Apple Newton Utilities Guide de l'utilisateur télécharger pdf (Page 633)

100

101

CHAPTER 17

Additional System Services

Using Additional System Services 17-17

performing the myFunc function, pass it as the value of the workFunc parameter to

the

DoProgress function, as illustrated in the following code fragment:

// options and data are accessible from workFunc because

// the workFunc "closes over" this context

myOpts := { wFnData:"Confabulating",

closebox:nil,

icon: kMyIcon,

statusText: kAppName,

gauge: 10,

titleText:"One moment, please."};

workFunc := func (theContextView)

begin

for x := 1 to 10 do

begin

myOpts.titleText:= :SomeWork(myOpts.wFnData);

myOpts.gauge := x * 10;

try

theContextView:SetStatus('vGauge,myOpts);

// handle any exceptions you anticipate

onexception |evt.ex.foo| do

// handle & possibly rethrow if it's fatal

onexception |evt.ex.bar| do

// handle & possibly rethrow if it's fatal

onexception |evt.ex| do

// either an unexpected exception has been

// thrown or the user has canceled our

// operation. Perform any cleanup

// necessary, and be sure to rethrow..

ReThrow();

end; // for loop

end; // workFunc

progress := DoProgress('vGauge, myOpts, workFunc);

if progress = 'cancelled then

// this is another place to clean up after being

// cancelled

The workFunc function’s argument, theContextView, is the status slip that

contains the gauge. A reference to this view is passed to your work function so that

you can send it

SetStatus messages. Note that workFunc is structured in a way

that permits it to call the progress slip’s

SetStatus method at regular intervals,

passing values used to update the progress slip’s gauge and message string.

1 2 ... 628 629 630 631 632 633 634 635 636 637 638 ... 941 942

Commentaires sur ces manuels

Pas de commentaire

Apple Newton Utilities Guide de l'utilisateur Page 633

Commentaires sur ces manuels

Produits connexes et manuels pour Logiciel Apple Newton Utilities