Adding basic overrides of apropos buttons to use helpful.

Possible problems:

1. I don't know _where_ these should go structurally. This file looks
upside down to me.
2. I don't currently have any way to toggle this functionality on/off
with the mode.

Author: zenspider

helpful.el

@@ -2682,6 +2682,100 @@ See also `helpful-max-buffers'."
     (when (eq (buffer-local-value 'major-mode buffer) 'helpful-mode)
       (kill-buffer buffer))))
 
+;; overrides in apropos to try to use helpful-* instead.
+
+(require 'apropos)
+
+(define-button-type 'apropos-function
+  'apropos-label "Function"
+  'apropos-short-label "f"
+  'face 'apropos-function-button
+  'help-echo "mouse-2, RET: Display more help on this function"
+  'follow-link t
+  'action (lambda (button)
+            (helpful-function (button-get button 'apropos-symbol))))
+
+(define-button-type 'apropos-macro
+  'apropos-label "Macro"
+  'apropos-short-label "m"
+  'face 'apropos-function-button
+  'help-echo "mouse-2, RET: Display more help on this macro"
+  'follow-link t
+  'action (lambda (button)
+            (helpful-function (button-get button 'apropos-symbol))))
+
+(define-button-type 'apropos-command
+  'apropos-label "Command"
+  'apropos-short-label "c"
+  'face 'apropos-function-button
+  'help-echo "mouse-2, RET: Display more help on this command"
+  'follow-link t
+  'action (lambda (button)
+            (helpful-function (button-get button 'apropos-symbol))))
+
+(define-button-type 'apropos-variable
+  'apropos-label "Variable"
+  'apropos-short-label "v"
+  'face 'apropos-variable-button
+  'help-echo "mouse-2, RET: Display more help on this variable"
+  'follow-link t
+  'action (lambda (button)
+            (helpful-variable (button-get button 'apropos-symbol))))
+
+(define-button-type 'apropos-user-option
+  'apropos-label "User option"
+  'apropos-short-label "o"
+  'face 'apropos-user-option-button
+  'help-echo "mouse-2, RET: Display more help on this user option"
+  'follow-link t
+  'action (lambda (button)
+            (helpful-variable (button-get button 'apropos-symbol))))
+
+;;; TODO: these need helpful functions before they can be hooked up:
+
+;; (define-button-type 'apropos-face
+;;   'apropos-label "Face"
+;;   'apropos-short-label "F"
+;;   'face '(font-lock-variable-name-face button)
+;;   'help-echo "mouse-2, RET: Display more help on this face"
+;;   'follow-link t
+;;   'action (lambda (button)
+;;             (describe-face (button-get button 'apropos-symbol))))
+
+;; (define-button-type 'apropos-group
+;;   'apropos-label "Group"
+;;   'apropos-short-label "g"
+;;   'face 'apropos-misc-button
+;;   'help-echo "mouse-2, RET: Display more help on this group"
+;;   'follow-link t
+;;   'action (lambda (button)
+;;             (customize-group-other-window
+;;              (button-get button 'apropos-symbol))))
+
+;; (define-button-type 'apropos-widget
+;;   'apropos-label "Widget"
+;;   'apropos-short-label "w"
+;;   'face 'apropos-misc-button
+;;   'help-echo "mouse-2, RET: Display more help on this widget"
+;;   'follow-link t
+;;   'action (lambda (button)
+;;             (widget-browse-other-window (button-get button 'apropos-symbol))))
+
+;; (define-button-type 'apropos-plist
+;;   'apropos-label "Properties"
+;;   'apropos-short-label "p"
+;;   'face 'apropos-misc-button
+;;   'help-echo "mouse-2, RET: Display more help on this plist"
+;;   'follow-link t
+;;   'action (lambda (button)
+;;             (apropos-describe-plist (button-get button 'apropos-symbol))))
+
+;; (define-button-type 'apropos-library
+;;   'help-echo "mouse-2, RET: Display more help on this library"
+;;   'follow-link t
+;;   'action (lambda (button)
+;;             (apropos-library (button-get button 'apropos-symbol))))
+
 (defvar helpful-mode-map
   (let* ((map (make-sparse-keymap)))
     (define-key map (kbd "g") #'helpful-update)