Progress of processing Nxtables

Hi,

Not quite a NexusDB-problem, but still related...

I want to inform my users about the progress of 'doing something' with my
tables.

Something like this

progressbar1.visible := true;
progressbar1.max := nxtable1.recordcount;
progressbar1.position := 0;
while not nxtable1.eof do
begin
// do something with all kinds of records...
progressbar1.position := progressbar.position + 1;
// the progressbar is not on screen until the complete loop has finished.
// so I add:
progressbar1.repaint;
// still no effect. The square where the progressbar should come is
'blanked', and after the complete loop
has finished, it is on screen. But: too late....
nxtable1.next;
end;

How can I show the complete process in the progressbar?

Hans

On Mon, 14 Apr 2008 17:19:37 +0200, "Hans" <hans at zze dot nl> wrote:

>Hi,
>
>Not quite a NexusDB-problem, but still related...
>
>I want to inform my users about the progress of 'doing something' with my
>tables.
>
>Something like this
>
>progressbar1.visible := true;
>progressbar1.max := nxtable1.recordcount;
>progressbar1.position := 0;
>while not nxtable1.eof do
> begin
> // do something with all kinds of records...
> progressbar1.position := progressbar.position + 1;
> // the progressbar is not on screen until the complete loop has finished.
> // so I add:
> progressbar1.repaint;
> // still no effect. The square where the progressbar should come is
>'blanked', and after the complete loop
> has finished, it is on screen. But: too late....
> nxtable1.next;
> end;
>
>How can I show the complete process in the progressbar?

Repaint triggers an Invalidate message, which triggers the real Paint
message. Thus in any case the application has to process more than one
message to generate a full repaint option. So you need a safeguarded
message processor if Application.ProcessMessages might have unwanted
side effects.

Regards from Germany

Franz-Leo Chomse [NexusDB Expert]
franz.leo.chomse@ndx.nexusdb_x.com (please remove "_x" to reply)

Ehh,
What, and how, do you mean??

Hans

"Franz-Leo Chomse [NDX]" <franz.leo.chomse@ndx.nexusdb.com> schreef in
bericht news:bdu604hnrnl4b71ev9o5glooctab9iq506@4ax.com...
> On Mon, 14 Apr 2008 17:19:37 +0200, "Hans" <hans at zze dot nl> wrote:
>
>>Hi,
>>
>>Not quite a NexusDB-problem, but still related...
>>
>>I want to inform my users about the progress of 'doing something' with my
>>tables.
>>
>>Something like this
>>
>>progressbar1.visible := true;
>>progressbar1.max := nxtable1.recordcount;
>>progressbar1.position := 0;
>>while not nxtable1.eof do
>> begin
>> // do something with all kinds of records...
>> progressbar1.position := progressbar.position + 1;
>> // the progressbar is not on screen until the complete loop has
>> finished.
>> // so I add:
>> progressbar1.repaint;
>> // still no effect. The square where the progressbar should come is
>>'blanked', and after the complete loop
>> has finished, it is on screen. But: too late....
>> nxtable1.next;
>> end;
>>
>>How can I show the complete process in the progressbar?
>
> Repaint triggers an Invalidate message, which triggers the real Paint
> message. Thus in any case the application has to process more than one
> message to generate a full repaint option. So you need a safeguarded
> message processor if Application.ProcessMessages might have unwanted
> side effects.
>
> Regards from Germany
>
> Franz-Leo Chomse [NexusDB Expert]
> franz.leo.chomse@ndx.nexusdb_x.com (please remove "_x" to reply)

On Mon, 14 Apr 2008 19:04:48 +0200, "Hans" <hans at zze dot nl> wrote:

>Ehh,
>What, and how, do you mean??

put an application.processmessages call

after the repaint call.

If this has side effects like unwanted triggering of
events you either have to implement your own message loop
filtering the processed messages or prevent the calling of the
problematic event handlers during the time your loop is
executing.

