[Emacs-diffs] trunk r113574: lisp/desktop.el: Optionally force offscreen frames back onscreen.

[Juanma Barranquero]

------------------------------------------------------------
revno: 113574
revision-id: address@hidden
parent: address@hidden
committer: Juanma Barranquero <address@hidden>
branch nick: trunk
timestamp: Sun 2013-07-28 05:03:45 +0200
message:
  lisp/desktop.el: Optionally force offscreen frames back onscreen.
  (desktop-restoring-reuses-frames): New option.
  (desktop--compute-pos, desktop--move-onscreen): New functions.
  (desktop--make-frame): Use desktop--move-onscreen.
modified:
  lisp/ChangeLog                 changelog-20091113204419-o5vbwnq5f7feedwu-1432
  lisp/desktop.el                desktop.el-20091113204419-o5vbwnq5f7feedwu-591

=== modified file 'lisp/ChangeLog'
--- a/lisp/ChangeLog    2013-07-27 17:35:04 +0000
+++ b/lisp/ChangeLog    2013-07-28 03:03:45 +0000
@@ -1,3 +1,10 @@
+2013-07-28  Juanma Barranquero  <address@hidden>
+
+       * desktop.el: Optionally force offscreen frames back onscreen.
+       (desktop-restoring-reuses-frames): New option.
+       (desktop--compute-pos, desktop--move-onscreen): New functions.
+       (desktop--make-frame): Use desktop--move-onscreen.
+
 2013-07-27  Alan Mackenzie  <address@hidden>
 
        Fontify a Java generic method as a function.

=== modified file 'lisp/desktop.el'
--- a/lisp/desktop.el   2013-07-27 01:02:00 +0000
+++ b/lisp/desktop.el   2013-07-28 03:03:45 +0000
@@ -387,6 +387,18 @@
   :group 'desktop
   :version "24.4")
 
+(defcustom desktop-restore-forces-onscreen t
+  "If t, offscreen frames are restored onscreen instead.
+If `all', frames that are partially offscreen are also forced onscren.
+NOTE: Checking of frame boundaries is only approximate and can fail
+to reliably detect frames whose onscreen/offscreen state depends on a
+few pixels, especially near the right / bottom borders of the screen."
+  :type '(choice (const :tag "Only fully offscreen frames" t)
+                (const :tag "Also partially offscreen frames" 'all)
+                (const :tag "Do not force frames onscreen" nil))
+  :group 'desktop
+  :version "24.4")
+
 (defcustom desktop-restoring-reuses-frames t
   "If t, restoring frames reuses existing frames.
 If nil, existing frames are deleted.
@@ -1201,6 +1213,68 @@
 (defvar desktop--reuse-list nil
   "Internal use only.")
 
+(defun desktop--compute-pos (value left/top right/bottom)
+  (pcase value
+    (`(+ ,val) (+ left/top val))
+    (`(- ,val) (+ right/bottom val))
+    (val val)))
+
+(defun desktop--move-onscreen (frame)
+  "If FRAME is offscreen, move it back onscreen and, if necessary, resize it.
+When forced onscreen, frames wider than the monitor's workarea are converted
+to fullwidth, and frames taller than the workarea are converted to fullheight.
+NOTE: This only works for non-iconified frames."
+  (pcase-let* ((`(,left ,top ,width ,height) (cl-cdadr 
(frame-monitor-attributes frame)))
+              (right (+ left width -1))
+              (bottom (+ top height -1))
+              (fr-left (desktop--compute-pos (frame-parameter frame 'left) 
left right))
+              (fr-top (desktop--compute-pos (frame-parameter frame 'top) top 
bottom))
+              (ch-width (frame-char-width frame))
+              (ch-height (frame-char-height frame))
+              (fr-width (max (frame-pixel-width frame) (* ch-width 
(frame-width frame))))
+              (fr-height (max (frame-pixel-height frame) (* ch-height 
(frame-height frame))))
+              (fr-right (+ fr-left fr-width -1))
+              (fr-bottom (+ fr-top fr-height -1)))
+    (when (pcase desktop-restore-forces-onscreen
+           ;; Any corner is outside the screen.
+           (`all (or (< fr-bottom top)  (> fr-bottom bottom)
+                     (< fr-left   left) (> fr-left   right)
+                     (< fr-right  left) (> fr-right  right)
+                     (< fr-top    top)  (> fr-top    bottom)))
+           ;; Displaced to the left, right, above or below the screen.
+           (`t   (or (> fr-left   right)
+                     (< fr-right  left)
+                     (> fr-top    bottom)
+                     (< fr-bottom top)))
+           (_ nil))
+      (let ((fullwidth (> fr-width width))
+           (fullheight (> fr-height height))
+           (params nil))
+       ;; Position frame horizontally.
+       (cond (fullwidth
+              (push `(left . ,left) params))
+             ((> fr-right right)
+              (push `(left . ,(+ left (- width fr-width))) params))
+             ((< fr-left left)
+              (push `(left . ,left) params)))
+       ;; Position frame vertically.
+       (cond (fullheight
+              (push `(top . ,top) params))
+             ((> fr-bottom bottom)
+              (push `(top . ,(+ top (- height fr-height))) params))
+             ((< fr-top top)
+              (push `(top . ,top) params)))
+       ;; Compute fullscreen state, if required.
+       (when (or fullwidth fullheight)
+         (push (cons 'fullscreen
+                     (cond ((not fullwidth) 'fullheight)
+                           ((not fullheight) 'fullwidth)
+                           (t 'maximized)))
+               params))
+       ;; Finally, move the frame back onscreen.
+       (when params
+         (modify-frame-parameters frame params))))))
+
 (defun desktop--find-frame (predicate display &rest args)
   "Find a suitable frame in `desktop--reuse-list'.
 Look through frames whose display property matches DISPLAY and
@@ -1328,6 +1402,13 @@
                                 (assq-delete-all 'fullscreen filtered-cfg)
                               filtered-cfg))
 
+    ;; If requested, force frames to be onscreen.
+    (when (and desktop-restore-forces-onscreen
+              ;; FIXME: iconified frames should be checked too,
+              ;; but it is impossible without deiconifying them.
+              (not (eq (frame-parameter frame 'visibility) 'icon)))
+      (desktop--move-onscreen frame))
+
     ;; Let's give the finishing touches (visibility, tool-bar, maximization).
     (when lines (push lines alt-cfg))
     (when alt-cfg (modify-frame-parameters frame alt-cfg))