Chat window - load messages from history problem

Hi all,

I don't know if I mentioned before but now I'm working on
invoking the 
queries to the history in separate threads to prevent the
gui from 
blocking while waiting the history to finish. I need an
advice for the 
following situation:

When opening a chat window we load 10 last messages from
history. This 
is now invoked in a different thread for the reasons
mentioned above. 
When we receive a message from someone and we don't have an
opened chat 
with this person, three things should happen:
1) open the chat window
2) load the 10 last messages from history (in a new Thread
which calls 
invokeLater to show messages coming from history)
3) show the message that was just received

Maybe you already see the problem..When the query to the
history is 
invoked in another thread, the message  that was just
received is always 
shown before the messages from the history.

Thanks,
Yana

------------------------------------------------------------
---------
To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
For additional commands, e-mail: dev-helpsip-communicator.dev.java.net

Hi Yana

Yana Stamcheva wrote:
> When opening a chat window we load 10 last messages
from history. This
> is now invoked in a different thread for the reasons
mentioned above. 

Yes I actually had a question here. Are you loading these
messages one 
by one? Cause that's how it seems to fill the message pane.
Wouldn't it 
be better to have them loaded all at once so that they show
all in the 
same time?

> When we receive a message from someone and we don't
have an opened chat 
> with this person, three things should happen:
> 1) open the chat window
> 2) load the 10 last messages from history (in a new
Thread which calls 
> invokeLater to show messages coming from history)
> 3) show the message that was just received
> 
> Maybe you already see the problem..When the query to
the history is 
> invoked in another thread, the message  that was just
received is always 
> shown before the messages from the history.

I don't really see the problem. Why don't you simply
insert all history 
messages in the beginning of the document instead of
appending them to 
the end?

Emil

> 
> Thanks,
> Yana
> 
>
------------------------------------------------------------
---------
> To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
> For additional commands, e-mail: dev-helpsip-communicator.dev.java.net
> 
> 

------------------------------------------------------------
---------
To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
For additional commands, e-mail: dev-helpsip-communicator.dev.java.net

Hi Emil,

Thanks a lot for your answer!

Emil Ivov wrote:
> Hi Yana
>
> Yana Stamcheva wrote:
>> When opening a chat window we load 10 last messages
from history. This
>> is now invoked in a different thread for the
reasons mentioned above. 
>
> Yes I actually had a question here. Are you loading
these messages one 
> by one? Cause that's how it seems to fill the message
pane. Wouldn't 
> it be better to have them loaded all at once so that
they show all in 
> the same time?
>
Til now I've used the same mechanism as when loading
currently received 
messages. It's more natural I think, because I get messages
from history 
as message events that are the same events when new messages
are 
received. If I do it like you said I should process them one
by one then 
save them as html and after that insert them in the
document. Do you 
think it's worth it?
>> When we receive a message from someone and we
don't have an opened 
>> chat with this person, three things should happen:
>> 1) open the chat window
>> 2) load the 10 last messages from history (in a new
Thread which 
>> calls invokeLater to show messages coming from
history)
>> 3) show the message that was just received
>>
>> Maybe you already see the problem..When the query
to the history is 
>> invoked in another thread, the message  that was
just received is 
>> always shown before the messages from the history.
>
> I don't really see the problem. Why don't you simply
insert all 
> history messages in the beginning of the document
instead of appending 
> them to the end?
>
I could try this. For now I insert the message in the same
thread where 
history messages are loaded. WDYT about that?
> Emil
>
>>
>> Thanks,
>> Yana
>>
>>
------------------------------------------------------------
---------
>> To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
>> For additional commands, e-mail: dev-helpsip-communicator.dev.java.net
>>
>>
>
>
------------------------------------------------------------
---------
> To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
> For additional commands, e-mail: dev-helpsip-communicator.dev.java.net
>
>


------------------------------------------------------------
---------
To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
For additional commands, e-mail: dev-helpsip-communicator.dev.java.net

Hey,

> Til now I've used the same mechanism as when loading
currently received 
> messages. It's more natural I think, because I get
messages from history 
> as message events that are the same events when new
messages are 
> received. If I do it like you said I should process
them one by one then 
> save them as html and after that insert them in the
document. Do you 
> think it's worth it?

Yes, because right now the gui is revalidated after each
message that 
you append and it's this revalidation that slows down the
whole thing. 
Whereas if you process them all together you could show them
all with a 
single repaint (i.e. 10 times less ;) ).

> I could try this. For now I insert the message in the
same thread where 
> history messages are loaded. WDYT about that?

I think it would be better not to do so. You could add new
incoming 
messages as they arrive, and only use the history thread to
insert the 
history messages at index 0. Otherwise, if you do the
concatenation of 
the new message and the history messages yourself, you would
face the 
same race condition problem in the case where you have
multiple incoming 
messages. For example: if history messages are H, and you
have a new 
message A. As long as A is the only new message it would be
ok for you to do

msgPane.append(H + A);

but the situation changes if while you are doing the
concatenation you 
receive a new message B. You risk to end up with a
B
H
A
sequence in the message pane.

Wouldn't it be simpler to do

MessageReceptionThread
{
	msgPane.append(newMsg)
}

HistoryMessagesThread
{
	msgPane.insert(0, historyMessages)
}

WDYT?

Emil

>> Emil
>>
>>> Thanks,
>>> Yana
>>>
>>>
------------------------------------------------------------
---------
>>> To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
>>> For additional commands, e-mail: dev-helpsip-communicator.dev.java.net
>>>
>>>
>>
------------------------------------------------------------
---------
>> To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
>> For additional commands, e-mail: dev-helpsip-communicator.dev.java.net
>>
>>
> 
> 
>
------------------------------------------------------------
---------
> To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
> For additional commands, e-mail: dev-helpsip-communicator.dev.java.net
> 
> 

------------------------------------------------------------
---------
To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
For additional commands, e-mail: dev-helpsip-communicator.dev.java.net