(mouse-drag-mode-line): New function (from mldrag.el,

but changed a little).  Put it on mode-line down-mouse-1.
(mouse-select-window): Bind to mode-line drag-mouse-1.

1 files changed, 108 insertions, 0 deletions

diff --git a/lisp/mouse.el b/lisp/mouse.el
index b57cf45bf0b..d6d0c4bb43c 100644
--- a/lisp/mouse.el
+++ b/lisp/mouse.el
@@ -39,6 +39,8 @@
 (defvar mouse-yank-at-point nil
   "*If non-nil, mouse yank commands yank at point instead of at click.")
 
+;; Commands that operate on windows.
+
 (defun mouse-minibuffer-check (event)
   (let ((w (posn-window (event-start event))))
     (and (window-minibuffer-p w)
@@ -113,6 +115,110 @@ This command must be bound to a mouse click."
 	(split-window-horizontally
 	 (min (max new-width first-col) last-col))))))
 
+(defun mouse-drag-mode-line (start-event)
+  "Change the height of a window by dragging on the mode line."
+  (interactive "e")
+  (let ((done nil)
+	(echo-keystrokes 0)
+	(start-event-frame (window-frame (car (car (cdr start-event)))))
+	(start-event-window (car (car (cdr start-event))))
+	(start-nwindows (count-windows t))
+	(old-selected-window (selected-window))
+	should-enlarge-minibuffer
+	event mouse minibuffer y top bot edges wconfig params growth)
+    (setq params (frame-parameters))
+    (if (and (not (setq minibuffer (cdr (assq 'minibuffer params))))
+	     (one-window-p t))
+	(error "Attempt to resize sole window"))
+    (track-mouse
+      (progn
+	;; enlarge-window only works on the selected window, so
+	;; we must select the window where the start event originated.
+	;; unwind-protect will restore the old selected window later.
+	(select-window start-event-window)
+	;; if this is the bottommost ordinary window, then to
+	;; move its modeline the minibuffer must be enlarged.
+	(setq should-enlarge-minibuffer
+	      (and minibuffer
+		   (not (one-window-p t))
+		   (= (nth 1 (window-edges minibuffer))
+		      (nth 3 (window-edges)))))
+	;; loop reading events and sampling the position of
+	;; the mouse.
+	(while (not done)
+	  (setq event (read-event)
+		mouse (mouse-position))
+	  ;; do nothing if
+	  ;;   - there is a switch-frame event.
+	  ;;   - the mouse isn't in the frame that we started in
+	  ;;   - the mouse isn't in any Emacs frame
+	  ;; drag if
+	  ;;   - there is a mouse-movement event
+	  ;;   - there is a scroll-bar-movement event
+	  ;;     (same as mouse movement for our purposes)
+	  ;; quit if
+	  ;;   - there is a keyboard event or some other unknown event
+	  ;;     unknown event.
+	  (cond ((integerp event)
+		 (setq done t))
+		((eq (car event) 'switch-frame)
+		 nil)
+		((not (memq (car event)
+			    '(mouse-movement scroll-bar-movement)))
+		 (if (consp event)
+		     (setq unread-command-events
+			   (cons event unread-command-events)))
+		 (setq done t))
+		((not (eq (car mouse) start-event-frame))
+		 nil)
+		((null (car (cdr mouse)))
+		 nil)
+		(t
+		 (setq y (cdr (cdr mouse))
+		       edges (window-edges)
+		       top (nth 1 edges)
+		       bot (nth 3 edges))
+		 ;; scale back a move that would make the
+		 ;; window too short.
+		 (cond ((< (- y top -1) window-min-height)
+			(setq y (+ top window-min-height -1))))
+		 ;; compute size change needed
+		 (setq growth (- y bot -1)
+		       wconfig (current-window-configuration))
+		 ;; grow/shrink minibuffer?
+		 (if should-enlarge-minibuffer
+		     (progn
+		       ;; yes.  briefly select minibuffer so
+		       ;; enlarge-window will affect the
+		       ;; correct window.
+		       (select-window minibuffer)
+		       ;; scale back shrinkage if it would
+		       ;; make the minibuffer less than 1
+		       ;; line tall.
+		       (if (and (> growth 0)
+				(< (- (window-height minibuffer)
+				      growth)
+				   1))
+			   (setq growth (1- (window-height minibuffer))))
+		       (enlarge-window (- growth))
+		       (select-window start-event-window))
+		   ;; no.  grow/shrink the selected window
+		   (enlarge-window growth))
+		 ;; if this window's growth caused another
+		 ;; window to be deleted because it was too
+		 ;; short, rescind the change.
+		 ;;
+		 ;; if size change caused space to be stolen
+		 ;; from a window above this one, rescind the
+		 ;; change, but only if we didn't grow/srhink
+		 ;; the minibuffer.  minibuffer size changes
+		 ;; can cause all windows to shrink... no way
+		 ;; around it.
+		 (if (or (/= start-nwindows (count-windows t))
+			 (and (not should-enlarge-minibuffer)
+			      (/= top (nth 1 (window-edges)))))
+		     (set-window-configuration wconfig)))))))))
+
 (defun mouse-set-point (event)
   "Move point to the position clicked on with the mouse.
 This should be bound to a mouse click event type."
@@ -1343,6 +1449,8 @@ and selects that window."
 ;; (global-set-key [S-mouse-1]	'mouse-set-mark)
 
 (global-set-key [mode-line mouse-1] 'mouse-select-window)
+(global-set-key [mode-line drag-mouse-1] 'mouse-select-window)
+(global-set-key [mode-line down-mouse-1] 'mouse-drag-mode-line)
 (global-set-key [mode-line mouse-2] 'mouse-delete-other-windows)
 (global-set-key [mode-line mouse-3] 'mouse-delete-window)
 (global-set-key [mode-line C-mouse-2] 'mouse-split-window-horizontally)