Regards from Germany

Franz-Leo Chomse [NexusDB Expert]
franz.leo.chomse@ndx.nexusdb_x.com (please remove "_x" to reply)

Hans wrote:
> Hi,
>
> Not quite a NexusDB-problem, but still related...
>
> I want to inform my users about the progress of 'doing something' with my
> tables.
>
> Something like this
>
> progressbar1.visible := true;
> progressbar1.max := nxtable1.recordcount;
> progressbar1.position := 0;
> while not nxtable1.eof do
> begin
> // do something with all kinds of records...
> progressbar1.position := progressbar.position + 1;
> // the progressbar is not on screen until the complete loop has finished.
> // so I add:
> progressbar1.repaint;
> // still no effect. The square where the progressbar should come is
> 'blanked', and after the complete loop
> has finished, it is on screen. But: too late....
> nxtable1.next;
> end;
>
> How can I show the complete process in the progressbar?
>
> Hans
>
>

I wrote a TSSProgessDialog component about 10 years ago that I have
modified as needed over the years and it acts as follows:

1) Drop a TSSProgessDialog component on your form (or datamodule).

2) Create an OnSSProgressDialogExecute method within parent component.

3) Set TSSProgressDialog instance properties.

4) Execute TSSProgressDialog Execute() method which shows a progress
dialog (on main VCL thread), creates a worker thread, and calls the
OnSSProgressDialogExecute event method.

This method assumes:

That the OnSSProgessDialogExecute method is thread safe (i.e. all
DisableControls() / control .BeginUpdate(), etc. were called before
progress dialog started.

Benefits include:

1) Component allows the progress to be aborted if a flag is set from
within the Execute event...

2) An elapsed progress is being displayed allowing user to know that
application hasn't locked up.

3) The dialog has an optinal progress bar which can be updated via the
OnSSProgressDialogExecute.

4) During a lengthly process, if the user switches applications and then
switches back, your application will draw the screen immediately as the
main VCL thread isn't locked down.


My component is in C++ and I do use a component from TMS for the
progress bar.

If anyone is interested, please drop me an email at ShaneATStumpWare.com
(replace AT with @) and I will put the bar basics together for you.

Best Regards,

Shane

I mean you can just use the .update method of the component. I use on other
visuel components and this does not fire other events or need the
application.processmessages loop.
Bo Nielsen



"Hans" <hans at zze dot nl> skrev i en meddelelse
news:48037351$1@nexus-vkpb9bih5.Nexus.local...
> Hi,
>
> Not quite a NexusDB-problem, but still related...
>
> I want to inform my users about the progress of 'doing something' with my
> tables.
>
> Something like this
>
> progressbar1.visible := true;
> progressbar1.max := nxtable1.recordcount;
> progressbar1.position := 0;
> while not nxtable1.eof do
> begin
> // do something with all kinds of records...
> progressbar1.position := progressbar.position + 1;
> // the progressbar is not on screen until the complete loop has finished.
> // so I add:
> progressbar1.repaint;
> // still no effect. The square where the progressbar should come is
> 'blanked', and after the complete loop
> has finished, it is on screen. But: too late....
> nxtable1.next;
> end;
>
> How can I show the complete process in the progressbar?
>
> Hans
>

Hi Hans,

the only thing you have to do is calling "Application.Processmessages" in
your loop...

> progressbar1.visible := true;
> progressbar1.max := nxtable1.recordcount;
> progressbar1.position := 0;
> while not nxtable1.eof do
> begin
> // do something with all kinds of records...
> progressbar1.position := progressbar.position + 1;
----
// update screen every 10th action
if ProgressBar1.Position mod 10 = 0 then Application.ProcessMessages;
----
> // the progressbar is not on screen until the complete loop has finished.
> // so I add:
> progressbar1.repaint;
> // still no effect. The square where the progressbar should come is
> 'blanked', and after the complete loop
> has finished, it is on screen. But: too late....
> nxtable1.next;
> end;

Kind Regards
Otto

Hans wrote:

> Hi,
>
> Not quite a NexusDB-problem, but still related...
>
> I want to inform my users about the progress of 'doing something'
> with my tables.
>
> How can I show the complete process in the progressbar?

Use the StepIt method.

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