierarchy cider-cheatsheet-hierarchy)
+    (buffer-string)))
+
+;;;###autoload
+(defun cider-cheatsheet ()
+  "Display cheatsheet in a popup buffer."
+  (interactive)
+  (with-current-buffer (cider-popup-buffer "*cider-cheatsheet*")
+    (read-only-mode -1)
+    (insert (cider-cheatsheet--buffer-contents))
+    (read-only-mode 1)
+    (goto-char (point-min))))
+
 (provide 'cider-cheatsheet)
 
 ;;; cider-cheatsheet.el ends here