progress dialog

[wes]

I'd like to create a progress dialog box while saving a large file
from my application. I have tried to create a modal DB and calling
DoDialog() inside the for loop of my saving routine, however, I can
only see a "blank" dialox, there is no content in it, my code is as
follows:

StDialogHandler theHandler(RESID, ...);

for (i=0; i<totalLineNum; i++)
{
// save data one line at a time
saveData(buf, ...);

theHandler.DoDialog();

}

I wonder if it is necessary for me to create a more complicated
progress dialog (for example, using another thread to launch the
dialog)? And if there is any sample code I can use? Thanks!

[David Phillip Oster]

In article <5fb7ca71.0309151532.36acc2e2@posting.google.com >,
[email]wkung@hotmail.com[/email] (wes) wrote:

> I'd like to create a progress dialog box while saving a large file
> from my application. I have tried to create a modal DB and calling
> DoDialog() inside the for loop of my saving routine, however, I can
> only see a "blank" dialox, there is no content in it, my code is as
> follows:
>
> StDialogHandler theHandler(RESID, ...);
>
> for (i=0; i<totalLineNum; i++)
> {
> // save data one line at a time
> saveData(buf, ...);
>
> theHandler.DoDialog();
>
> }
>
> I wonder if it is necessary for me to create a more complicated
> progress dialog (for example, using another thread to launch the
> dialog)? And if there is any sample code I can use? Thanks!

1.) This is a powerplant question, so you should be asking in
<news:comp.sys.mac.oop.powerplant>

2.) You don't need threads, but you will need to
2.a) tell the LProgressBar how manu lines you've got (and
you may need to put up an indeterminate progress bar before that.)
2.b) every few lines, tell the LProgressBar how much progress you've
made.

3.) Either look at the return value of theHandler.DoDialog(), or
throw or make something a listener to listen for the "Stop" button
on the progress dialog. (Use "Cancel" if your application can
revert the state to undo the long operation. Use "Stop" if you can't
undo the partial long operation.)


4.) When debugging progress dialogs, it is useful to add a temporary
"test" menu command that just LWindow::CreateWindow() the window
to make certain that it would draw correctly if it were a normal,
modeless window. (I think you've got some problems here, since
theHandler.DoDialog() would draw it if it were correct.)

5.) It is nice to let the user know how long its going to take.
Here is my code for that:

void StProgress::UpdateTimeEstimate(float n, SInt16 units){
Str255 s, s1, s2;
if(20 < n){
SInt32 m = (n + 2.5) / 5;
n = m*5;
}
NumToString(n + 0.5, s1);
if(EqualString(s1, "\p1", true, true)){
ParamString(s, kProgressTime1Strings, units, s1);
}else{
ParamString(s, kProgressTime2Strings, units, s1);
}
ParamString(s2, kProgressStrings, kTimeEstimateS, s);
if(not EqualString(s2, mSaveTimeEstimate, true, true)){
LString::CopyPStr(s2, mSaveTimeEstimate);
mTimeEstimate->SetDescriptor(s2);
}
}

void StProgress::UpdateTimeEstimate(){
if(0 == mMax or 0 == mValue){
return;
}
SInt32 elapsedTime = TickCount() - mInitialTime;
SInt32 totalTime = elapsedTime*mMax/static_cast<float>(mValue);
SInt32 remaining = totalTime - elapsedTime;

// don't estimate too early on a long progress.
if(elapsedTime < 10*60 and 60*60 < totalTime){
return;
}

if((60*60*60*24*364.25) <= remaining){
UpdateTimeEstimate(remaining / ( 60*60*60*24*364.25), kYearS);
}else if((60*60*60*24*30.) <= remaining){
UpdateTimeEstimate(remaining / ( 60*60*60*24*30.), kMonthS);
}else if((60*60*60*24*7) <= remaining){
UpdateTimeEstimate(remaining / ( 60*60*60*24*7.), kWeekS);
}else if((60*60*60*24) <= remaining){
UpdateTimeEstimate(remaining / ( 60*60*60*24.), kDayS);
}else if((60*60*60) <= remaining){
UpdateTimeEstimate(remaining / ( 60*60*60.), kHourS);
}else if((60*60) <= remaining){
UpdateTimeEstimate(remaining / ( 60*60.), kMinuteS);
}else if((60) <= remaining){
UpdateTimeEstimate(remaining / ( 60.), kSecondS);
}
}