(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.

diff --git a/lisp/mouse.el b/lisp/mouse.el
index b57cf45bf0b8b3342b4a6167c3bc42277b3fe090..d6d0c4bb43cbe93067a5c0c3ebd86b299b05691d 100644 (file)
--- 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.")
 \f
+;; 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)))))))))
+\f
 (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)