another try at fixing gtk dialog placement

original commit: 647ce060ab1abe89eb22d0f974b93d619d2fc612

collects/mred/private/wx/gtk/dialog.rkt

@@ -57,10 +57,7 @@
     (super direct-show on?))
 
   (define/override (center dir wrt)
-    ;; We're supposed to use gtk_window_set_position() for dialogs,
-    ;;  but we must be doing something else wrong so that it doesn't
-    ;;  work.
-    (if #f ; (eq? dir 'both)
+    (if (eq? dir 'both)
         (gtk_window_set_position (get-gtk) 
                                  (if (get-parent)
                                      GTK_WIN_POS_CENTER_ON_PARENT

collects/mred/private/wx/gtk/frame.rkt

@@ -180,6 +180,8 @@
     (define/override (get-dialog-level) 0)
     (define/public (frame-relative-dialog-status win) #f)
 
+    (define/override (get-unset-pos) -11111)
+
     (define/override (center dir wrt)
       (let ([w-box (box 0)]
             [h-box (box 0)]

collects/mred/private/wx/gtk/window.rkt

@@ -287,11 +287,13 @@
                [extra-gtks extra-gtks]
                [parent parent])
 
-    (define save-x 0)
-    (define save-y 0)
+    (define save-x (get-unset-pos))
+    (define save-y (get-unset-pos))
     (define save-w 0)
     (define save-h 0)
 
+    (define/public (get-unset-pos) 0)
+
     (connect-size-allocate gtk)
 
     (when add-to-parent?
@@ -399,8 +401,8 @@
 
     (unless no-show? (show #t))
 
-    (define/public (get-x) save-x)
-    (define/public (get-y) save-y)
+    (define/public (get-x) (if (= save-x -11111) 0 save-x))
+    (define/public (get-y) (if (= save-y -11111) 0 save-y))
     (define/public (get-width) save-w)
     (define/public (get-height) save-h)
 

collects/mred/private/wxtop.rkt

@@ -345,7 +345,7 @@
 		    (set! last-height correct-h)
 		    (set! already-trying? #t)
 		    (enforce-size -1 -1 -1 -1 1 1)
-		    (set-size -1 -1 correct-w correct-h)
+		    (set-size -11111 -11111 correct-w correct-h)
 		    (enforce-size min-w min-h
 				  (if sx? -1 min-w) (if sy? -1 min-h)
 				  1 1)