diff --git a/gui.rkt b/gui.rkt
index 655a3d5..16e09fd 100644
--- a/gui.rkt
+++ b/gui.rkt
@@ -103,6 +103,100 @@
 
 ;;---------------------------------------------------------------------------
 
+(struct horizontal-layout (key) #:transparent)
+(struct vertical-layout (key) #:transparent)
+(struct tabular-layout (row col) #:transparent)
+
+(struct requested-layout-size (container-id size) #:transparent)
+(struct computed-layout-size (container-id size) #:transparent)
+(struct layout-solution (container-id
+                         spec
+                         size
+                         rectangle) #:transparent)
+
+(struct layout-item (spec size) #:transparent)
+
+(define (layout-item-spec-key li)
+  (define v (layout-item-spec li))
+  (if (number? v) (exact->inexact v) v))
+
+(actor #:name 'layout-driver
+       (during/actor (observe (layout-solution $container-id (horizontal-layout _) _ _))
+                     #:name (list 'horizontal-layout container-id)
+                     (solve-hv-layout #f container-id))
+       (during/actor (observe (layout-solution $container-id (vertical-layout _) _ _))
+                     #:name (list 'vertical-layout container-id)
+                     (solve-hv-layout #t container-id))
+       (during/actor (observe (layout-solution $container-id (tabular-layout _ _) _ _))
+                     #:name (list 'tabular-layout container-id)
+                     (solve-tabular-layout container-id)))
+
+(define (solve-hv-layout vertical? container-id)
+  (define ctor (if vertical? vertical-layout horizontal-layout))
+  (define/query-set items
+    (observe (layout-solution container-id (ctor $key) $size _))
+    (layout-item key size))
+  (define/dataflow ordered-items (sort (set->list (items))
+                                       (order-<? datum-order)
+                                       #:key layout-item-spec-key)
+    #:default '())
+  (define/dataflow table
+    (if vertical?
+        (map list (map layout-item-size (ordered-items)))
+        (list (map layout-item-size (ordered-items)))))
+  (solve-layout* container-id
+                 table
+                 (lambda (layout)
+                   (for [(item (ordered-items))
+                         (cell (if vertical? (map car layout) (car layout)))]
+                     (assert! (layout-solution container-id
+                                               (ctor (layout-item-spec item))
+                                               (layout-item-size item)
+                                               cell))))))
+
+(define (solve-layout* container-id table on-layout)
+  (during (requested-layout-size container-id $reqsize)
+    (define/dataflow total-size (or reqsize (table-sizing (table))))
+    (assert (computed-layout-size container-id (total-size)))
+    (define (total-width) (sizing-ideal (box-size-horizontal (total-size))))
+    (define (total-height) (sizing-ideal (box-size-vertical (total-size))))
+    (define/dataflow layout (table-layout (table) 0 0 (total-width) (total-height)) #:default '())
+    (begin/dataflow
+      (retract! (layout-solution container-id ? ? ?))
+      (on-layout (layout)))))
+
+(define (solve-tabular-layout container-id)
+  (define/query-set items
+    (observe (layout-solution container-id (tabular-layout $row $col) $size _))
+    (layout-item (cons row col) size))
+  (define/dataflow items-table
+    (let* ((specs (map layout-item-spec (set->list (items))))
+           (row-count (+ 1 (apply max -1 (map car specs))))
+           (col-count (+ 1 (apply max -1 (map cdr specs))))
+           (mtx (for/vector [(r row-count)] (make-vector col-count #f))))
+      (for [(item (items))]
+        (vector-set! (vector-ref mtx (car (layout-item-spec item)))
+                     (cdr (layout-item-spec item))
+                     item))
+      mtx))
+  (define/dataflow table
+    (for/list [(row (items-table))]
+      (for/list [(item row)]
+        (if item (layout-item-size item) weak-fill-box-size))))
+
+  (solve-layout* container-id
+                 table
+                 (lambda (layout)
+                   (define mtx (list->vector (map list->vector layout)))
+                   (for [(item (items))]
+                     (match-define (cons row col) (layout-item-spec item))
+                     (assert! (layout-solution container-id
+                                               (tabular-layout row col)
+                                               (layout-item-size item)
+                                               (vector-ref (vector-ref mtx row) col)))))))
+
+;;---------------------------------------------------------------------------
+
 (struct pop-up-menu-trigger (menu-id x y x-pin y-pin release-event) #:transparent)
 (struct menu-separator (menu-id order) #:transparent)
 (struct menu-item (menu-id order image message) #:transparent)
@@ -111,82 +205,63 @@
        (on (message (pop-up-menu-trigger $menu-id $x $y $x-pin $y-pin $release-event))
            (run-pop-up-menu menu-id x y x-pin y-pin release-event)))
 
