mu4e: contexts: auto select one at startup, document

When contexts have been defined, automatically select one at startup --
either the first whose match-function returns non-nil, or simply the
first one.

Document this, too.

mu4e/mu4e-context.el

@@ -87,17 +87,27 @@ for the message replied to or forwarded, and nil otherwise. Before composing a n
     (mu4e-message "Switched context to %s" (mu4e-context-name context))
     context))
 
-(defun mu4e-context-determine (msg)
+(defun mu4e-context-autoselect ()
+  "When contexts are defined but there is no context yet, switch
+to the first whose :match-func return non-nil. If none of them
+match, return the first."
+ (when (and mu4e-contexts (not (mu4e-context-current)))
+   (mu4e-context-switch
+     (mu4e-context-name  (mu4e-context-determine nil 'pick-first)))))
+
+(defun mu4e-context-determine (msg &optional pick-first)
   "Return the first context with a match-func that returns t. MSG
   points to the plist for the message replied to or forwarded, or
   nil if there is no such MSG; similar to what
-  `mu4e-compose-pre-hook' does. If no context matches, return
-  nil."
+  `mu4e-compose-pre-hook' does.
+
+If there are contexts but none match, return nil, unless
+  PICK-FIRST is non-nil, in which case return the first context."
   (when mu4e-contexts
-    (find-if (lambda (context)
-	       (and (mu4e-context-match-func context)
-		 (funcall (mu4e-context-match-func context) msg)))
-      mu4e-contexts)))
+    (or (find-if (lambda (context)
+		   (and (mu4e-context-match-func context)
+		     (funcall (mu4e-context-match-func context) msg))) mu4e-contexts)
+      (car mu4e-contexts))))
 
 (provide 'mu4e-context)
  

mu4e/mu4e-utils.el

@@ -46,6 +46,8 @@
 (declare-function mu4e~proc-mkdir     "mu4e-proc")
 (declare-function mu4e~proc-running-p "mu4e-proc")
 
+(declare-function mu4e-context-autoselect  "mu4e-context")
+
 (declare-function show-all "org")
 
 
@@ -148,8 +150,6 @@ see its docstring)."
       (mu4e-error (mu4e-error "mu4e-attachment-dir evaluates to nil")))))
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
-
-
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 (defun mu4e~guess-maildir (path)
   "Guess the maildir for some path, or nil if cannot find it."
@@ -163,8 +163,6 @@ see its docstring)."
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 
-
-
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 (defun mu4e-create-maildir-maybe (dir)
   "Offer to create maildir DIR if it does not exist yet.
@@ -722,9 +720,18 @@ list of contacts we use for autocompletion; otherwise, do nothing."
 	    (mu4e-parse-time-string mu4e-compose-complete-only-after)))))))
 
 (defun mu4e~start (&optional func)
-  "If mu4e is already running, execute function FUNC (if non-nil).
+  "If `mu4e-contexts' have been defined, but we don't have a
+context yet, switch to the matching one, or none matches, the
+first.
+If mu4e is already running, execute function FUNC (if non-nil).
 Otherwise, check various requirements, then start mu4e. When
 successful, call FUNC (if non-nil) afterwards."
+
+  ;; auto-select some account
+  (mu4e-context-autoselect)
+ 
+  ;; (when (and mu4e-contexts (not (mu4e-context-current)))
+  ;;   (mu4e-switch-context (mu4e-context-determine nil 'pick-first))
   ;; if we're already running, simply go to the main view
   (if (mu4e-running-p)   ;; already running?
     (when func                 ;; yes! run func if defined

mu4e/mu4e.texi

@@ -2255,13 +2255,14 @@ example:
 
 @menu
 * Defining a context::
+* Default context::
 * Contexts example::  
 * Contexts notes::
+* Some context tricks::
 @end menu
 
-
 It can be useful to be able to switch between different sets of settings
-in mu4e; typical examples include the case where you have different
+in @t{mu4e}; typical examples include the case where you have different
 e-mail accounts for private and work email, each with their own settings
 for e-mail addresses, mailservers etc.
 
@@ -2293,6 +2294,11 @@ an optional function that is invoked before replying to or forwarding a
 message with the given message plist as parameter, or @t{nil} when
 composing a brand new message. The function should return @t{t} when
 this context is the right one for this message, or @t{nil} otherwise.
+
+The function is also invoked when starting @t{mu4e} to determine the
+starting context; in that case, the message-parameter is nil. You can
+use e.g. the host you're running or or perhaps the time of day or even
+your location to determine the context.
 @item @t{vars}:
 an alist of variable settings for this account.
 @end itemize
@@ -2300,18 +2306,29 @@ an alist of variable settings for this account.
 @t{mu4e} uses a variable @code{mu4e-contexts}, which is a list of such
 objects.
 
