[Erc-commit] [commit][emacs22] erc-track: Make C-c C-SPC comply with Emacs devel rules

[mwolson]

commit 9638facd896730c4ef573ccc4c7922b73bd8cd08
Author: Michael Olson <address@hidden>
Date:   Fri Mar 30 03:19:13 2007 +0000

    erc-track: Make C-c C-SPC comply with Emacs devel rules
    
    2007-03-30  Michael Olson  <address@hidden>
    
        * FOR-RELEASE: Solve C-c C-SPC keybinding dilemma.
    
        * erc-track.el (track): Call
        erc-track-minor-mode-maybe, and tear down the minor mode when
        disabling.
        (erc-track-enable-keybindings): New option which determines
        whether to enable the global-level tracking keybindings.  The
        default is to do so, unless they would override another binding,
        in which case we prompt the user about it.
        (erc-track-minor-mode-map): Move global keybindings here.
        (erc-track-minor-mode): New minor mode which only enables the
        keybindings and does nothing else.
        (erc-track-minor-mode-maybe): New function which starts
        erc-track-minor-mode, but only if it hasn't already been started,
        an ERC buffer exists, and the user OK's it, depending on the value
        of `erc-track-enable-keybindings'.
        (erc-track-switch-buffer): Display a message if someone calls this
        without first enabling erc-track-mode.
    git-archimport-id: address@hidden/erc--main--0--patch-124

diff --git a/ChangeLog b/ChangeLog
index 82ecfb4..06500dc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,7 @@
 2007-03-30  Michael Olson  <address@hidden>
 
+       * FOR-RELEASE: Solve C-c C-SPC keybinding dilemma.
+
        * erc-autoaway.el (erc-autoaway-idle-method): Use `if' rather than
        `cond' and `set' rather than `set-default'.
 
@@ -13,11 +15,26 @@
 
        * erc-track.el (track): Assimilate track-when-active module, since
        there's no need to have two modules in one file -- an option will
-       do.  Remove track-modified-channels alias.
+       do.  Remove track-modified-channels alias.  Call
+       erc-track-minor-mode-maybe, and tear down the minor mode when
+       disabling.
        (erc-track-when-inactive): New option which determines whether to
        track visible buffers when inactive.  The default is not to do so.
        (erc-track-visibility): Mention erc-track-when-inactive.
        (erc-buffer-visible): Use erc-track-when-inactive.
+       (erc-track-enable-keybindings): New option which determines
+       whether to enable the global-level tracking keybindings.  The
+       default is to do so, unless they would override another binding,
+       in which case we prompt the user about it.
+       (erc-track-minor-mode-map): Move global keybindings here.
+       (erc-track-minor-mode): New minor mode which only enables the
+       keybindings and does nothing else.
+       (erc-track-minor-mode-maybe): New function which starts
+       erc-track-minor-mode, but only if it hasn't already been started,
+       an ERC buffer exists, and the user OK's it, depending on the value
+       of `erc-track-enable-keybindings'.
+       (erc-track-switch-buffer): Display a message if someone calls this
+       without first enabling erc-track-mode.
 
 2007-03-17  Michael Olson  <address@hidden>
 
diff --git a/FOR-RELEASE b/FOR-RELEASE
index 8d8c486..0a26ba5 100644
--- a/FOR-RELEASE
+++ b/FOR-RELEASE
@@ -31,12 +31,17 @@ erc--main--0 branch.
 *** [DONE] Make M-x erc start a session.
 New users never think of using M-x erc-select.
 
-*** Change keybinding definitions for `erc-track-switch-buffer'.
+*** [DONE] Change keybinding definitions for `erc-track-switch-buffer'.
 `C-c C-SPC' / `C-c C-@' is set as a global keybinding and is known to
 conflict with rcirc, for example.  Would setting `erc-track-mode-map'
 work?  Otherwise we could encourage people to use something like
 `C-c e SPC' or `C-c c'.
 
+**** Solution: We went with a global minor mode which does nothing
+but set the global-level C-c C-SPC and C-c C-@ keybindings.  It
+defaults to warning the user if one of their keybindings would be
+overridden, so this solution should be OK to install in Emacs.
+
 *** Make a tarball with the modules that weren't included with
 Emacs 22 that can be downloaded from GNU's ftp server.
 
diff --git a/erc-track.el b/erc-track.el
index baacba5..4a8b673 100644
--- a/erc-track.el
+++ b/erc-track.el
@@ -47,6 +47,27 @@
   "Track active buffers and show activity in the modeline."
   :group 'erc)
 
+(defcustom erc-track-enable-keybindings 'ask
+  "Whether to enable the ERC track keybindings, namely:
+`C-c C-SPC' and `C-c C-@', which both do the same thing.
+
+The default is to check to see whether these keys are used
+already: if not, then enable the ERC track minor mode, which
+provides these keys.  Otherwise, do not touch the keys.
+
+This can alternatively be set to either t or nil, which indicate
+respectively always to enable ERC track minor mode or never to
+enable ERC track minor mode.
+
+The reason for using this default value is to both (1) adhere to
+the Emacs development guidelines which say not to touch keys of
+the form C-c C-<something> and also (2) to meet the expectations
+of long-time ERC users, many of whom rely on these keybindings."
+  :group 'erc-track
+  :type '(choice (const :tag "Ask, if used already" ask)
+                (const :tag "Enable" t)
+                (const :tag "Disable" nil)))
+
 (defcustom erc-track-visibility t
   "Where do we look for buffers to determine their visibility?
 The value of this variable determines, when a buffer is considered
@@ -489,6 +510,61 @@ START is the minimum length of the name used."
         (equal (erc-unique-substrings '("abc" "abcdefg"))
                '("abc" "abcd"))))))
 