-(define (menu-item-order-key i)
-  (define v (cond [(menu-item? i) (menu-item-order i)]
-                  [(menu-separator? i) (menu-separator-order i)]))
-  (if (number? v)
-      (exact->inexact v)
-      v))
-
 (define (run-pop-up-menu menu-id pop-up-cursor-x pop-up-cursor-y x-pin y-pin release-event)
   (define instance-id (list menu-id (gensym 'instance)))
   (define pad (theme-menu-item-padding))
   (define pad2 (* pad 2))
+  (define normal (i:rectangle 1 1 "solid" (theme-menu-item-background-color)))
   (define highlight (i:rectangle 1 1 "solid" (theme-menu-item-selected-background-color)))
   (define separator (i:rectangle 1 1 "solid" (theme-menu-separator-color)))
   (actor #:name instance-id
-         (define/query-set items ($ i (menu-item menu-id _ _ _)) i)
-         (define/query-set separators ($ s (menu-separator menu-id _)) s)
-         (define/dataflow ordered-items (sort (append (set->list (items))
-                                                      (set->list (separators)))
-                                              (order-<? datum-order)
-                                              #:key menu-item-order-key)
-           #:default '())
-         (define/dataflow menu-table (for/list [(i (ordered-items))]
-                                       (match i
-                                         [(menu-item _ _ (seal im) _)
-                                          (list (box-size (sizing (+ pad2 (*width im)) 0 0)
-                                                          (sizing (+ pad2 (*height im)) 0 0)))]
-                                         [(menu-separator _ _)
-                                          (list (box-size (sizing 0 weak-fill 0)
-                                                          (sizing (theme-menu-separator-width) 0 0)))])))
-         (define/dataflow total-size (table-sizing (menu-table))
-           #:default zero-box-size)
-         (define (menu-width) (sizing-ideal (box-size-horizontal (total-size))))
-         (define (menu-height) (sizing-ideal (box-size-vertical (total-size))))
-         (define/dataflow layout (table-layout (menu-table) 0 0 (menu-width) (menu-height))
-           #:default '())
+         (assert (requested-layout-size instance-id #f))
+         (during (menu-item menu-id $order $sealed-image $msg)
+           (define item-id (gensym 'item))
+           (define im (seal-contents sealed-image))
+           (define imsize (box-size (sizing (+ pad2 (*width im)) 0 0)
+                                    (sizing (+ pad2 (*height im)) 0 0)))
+           (during (layout-solution instance-id (vertical-layout order) imsize $rect)
+             (match-define (rectangle left top width height) rect)
+             (assert (outbound
+                      (sprite #:id item-id #:parent instance-id
+                              0
+                              `((translate ,left ,top)
+                                (push-matrix
+                                 (scale ,width ,height)
+                                 (touchable (,instance-id ,item-id ,msg) ,in-unit-square?)
+                                 (texture ,(if (eq? (selected-item) item-id) highlight normal)))
+                                (push-matrix
+                                 (translate ,pad ,pad)
+                                 (scale ,(*width im) ,(*height im))
+                                 (texture ,im))))))))
 
