fix usages of cond/case

extra/ui/gadgets/buttons/buttons.factor

@@ -55,7 +55,7 @@ C: <button-paint> button-paint
         { [ dup button-pressed? ] [ drop button-paint-pressed ] }
         { [ dup button-selected? ] [ drop button-paint-selected ] }
         { [ dup button-rollover? ] [ drop button-paint-rollover ] }
-        { [ t ] [ drop button-paint-plain ] }
+        [ drop button-paint-plain ]
     } cond ;
 
 M: button-paint draw-interior

extra/ui/gadgets/gadgets.factor

@@ -378,7 +378,7 @@ SYMBOL: in-layout?
     {
         { [ 2dup eq? ] [ 2drop t ] }
         { [ dup not ] [ 2drop f ] }
-        { [ t ] [ gadget-parent child? ] }
+        [ gadget-parent child? ]
     } cond ;
 
 GENERIC: focusable-child* ( gadget -- child/t )

extra/ui/gadgets/panes/panes.factor

@@ -88,7 +88,7 @@ C: <pane-stream> pane-stream
     dup gadget-children {
         { [ dup empty? ] [ 2drop "" <label> ] }
         { [ dup length 1 = ] [ nip first ] }
-        { [ t ] [ drop ] }
+        [ drop ]
     } cond ;
 
 : smash-pane ( pane -- gadget ) pane-output smash-line ;

extra/ui/gadgets/scrollers/scrollers.factor

@@ -119,7 +119,7 @@ scroller H{
         { [ dup t eq? ] [ drop (scroll>bottom) ] }
         { [ dup rect? ] [ swap (scroll>rect) ] }
         { [ dup ] [ swap (scroll>gadget) ] }
-        { [ t ] [ drop dup scroller-value swap scroll ] }
+        [ drop dup scroller-value swap scroll ]
     } cond ;
 
 M: scroller layout*

extra/ui/gestures/gestures.factor

@@ -191,7 +191,7 @@ SYMBOL: drag-timer
         { [ multi-click-button?   not ] [ f ] }
         { [ multi-click-position? not ] [ f ] }
         { [ multi-click-position? not ] [ f ] }
-        { [ t ] [ t ] }
+        [ t ]
     } cond nip ;
 
 : update-click# ( button -- )

extra/ui/render/render.factor

@@ -80,7 +80,7 @@ DEFER: draw-gadget
     {
         { [ dup gadget-visible? not ] [ drop ] }
         { [ dup gadget-clipped? not ] [ (draw-gadget) ] }
-        { [ t ] [ [ (draw-gadget) ] with-clipping ] }
+        [ [ (draw-gadget) ] with-clipping ]
     } cond ;
 
 ! Pen paint properties

extra/ui/tools/interactor/interactor.factor

@@ -145,17 +145,17 @@ M: interactor stream-read-partial
     tuck try-parse {
         { [ dup quotation? ] [ nip t ] }
         { [ dup not ] [ drop "\n" swap user-input f f ] }
-        { [ t ] [ handle-parse-error f f ] }
+        [ handle-parse-error f f ]
     } cond ;
 
 M: interactor stream-read-quot
     [ interactor-yield ] keep {
         { [ over not ] [ drop ] }
         { [ over callable? ] [ drop ] }
-        { [ t ] [
+        [
             [ handle-interactive ] keep swap
             [ interactor-finish ] [ nip stream-read-quot ] if
-        ] }
+        ]
     } cond ;
 
 M: interactor pref-dim*

extra/ui/tools/listener/listener.factor

@@ -119,7 +119,7 @@ M: tuple-dispatch-engine-word word-completion-string
     {
         { [ dup not ] [ 2drop ] }
         { [ 2dup memq? ] [ 2drop ] }
-        { [ t ] [ push ] }
+        [ push ]
     } cond ;
 
 : insert-word ( word -- )

extra/ui/tools/walker/walker.factor

@@ -81,7 +81,7 @@ walker-gadget "toolbar" f {
     {
         { [ dup walker-gadget? not ] [ 2drop f ] }
         { [ dup walker-gadget-closing? ] [ 2drop f ] }
-        { [ t ] [ walker-gadget-thread eq? ] }
+        [ walker-gadget-thread eq? ]
     } cond ;
 
 : find-walker-window ( thread -- world/f )

extra/ui/traverse/traverse.factor

@@ -70,7 +70,7 @@ DEFER: (gadget-subtree)
         { [ pick empty? ] [ rot drop traverse-to-path ] }
         { [ over empty? ] [ nip traverse-from-path ] }
         { [ pick first pick first = ] [ traverse-child ] }
-        { [ t ] [ traverse-middle ] }
+        [ traverse-middle ]
     } cond ;
 
 : gadget-subtree ( frompath topath gadget -- seq )

extra/ui/windows/windows.factor

@@ -381,11 +381,11 @@ SYMBOL: trace-messages?
         { [ windows get empty? ] [ drop ] }
         { [ dup peek-message? ] [ ui-wait event-loop ] }
         { [ dup MSG-message WM_QUIT = ] [ drop ] }
-        { [ t ] [
+        [
             dup TranslateMessage drop
             dup DispatchMessage drop
             event-loop
-        ] }
+        ]
     } cond ;
 
 : register-wndclassex ( -- class )

extra/ui/x11/x11.factor

@@ -133,7 +133,7 @@ M: world selection-notify-event
     {
         { [ dup XA_PRIMARY = ] [ drop selection get ] }
         { [ dup XA_CLIPBOARD = ] [ drop clipboard get ] }
-        { [ t ] [ drop <clipboard> ] }
+        [ drop <clipboard> ]
     } cond ;
 
 : encode-clipboard ( string type -- bytes )
@@ -156,7 +156,7 @@ M: world selection-request-event
         { [ dup supported-type? ] [ drop dup set-selection-prop send-notify-success ] }
         { [ dup "TARGETS" x-atom = ] [ drop dup set-targets-prop send-notify-success ] }
         { [ dup "TIMESTAMP" x-atom = ] [ drop dup set-timestamp-prop send-notify-success ] }
-        { [ t ] [ drop send-notify-failure ] }
+        [ drop send-notify-failure ]
     } cond ;
 
 M: x11-ui-backend (close-window) ( handle -- )