RosettaCodeData/Task/Animation/Standard-ML/animation.ml

47 lines
2.2 KiB
Standard ML

open XWindows ;
open Motif ;
structure TTd = Thread.Thread ;
structure TTm = Thread.Mutex ;
val bannerWindow = fn () =>
let
datatype thron = nothr | thr of TTd.thread ;
val toThr = fn thr x=> x;
val on = ref nothr ;
val mx = TTm.mutex ();
val dim = {tw=77,th=14} ;
val shell = XtAppInitialise "" "click text to start or redirect" "top" [] [ XmNwidth 320, XmNheight 60 ] ;
val main = XmCreateMainWindow shell "main" [ XmNmappedWhenManaged true ] ;
val canvas = XmCreateDrawingArea main "drawarea" [ XmNwidth (#tw dim), XmNheight (#th dim)] ;
val usegc = DefaultGC (XtDisplay canvas) ;
val buf = XCreatePixmap (RootWindow (XtDisplay shell)) (Area{x=0,y=0,w = #tw dim, h= (#th dim) }) 24 ;
val _ = (XSetBackground usegc 0xfffffff ;
XDrawImageString buf usegc (XPoint {x=0,y= (#th dim)-1 } ) "Hello World! ") ;
val drawparts = fn pos => (
XCopyArea buf (XtWindow canvas) usegc ( XPoint {x=pos,y=0} ) (Area{x=0,y=0,w = (#tw dim) - pos , h= #th dim }) ;
XCopyArea buf (XtWindow canvas) usegc ( XPoint {x=00,y=0} ) (Area{x= (#tw dim) - pos ,y=0,w = pos, h= #th dim }) ;
XFlush (XtDisplay canvas) ) ;
val direct = ref 1 ;
fun shift s = ( drawparts ( s mod (#tw dim)) ; Posix.Process.sleep (Time.fromReal 0.1) ; shift ( s + (!direct)) ) ;
val swdir = fn () => direct := ~ (!direct) ;
val finish = fn () =>
( if !on <> nothr then if TTd.isActive (toThr (!on)) then TTd.kill (toThr (!on)) else () else () ;
on := nothr );
val movimg = fn () => ( finish () ; swdir () ; on := thr (TTd.fork (fn () => shift 0,[]) ) ) ;
val setimg = fn (w,s,t) => ( finish () ; drawparts 0 ; t )
in
(
XtSetCallbacks canvas [ (XmNexposeCallback , setimg) , (XmNdestroyCallback, (fn (w,c,t)=>(finish();t))) ] XmNarmCallback ;
XtAddEventHandler canvas [ ButtonPressMask ] false (fn (w,ButtonPress a)=> movimg ()|_=> ()) ;
XtManageChild canvas ;
XtManageChild main ;
XtRealizeWidget shell (* add loop here to compile *)
)
end;