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update a dialog with a thread [message #440661]

Thu, 05 August 2004 12:51

william

Messages: 15
Registered: July 2009

Junior Member

hi,

i'm trying to create a progress bar for transfering files between a client
and a server.

so, i made a dialog containing a progress bar, and a cancel button (for
stoping the transfert if i want).
next, i create a thread (which takes the dialog as parameter allowing the
thread to access to the elements of the dialog) and i start it.

i'can't see the progress bar moving but all the dialog is block and i
can't push the cancel button.

thanks for helping me

William

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Re: update a dialog with a thread [message #440670 is a reply to message #440661]

Thu, 05 August 2004 14:27

Steve Northover

Messages: 1636
Registered: July 2009

Senior Member

You need to make sure that the UI-thread is processing events. The
sync/asyncExec() runnables that you are using to update the progress bar
from the background thread need to just update the bar and return. If you
run a loop in the runnable, this will block the UI-thread.

"william" <william.ferreira@laposte.net> wrote in message
news:cetag9$ild$1@eclipse.org...
> hi,
>
> i'm trying to create a progress bar for transfering files between a client
> and a server.
>
> so, i made a dialog containing a progress bar, and a cancel button (for
> stoping the transfert if i want).
> next, i create a thread (which takes the dialog as parameter allowing the
> thread to access to the elements of the dialog) and i start it.
>
> i'can't see the progress bar moving but all the dialog is block and i
> can't push the cancel button.
>
> thanks for helping me
>
>
> William
>

Report message to a moderator

Re: update a dialog with a thread [message #440681 is a reply to message #440670]

Fri, 06 August 2004 07:52

william

Messages: 15
Registered: July 2009

Junior Member

thanks a lot, it's working...
but there is a little problem...
i created a runnable taking the dialog in parameter, and in the runnable i
did a loop in which i call syncExec() runnable for udpating my progress
bar (update and return). But the cancel button is activated only when the
syncExec() runnable runs (during all the treatment of the first runnable
the dialog is block) and i don't understand why....

i have an other question : what is the difference between sync and
asyncExec() ?

thanks

Steve Northover wrote:

> You need to make sure that the UI-thread is processing events. The
> sync/asyncExec() runnables that you are using to update the progress bar
> from the background thread need to just update the bar and return. If you
> run a loop in the runnable, this will block the UI-thread.

> "william" <william.ferreira@laposte.net> wrote in message
> news:cetag9$ild$1@eclipse.org...
> > hi,
> >
> > i'm trying to create a progress bar for transfering files between a client
> > and a server.
> >
> > so, i made a dialog containing a progress bar, and a cancel button (for
> > stoping the transfert if i want).
> > next, i create a thread (which takes the dialog as parameter allowing the
> > thread to access to the elements of the dialog) and i start it.
> >
> > i'can't see the progress bar moving but all the dialog is block and i
> > can't push the cancel button.
> >
> > thanks for helping me
> >
> >
> > William
> >

Report message to a moderator

Re: update a dialog with a thread [message #440688 is a reply to message #440681]

Fri, 06 August 2004 09:30

william

Messages: 15
Registered: July 2009

Junior Member

it's ok, i found my problem
the next time i will test my program before writing....

but i don't ever know the answer of my second question ...(what is the
difference between sync and asyncExec() ?)

thanks a lot ....

william wrote:

> thanks a lot, it's working...
> but there is a little problem...
> i created a runnable taking the dialog in parameter, and in the runnable i
> did a loop in which i call syncExec() runnable for udpating my progress
> bar (update and return). But the cancel button is activated only when the
> syncExec() runnable runs (during all the treatment of the first runnable
> the dialog is block) and i don't understand why....

> i have an other question : what is the difference between sync and
> asyncExec() ?

> thanks

> Steve Northover wrote:

> > You need to make sure that the UI-thread is processing events. The
> > sync/asyncExec() runnables that you are using to update the progress bar
> > from the background thread need to just update the bar and return. If you
> > run a loop in the runnable, this will block the UI-thread.

> > "william" <william.ferreira@laposte.net> wrote in message
> > news:cetag9$ild$1@eclipse.org...
> > > hi,
> > >
> > > i'm trying to create a progress bar for transfering files between a
client
> > > and a server.
> > >
> > > so, i made a dialog containing a progress bar, and a cancel button (for
> > > stoping the transfert if i want).
> > > next, i create a thread (which takes the dialog as parameter allowing the
> > > thread to access to the elements of the dialog) and i start it.
> > >
> > > i'can't see the progress bar moving but all the dialog is block and i
> > > can't push the cancel button.
> > >
> > > thanks for helping me
> > >
> > >
> > > William
> > >

Report message to a moderator

Re: update a dialog with a thread [message #440692 is a reply to message #440688]

Fri, 06 August 2004 12:51

Jeff Myers

Messages: 396
Registered: July 2009

Senior Member

William,

With syncExec() the calling thread is suspended (blocked) until the run
on the UI thread is finished. With asyncExec() the calling thread
continues to run in parallel and independent of the run on the UI
thread. So in your code you need to wait for the UI update to occur
then continue, use syncExec. If what you're doing is independent of the
UI update (i.e. the UI update is just updating a status, etc) you should
use asyncExec.

- Jeff

william wrote:
> it's ok, i found my problem
> the next time i will test my program before writing....
>
> but i don't ever know the answer of my second question ...(what is the
> difference between sync and asyncExec() ?)
>
> thanks a lot ....
>
> william wrote:

Report message to a moderator

Re: update a dialog with a thread [message #440696 is a reply to message #440692]

Fri, 06 August 2004 13:14

william

Messages: 15
Registered: July 2009

Junior Member

ok
thanks a lot...

Jeff Myers wrote:

> William,

> With syncExec() the calling thread is suspended (blocked) until the run
> on the UI thread is finished. With asyncExec() the calling thread
> continues to run in parallel and independent of the run on the UI
> thread. So in your code you need to wait for the UI update to occur
> then continue, use syncExec. If what you're doing is independent of the
> UI update (i.e. the UI update is just updating a status, etc) you should
> use asyncExec.

> - Jeff

> william wrote:
> > it's ok, i found my problem
> > the next time i will test my program before writing....
> >
> > but i don't ever know the answer of my second question ...(what is the
> > difference between sync and asyncExec() ?)
> >
> > thanks a lot ....
> >
> > william wrote:

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