bug#19131: 25.0.50; [PATCH] eww.el: Create simple mode to manage eww buffers

[Andrey Kotlarski <m00naticus@gmail.com>]

Once opening new buffers becomes easier, there should be way to manage
the ensuing chaos.  Following patch adds simple interface that allows
showing, switching to and killing eww buffers.

(worry not about size, me papers has signed)

---
 lisp/ChangeLog  |   7 +++
 lisp/net/eww.el | 130 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 137 insertions(+)

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 473a1f8..2b28946 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,10 @@
+2014-11-20  Andrey Kotlarski  <m00naticus@gmail.com>
+
+	* net/eww.el (eww-buffers-mode): New major mode.
+	(eww-list-buffers, eww-buffer-select, eww-buffer-show-next)
+	(eww-buffer-show-previous, eww-buffer-kill, eww-buffer-show): New
+	commands/functions.
+
 2014-11-20  Eric S. Raymond  <esr@snark>
 
 	* vc/vc-bzr.el, vc/vc-cvs.el, vc/vc-dav.el, vc/vc-git.el,
diff --git a/lisp/net/eww.el b/lisp/net/eww.el
index 6746668..5f8ebae 100644
--- a/lisp/net/eww.el
+++ b/lisp/net/eww.el
@@ -567,6 +567,7 @@ the like."
     (define-key map "v" 'eww-view-source)
     (define-key map "R" 'eww-readable)
     (define-key map "H" 'eww-list-histories)
+    (define-key map "S" 'eww-list-buffers)
 
     (define-key map "b" 'eww-add-bookmark)
     (define-key map "B" 'eww-list-bookmarks)
@@ -587,6 +588,7 @@ the like."
 	["View page source" eww-view-source]
 	["Copy page URL" eww-copy-page-url t]
 	["List histories" eww-list-histories t]
+	["List buffers" eww-list-buffers t]
 	["Add bookmark" eww-add-bookmark t]
 	["List bookmarks" eww-list-bookmarks t]
 	["List cookies" url-cookie-list t]))
@@ -1560,6 +1562,134 @@ Differences in #targets are ignored."
   (setq buffer-read-only t
 	truncate-lines t))
 
+;;; eww buffers list
+
+(defun eww-list-buffers ()
+  "List the eww-histories."
+  (interactive)
+  (let (buffers-info
+        (current (current-buffer)))
+    (dolist (buffer (buffer-list))
+      (with-current-buffer buffer
+        (if (derived-mode-p 'eww-mode)
+            (push (vector buffer (plist-get eww-data :title)
+                          (plist-get eww-data :url))
+                  buffers-info))))
+    (or buffers-info
+        (error "No eww buffers"))
+    (setq buffers-info (nreverse buffers-info)) ;get more recent on top
+    (set-buffer (get-buffer-create "*eww buffers*"))
+    (eww-buffers-mode)
+    (let ((inhibit-read-only t)
+          (domain-length 0)
+          (title-length 0)
+          url title format start)
+      (erase-buffer)
+      (dolist (buffer-info buffers-info)
+        (setq title-length (max title-length
+                                (length (elt buffer-info 1)))
+              domain-length (max domain-length
+                                 (length (elt buffer-info 2)))))
+      (setq format (format "%%-%ds %%-%ds" title-length domain-length)
+            header-line-format
+            (concat " " (format format "Title" "URL")))
+      (let ((line 0)
+            (current-buffer-line 1))
+        (dolist (buffer-info buffers-info)
+          (setq start (point)
+                title (elt buffer-info 1)
+                url (elt buffer-info 2)
+                line (1+ line))
+          (insert (format format title url))
+          (insert "\n")
+          (let ((buffer (elt buffer-info 0)))
+            (put-text-property start (1+ start) 'eww-buffer
+                               buffer)
+            (if (eq current buffer)
+                (setq current-buffer-line line))))
+        (goto-char (point-min))
+        (forward-line (1- current-buffer-line)))))
+  (pop-to-buffer "*eww buffers*"))
+
+(defun eww-buffer-select ()
+  "Switch to eww buffer."
+  (interactive)
+  (let ((buffer (get-text-property (line-beginning-position)
+                                   'eww-buffer)))
+    (or buffer
+        (error "No buffer on current line"))
+    (quit-window)
+    (switch-to-buffer buffer)))
+
+(defun eww-buffer-show ()
+  "Display buffer under point in eww buffer list."
+  (let ((buffer (get-text-property (line-beginning-position)
+                                   'eww-buffer)))
+    (or buffer
+        (error "No buffer on current line"))
+    (other-window -1)
+    (switch-to-buffer buffer)
+    (other-window 1)))
+
+(defun eww-buffer-show-next ()
+  "Move to next eww buffer in the list and display it."
+  (interactive)
+  (forward-line)
+  (if (eobp)
+      (goto-char (point-min)))
+  (eww-buffer-show))
+
+(defun eww-buffer-show-previous ()
+  "Move to previous eww buffer in the list and display it."
+  (interactive)
+  (beginning-of-line)
+  (if (bobp)
+      (goto-char (point-max)))
+  (forward-line -1)
+  (eww-buffer-show))
+
+(defun eww-buffer-kill ()
+  "Kill buffer from eww list."
+  (interactive)
+  (let* ((start (line-beginning-position))
+	 (buffer (get-text-property start 'eww-buffer))
+	 (inhibit-read-only t))
+    (or buffer
+        (user-error "No buffer on the current line"))
+    (kill-buffer buffer)
+    (forward-line 1)
+    (delete-region start (point)))
+  (if (eobp)
+      (forward-line -1))
+  (eww-buffer-show))
+
+(defvar eww-buffers-mode-map
+  (let ((map (make-sparse-keymap)))
+    (suppress-keymap map)
+    (define-key map "q" 'quit-window)
+    (define-key map [(control k)] 'eww-buffer-kill)
+    (define-key map "\r" 'eww-buffer-select)
+    (define-key map "n" 'eww-buffer-show-next)
+    (define-key map "p" 'eww-buffer-show-previous)
+
+    (easy-menu-define nil map
+      "Menu for `eww-buffers-mode-map'."
+      '("Eww Buffers"
+        ["Exit" quit-window t]
+        ["Select" eww-buffer-select
+         :active (get-text-property (line-beginning-position) 'eww-buffer)]
+        ["Kill" eww-buffer-kill
+         :active (get-text-property (line-beginning-position) 'eww-buffer)]))
+    map))
+
+(define-derived-mode eww-buffers-mode nil "eww buffers"
+  "Mode for listing buffers.
+
+\\{eww-buffers-mode-map}"
+  (buffer-disable-undo)
+  (setq buffer-read-only t
+	truncate-lines t))
+
 ;;; Desktop support
 
 (defvar eww-desktop-data-save
-- 
2.1.3