-         (define (render-menu)
-           (define offset-x (- pop-up-cursor-x (* x-pin (+ (menu-width) 2)) -1))
-           (define offset-y (- pop-up-cursor-y (* y-pin (+ (menu-height) 2)) -1))
-           (sprite #:id instance-id
-                   -1
-                   `((translate ,offset-x ,offset-y)
-                     (push-matrix (scale ,(menu-width) ,(menu-height))
-                                  (texture ,(i:rectangle 1 1 "solid" (theme-menu-item-background-color))))
-                     ,@(for/list [(item (ordered-items)) (row (layout))]
-                         (match-define (rectangle left top width height) (car row))
-                         (match item
-                           [(menu-item _ _ (seal im) _)
-                            `(begin
-                               (push-matrix (translate ,left ,top)
-                                            (scale ,width ,height)
-                                            (touchable (,instance-id ,(seal item)) ,in-unit-square?)
-                                            ,@(if (eq? (selected-item) item)
-                                                  `((texture ,highlight))
-                                                  `()))
-                               (push-matrix (translate ,(+ left pad) ,(+ top pad))
-                                            (scale ,(*width im) ,(*height im))
-                                            (texture ,im)))]
-                           [(menu-separator _ _)
-                            `(push-matrix (translate ,left ,top)
-                                          (scale ,width ,height)
-                                          (texture ,separator))]))
-                     (render-children))))
+         (during (menu-separator menu-id $order)
+           (define sep-id (gensym 'sep))
+           (during (layout-solution instance-id (vertical-layout order)
+                                    (box-size weak-fill-sizing
+                                              (sizing (theme-menu-separator-width) 0 0))
+                                    $rect)
+             (match-define (rectangle left top width height) rect)
+             (assert (outbound
+                      (sprite #:id sep-id #:parent instance-id
+                              0
+                              `((translate ,left ,top)
+                                (scale ,width ,height)
+                                (texture ,separator)))))))
 
-         (define/query-value selected-item* #f (inbound (touching `(,instance-id ,$sealed-item)))
-           (seal-contents sealed-item))
-         (field [selected-item #f])
-         (begin/dataflow (when (not (eq? (selected-item) (selected-item*)))
-                           (selected-item (selected-item*))))
+         (during (computed-layout-size instance-id $menu-size)
+           (match-define (box-size (sizing menu-width _ _) (sizing menu-height _ _)) menu-size)
+           (define offset-x (- pop-up-cursor-x (* x-pin (+ menu-width 2)) -1))
+           (define offset-y (- pop-up-cursor-y (* y-pin (+ menu-height 2)) -1))
+           (assert (outbound
+                    (sprite #:id instance-id
+                            -1
+                            `((translate ,offset-x ,offset-y)
+                              (render-children))))))
 
-         (assert (outbound (render-menu)))
+         (define/query-value selected-item #f (inbound (touching `(,instance-id ,$i ,_))) i)
+         (define/query-value selected-msg #f (inbound (touching `(,instance-id ,_ ,$msg))) msg)
          (stop-when (message (inbound (mouse-event release-event _)))
-                    (when (selected-item)
-                      (send! (menu-item-message (selected-item)))))
-         (on (asserted ($ s (mouse-state _ _ _ _ _)))
-             (log-info "MENU ~v: ~v" menu-id s))))
+                    (when (selected-item) (send! (selected-msg))))))
 
 ;;---------------------------------------------------------------------------
 
@@ -350,7 +425,7 @@
 ;;---------------------------------------------------------------------------
 
 (actor #:name 'fullscreen-menu-item
-       (field [fullscreen? #t])
+       (field [fullscreen? #f])
        (assert (menu-item/text 'system-menu -1
                                (if (fullscreen?)
                                    "Fullscreen ✓"
diff --git a/layout/sizing.rkt b/layout/sizing.rkt
index 220c22a..283c542 100644
--- a/layout/sizing.rkt
+++ b/layout/sizing.rkt
@@ -8,7 +8,9 @@
 
          weak-fill
          zero-sizing
+         weak-fill-sizing
          zero-box-size
+         weak-fill-box-size
          zero-rectangle
 
          fill+
@@ -54,8 +56,12 @@
 
 (define zero-sizing (sizing 0 0 0))
 
+(define weak-fill-sizing (sizing 0 weak-fill 0))
+
 (define zero-box-size (box-size zero-sizing zero-sizing))
 
+(define weak-fill-box-size (box-size weak-fill-sizing weak-fill-sizing))
+
 (define zero-rectangle (rectangle 0 0 0 0))
 
 ;;---------------------------------------------------------------------------