progress bar example

Nicolas Cueto niconiko at gmail.com
Thu Jul 10 07:50:33 EDT 2008


Hello,

A few years back, Dave Cragg was
kind enough to explain in detail how
to build a stack that shows the progress
of a download (I've included his message
below).

The script works, but there's a glitch.
When the progress-stack is called up
only its edge can be seen. Its body,
instead of showing a progres bar
increasing as the download progresses,
shows nothing but a freeze-view of whatever
was on the screen beneath it before it
popped open.

I've tried setting buffer properties,
but that did not work.

Is there a way of getting this to work?

Thank you.

-- Nicolas Cueto

<here's Dave Cragg's message and script>

You can show status using "go" as well. libUrlSetStatusCallback works
for both blocking (e.g. load url) and non-blocking (.e.g. get url)
calls.

Below is the script of a *very crude* progress palette. The stack
consists of two fields (one named "url" and the other named
"status"), and a scrollbar (progress bar) named "progress" . Name the
stack "url_status" (or anything you want).

Make this stack a substack of your main stack. Then somewhere (e.g in
your mainstack's preopenstack handler), include the following:

   start using "url_status"

That's it. After that, it should work for all downloads and uploads
(which may not be what you want).

Cheers
Dave

--------------------------------------------------
local sUrls
----------------------------
on libraryStack
   libUrlSetStatusCallback "urlCallback", the long id of me
   palette me
   hide me
end libraryStack

-------------------------
on releaseStack
   libUrlSetStatusCallback empty
   close me
end releaseStack
---------------------------

on urlCallback pUrl, pStatusString

   show me
   put pUrl into field "url" of card 1 of me
   put item 1 of pStatusString into tStatus
   put tStatus into field "status" of card 1 of me
   put 1 into sUrls[pUrl]
   if tStatus is among the items of "loading,downloading,uploading" then

     put item 2 of pStatusString into tPart
     put item 3 of pStatusString into tWhole
     if tWhole <> empty then

       showProgress tPart,tWhole
     else
       hide scrollbar "progress" of me
       put "," && tPart && "bytes" after field "status" of card 1 of me
     end if
     --unlock screen
   else if tStatus is among the items of
"loaded,downloaded,uploaded,cached" then
     delete local sUrls[pUrl]
     if the visible of scrollbar "progress" of me then showProgress 1,1
     send "hideStatus" to me in 200 milliseconds ##leave visible for
short time

   else if tStatus is among the items of "error,timeout" then
     delete local sUrls[pUrl]
     send "hideStatus" to me in 200 milliseconds ##leave visible for
short time
   else
     hide scrollbar "progress" of me
   end if
end urlCallback
-------------------------
on showProgress pPart,pWhole
   put the endValue of scrollbar  "progress" of me into tMax
   set the thumbPosition of scrollbar "progress" of me to round(tMax
* pPart / pWhole)
   show scrollbar "progress" of me
   wait 10 milliseconds
end showProgress
-----------------------
on hideStatus
   if keys(sUrls) is empty then
     hide me
   end if
end hideStatus



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