Additional System Services

Using Additional System Services

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.