[nongnu] elpa/engine-mode 449c09afe5 26/71: Nest prefixed keymaps correctly

[ELPA Syncer]

branch: elpa/engine-mode
commit 449c09afe58372c76fc2729f252ef86d79c181d8
Author: Harry Schwartz <hello@harryrschwartz.com>
Commit: Harry Schwartz <hello@harryrschwartz.com>

    Nest prefixed keymaps correctly
    
    We'd been handling prefixes by defining a string `engine/keymap-prefix`
    which contained the prefix, concatenating that with the `:keybinding`
    when an engine was defined, and then binding the engine to that
    resulting string. That's not great:
    
    * Sometimes perfectly valid prefix keys aren't represented as
      strings (e.g. `(kbd "s-/")`), so concatenation fails.
    * Engines can't be automatically rebound to a new prefix once they've
      been defined.
    * Keymaps are just cleaner and easier to handle.
    
    Instead, we're defining a proper keymap and doing away with
    `engine/keymap-prefix`. This isn't great for backwards compatibility,
    since folks may have been relying on setting that to get the correct
    keymap. Sorry about that. =/
    
    Now users will need to use `engine/set-prefix-key`, which binds the
    keymap. This has the advantage of being a function, instead of just a
    variable, so we should be able to modify it in the future without
    disturbing the interface.
---
 README.md      | 10 +++-------
 engine-mode.el | 29 ++++++++++++++++-------------
 2 files changed, 19 insertions(+), 20 deletions(-)

diff --git a/README.md b/README.md
index 108b6cbbb6..ac0be62837 100644
--- a/README.md
+++ b/README.md
@@ -80,17 +80,13 @@ As mentioned about, see the implementation of the
 ## Changing the keymap prefix
 
 The default keymap prefix for `engine-mode` is `C-c /`. If you'd like
-to use a different prefix (say, `C-c s`), you can redefine it:
+to bind the keymap to an additional prefix (say, `C-c s`), you totally
+can:
 
 ```emacs
-(setq engine/keymap-prefix (kbd "C-c s"))
+(engine/set-keymap-prefix (kbd "C-c s"))
 ```
 
-Make sure you redefine the keymap prefix *before* you define your
-engines. `defengine` uses the prefix internally, so if you change the
-prefix after defining your engines you'll find that they still use the
-old prefix.
-
 ## Custom docstrings
 
 `defengine` assigns each engine a reasonable default docstring, but
diff --git a/engine-mode.el b/engine-mode.el
index 6ad319178f..39067525ad 100644
--- a/engine-mode.el
+++ b/engine-mode.el
@@ -1,7 +1,7 @@
 ;;; engine-mode.el --- Define and query search engines from within Emacs.
 
 ;; Author: Harry R. Schwartz <hello@harryrschwartz.com>
-;; Version: 2015.05.19
+;; Version: 2015.06.13
 ;; URL: https://github.com/hrs/engine-mode/engine-mode.el
 
 ;; This file is NOT part of GNU Emacs.
@@ -23,7 +23,7 @@
 ;; results in your default browser.
 
 ;; The `defengine' macro can also take an optional key combination,
-;; prefixed with `engine/keymap-prefix' (which defaults to "C-c /"):
+;; prefixed with "C-c /":
 
 ;; (defengine duckduckgo
 ;;   "https://duckduckgo.com/?q=%s";
@@ -50,17 +50,24 @@
 ;;; Code:
 (eval-when-compile (require 'cl))
 
+(defvar engine-mode-map (make-sparse-keymap))
+(defvar engine-mode-prefixed-map (make-sparse-keymap))
+
 (define-minor-mode engine-mode
   "Minor mode for defining and querying search engines through Emacs.
 
 \\{engine-mode-map}"
   :global t
-  :keymap (make-sparse-keymap))
+  :keymap engine-mode-map)
 
-(defcustom engine/keymap-prefix (kbd "C-c /")
-  "Engine-mode keymap prefix."
-  :group 'engine-mode
-  :type 'string)
+(defun engine/set-keymap-prefix (prefix-key)
+  "Bind the engine-mode keymap to a new prefix.
+For example, to use \"C-c s\" instead of the default \"C-c /\":
+
+(engine/set-keymap-prefix (kbd \"C-c s\"))"
+  (define-key engine-mode-map prefix-key engine-mode-prefixed-map))
+
+(engine/set-keymap-prefix (kbd "C-c /"))
 
 (defcustom engine/browser-function browse-url-browser-function
   "The default browser function used when opening a URL in an engine.
@@ -96,12 +103,9 @@ Defaults to `browse-url-browser-function'."
           (capitalize (symbol-name engine-name))
           " for the selected text. Prompt for input if none is selected."))
 
-(defun engine/scope-keybinding (keybinding)
-  (concat engine/keymap-prefix " " keybinding))
-
 (defun engine/bind-key (engine-name keybinding)
   (when keybinding
-    `(define-key engine-mode-map (kbd ,(engine/scope-keybinding keybinding))
+    `(define-key engine-mode-prefixed-map ,keybinding
        (quote ,(engine/function-name engine-name)))))
 
 (cl-defmacro defengine (engine-name search-engine-url &key keybinding 
docstring (browser 'engine/browser-function) (term-transformation-hook 
'identity))
@@ -130,8 +134,7 @@ In this case, searching for \"foobar\" will hit the url
 The optional keyword argument `keybinding' is a string describing
 the key to bind the new function.
 
-Keybindings are prefixed by the `engine/keymap-prefix', which
-defaults to `C-c /'.
+Keybindings are in the `engine-mode-map', so they're prefixed.
 
 For example, to search Wikipedia, use: