;;; gnus-win.el --- window configuration functions for Gnus
;; Copyright (C) 1996, 1997, 1998, 1999, 2000
;;        Free Software Foundation, Inc.

;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; Keywords: news

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;;; Code:

(eval-when-compile (require 'cl))

(require 'gnus)

(defgroup gnus-windows nil
  "Window configuration."
  :group 'gnus)

(defcustom gnus-use-full-window t
  "*If non-nil, use the entire Emacs screen."
  :group 'gnus-windows
  :type 'boolean)

(defvar gnus-window-configuration nil
  "Obsolete variable.  See `gnus-buffer-configuration'.")

(defcustom gnus-window-min-width 2
  "*Minimum width of Gnus buffers."
  :group 'gnus-windows
  :type 'integer)

(defcustom gnus-window-min-height 1
  "*Minimum height of Gnus buffers."
  :group 'gnus-windows
  :type 'integer)

(defcustom gnus-always-force-window-configuration nil
  "*If non-nil, always force the Gnus window configurations."
  :group 'gnus-windows
  :type 'boolean)

(defvar gnus-buffer-configuration
  '((group
     (vertical 1.0
	       (group 1.0 point)
	       (if gnus-carpal '(group-carpal 4))))
    (summary
     (vertical 1.0
	       (summary 1.0 point)
	       (if gnus-carpal '(summary-carpal 4))))
    (article
     (cond
      ((and gnus-use-picons
	    (eq gnus-picons-display-where 'picons))
       '(frame 1.0
	       (vertical 1.0
			 (summary 0.25 point)
			 (if gnus-carpal '(summary-carpal 4))
			 (article 1.0))
	       (vertical ((height . 5) (width . 15)
			  (user-position . t)
			  (left . -1) (top . 1))
			 (picons 1.0))))
      (gnus-use-trees
       '(vertical 1.0
		  (summary 0.25 point)
		  (tree 0.25)
		  (article 1.0)))
      (t
       '(vertical 1.0
		  (summary 0.25 point)
		  (if gnus-carpal '(summary-carpal 4))
		  (article 1.0)))))
    (server
     (vertical 1.0
	       (server 1.0 point)
	       (if gnus-carpal '(server-carpal 2))))
    (browse
     (vertical 1.0
	       (browse 1.0 point)
	       (if gnus-carpal '(browse-carpal 2))))
    (message
     (vertical 1.0
	       (message 1.0 point)))
    (pick
     (vertical 1.0
	       (article 1.0 point)))
    (info
     (vertical 1.0
	       (info 1.0 point)))
    (summary-faq
     (vertical 1.0
	       (summary 0.25)
	       (faq 1.0 point)))
    (edit-article
     (vertical 1.0
	       (article 1.0 point)))
    (edit-form
     (vertical 1.0
	       (group 0.5)
	       (edit-form 1.0 point)))
    (edit-score
     (vertical 1.0
	       (summary 0.25)
	       (edit-score 1.0 point)))
    (post
     (vertical 1.0
	       (post 1.0 point)))
    (reply
     (vertical 1.0
	       (article-copy 0.5)
	       (message 1.0 point)))
    (forward
     (vertical 1.0
	       (message 1.0 point)))
    (reply-yank
     (vertical 1.0
	       (message 1.0 point)))
    (mail-bounce
     (vertical 1.0
	       (article 0.5)
	       (message 1.0 point)))
    (pipe
     (vertical 1.0
	       (summary 0.25 point)
	       (if gnus-carpal '(summary-carpal 4))
	       ("*Shell Command Output*" 1.0)))
    (bug
     (vertical 1.0
	       ("*Gnus Help Bug*" 0.5)
	       ("*Gnus Bug*" 1.0 point)))
    (score-trace
     (vertical 1.0
	       (summary 0.5 point)
	       ("*Score Trace*" 1.0)))
    (score-words
     (vertical 1.0
	       (summary 0.5 point)
	       ("*Score Words*" 1.0)))
    (split-trace
     (vertical 1.0
	       (summary 0.5 point)
	       ("*Split Trace*" 1.0)))
    (category
     (vertical 1.0
	       (category 1.0)))
    (compose-bounce
     (vertical 1.0
	       (article 0.5)
	       (message 1.0 point))))
  "Window configuration for all possible Gnus buffers.
See the Gnus manual for an explanation of the syntax used.")

(defvar gnus-window-to-buffer
  '((group . gnus-group-buffer)
    (summary . gnus-summary-buffer)
    (article . gnus-article-buffer)
    (server . gnus-server-buffer)
    (browse . "*Gnus Browse Server*")
    (edit-group . gnus-group-edit-buffer)
    (edit-form . gnus-edit-form-buffer)
    (edit-server . gnus-server-edit-buffer)
    (group-carpal . gnus-carpal-group-buffer)
    (summary-carpal . gnus-carpal-summary-buffer)
    (server-carpal . gnus-carpal-server-buffer)
    (browse-carpal . gnus-carpal-browse-buffer)
    (edit-score . gnus-score-edit-buffer)
    (message . gnus-message-buffer)
    (mail . gnus-message-buffer)
    (post-news . gnus-message-buffer)
    (faq . gnus-faq-buffer)
    (picons . gnus-picons-buffer-name)
    (tree . gnus-tree-buffer)
    (score-trace . "*Score Trace*")
    (split-trace . "*Split Trace*")
    (info . gnus-info-buffer)
    (category . gnus-category-buffer)
    (article-copy . gnus-article-copy)
    (draft . gnus-draft-buffer))
  "Mapping from short symbols to buffer names or buffer variables.")

;;; Internal variables.

(defvar gnus-current-window-configuration nil
  "The most recently set window configuration.")

(defvar gnus-created-frames nil)
(defvar gnus-window-frame-focus nil)

(defun gnus-kill-gnus-frames ()
  "Kill all frames Gnus has created."
  (while gnus-created-frames
    (when (frame-live-p (car gnus-created-frames))
      ;; We slap a condition-case around this `delete-frame' to ensure
      ;; against errors if we try do delete the single frame that's left.
      (ignore-errors
	(delete-frame (car gnus-created-frames))))
    (pop gnus-created-frames)))

(defun gnus-window-configuration-element (list)
  (while (and list
	      (not (assq (car list) gnus-window-configuration)))
    (pop list))
  (cadr (assq (car list) gnus-window-configuration)))

(defun gnus-windows-old-to-new (setting)
  ;; First we take care of the really, really old Gnus 3 actions.
  (when (symbolp setting)
    (setq setting
	  ;; Take care of ooold GNUS 3.x values.
	  (cond ((eq setting 'SelectArticle) 'article)
		((memq setting '(SelectNewsgroup SelectSubject ExpandSubject))
		 'summary)
		((memq setting '(ExitNewsgroup)) 'group)
		(t setting))))
  (if (or (listp setting)
	  (not (and gnus-window-configuration
		    (memq setting '(group summary article)))))
      setting
    (let* ((elem
	    (cond
	     ((eq setting 'group)
	      (gnus-window-configuration-element
	       '(group newsgroups ExitNewsgroup)))
	     ((eq setting 'summary)
	      (gnus-window-configuration-element
	       '(summary SelectNewsgroup SelectSubject ExpandSubject)))
	     ((eq setting 'article)
	      (gnus-window-configuration-element
	       '(article SelectArticle)))))
	   (total (apply '+ elem))
	   (types '(group summary article))
	   (pbuf (if (eq setting 'newsgroups) 'group 'summary))
	   (i 0)
	   perc out)
      (while (< i 3)
	(or (not (numberp (nth i elem)))
	    (zerop (nth i elem))
	    (progn
	      (setq perc (if (= i 2)
			     1.0
			   (/ (float (nth i elem)) total)))
	      (push (if (eq pbuf (nth i types))
			(list (nth i types) perc 'point)
		      (list (nth i types) perc))
		    out)))
	(incf i))
      `(vertical 1.0 ,@(nreverse out)))))

;;;###autoload
(defun gnus-add-configuration (conf)
  "Add the window configuration CONF to `gnus-buffer-configuration'."
  (setq gnus-buffer-configuration
	(cons conf (delq (assq (car conf) gnus-buffer-configuration)
			 gnus-buffer-configuration))))

(defvar gnus-frame-list nil)

(defun gnus-window-to-buffer-helper (obj)
  (cond ((not (symbolp obj))
	 obj)
	((boundp obj)
	 (symbol-value obj))
	((fboundp obj)
	 (funcall obj))
	(t
	 nil)))

(defun gnus-configure-frame (split &optional window)
  "Split WINDOW according to SPLIT."
  (let ((current-window
	 (or (get-buffer-window (current-buffer)) (selected-window))))
    (unless window
      (setq window current-window))
    (select-window window)
    ;; This might be an old-stylee buffer config.
    (when (vectorp split)
      (setq split (append split nil)))
    (when (or (consp (car split))
	      (vectorp (car split)))
      (push 1.0 split)
      (push 'vertical split))
    ;; The SPLIT might be something that is to be evaled to
    ;; return a new SPLIT.
    (while (and (not (assq (car split) gnus-window-to-buffer))
		(gnus-functionp (car split)))
      (setq split (eval split)))
    (let* ((type (car split))
	   (subs (cddr split))
	   (len (if (eq type 'horizontal) (window-width) (window-height)))
	   (total 0)
	   (window-min-width (or gnus-window-min-width window-min-width))
	   (window-min-height (or gnus-window-min-height window-min-height))
	   s result new-win rest comp-subs size sub)
      (cond
       ;; Nothing to do here.
       ((null split))
       ;; Don't switch buffers.
       ((null type)
	(and (memq 'point split) window))
       ;; This is a buffer to be selected.
       ((not (memq type '(frame horizontal vertical)))
	(let ((buffer (cond ((stringp type) type)
			    (t (cdr (assq type gnus-window-to-buffer))))))
	  (unless buffer
	    (error "Invalid buffer type: %s" type))
	  (let ((buf (gnus-get-buffer-create
		      (gnus-window-to-buffer-helper buffer))))
	    (if (eq buf (window-buffer (selected-window))) (set-buffer buf)
	      (switch-to-buffer buf)))
	  (when (memq 'frame-focus split)
	    (setq gnus-window-frame-focus window))
	  ;; We return the window if it has the `point' spec.
	  (and (memq 'point split) window)))
       ;; This is a frame split.
       ((eq type 'frame)
	(unless gnus-frame-list
	  (setq gnus-frame-list (list (window-frame current-window))))
	(let ((i 0)
	      params frame fresult)
	  (while (< i (length subs))
	    ;; Frame parameter is gotten from the sub-split.
	    (setq params (cadr (elt subs i)))
	    ;; It should be a list.
	    (unless (listp params)
	      (setq params nil))
	    ;; Create a new frame?
	    (unless (setq frame (elt gnus-frame-list i))
	      (nconc gnus-frame-list (list (setq frame (make-frame params))))
	      (push frame gnus-created-frames))
	    ;; Is the old frame still alive?
	    (unless (frame-live-p frame)
	      (setcar (nthcdr i gnus-frame-list)
		      (setq frame (make-frame params))))
	    ;; Select the frame in question and do more splits there.
	    (select-frame frame)
	    (setq fresult (or (gnus-configure-frame (elt subs i)) fresult))
	    (incf i))
	  ;; Select the frame that has the selected buffer.
	  (when fresult
	    (select-frame (window-frame fresult)))))
       ;; This is a normal split.
       (t
	(when (> (length subs) 0)
	  ;; First we have to compute the sizes of all new windows.
	  (while subs
	    (setq sub (append (pop subs) nil))
	    (while (and (not (assq (car sub) gnus-window-to-buffer))
			(gnus-functionp (car sub)))
	      (setq sub (eval sub)))
	    (when sub
	      (push sub comp-subs)
	      (setq size (cadar comp-subs))
	      (cond ((equal size 1.0)
		     (setq rest (car comp-subs))
		     (setq s 0))
		    ((floatp size)
		     (setq s (floor (* size len))))
		    ((integerp size)
		     (setq s size))
		    (t
		     (error "Invalid size: %s" size)))
	      ;; Try to make sure that we are inside the safe limits.
	      (cond ((zerop s))
		    ((eq type 'horizontal)
		     (setq s (max s window-min-width)))
		    ((eq type 'vertical)
		     (setq s (max s window-min-height))))
	      (setcar (cdar comp-subs) s)
	      (incf total s)))
	  ;; Take care of the "1.0" spec.
	  (if rest
	      (setcar (cdr rest) (- len total))
	    (error "No 1.0 specs in %s" split))
	  ;; The we do the actual splitting in a nice recursive
	  ;; fashion.
	  (setq comp-subs (nreverse comp-subs))
	  (while comp-subs
	    (if (null (cdr comp-subs))
		(setq new-win window)
	      (setq new-win
		    (split-window window (cadar comp-subs)
				  (eq type 'horizontal))))
	    (setq result (or (gnus-configure-frame
			      (car comp-subs) window)
			     result))
	    (select-window new-win)
	    (setq window new-win)
	    (setq comp-subs (cdr comp-subs))))
	;; Return the proper window, if any.
	(when result
	  (select-window result)))))))

(defvar gnus-frame-split-p nil)

(defun gnus-configure-windows (setting &optional force)
  (if (window-configuration-p setting)
      (set-window-configuration setting)
    (setq gnus-current-window-configuration setting)
    (setq force (or force gnus-always-force-window-configuration))
    (setq setting (gnus-windows-old-to-new setting))
    (let ((split (if (symbolp setting)
		     (cadr (assq setting gnus-buffer-configuration))
		   setting))
	  all-visible)

      (setq gnus-frame-split-p nil)

      (unless split
	(error "No such setting in `gnus-buffer-configuration': %s" setting))

      (if (and (setq all-visible (gnus-all-windows-visible-p split))
	       (not force))
	  ;; All the windows mentioned are already visible, so we just
	  ;; put point in the assigned buffer, and do not touch the
	  ;; winconf.
	  (select-window all-visible)
	
	;; Make sure "the other" buffer, nntp-server-buffer, is live.
	(unless (gnus-buffer-live-p nntp-server-buffer)
	  (nnheader-init-server-buffer))

	;; Either remove all windows or just remove all Gnus windows.
	(let ((frame (selected-frame)))
	  (unwind-protect
	      (if gnus-use-full-window
		  ;; We want to remove all other windows.
		  (if (not gnus-frame-split-p)
		      ;; This is not a `frame' split, so we ignore the
		      ;; other frames.
		      (delete-other-windows)
		    ;; This is a `frame' split, so we delete all windows
		    ;; on all frames.
		    (gnus-delete-windows-in-gnusey-frames))
		;; Just remove some windows.
		(gnus-remove-some-windows)
		(if (featurep 'xemacs)
		    (switch-to-buffer nntp-server-buffer)
		  (set-buffer nntp-server-buffer)))
	    (select-frame frame)))

	(let (gnus-window-frame-focus)
	  (if (featurep 'xemacs)
	      (switch-to-buffer nntp-server-buffer)
	    (set-buffer nntp-server-buffer))
	  (gnus-configure-frame split)
	  (when gnus-window-frame-focus
	    (select-frame (window-frame gnus-window-frame-focus))))))))

(defun gnus-delete-windows-in-gnusey-frames ()
  "Do a `delete-other-windows' in all frames that have Gnus windows."
  (let ((buffers (gnus-buffers)))
    (mapcar
     (lambda (frame)
       (unless (eq (cdr (assq 'minibuffer
			      (frame-parameters frame)))
		   'only)
	 (select-frame frame)
	 (let (do-delete)
	   (walk-windows
	    (lambda (window)
	      (when (memq (window-buffer window) buffers)
		(setq do-delete t))))
	   (when do-delete
	     (delete-other-windows)))))
     (frame-list))))

(defun gnus-all-windows-visible-p (split)
  "Say whether all buffers in SPLIT are currently visible.
In particular, the value returned will be the window that
should have point."
  (let ((stack (list split))
	(all-visible t)
	type buffer win buf)
    (while (and (setq split (pop stack))
		all-visible)
      ;; Be backwards compatible.
      (when (vectorp split)
	(setq split (append split nil)))
      (when (or (consp (car split))
		(vectorp (car split)))
	(push 1.0 split)
	(push 'vertical split))
      ;; The SPLIT might be something that is to be evaled to
      ;; return a new SPLIT.
      (while (and (not (assq (car split) gnus-window-to-buffer))
		  (gnus-functionp (car split)))
	(setq split (eval split)))

      (setq type (elt split 0))
      (cond
       ;; Nothing here.
       ((null split) t)
       ;; A buffer.
       ((not (memq type '(horizontal vertical frame)))
	(setq buffer (cond ((stringp type) type)
			   (t (cdr (assq type gnus-window-to-buffer)))))
	(unless buffer
	  (error "Invalid buffer type: %s" type))
	(if (and (setq buf (get-buffer (gnus-window-to-buffer-helper buffer)))
		 (setq win (get-buffer-window buf t)))
	    (if (memq 'point split)
		(setq all-visible win))
	  (setq all-visible nil)))
       (t
	(when (eq type 'frame)
	  (setq gnus-frame-split-p t))
	(setq stack (append (cddr split) stack)))))
    (unless (eq all-visible t)
      all-visible)))

(defun gnus-window-top-edge (&optional window)
  (nth 1 (window-edges window)))

(defun gnus-remove-some-windows ()
  (let ((buffers (gnus-buffers))
	buf bufs lowest-buf lowest)
    (save-excursion
      ;; Remove windows on all known Gnus buffers.
      (while (setq buf (pop buffers))
	(when (get-buffer-window buf)
	  (push buf bufs)
	  (pop-to-buffer buf)
	  (when (or (not lowest)
		    (< (gnus-window-top-edge) lowest))
	    (setq lowest (gnus-window-top-edge)
		  lowest-buf buf))))
      (when lowest-buf
	(pop-to-buffer lowest-buf)
	(if (featurep 'xemacs)
	    (switch-to-buffer nntp-server-buffer)
	  (set-buffer nntp-server-buffer)))
      (mapcar (lambda (b) (delete-windows-on b t)) bufs))))

(provide 'gnus-win)

;;; gnus-win.el ends here