+@node Default context
+@section Default context
+
+When you have defined contexts and you start @t{mu4e}, it automatically
+switches to the first context whose @code{match-func} returns
+non-nil. If none of them do, it picks the first. So, put your 'default'
+context as the first in @code{mu4e-contexts}.
+
 @node Contexts example
 @section Example
 
 Let's look at an example; we define two contexts, 'Private' and 'Work'
 for a fictional user Alice Derleth.
 
+Note that in this case, we automatically switch to the first context
+when starting; see the discussion in the previous section.
+
 @lisp
 (setq mu4e-contexts
   `( ,(make-mu4e-context
 	:name "Private"
-	:enter-func (lambda () (mu4e-message "Private mail"))
-        ;; no leave-func
+	:enter-func (lambda () (mu4e-message "Switch to the Private context")) 
+        ;; leave-func not defined
 	:match-func (lambda (msg)
 		      (when msg (mu4e-message-contact-field-matches msg :to "aliced@@home.com")))
 	:vars '(  ( mail-reply-to          . "aliced@@home.com" )	
@@ -2323,7 +2340,8 @@ for a fictional user Alice Derleth.
 		      "Lauttasaari, Finland\n")))) 
      ,(make-mu4e-context
 	:name "Work"
-	:enter-func (lambda () (message "Work"))
+	:enter-func (lambda () (mu4e-message "Switch to the Work context"))
+        ;; leave-fun not defined
 	:match-func (lambda (msg)
 		      (when msg (mu4e-message-contact-field-matches msg :to "aderleth@@miskatonic.edu")))
 	:vars '(  ( mail-reply-to          . "aderleth@@miskatonic.edu" )	
@@ -2333,10 +2351,31 @@ for a fictional user Alice Derleth.
 		    (concat
 		      "Prof. Alice Derleth\n"
 		      "Miskatonic University, Dept. of Occult Sciences\n"))))))
+@end lisp
 
-;; Set default context
-(mu4e-context-switch "Private")
-;; Set mu4e-user-mail-address-list to reflect the contexts' addresses
+@node Contexts notes
+@section Context notes
+
+Couple of notes:
+@itemize
+@item You can manually switch the focus use @code{M-x mu4e-context-switch}, by default bound to @code{;} in headers, view and main mode. The current focus appears in the mode-line.
+@item The function @code{mu4e-context-current} returns the current-context; the current context is also visiable in the mode-line when in headers, view or main mode.
+@item You can set any kind of variable; including settings for mail servers etc. However, settings like @code{mu4e-maildir} and @code{mu4e-mu-home} are not changeable after they have been set without quiting @t{mu4e} first.
+@item @code{leave-func} (if defined) for the context we are leaving, is invoked before the @code{enter-func} (if defined) of the context we are entering.
+@item @code{enter-func} (if defined) is invoked before setting the variables.
+@item @code{match-func} (if defined) is invoked just before @code{mu4e-compose-pre-hook}. 
+@item Finally, be careful to get the quotations right -- backticks, single quotes and commas and note the '.' between variable name and value.
+@end itemize
+
+@section Some context tricks
+@node Some context tricks
+
+It is possible to automatically fill @code{mu4e-user-address-list} by
+concatenating the @code{user-mail-address} fields of all contexts:
+
+@lisp
+;; This sets `mu4e-user-mail-address-list' to the concatenation of all `user-mail-address' values
+;; for all contexts. If you have other mail addresses as well, you'll need to add those manually. 
 (setq mu4e-user-mail-address-list
       (delq nil
             (mapcar (lambda (context)
@@ -2345,19 +2384,6 @@ for a fictional user Alice Derleth.
                     mu4e-contexts)))
 @end lisp
 
-@node Contexts notes
-@section Notes
-
-Couple of notes:
-@itemize
-@item You can manually switch the focus use @code{M-x mu4e-context-switch}, by default bound to @code{;} in headers, view and main mode. The current focus shows in the mode-line.
-@item The function @code{mu4e-context-current} returns the current-context; the current context is also visiable in the mode-line when in headers, view or main mode.
-@item You can set any kind of variable; including settings for mail servers etc. However, settings like @code{mu4e-maildir} and @code{mu4e-mu-home} are not changeable after they have been set without quiting @t{mu4e} firts.
-@item @code{leave-func} (if defined) for the context we are leaving, is invoked before the @code{enter-func} (if defined) of the context we are entering.
-@item @code{enter-func} (if defined) is invoked before setting the variables.
-@item @code{match-func} (if defined) is invoked just before @code{mu4e-compose-pre-hook}. 
-@item Finally, be careful to get the quotations right -- backticks, single quotes and commas and note the '.' between variable name and value.
-@end itemize
 
 
 @node Dynamic folders