+;;; Minor mode
+
+;; Play nice with other IRC clients (and Emacs development rules) by
+;; making this a minor mode
+
+(defvar erc-track-minor-mode-map (make-sparse-keymap)
+  "Keymap for rcirc track minor mode.")
+
+(define-key erc-track-minor-mode-map (kbd "C-c C-@") 'erc-track-switch-buffer)
+(define-key erc-track-minor-mode-map (kbd "C-c C-SPC")
+  'erc-track-switch-buffer)
+
+;;;###autoload
+(define-minor-mode erc-track-minor-mode
+  "Global minor mode for tracking ERC buffers and showing activity in the
+mode line.
+
+This exists for the sole purpose of providing the C-c C-SPC and
+C-c C-@ keybindings.  Make sure that you have enabled the track
+module, otherwise the keybindings will not do anything useful."
+  :init-value nil
+  :lighter ""
+  :keymap erc-track-minor-mode-map
+  :global t
+  :group 'erc-track)
+
+(defun erc-track-minor-mode-maybe ()
+  "Enable `erc-track-minor-mode', depending on `erc-track-enable-keybindings'."
+  (unless (or erc-track-minor-mode
+             ;; don't start the minor mode until we have an ERC
+             ;; process running, because we don't want to prompt the
+             ;; user while starting Emacs
+             (null (erc-buffer-list)))
+    (cond ((eq erc-track-enable-keybindings 'ask)
+          (let ((key (or (and (key-binding (kbd "C-c C-SPC")) "C-SPC")
+                         (and (key-binding (kbd "C-c C-@")) "C-@"))))
+            (if key
+                (if (y-or-n-p
+                     (concat "The C-c " key " binding is in use;"
+                             " override it for tracking? "))
+                    (progn
+                      (message (concat "Will change it; set"
+                                       " `erc-track-enable-keybindings'"
+                                       " to disable this message"))
+                      (sleep-for 3)
+                      (erc-track-minor-mode 1))
+                  (message (concat "Not changing it; set"
+                                   " `erc-track-enable-keybindings'"
+                                   " to disable this message"))
+                  (sleep-for 3))
+              (erc-track-minor-mode 1))))
+         ((eq erc-track-enable-keybindings t)
+          (erc-track-minor-mode 1))
+         (t nil))))
+
 ;;; Module
 
 ;;;###autoload (autoload 'erc-track-mode "erc-track" nil t)
@@ -514,7 +590,9 @@ START is the minimum length of the name used."
         (add-hook 'window-configuration-change-hook
                   'erc-modified-channels-update))
        (add-hook 'erc-insert-post-hook 'erc-track-modified-channels)
-       (add-hook 'erc-disconnected-hook 'erc-modified-channels-update))))
+       (add-hook 'erc-disconnected-hook 'erc-modified-channels-update))
+     ;; enable the tracking keybindings
+     (erc-track-minor-mode-maybe)))
   ;; Disable:
   ((when (boundp 'erc-track-when-inactive)
      (erc-track-remove-from-mode-line)
@@ -533,7 +611,10 @@ START is the minimum length of the name used."
         (remove-hook 'window-configuration-change-hook
                      'erc-modified-channels-update))
        (remove-hook 'erc-disconnected-hook 'erc-modified-channels-update)
-       (remove-hook 'erc-insert-post-hook 'erc-track-modified-channels)))))
+       (remove-hook 'erc-insert-post-hook 'erc-track-modified-channels))
+     ;; disable the tracking keybindings
+     (when erc-track-minor-mode
+       (erc-track-minor-mode -1)))))
 
 (defcustom erc-track-when-inactive nil
   "Enable channel tracking even for visible buffers, if you are
@@ -835,7 +916,9 @@ relative to `erc-track-switch-direction'"
 switch back to the last non-ERC buffer visited.  Next is defined by
 `erc-track-switch-direction', a negative argument will reverse this."
   (interactive "p")
-  (when erc-track-mode
+  (if (not erc-track-mode)
+      (message (concat "Enable the ERC track module if you want to use the"
+                      " tracking minor mode"))
     (cond (erc-modified-channels-alist
           ;; if we're not in erc-mode, set this buffer to return to
           (unless (eq major-mode 'erc-mode)
@@ -848,12 +931,6 @@ switch back to the last non-ERC buffer visited.  Next is 
defined by
                (buffer-live-p erc-track-last-non-erc-buffer))
           (switch-to-buffer erc-track-last-non-erc-buffer)))))
 
-;; These bindings are global, because they pop us from any other
-;; buffer to an active ERC buffer!
-
-(global-set-key (kbd "C-c C-@") 'erc-track-switch-buffer)
-(global-set-key (kbd "C-c C-SPC") 'erc-track-switch-buffer)
-
 (provide 'erc-track)
 
 ;;; erc-track.el ends here